ORCID Profile
0000-0001-7124-3788
Current Organisations
University of Southampton
,
University of the Witwatersrand
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Publisher: Elsevier BV
Date: 12-2022
DOI: 10.1016/J.PREGHY.2022.09.005
Abstract: The prediction of preecl sia in pregnancy has resulted in a plethora of prognostic models. Yet, very few make it past the development stage and most fail to influence clinical practice. The timely identification of high-risk pregnant women could deliver a tailored antenatal care regimen, particularly in low-resource settings. This study externally validated and calibrated previously published models that predicted the risk of preecl sia, based on blood pressure (BP) at multiple time points in pregnancy, in a geographically erse population. The prospective INTERBIO-21st Fetal Study included 3,391 singleton pregnancies from Brazil, Kenya, Pakistan, South Africa, Thailand and the UK, 2012-2018. Preecl sia prediction was based on baseline characteristics, BP and deviation from the expected BP trajectory at multiple time points in pregnancy. The prediction rules from the Avon Longitudinal Study of Parents and Children (ALSPAC) were implemented in the INTERBIO-21st cohort. Model discrimination was similar to the development cohort. Performance was best with baseline characteristics and a BP measurement at 34 weeks' gestation (AUC 0.85, 95 % CI 0.80-0.90). The ALSPAC models largely overestimated the true risk of preecl sia incidence in the INTERBIO-21st cohort. After recalibration, these prediction models could potentially serve as a risk stratifying tool to help identify women who might benefit from increased surveillance during pregnancy.
Publisher: IEEE
Date: 12-2017
Publisher: Informa UK Limited
Date: 08-05-2013
Publisher: Elsevier BV
Date: 06-2020
Publisher: MDPI AG
Date: 29-07-2020
Abstract: This study aimed to investigate the extent to which preschool children meet guidelines for screen time ( h/day) and sleep (10–13 h/24-h) and explored home factors that affect these behaviors. Parents of preschoolers across income settings in South Africa (urban high-income n = 27, urban low-income n = 96 and rural low-income n = 142) completed a questionnaire. Urban high-income children had higher rates of exceeding screen time guidelines (67.0%) than children from urban low-income (26.0%) and rural low-income (3.5%) settings. Most children (81.0%) met sleep guidelines on weekdays and on weekends (75.0%). More urban high-income children met the sleep guideline, in comparison to both low-income settings. Fewer urban high-income parents (50.0%) thought that screen time would not affect their preschooler’s health, compared to urban low-income (90.4%) and rural low-income (81.7%) parents. Weeknight bedtime was positively correlated with both weekday screen time (p = 0.001) and weekday TV time (p = 0.005), indicating that more time on screens correlated with later bedtimes. Meeting screen time and sleep guidelines differs across income settings, but it is evident that parents of preschoolers across all income settings would benefit from greater awareness about guidelines.
Publisher: Ubiquity Press, Ltd.
Date: 06-2017
Publisher: Hindawi Limited
Date: 2016
DOI: 10.1017/GHEG.2016.17
Abstract: Africa is experiencing a rapid increase in adult obesity and associated cardiometabolic diseases (CMDs). The H3Africa AWI-Gen Collaborative Centre was established to examine genomic and environmental factors that influence body composition, body fat distribution and CMD risk, with the aim to provide insights towards effective treatment and intervention strategies. It provides a research platform of over 10 500 participants, 40–60 years old, from Burkina Faso, Ghana, Kenya and South Africa. Following a process that involved community engagement, training of project staff and participant informed consent, participants were administered detailed questionnaires, anthropometric measurements were taken and biospecimens collected. This generated a wealth of demographic, health history, environmental, behavioural and biomarker data. The H3Africa SNP array will be used for genome-wide association studies. AWI-Gen is building capacity to perform large epidemiological, genomic and epigenomic studies across several African counties and strives to become a valuable resource for research collaborations in Africa.
Publisher: Springer Science and Business Media LLC
Date: 22-02-2022
DOI: 10.1038/S41467-021-27917-X
Abstract: Human gut microbiome research focuses on populations living in high-income countries and to a lesser extent, non-urban agriculturalist and hunter-gatherer societies. The scarcity of research between these extremes limits our understanding of how the gut microbiota relates to health and disease in the majority of the world’s population. Here, we evaluate gut microbiome composition in transitioning South African populations using short- and long-read sequencing. We analyze stool from adult females living in rural Bushbuckridge ( n = 118) or urban Soweto ( n = 51) and find that these microbiomes are taxonomically intermediate between those of in iduals living in high-income countries and traditional communities. We demonstrate that reference collections are incomplete for characterizing microbiomes of in iduals living outside high-income countries, yielding artificially low beta ersity measurements, and generate complete genomes of undescribed taxa, including Treponema , Lentisphaerae, and Succinatimonas . Our results suggest that the gut microbiome of South Africans does not conform to a simple “western-nonwestern” axis and contains undescribed microbial ersity.
Publisher: Springer Science and Business Media LLC
Date: 18-03-2021
Publisher: AOSIS
Date: 25-08-2023
Abstract: Background: While there is now considerable evidence in support of a relationship between executive function (EF) and academic success, these findings almost uniformly derive from Western and high-income countries. Yet, recent findings from low- to -middle-income countries have suggested that patterns of EF and academic skills differ in these contexts, but there is little clarity on the extent, direction and nature of their association.Aim: This study aimed to investigate the contribution of EF to pre-academic skills in a s le of preschool children (N = 124 Mage = 50.91 months 45% female).Setting: Two preschools were recruited from an urban setting in a community with both formal and informal housing, overcrowding, high levels of crime and violence, and poor service delivery. Three preschools were recruited from rural communities with household plots, a slow rate of infrastructure development, reliance on open fires for cooking, limited access to running water and rudimentary sanitation.Methods: Pre-academic skills were assessed using the Herbst Early Childhood Development Criteria test, and EF was assessed using the Early Years Toolbox.Results: Although EF scores appeared high and pre-academic skills were low (in norm comparisons), EF inhibition (ß = 0.23, p = 0.001) and working memory (ß = 0.25, p 0.001) nevertheless showed strong prediction of pre-academic skills while shifting was not significant.Conclusion: While EF is an important predictor of pre-academic skills even in this low- and middle-income country context, factors in addition to EF may be equally important targets to foster school readiness in these settings.Contribution: The current study represents a first step towards an understanding of the current strengths that can be leveraged, and opportunities for additional development, in the service of preparing all children for the demands of school.
