ORCID Profile
0000-0001-7034-6750
Current Organisation
University of Southampton
Does something not look right? The information on this page has been harvested from data sources that may not be up to date. We continue to work with information providers to improve coverage and quality. To report an issue, use the Feedback Form.
Publisher: Elsevier BV
Date: 10-2016
Publisher: Frontiers Media SA
Date: 16-04-2018
Publisher: Wiley
Date: 07-05-2021
DOI: 10.1002/JBMR.4295
Abstract: In pregnancy, changes in maternal calcium (Ca) economy occur to satisfy fetal Ca demand. It is unclear whether maternal mineral reserves facilitate these requirements and no data exist from sub‐Saharan Africa. The aim was to determine skeletal changes with peripheral quantitative computed tomography (pQCT) and bone biochemistry between early second and third trimesters. Pregnant rural Gambians aged 18 to 45 years ( n = 467) participating in a trial of antenatal nutritional supplements (ISRCTN49285450) had pQCT scans and blood collections at mean (SD) 14 (3) and 31 (1) weeks’ gestation. Outcomes were pQCT: radius/tibia 4% total volumetric bone mineral density (vBMD), trabecular vBMD, total cross‐sectional area (CSA), 33%/38% radius/tibia cortical vBMD, bone mineral content (BMC), total CSA biochemistry: collagen type 1 cross‐linked β‐C‐telopeptide (β‐CTX), type 1 procollagen N‐terminal (P1NP), parathyroid hormone (PTH), and 1,25(OH) 2 D. Independent t tests tested whether pooled or within‐group changes differed from 0. Multiple regression was performed adjusting for age. Data for change are expressed as mean (confidence interval [CI] 2.5, 97.5%). Radius trabecular vBMD, cortical vBMD, and BMC increased by 1.15 (0.55, 1.75)%, 0.41 (0.24, 0.58)%, and 0.47 (0.25, 0.69)%. Tibia total and trabecular vBMD increased by 0.34 (0.15, 0.54)% and 0.46 (0.17, 0.74)%, while tibia cortical vBMD, BMC, and cortical CSA increased by 0.35 (0.26, 0.44)%, 0.55 (0.41, 0.68)% and 0.20 (0.09, 0.31)%, respectively. CTX, PTH, and 1,25(OH) 2 D increased by 23.0 (15.09, 29.29)%, 13.2 (8.44, 19.34)%, and 21.0 (17.67, 24.29)%, while P1NP decreased by 32.4 (−37.19, −28.17)%. No evidence of mobilization was observed in the peripheral skeleton. Resorption, although higher in late versus early gestation, was lower throughout pregnancy compared with non‐pregnant non‐lactating (NPNL) in the same community. Formation was lower in late pregnancy than in early, and below NPNL levels. This suggests a shift in the ratio of resorption to formation. Despite some evidence of change in bone metabolism, in this population, with habitually low Ca intakes, the peripheral skeleton was not mobilized as a Ca source for the fetus. © 2021 crown copyright . Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR). The article published with the permission of the Controller of HMSO and the Queen's Printer of Scotland..