Publisher: Springer Science and Business Media LLC
Date: 19-10-2020
DOI: 10.1186/S12992-020-00630-Y
Abstract: Non-communicable diseases (NCDs) are the leading cause of death globally. While upstream approaches to tackle NCD risk factors of poor quality diets and physical inactivity have been trialled in high income countries (HICs), there is little evidence from low and middle-income countries (LMICs) that bear a disproportionate NCD burden. Sub-Saharan Africa and the Caribbean are therefore the focus regions for a novel global health partnership to address upstream determinants of NCDs. The Global Diet and Activity research Network (GDAR Network) was formed in July 2017 with funding from the UK National Institute for Health Research (NIHR) Global Health Research Units and Groups Programme. We describe the GDAR Network as a case ex le and a potential model for research generation and capacity strengthening for others committed to addressing the upstream determinants of NCDs in LMICs. We highlight the dual equity targets of research generation and capacity strengthening in the description of the four work packages. The work packages focus on learning from the past through identifying evidence and policy gaps and priorities, understanding the present through adolescent lived experiences of healthy eating and physical activity, and co-designing future interventions with non-academic stakeholders. We present five lessons learned to date from the GDAR Network activities that can benefit other global health research partnerships. We close with a summary of the GDAR Network contribution to cultivating sustainable capacity strengthening and cutting-edge policy-relevant research as a beacon to exemplify the need for such collaborative groups.
Publisher: Informa UK Limited
Date: 17-02-2018
Publisher: Elsevier BV
Date: 12-2013
DOI: 10.1016/J.BONE.2013.08.027
Abstract: We examined the interplay between ethnicity and weight-bearing physical activity on the content and volumetric properties of bone in a pre- to early pubertal South African Black and White population. Sixty six children [Black boys, 10.4 (1.4)yrs, n=15 Black girls, 10.1 (1.2)yrs, n=27 White boys, 10.1 (1.1)yrs, n=7 White girls, 9.6 (1.3)yrs, n=17] reported on all their physical activities over the past two years in an interviewer administered physical activity questionnaire (PAQ). All participants underwent a whole body and site-specific DXA scan and we also assessed bone structure and estimated bone strength with pQCT. Children were classified as being either high or low bone loaders based on the cohort's median peak bone strain score estimated from the PAQ. In the low bone loading group, Black children had greater femoral neck bone mineral content (BMC) (2.9 (0.08)g) than White children (2.4 (0.11)g p=0.05). There were no ethnic differences in the high bone loaders for femoral neck BMC. At the cortical site, the Black low bone loaders had a greater radius area (97.3 (1.3) vs 88.8 (2.6)mm(2) p=0.05) and a greater tibia total area (475.5 (8.7) vs. 397.3 (14.0)mm(2) p=0.001) and strength (1633.7 (60.1) vs. 1271.8 (98.6)mm(3) p=0.04) compared to the White low bone loaders. These measures were not different between the Black low and high bone loaders or between the Black and White high bone loaders. In conclusion, the present study shows that there may be ethnic and physical activity associations in the bone health of Black and White pre-pubertal children and further prospective studies are required to determine the possible ethnic specific response to mechanical loading.
Publisher: American Medical Association (AMA)
Date: 05-2021
Publisher: JMIR Publications Inc.
Date: 23-12-2020
Abstract: he increasing burden of noncommunicable diseases that are prevalent in low- and middle-income countries (LMICs) is largely attributed to modifiable behavioral risk factors such as unhealthy diets and insufficient physical activity (PA). The adolescent stage, defined as 10 to 24 years of age, is an important formative phase of life and offers an opportunity to reduce the risk of noncommunicable diseases across the life course and for future generations. he aim of this paper is to describe a protocol for a study using a convergent mixed methods design to explore exposures in the household, neighborhood, school, and the journey from home to school that may influence diet and PA behaviors in adolescents from LMICs. ale and female adolescents (n≥150) aged between 13 and 24 years will be recruited from selected high schools or households in project site countries to ensure the socioeconomic ersity of perspectives and experiences at the in idual, home, and neighborhood levels. The project will be conducted at 5 sites in 4 countries: Kenya, Cameroon, Jamaica, and South Africa (Cape Town and Johannesburg). Data on anthropometric measures, food intake, and PA knowledge and behavior will be collected using self-report questionnaires. In addition, a small number of learners (n=30-45) from each site will be selected as citizen scientists to capture data (photographs, audio notes, text, and geolocations) on their i lived experiences /i in relation to food and PA in their homes, the journey to and from school, and the school and neighborhood environments using a mobile app, and for objective PA measurements. In-depth interviews will be conducted with the citizen scientists and their caregivers to explore household experiences and determinants of food intake and foodways, as well as the PA of household members. he study described in this protocol paper was primarily funded through a UK National Institute for Health Research grant in 2017 and approved by the relevant institutional ethics review boards in the country sites (South Africa, Cameroun, and Jamaica in 2019, and Kenya in 2020). As of December 23, 2020, we had completed data collection from adolescents (n≥150) in all the country sites, except Kenya, and data collection for the subgroup (n=30-45) is ongoing. Data analysis is ongoing and the output of findings from the study described in this protocol is expected to be published by 2022. his project protocol contributes to research that focuses on adolescents and the socioecological determinants of food intake and PA in LMIC settings. It includes innovative methodologies to interrogate and map the contexts of these determinants and will generate much-needed data to understand the multilevel system of factors that can be leveraged through upstream and downstream strategies and interventions to improve health outcomes. ERR1-10.2196/26739
Publisher: Human Kinetics
Date: 09-2016
Abstract: An area of growth in physical activity research has involved investigating effects of physical activity on children’s executive functions. Many of these efforts seek to increase the energy expenditure of young children as a healthy and low-cost way to affect physical, health, and cognitive outcomes. We review theory and research from neuroscience and evolutionary biology, which suggest that interventions seeking to increase the energy expenditure of young children must also consider the energetic trade-offs that occur to accommodate changing metabolic costs of brain development. According to Life History Theory, and supported by recent evidence, the high relative energy-cost of early brain development requires that other energy-demanding functions of development (ie, physical growth, activity) be curtailed. This is important for interventions seeking to dramatically increase the energy expenditure of young children who have little excess energy available, with potentially negative cognitive consequences. Less energy-demanding physical activities, in contrast, may yield psychosocial and cognitive benefits while not overburdening an underweight child’s already scarce energy supply. While further research is required to establish the extent to which increases in energy-demanding physical activities may compromise or displace energy available for brain development, we argue that action cannot await these findings.
Publisher: Wiley
Date: 07-2004
DOI: 10.1111/J.1651-2227.2004.TB02699.X
Abstract: To examine: (1) the associations between socio-economic status, physical activity, anthropometric and body composition variables in South African children (2) the influence maternal characteristics have on children's physical activity levels and (3) associations between television watching, activity level and body composition. In 381 South African children, physical activity and socio-economic status were assessed via structured retrospective interview using validated questionnaires. An asset indicator score was calculated as a proxy measure of socio-economic status and used to ide children into quartiles. Children falling into the highest socio-economic status quartile had mothers with the highest educational levels, generally came from dual parent homes, were highly physically active, watched less television, weighed more and had greater lean tissue than children in lower quartiles. A greater percentage of children living in dual parent homes and with mothers of a higher educational status were highly active compared with children living in single parent homes and with mothers of a lower educational status. We found greater levels of lean mass with increased activity level after controlling for television watching time and fat mass. There were high levels of low activity and high television watching time among lower socio-economic status groups. There were significant racial differences in patterns of activity. White children were found to be more active than black children, more likely to participate in physical education classes at school and watched less television than black children. Physical activity levels and socio-economic variables are closely related in this population of South African children.
Publisher: Elsevier BV
Date: 11-2022
DOI: 10.1016/J.BONE.2022.116543
Abstract: Menopause transition is associated with accelerated bone loss, though data are limited from sub-Saharan African (SSA). Our objective was to describe bone density, geometry and estimated strength in women by menopause status and to explore whether patterns differed within those living with HIV. Radius and tibia peripheral QCT data were collected for Black South African women (n = 430) aged 40-61 years with verified menopause and HIV status. pQCT outcomes were distal 4 % radius and tibia total cross-sectional area (CSA), total volumetric bone mineral density (vBMD), and compressive bone strength (BSIc) proximal 66 % radius and 38 % tibia cortical vBMD, total CSA, cortical thickness, and Stress-strain Index (SSI). Linear regression assessed associations between pre, peri-, and postmenopausal groups and pQCT outcomes adjusting for age, height, and weight, and then stratified by HIV status. Mean [95%CI] and tests for trend (p-trend) across menopausal groups are presented. Women were mean (SD) age 49.2 (5.3) years, with a body mass index (BMI) of 32.4 (6.3) m/kg In black South African women, menopause is associated with lower bone density and strength at the distal radius, a common site of osteoporotic fracture, in addition to lower cortical density and thickness at the proximal radius. Although the s le size was small, following stratification by HIV, women living with HIV had evidence of lower cortical density across menopause stages, unlike those without HIV. These findings raise concern for the incidence of Colles' fractures in postmenopausal women in South Africa longitudinal studies of fracture incidence and implications of living with HIV are required.
Publisher: Springer Science and Business Media LLC
Date: 10-07-2022
DOI: 10.1186/S12966-022-01325-W
Abstract: Relationships between mental health and multiple health behaviours have not been explored in young South African women experiencing social constraints. The aim of this study was to identify associations between mental health indicators and risk factors with physical activity, sedentary behaviour, and sleep, amongst young women living in Soweto, a predominantly low-income, urban South African setting. For this cross-sectional study, baseline measurements for participants ( n = 1719, 18.0–25.9 years old) recruited for the Healthy Life Trajectories Initiative were used including: physical activity, sedentary behaviour (sitting, screen and television time), sleep (duration and quality), depression and anxiety indicators, emotional health, adverse childhood experiences, alcohol-use risk social vulnerability, self-efficacy, and social support. Multiple regression analyses showed that depression (β = 0.161, p 0.001), anxiety (β = 0.126, p = 0.001), adverse childhood experiences (β = 0.076, p = 0.014), and alcohol-use risk (β = 0.089, p = 0.002) were associated with poor quality sleep. Alcohol-use risk was associated with more screen time (β = 0.105, p 0.001) and television time (β = 0.075, p 0.016). Social vulnerability was associated with lower sitting time (β = − 0.187, p 0001) and screen time (β = − 0.014, p 0.001). Higher self-efficacy was associated with more moderate- to vigorous-intensity physical activity (β = 0.07, p = 0.036), better-quality sleep (β = − 0.069, p = 0.020) and less television time (β = − 0.079, p = 0.012). Having no family support was associated with more sitting time (β = 0.075, p = 0.022). Binomial logistic regression analyses supported these findings regarding sleep quality, with anxiety and depression risk doubling the risk of poor-quality sleep (OR = 2.425, p 0.001, OR = 2.036, p = 0.003 respectively). These findings contribute to our understanding of how mental health indicators and risk factors can be barriers to health behaviours of young women in Soweto, and that self-efficacy and social support can be protective for certain of these behaviours for these women. Our results highlight the uniqueness of this setting regarding associations between mental health and behaviours associated with non-communicable diseases risk.