Publisher: Wiley
Date: 28-11-2020
DOI: 10.1002/JBMR.4196
Publisher: Wiley
Date: 15-06-2019
DOI: 10.1002/JCSM.13069
Abstract: In Sub‐Saharan Africa, the prevalence of obesity, cardiovascular disease (CVD) and impaired physical function are increasing due to rapid urbanization. We investigated sex differences in associations between cardiac workload, arterial stiffness, peripheral vascular calcification (PVC) and physical function in Gambian adults. A total of 488 Gambians aged 40–75+ years were recruited (men: 239 and women: 249). Supine blood pressure and heart rate were measured to calculate rate pressure product and pulse pressure. Presence of PVC was determined from tibia peripheral quantitative computed tomography scans. Physical function was assessed by chair rise test (CRT), single two‐legged jump (s2LJ) and hand grip strength (HGS). Body composition was measured by dual‐energy x‐ray absorptiometry body size corrections were used to calculate fat mass index (FMI) and appendicular lean mass index (ALMI). Estimated glomerular filtration rate (eGFR) was measured from fasting blood s les. The relationship between rate pressure product, pulse pressure or presence of PVC (independent variable) with physical function parameters (dependent variable) was tested using linear regression. Sex‐interactions were tested (p‐int) adjusting for age, eGFR and ALMI/FMI. Results were expressed as mean differences between men and women with 95% confidence intervals. Mediation analyses used ALMI/FMI as mediator. Women weighed less (54.7 kg ± 10.3 vs. 59.9 kg ± 10.3) and were shorter (157.8 cm ± 6.0 vs. 169.2 cm ± 7.0) compared with men (both P 0.0001). Women had higher FMI (6.8 kg/m 2 ± 2.9 vs. 2.9 kg/m 2 ± 2.0, P 0.0001) and eGFR (263.7 mL/min/1.73 m 2 ± 133.1 vs. 237.6 mL/min/1.73 m 2 ± 134.6), but lower ALMI (6.2 kg/m 2 ± 0.7 vs. 8.02 kg/m 2 ± 1.0, P 0.0001) compared with men. There were significant mean differences between men and women in rate pressure product and s2LJ power (−1.08 [−1.21, −0.95]) and force (−0.57 [−0.63, −0.51]), only after adjusting for age, eGFR and FMI. There were significant mean differences in the associations between pulse pressure and CRT power (−0.28 [−0.31, −0.25]), s2LJ power (−1.07 [−1.20, −0.93]) and HGS (−11.94 [−13.35, −10.54]) these differences were greater after adjusting for age, eGFR and FMI, than ALMI. There were similar differences in the associations between PVC and physical function parameters. In men, FMI mediated the association between rate pressuree product and CRT power ( P = 0.002), s2LJ force ( P 0.001) and s2LJ power ( P = 0.001). ALMI did not mediate associations for either men or women. Multiple risk factors for CVD were associated with poorer physical function in men and were mediated by FMI. There is a need to identify strategies to slow revent the rising CVD burden and poor physical function in Sub‐Saharan Africa.
Publisher: Wiley
Date: 04-05-2017
DOI: 10.1002/JCSM.12198
Publisher: Wiley
Date: 16-09-2018
DOI: 10.1002/JCSM.12341
Publisher: Elsevier BV
Date: 07-2016
Publisher: Wiley
Date: 08-04-2020
DOI: 10.1002/JBMR.3998
Publisher: Springer Science and Business Media LLC
Date: 02-03-2023
DOI: 10.1007/S00223-023-01071-6
Abstract: Between-scanner differences in measures of bone and body composition can obscure or exaggerate physiological differences in multi-site studies or the magnitude of changes in longitudinal studies. We conducted a cross-calibration study at two bone imaging centres in The Gambia, West Africa where DXA (dual-energy X-ray absorptiometry) and pQCT (peripheral Quantitative-Computed Tomography) are routinely used. Repeat scans were obtained from 64 Gambian adults (58% Male) aged Mean(SD) 30.9 (13.5) years with Mean(SD) body mass index (BMI) 21.7 (4.0) kg/m 2 , using DXA (GE Lunar iDXA, whole body [WB], total hip [TH], lumbar spine [LS]) and pQCT (Stratec XCT2000L/XCT2000, tibia 4%, 50% sites). Between-scanner differences were tested using paired t tests ( p 0.05). Between-scanner correlation was explored with linear regression, and cross-calibration equations derived. Bland–Altman analysis investigated machine trend/bias. When differences were detected ( p 0.05), cross-calibration equations were applied to urban values, with t tests and Bland Altman analysis repeated. Between-scanner differences exceeded the predefined level of statistical significance ( p 0.05) for WB aBMD and BA all pQCT measures vBMD, BMC, cortical cross-sectional area (CSA) and stress–strain index (SSI). Between-scanner correlation was high ( R 2 :0.92–0.99), except pQCT Mu.Den ( R 2 = 0.51). Bland Altman plots indicated bias increased with increasing BMD. Cross-calibration equations attenuated all between-scanner differences and systematic bias. Cross-calibration, particularly of pQCT scanners, is an important consideration in multi-site studies particularly where between population comparisons are intended. Our experiences and findings may be generalisable to other resource-limited settings where the logistics of sourcing parts and in-country repair may result in lengthy scanner downtime.