Publisher: Rural and Remote Health
Date: 11-2019
DOI: 10.22605/RRH5249
Publisher: Research Square Platform LLC
Date: 20-03-2023
DOI: 10.21203/RS.3.RS-2648249/V1
Abstract: Background Given the importance of infancy for establishing growth trajectories, with later-life health consequences, we investigated longitudinal body composition among infants from six economically and ethnically erse countries. Methods We recruited mother-infant dyads using the WHO Multicenter Growth Reference Study criteria. We measured fat-free mass (FFM) in 1176 (49% female) infants from birth to 6-mo-of-age (Australia, India, and South Africa n = 468), 3 to 24-mo-of-age (Brazil, Pakistan, South Africa, and Sri Lanka n = 925), and derived fat mass (FM), fat mass (FMI), and fat-free mass (FFMI) indices. Height-for-age (HAZ), weight-for-age (WAZ), and weight-for-length (WFLZ) z-scores were computed. Sex differences were assessed using a t-test, and country differences using a one-way analysis of variance. We further compared subs les of children who tracked the median for HAZ (-0.25 HAZ + 0.25), and those who did not. Results HAZ tracked well between 0 and 6-mo, but less so between 3 and 24-mo. The stunting prevalence peaked at 10.3% for males and 7.8% for females, at 24-mo. By 24-mo, girls had greater FMI (10%) than boys. There were significant differences in FFM (South African and Sri Lankan males) and FM (South African females and Sri Lankan males) by 24-mo-of-age, between infants whose length tracked the WHO median and those that did not. Conclusion In a multi-country s le representing more ideal maternal conditions, body composition was heterogeneous, potentially due to ethnic, breastfeeding, and dietary-pattern differences. Tracking the median of the WHO standard reduced FFM heterogeneity but not FM, suggesting that other factors may influence adiposity.
Publisher: South African Medical Association NPC
Date: 30-06-2021
Publisher: JMIR Publications Inc.
Date: 13-07-2021
DOI: 10.2196/26739
Abstract: The increasing burden of noncommunicable diseases that are prevalent in low- and middle-income countries (LMICs) is largely attributed to modifiable behavioral risk factors such as unhealthy diets and insufficient physical activity (PA). The adolescent stage, defined as 10 to 24 years of age, is an important formative phase of life and offers an opportunity to reduce the risk of noncommunicable diseases across the life course and for future generations. The aim of this paper is to describe a protocol for a study using a convergent mixed methods design to explore exposures in the household, neighborhood, school, and the journey from home to school that may influence diet and PA behaviors in adolescents from LMICs. Male and female adolescents (n≥150) aged between 13 and 24 years will be recruited from selected high schools or households in project site countries to ensure the socioeconomic ersity of perspectives and experiences at the in idual, home, and neighborhood levels. The project will be conducted at 5 sites in 4 countries: Kenya, Cameroon, Jamaica, and South Africa (Cape Town and Johannesburg). Data on anthropometric measures, food intake, and PA knowledge and behavior will be collected using self-report questionnaires. In addition, a small number of learners (n=30-45) from each site will be selected as citizen scientists to capture data (photographs, audio notes, text, and geolocations) on their lived experiences in relation to food and PA in their homes, the journey to and from school, and the school and neighborhood environments using a mobile app, and for objective PA measurements. In-depth interviews will be conducted with the citizen scientists and their caregivers to explore household experiences and determinants of food intake and foodways, as well as the PA of household members. The study described in this protocol paper was primarily funded through a UK National Institute for Health Research grant in 2017 and approved by the relevant institutional ethics review boards in the country sites (South Africa, Cameroun, and Jamaica in 2019, and Kenya in 2020). As of December 23, 2020, we had completed data collection from adolescents (n≥150) in all the country sites, except Kenya, and data collection for the subgroup (n=30-45) is ongoing. Data analysis is ongoing and the output of findings from the study described in this protocol is expected to be published by 2022. This project protocol contributes to research that focuses on adolescents and the socioecological determinants of food intake and PA in LMIC settings. It includes innovative methodologies to interrogate and map the contexts of these determinants and will generate much-needed data to understand the multilevel system of factors that can be leveraged through upstream and downstream strategies and interventions to improve health outcomes. DERR1-10.2196/26739
Publisher: Springer Science and Business Media LLC
Date: 10-08-2023
DOI: 10.1038/S41430-023-01321-8
Abstract: Available evidence on infant body composition is limited. This study aimed to investigate factors associated with body composition at 6 and 24 months. Multicenter study with data from a 0 to 6-mo cohort (Australia, India and South Africa) and a 3 to 24-mo cohort (Brazil, Pakistan, South Africa, and Sri Lanka). For the 0–6-mo cohort, body composition was assessed by air-displacement plethysmography (ADP) and for the 3–24-month cohort by the deuterium dilution (DD) technique. Fat mass (FM), fat-free mass (FFM), FM index (FMI), and FFM index (FFMI) were calculated. Independent variables comprised the Gini index of the country, maternal and infant characteristics, and breastfeeding pattern at 3 months. For the 3–24-mo cohort, breastfeeding, and minimum dietary ersity (MDD) at 12 months were also included. Crude and adjusted analyses stratified by sex were conducted by multilevel modelling using mixed models. At 6 months, every 1 kg increase in birth weight was associated with an increase of 0.716 kg in FFM and 0.582 kg/m 2 in FFMI in girls, whereas in boys, the increase was of 0.277 kg in FFM. At 24 months, compared to those weaned before 12 months, girls still breastfed at 12 months presented a decrease of 0.225 kg in FM, 0.645 kg in FFM and 0.459 kg/m 2 in FFMI, and in boys the decreases were of 0.467 kg in FM, 0.603 kg in FFM and 0.628 kg/m 2 in FFMI. Birth weight and breastfeeding are independent predictors of body composition in early life, irrespective of sex.
Publisher: Research Square Platform LLC
Date: 25-04-2023
DOI: 10.21203/RS.3.RS-2798935/V1
Abstract: Background Two compartment (2C) models of body composition, including Air Displacement Plethysmography (ADP) and Deuterium Dilution (DD), assume constant composition of fat-free mass (FFM), while 3-compartment (3C) model overcomes some of these assumptions studies are limited in infants. Objective: To compare 3C estimates of body composition in 6-mo. old infants from Australia, India and South Africa, including FFM density and hydration, compare with published literature and to evaluate agreement of body composition estimates from ADP and DD. Methods : Body volume and water were measured in 176 healthy infants using ADP and DD. 3C-model estimates of fat mass (FM), FFM and its composition were calculated, compared between countries (age and sex adjusted) and with published literature. Agreement between estimates from ADP and DD were compared by Bland-Altman and correlation analyses. Results: South African infants had significantly higher % FM (11.5%) and density of FFM compared to Australian infants. Australian infants had significantly higher % FFM (74.7 ± 4.4%) compared to South African infants (71.4 ± 5.0) and higher FFMI (12.7 ± 0.8 kg/m 2 ) compared to South African (12.3 ± 1.2 kg/m 2 ) and Indian infants (11.9 ± 1.0 kg/m 2 ). FFM composition of present study differed significantly from literature. Pooled three country estimates of FM and FFM were comparable between ADP and DD mean difference of -0.05 (95% CI, -0.64, +0.55) kg and +0.05 (95% CI, -0.55, +0.64) kg. Conclusion: 3C-model estimates of body composition in infants differed between countries future studies are needed to confirm these findings and investigate causes for the differences.
Publisher: Springer Science and Business Media LLC
Date: 03-10-2017
DOI: 10.1038/IJO.2017.240
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 16-07-2019
Abstract: Studies on the determinants of carotid intima‐media thickness ( CIMT ), a marker of sub‐clinical atherosclerosis, mostly come from white, Asian, and diasporan black populations. We present CIMT data from sub‐Saharan Africa, which is experiencing a rising burden of cardiovascular diseases and infectious diseases. The H3 (Human Hereditary and Health) in Africa’s AWI‐Gen (African‐Wits‐INDEPTH partnership for Genomic) study is a cross‐sectional study conducted in adults aged 40 to 60 years from Burkina Faso, Kenya, Ghana, and South Africa. Cardiovascular disease risk and ultrasonography of the CIMT of right and left common carotids were measured. Multivariable linear and mixed‐effect multilevel regression modeling was applied to determine factors related to CIMT. Data included 8872 adults (50.8% men), mean age of 50±6 years with age‐ and sex‐adjusted mean (±SE) CIMT of 640±123μm. Participants from Ghana and Burkina Faso had higher CIMT compared with other sites. Age (β = 6.77, 95%CI [6.34–7.19]), body mass index (17.6[12.5–22.8]), systolic blood pressure (7.52[6.21–8.83]), low‐density lipoprotein cholesterol (5.08[2.10–8.06]) and men (10.3[4.75– 15.9]) were associated with higher CIMT. Smoking was associated with higher CIMT in men. High‐density lipoprotein cholesterol (−12.2 [−17.9– −6.41]), alcohol consumption (–13.5 [−19.1–−7.91]) and HIV (−8.86 [−15.7–−2.03]) were inversely associated with CIMT. Given the rising prevalence of cardiovascular diseases risk factors in sub‐Saharan Africa, atherosclerotic diseases may become a major pan‐African epidemic unless preventive measures are taken particularly for prevention of hypertension, obesity, and smoking. HIV ‐specific studies are needed to fully understand the association between HIV and CIMT in sub‐Saharan Africa.
Publisher: Springer Science and Business Media LLC
Date: 03-12-2014
DOI: 10.1038/NATURE13997
Publisher: Elsevier BV
Date: 05-2021
Publisher: Elsevier BV
Date: 12-2018
Publisher: Springer Science and Business Media LLC
Date: 17-09-2022
Publisher: Public Library of Science (PLoS)
Date: 18-10-2019
Publisher: Springer Science and Business Media LLC
Date: 13-10-2023
Publisher: Informa UK Limited
Date: 16-11-2018
Publisher: Elsevier BV
Date: 06-2019
DOI: 10.1016/J.JSAMS.2018.12.009
Abstract: No studies have investigated gross motor skill (GMS) proficiency of preschool-aged children across different income settings in South Africa. Research from high-income countries suggests that children from low-income settings display poorer GMS proficiency compared to higher-income peers. This study aimed to (1) describe GMS proficiency of preschool-aged children in urban high-income (UH), urban low-income (UL) and rural low-income (RL) settings and (2) explore differences in proficiency between income settings and sex. Descriptive cross-sectional study. The Test of Gross Motor Development-Edition 2 (TGMD-2) was used to assess GMS. The TGMD-2 gross motor quotient, standardised scores and raw scores were used to describe proficiency. GMS proficiency was assessed in n=259 3-6-year-old children (n=46 UH, n=91 UL, n=122 RL). Overall, 93% of the children were classified as having 'average' or better GMS. According to TGMD-2 standardised scores, the RL children performed significantly better than UH and UL children (p=0.028 and p=0.009, respectively). RL children were significantly more proficient than UH and UL children in the strike and horizontal jump when comparing raw scores. Overall, boys performed significantly better than girls in the strike, stationary dribble, kick and leap when comparing raw scores (all p<0.001). This study reports high GMS proficiency in preschool-aged children across income settings in South Africa. The factors associated with higher GMS in low-income settings are not immediately obvious. Thus, future research should explore potential factors and identify opportunities to ensure that GMS proficiency is capitalised on as preschool-aged children enter formal schooling.