Publisher: Wiley
Date: 11-11-2022
DOI: 10.1002/JBMR.4727
Abstract: Musculoskeletal aging in the most resource‐limited countries has not been quantified, and longitudinal data are urgently needed to inform policy. The aim of this prospective study was to describe musculoskeletal aging in Gambian adults. A total of 488 participants were recruited stratified by sex and 5‐year age band (aged 40 years and older) 386 attended follow‐up 1.7 years later. Outcomes were dual‐energy X‐ray absorptiometry (DXA) ( n = 383) total hip areal bone mineral density (aBMD), bone mineral content (BMC), bone area (BA) peripheral quantitative computed tomography (pQCT) diaphyseal and epiphyseal radius and tibia ( n = 313) total volumetric BMD (vBMD), trabecular vBMD, estimated bone strength indices (BSIc), cross‐sectional area (CSA), BMC, and cortical vBMD. Mean annualized percentage change in bone outcomes was assessed in 10‐year age bands and linear trends for age assessed. Bone turnover markers, parathyroid hormone (PTH), and 25‐hydroxyvitamin D (25(OH)D) were explored as predictors of change in bone. Bone loss was observed at all sites, with an annual loss of total hip aBMD of 1.2% in women after age 50 years and in men at age 70 years plus. Greater loss in vBMD and BSIc was found at the radius in both men and women strength was reduced by 4% per year in women and 3% per year in men ( p trend 0.02, 0.03, respectively). At cortical sites, reductions in BMC, CSA, and vBMD were observed, being greatest in BMC in women, between 1.4% and 2.0% per annum. Higher CTX and PINP predicted greater loss of trabecular vBMD in women and BMC in men at the radius, and higher 25(OH)D with less loss of tibial trabecular vBMD and CSA in women. The magnitude of bone loss was like those reported in countries where fragility fracture rates are much higher. Given the predicted rise in fracture rates in resource‐poor countries such as The Gambia, these data provide important insights into musculoskeletal health in this population. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
Publisher: Frontiers Media SA
Date: 31-08-2017
Publisher: Wiley
Date: 22-11-2022
DOI: 10.1002/JBM4.10696
Abstract: We investigated the predictive performance of peripheral quantitative computed tomography (pQCT) measures of both calf muscle density (an established surrogate for muscle adiposity, with higher values indicating lower muscle adiposity and higher muscle quality) and size (cross‐sectional area [CSA]) for incident fracture. pQCT (Stratec XCT2000/3000) measurements at the tibia were undertaken in Osteoporotic Fractures in Men (MrOS) United States (US), Hong Kong (HK), and Swedish (SW) cohorts. Analyses were by cohort and synthesized by meta‐analysis. The predictive value for incident fracture outcomes, illustrated here for hip fracture (HF), using an extension of Poisson regression adjusted for age and follow‐up time, was expressed as hazard ratio (HR) per standard deviation (SD) increase in exposure (HR/SD). Further analyses adjusted for femoral neck (fn) bone mineral density (BMD) T ‐score, Fracture Risk Assessment Tool (FRAX) 10‐year fracture probability (major osteoporotic fracture) and prior falls. We studied 991 (US), 1662 (HK), and 1521 (SW) men, mean ± SD age 77.0 ± 5.1, 73.9 ± 4.9, 80 ± 3.4 years, followed for a mean ± SD 7.8 ± 2.2, 8.1 ± 2.3, 5.3 ± 2.0 years, with 31, 47, and 78 incident HFs, respectively. Both greater muscle CSA and greater muscle density were associated with a lower risk of incident HF [HR/SD: 0.84 95% confidence interval [CI], 0.72–1.0 and 0.78 95% CI, 0.66–0.91, respectively]. The pattern of associations was not materially changed by adjustment for prior falls or FRAX probability. In contrast, after inclusion of fn BMD T ‐score, the association for muscle CSA was no longer apparent (1.04 95% CI, 0.88–1.24), whereas that for muscle density was not materially changed (0.69 95% CI, 0.59–0.82). Findings were similar for osteoporotic fractures. pQCT measures of greater calf muscle density and CSA were both associated with lower incidence of fractures in older men, but only muscle density remained an independent risk factor for fracture after accounting for fn BMD. These findings demonstrate a complex interplay between measures of bone, muscle size, and quality, in determining fracture risk. © 2022 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.