Publisher: F1000 Research Ltd
Date: 05-02-2019
DOI: 10.12688/GATESOPENRES.12869.2
Abstract: Background: INTERBIO-21 st is Phase II of the INTERGROWTH-21 st Project, the population-based, research initiative involving nearly 70,000 mothers and babies worldwide coordinated by Oxford University and performed by a multidisciplinary network of more than 400 healthcare professionals and scientists from 35 institutions in 21 countries worldwide. Phase I, conducted 2008-2015, consisted of nine complementary studies designed to describe optimal human growth and neurodevelopment, based conceptually on the WHO prescriptive approach. The studies generated a set of international standards for monitoring growth and neurodevelopment, which complement the existing WHO Child Growth Standards. Phase II aims to improve the functional classification of the highly heterogenous preterm birth and fetal growth restriction syndromes through a better understanding of how environmental exposures, clinical conditions and nutrition influence patterns of human growth from conception to childhood, as well as specific neurodevelopmental domains and associated behaviors at 2 years of age. Methods: In the INTERBIO-21 st Newborn Case-Control Study, a major component of Phase II, our objective is to investigate the mechanisms potentially responsible for preterm birth and small for gestational age and their interactions, using deep phenotyping of clinical, growth and epidemiological data and associated nutritional, biochemical, omic and histological profiles. Here we describe the study sites, population characteristics, study design, methodology and standardization procedures for the collection of longitudinal clinical data and biological s les (maternal blood, umbilical cord blood, placental tissue, maternal feces and infant buccal swabs) for the study that was conducted between 2012 and 2018 in Brazil, Kenya, Pakistan, South Africa, Thailand and the UK. Discussion: Our study provides a unique resource for the planned analyses given the range of potentially disadvantageous exposures (including poor nutrition, pregnancy complications and infections) in geographically erse populations worldwide. The study should enhance current medical knowledge and provide new insights into environmental influences on human growth and neurodevelopment.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2016
Publisher: Springer Science and Business Media LLC
Date: 23-03-2021
DOI: 10.1186/S12889-021-10591-5
Abstract: The extent to which income setting or rural and urban environments modify the association between sleep and obesity in young children is unclear. The aims of this cross-sectional observational study were to (i) describe and compare sleep in South African preschool children from rural low-income (RL), urban low-income (UL) and urban high-income (UH) settings and (ii) test for associations between sleep parameters and body mass index (BMI). Participants were preschoolers (5.2 ± 0.7y, 49.5% boys) from RL ( n = 111), UL ( n = 65) and UH ( n = 22) settings. Height and weight were measured. Sleep, sedentary behaviour and physical activity were assessed using accelerometery. UL children had higher BMI z-scores (median: 0.39 interquartile range: − 0.27, 0.99) than the UH (− 0.38 − 0.88, 0.11) and RL (− 0.08 − 0.83, 0.53) children ( p = 0.001). The UL children had later bedtimes ( p 0.001) and wake-up times ( p 0.001) and shorter 24 h ( p 0.001) and nocturnal ( p 0.001) sleep durations than the RL and UH children. After adjusting for age, sex, setting, SB and PA, for every hour less sleep obtained (24 h and nocturnal), children were 2.28 (95% CI: 1.28–4.35) and 2.22 (95% CI: 1.27–3.85) more likely, respectively, to belong to a higher BMI z-score quartile. Shorter sleep is associated with a higher BMI z-score in South African preschoolers, despite high levels of PA, with UL children appearing to be particularly vulnerable.
Publisher: Wiley
Date: 29-05-2019
DOI: 10.1111/DESC.12854
Abstract: The widely and internationally replicated socioeconomic status (SES) gradient of executive function (EF) implies that intervention approaches may do well to extrapolate conditions and practices from contexts that generate better child outcomes (in this case, higher SES circumstances) and translate these to contexts with comparatively poorer outcomes (often low-SES populations). Yet, can the reverse also be true? Using data from equivalent assessments of 1,092 pre-schoolers' EFs in South Africa and Australia, we evaluated: the SES gradient of EF within each s le and whether this SES gradient extended cross-culturally. The oft-found EF-SES gradients were replicated in both s les. However, contrary to the inferences of EF-SES associations found nationally, the most highly disadvantaged South African subs le outperformed middle- and high-SES Australian pre-schoolers on two of three EFs. This suggests the possibility of EF-protective and -promotive practices within low- and middle-income countries that may aid understandings of the nature and promotion of EFs.
Publisher: Research Square Platform LLC
Date: 26-06-2023
DOI: 10.21203/RS.3.RS-3018527/V1
Abstract: Background Accurate assessment of body composition during infancy is important, especially for understanding the effects of early growth on later health. This study aimed to develop an anthropometry-based approach to predict body composition in 3–24 month old infants from erse socioeconomic settings and ethnic groups. Methods An observational, longitudinal, prospective, multinational study of infants from birth to 24 months. Body composition was assessed at 3, 6, 9, 12, 18, and 24 months using deuterium dilution (DD) and anthropometry. Linear mixed modelling was utilized to generate sex-specific fat mass(FM) and fat-free mass(FFM) prediction equations. Length(m), weight-for-length(kg/m), triceps and subscapular skinfolds and Asian ethnicity were used as predictor variables. The study s le consisted of 1896(942 measurements from 310 girls) training data sets, 941(441 measurements from 154 girls) validation data sets from Brazil, Pakistan, South Africa and Sri Lanka, and 349(185 measurements from 124 girls) data sets of infants at 6 months from South Africa, Australia and India of external validation group. Results Sex-specific equations for three age categories (3-9 months 10-18 months 19-24 months) were developed and validated and an external validation was performed on the test group. The root mean squared error(RMSE) was similar between validation and test data for assessment of FM and FFM. Root mean squared percentage error(RMSPE) and mean absolute percentage error(MAPE) in validation data were higher for predicting FM but lower for FFM compared to test data. Conclusions Anthropometry-based FFM prediction equations provide acceptable results which have the potential to be developed as a field tool.
Publisher: Springer Science and Business Media LLC
Date: 09-06-2022
Publisher: Elsevier BV
Date: 12-2019
Publisher: Hindawi Limited
Date: 12-2009
DOI: 10.1111/J.1365-2524.2009.00891.X
Abstract: Caregivers of young children identified as HIV positive, residing in Agincourt, rural South Africa were advised of their child's status. How was this knowledge received, and how did it influence care-giving and support? Interviews were conducted in May to June 2008 with caregivers of HIV positive children aged 1-5 years, 1 year following the child's HIV test and disclosure of status. Drawing on data from 31 semi-structured questionnaires and 21 in-depth interviews, we describe caregivers' attitudes, reactions, fears and aspirations after learning a child's HIV status, the perceived usefulness of the knowledge, barriers to care-giving and support received. Sociodemographic data collected through the questionnaire were analysed using Stata. Qualitative data were coded in NVIVO 8 and analysed inductively to identify themes and their repetitions and variations. Although almost half of the caregivers responded negatively initially, 1 year later, almost all had accepted and valued knowing their child's HIV status as this had enhanced their competency in care-giving. Counselling from health providers and personal spirituality helped caregivers to accept the child's status and cope with its implications. Most caregivers had high aspirations for the child's future, despite some expressed difficulties associated with care-giving, including financial constraints, information gaps and barriers to healthcare. The results indicate an opportunity for paediatric HIV screening in communities with high HIV prevalence. This would facilitate early uptake of available interventions, so enhancing the survival of HIV positive children.
Publisher: Wiley
Date: 24-05-2007
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2020
DOI: 10.1161/HYPERTENSIONAHA.119.14147
Abstract: Hypertension and obesity are the most important modifiable risk factors for cardiovascular diseases, but their association is not well characterized in Africa. We investigated regional patterns and association of obesity with hypertension among 30 044 continental Africans. We harmonized data on hypertension (defined as previous diagnosis/use of antihypertensive drugs or blood pressure [BP]≥140/90 mmHg/BP≥130/80 mmHg) and obesity from 30 044 in iduals in the Cardiovascular H3Africa Innovation Resource across 13 African countries. We analyzed data from population-based controls and the Entire Harmonized Dataset. Age-adjusted and crude proportions of hypertension were compared regionally, across sex, and between hypertension definitions. Logit generalized estimating equation was used to determine the independent association of obesity with hypertension ( P value %). Participants were 56% women with mean age 48.5±12.0 years. Crude proportions of hypertension (at BP≥140/90 mmHg) were 47.9% (95% CI, 47.4–48.5) for Entire Harmonized Dataset and 42.0% (41.1–42.7) for population-based controls and were significantly higher for the 130/80 mm Hg threshold at 59.3% (58.7–59.9) in population-based controls. The age-adjusted proportion of hypertension at BP≥140/90 mmHg was the highest among men (33.8% [32.1–35.6]), in western Africa (34.7% [33.3–36.2]), and in obese in iduals (43.6% 40.3–47.2). Obesity was independently associated with hypertension in population-based controls (adjusted odds ratio, 2.5 [2.3–2.7]) and odds of hypertension in obesity increased with increasing age from 2.0 (1.7–2.3) in younger age to 8.8 (7.4–10.3) in older age. Hypertension is common across multiple countries in Africa with 11.9% to 51.7% having BP≥140/90 mmHg and 39.5% to 69.4% with BP≥130/80 mmHg. Obese Africans were more than twice as likely to be hypertensive and the odds increased with increasing age.
Publisher: Informa UK Limited
Date: 2019
Publisher: Cambridge University Press (CUP)
Date: 26-12-2018
DOI: 10.1017/S1368980018003579
Abstract: The study aimed to investigate the relationship between physical activity, gross motor skills and adiposity in South African children of pre-school age. Cross-sectional study. High-income urban, and low-income urban and rural settings in South Africa. Children (3–6 years old, n 268) were recruited from urban high-income ( n 46), urban low-income ( n 91) and rural low-income ( n 122) settings. Height and weight were measured to calculate the main outcome variables: BMI and BMI-for-age Z -score (BAZ). Height-for-age and weight-for-age Z -scores were also calculated. Actigraph GT3X+ accelerometers were used to objectively measure physical activity the Test of Gross Motor Development (Version 2) was used to assess gross motor skills. More children were overweight/obese and had a higher BAZ from urban low-income settings compared with urban high-income settings and rural low-income settings. Being less physically active was associated with thinness, but not overweight/obesity. Time spent in physical activity at moderate and vigorous intensities was positively associated with BMI and BAZ. Gross motor proficiency was not associated with adiposity in this s le. The findings of this research highlight the need for obesity prevention particularly in urban low-income settings, as well as the need to take into consideration the complexity of the relationship between adiposity, physical activity and gross motor skills in South African pre-school children.
Publisher: Wiley
Date: 10-02-2022
DOI: 10.1111/DOM.14655
Publisher: Wiley
Date: 05-03-2017
DOI: 10.1002/UOG.17347
Publisher: Elsevier BV
Date: 12-2020
Publisher: Springer Science and Business Media LLC
Date: 26-02-2021
DOI: 10.1038/S41366-021-00761-1
Abstract: Admixed populations are a resource to study the global genetic architecture of complex phenotypes, which is critical, considering that non-European populations are severely underrepresented in genomic studies. Here, we study the genetic architecture of BMI in children, young adults, and elderly in iduals from the admixed population of Brazil. Leveraging admixture in Brazilians, whose chromosomes are mosaics of fragments of Native American, European, and African origins, we used genome-wide data to perform admixture mapping/fine-mapping of body mass index (BMI) in three Brazilian population-based cohorts from Northeast (Salvador), Southeast (Bambuí), and South (Pelotas). We found significant associations with African-associated alleles in children from Salvador (PALD1 and ZMIZ1 genes), and in young adults from Pelotas (NOD2 and MTUS2 genes). More importantly, in Pelotas, rs114066381, mapped in a potential regulatory region, is significantly associated only in females (p = 2.76e-06). This variant is rare in Europeans but with frequencies of ~3% in West Africa and has a strong female-specific effect (95% CI: 2.32-5.65 kg/m We identified six candidate SNPs associated with BMI. rs114066381 stands out for its high effect that was replicated and its high frequency in women with morbid obesity. We demonstrate how admixed populations are a source of new relevant phenotype-associated genetic variants.