Publisher: Springer Science and Business Media LLC
Date: 25-02-2022
DOI: 10.1007/S00223-022-00953-5
Abstract: As muscle strength and function decline with age the optimal high-impact physical activity (PA) required for bone remodelling is rarely achievable in older adults. This study aimed to explore the activity profiles of community-dwelling older men and women and to assess the relationship between in idual PA profiles and lower limb bone parameters. Participants from the Hertfordshire Cohort Study wore triaxial accelerometers for 7 days and counts of low (0.5–1.0 g), medium (1.0–1.5 g), and high ( 1.5 g) vertical-impact activity were calculated. Two years later, participants underwent a pQCT scan of the tibia (4% and 38% sites) to obtain measures of bone mineral density and bone geometry. Linear regression was used to quantify associations between bone and PA loading profiles adjusting for age, sex, loading category, and BMI. Results are presented as β [95% confidence interval]. Bone and PA data were available for 82 participants. The mean (SD) age at follow-up was 81.4(2.7) years, 41.5% ( n = 34) were women. The median low-impact PA count was 5281 (Inter-quartile range (IQR) 2516–12,977), compared with a median of only 189 (IQR 54–593) in medium, and 39 (IQR 9–105) in high-impact counts. Positive associations between high-impact PA and cortical area (mm 2 ), polar SSI (mm 3 ), and total area (mm 2 ) at the 38% slice (6.21 [0.88, 11.54] 61.94 [25.73, 98.14] 10.09 [3.18, 16.99], respectively). No significant associations were found at distal tibia. These data suggest that maintaining high ( 1.5 g)-impact activity is difficult for older adults to achieve however, even small amounts of high-impact PA are positively associated with selected cortical bone parameters 2 years later.
Publisher: Wiley
Date: 10-12-2022
DOI: 10.1002/JBMR.4752
Abstract: HIV infection has multi‐system adverse effects in children, including on the growing skeleton. We aimed to determine the association between chronic HIV infection and bone architecture (density, size, strength) in peripubertal children. We conducted a cross‐sectional study of children aged 8 to 16 years with HIV (CWH) on antiretroviral therapy (ART) and children without HIV (CWOH) recruited from schools and frequency‐matched for age strata and sex. Outcomes, measured by tibial peripheral quantitative computed tomography (pQCT), included 4% trabecular and 38% cortical volumetric bone mineral density (vBMD), 4% and 38% cross‐sectional area (CSA), and 38% stress–strain index (SSI). Multivariable linear regression tested associations between HIV status and outcomes, stratified by sex and puberty (Tanner 1–2 versus 3–5), adjusting for age, height, fat mass, physical activity, and socioeconomic and orphanhood statuses. We recruited 303 CWH and 306 CWOH 50% were female. Although CWH were similar in age to CWOH (overall mean ± SD 12.4 ± 2.5 years), more were prepubertal (ie, Tanner 1 41% versus 23%). Median age at ART initiation was 4 (IQR 2–7) years, whereas median ART duration was 8 (IQR 6–10) years. CWH were more often stunted (height‐for‐age Z ‐score −2) than those without HIV (33% versus 7%). Both male and female CWH in later puberty had lower trabecular vBMD, CSA (4% and 38%), and SSI than those without HIV, whereas cortical density was similar. Adjustment explained some of these differences however, deficits in bone size persisted in CWH in later puberty (HIV*puberty interaction p = 0.035 [males 4% CSA] and p = 0.029 [females 38% CSA]). Similarly, puberty further worsened the inverse association between HIV and bone strength (SSI) in both males (interaction p = 0.008) and females (interaction p = 0.004). Despite long‐term ART, we identified deficits in predicted bone strength in those living with HIV, which were more overt in the later stages of puberty. This is concerning, as this may translate to higher fracture risk later in life. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).
Publisher: Frontiers Media SA
Date: 17-03-2015
Publisher: Wiley
Date: 06-10-2015
DOI: 10.1002/JBMR.2706
Publisher: Elsevier BV
Date: 06-2021
Publisher: Wiley
Date: 07-09-2016
DOI: 10.1002/JBMR.2935
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Kate Ward.