Publisher: Wiley
Date: 10-03-2019
DOI: 10.1111/DESC.12820
Abstract: Executive function is foundational for cognitive development. Previous research has shown both gross motor skills and physical activity to be related to executive function. However, evidence for these relationships in the preschool years, as well as in low- and middle-income countries is lacking. Therefore, this study aimed to investigate the relationships between components of executive function (inhibition, shifting and working memory) and gross motor skills (locomotor skills and object control skills) in a s le of preschool children from urban and rural low-income settings in South Africa. Results revealed that inhibition and working memory, but not shifting, were associated with gross motor skills. More specifically: inhibition was associated with both locomotor [β = 0.20, p = 0.047] and object control skills [β = 0.24, p = 0.024], whereas working memory was only associated with locomotor skills [β = 0.21, p = 0.039]. Physical activity was not associated with inhibition and shifting but was negatively associated with working memory. These results elaborate a growing evidence base linking executive function and gross motor skills in the early years, and it is the first to look at specific associations of locomotor and object control skills with executive function in the South African context (a low- and middle-income country).
Publisher: American Physiological Society
Date: 09-2004
DOI: 10.1152/JAPPLPHYSIOL.00068.2004
Abstract: We investigated differences in physical activity (PA) levels between black and white South African 9-yr-old children and their association with bone mineral content (BMC) and density (BMD) by using dual-energy X-ray absorptiometry. PA was analyzed in terms of a metabolic (METPA weighted metabolic score of intensity, frequency, and duration) and a mechanical (MECHPA sum of all ground reaction forces multiplied by duration) component. There were significant ethnic differences in patterns of activity. White children expended a significantly greater energy score (METPA of 21.7 ± 2.9) than black children (METPA of 9.5 ± 0.5) ( P 0.001). When children were ided into quartiles according to the amount and intensity of sport played, the most active white children (using METPA scores) had significantly higher whole body BMD and higher hip and spine BMC and BMD than less active children. White children in the highest MECHPA quartile also showed significantly higher whole body, hip, and spine BMC and BMD than those children in the lowest quartile. No association between exercise and bone mass of black children was found. In this population, PA has an osteogenic association with white children, but not black children, which may be explained by the lower levels of PA in the black children. Despite this, black children had significantly greater bone mass at the hip and spine (girls only) ( P 0.001) even after adjustment for body size. The role of exercise in increasing bone mass may become increasingly critical as a protective mechanism against osteoporosis in both ethnic groups, especially because the genetic benefit exhibited by black children to higher bone mass may be weakened with time, as environmental influences become stronger.
Publisher: Hindawi Limited
Date: 2017
DOI: 10.1155/2017/5283457
Abstract: Purpose . The purpose of this research was to collect data to inform intervention strategies to optimise body composition in South African preschool children. Methods . Data were collected in urban and rural settings. Weight status, physical activity, and gross motor skill assessments were conducted with 341 3–6-year-old children, and 55 teachers and parents/caregivers participated in focus groups. Results . Overweight and obesity were a concern in low-income urban settings (14%), but levels of physical activity and gross motor skills were adequate across all settings. Focus group findings from urban and rural settings indicated that teachers would welcome input on leading activities to promote physical activity and gross motor skill development. Teachers and parents/caregivers were also positive about young children being physically active. Recommendations for potential intervention strategies include a teacher-training component, parent/child activity mornings, and a home-based component for parents/caregivers. Conclusion . The findings suggest that an intervention focussed on increasing physical activity and improving gross motor skills per se is largely not required but that contextually relevant physical activity and gross motor skills may still be useful for promoting healthy weight and a vehicle for engaging with teachers and parents/caregivers for promoting other child outcomes, such as cognitive development.
Publisher: Springer Science and Business Media LLC
Date: 10-08-2023
DOI: 10.1038/S41430-023-01322-7
Abstract: Providing all infants with the best start to life is a universal but challenging goal for the global community. Historically, the size and shape of infants, quantified by anthropometry and commencing with birthweight, has been the common yardstick for physical growth and development. Anthropometry has long been considered a proxy for nutritional status during infancy when, under ideal circumstances, changes in size and shape are most rapid. Developed from data collected in the Multicentre Growth Reference Study (MGRS), WHO Child Growth Standards for healthy infants and children have been widely accepted and progressively adopted. In contrast, and somewhat surprisingly, much less is understood about the ‘quality’ of growth as reflected by body composition during infancy. Recent advances in body composition assessment, including the more widespread use of air displacement plethysmography (ADP) across the first months of life, have contributed to a progressive increase in our knowledge and understanding of growth and development. Along with stable isotope approaches, most commonly the deuterium dilution (DD) technique, the criterion measure of total body water (TBW), our ability to quantify lean and fat tissue using a two-compartment model, has been greatly enhanced. However, until now, global reference charts for the body composition of healthy infants have been lacking. This paper details some of the historical challenges associated with the assessment of body composition across the first two years of life, and references the logical next steps in growth assessments, including reference charts.
Publisher: American Diabetes Association
Date: 12-04-2018
DOI: 10.2337/DC17-1795
Abstract: The extent to which diabetes (DM) practice guidelines, often based on evidence from high-income countries (HIC), can be implemented to improve outcomes in low- and middle-income countries (LMIC) is a critical challenge. We carried out a systematic review to compare type 2 DM guidelines in in idual LMIC versus HIC over the past decade to identify aspects that could be improved to facilitate implementation. Eligible guidelines were sought from online databases and websites of diabetes associations and ministries of health. Type 2 DM guidelines published between 2006 and 2016 with accessible full publications were included. Each of the 54 eligible guidelines was assessed for compliance with the Institute of Medicine (IOM) standards, coverage of the cardiovascular quadrangle (epidemiologic surveillance, prevention, acute care, and rehabilitation), translatability, and its target audiences. Most LMIC guidelines were inadequate in terms of applicability, clarity, and dissemination plan as well as socioeconomic and ethical-legal contextualization. LMIC guidelines targeted mainly health care providers, with only a few including patients (7%), payers (11%), and policy makers (18%) as their target audiences. Compared with HIC guidelines, the spectrum of DM clinical care addressed by LMIC guidelines was narrow. Most guidelines from the LMIC complied with less than half of the IOM standards, with 12% of the LMIC guidelines satisfying at least four IOM criteria as opposed to 60% of the HIC guidelines (P & 0.001). A new approach to the contextualization, content development, and delivery of LMIC guidelines is needed to improve outcomes.
Publisher: Informa UK Limited
Date: 27-09-2018
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Shane Norris.