ORCID Profile
0000-0003-1210-2437
Current Organisation
Deakin University
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Publisher: Springer Science and Business Media LLC
Date: 27-03-2021
DOI: 10.1007/S41999-021-00490-8
Abstract: To investigate the association between serum interleukin-6 (IL-6) and frailty. Participants were 581 men aged 60-90 yr (median (IQR): 74 yr (67-83 yr)) from the Geelong Osteoporosis Study. Tallies of ≥ 3, 1-2 and 0 for weight loss/exhaustion hysical-inactivity/slowness/weakness indicated frailty, pre-frailty and robustness, respectively. Anthropometry, lower-limb muscle strength and physical performance were measured and health behaviours self-reported. Serum IL-6 was measured using an enzyme-linked immunosorbent assay and log-transformed (ln-IL-6). Total antioxidant capacity (TAC) was also measured using quantitative colorimetric determination. Multivariable ordinal logistic regression models tested associations between ln-IL-6 and frailty while considering age, anthropometry, comorbidities, TAC, medications that affect inflammatory processes, lifestyle and socioeconomic status. There were 49(8.4%) frail and 315(54.2%) pre-fail men. A relationship was evident between ln-IL-6 and frailty before and after accounting for age (adjusted OR = 1.24, 95%CI 1.01-1.53). Adjusting for medications attenuated the association (OR = 1.20, 95%CI 0.98-1.48). No other confounders were identified. These data suggest that IL-6 is positively associated with frailty in men, partly explained by advancing age and medications known to affect inflammation.
Publisher: SAGE Publications
Date: 09-2020
Abstract: Frailty, a clinical syndrome characterized by multisystem dysregulation, has been associated with high levels of oxidative stress. We investigated the association between serum total antioxidant capacity (TAC) and frailty in older men. This cross-sectional study included 581 men (age 60–90 years) enrolled in the Geelong Osteoporosis Study. Frailty comprised at least three of unintentional weight loss, exhaustion, low physical activity, slowness, and weakness. Serum TAC was measured by quantitative colorimetric determination and expressed as uric acid equivalents (mM). Relationships between TAC (in SD units) and frailty were explored using multivariable logistic regression models. Sociodemographic, anthropometric, and lifestyle variables were tested as potential confounders and effect modifiers. A sensitivity analysis excluded participants ( n = 145) in the upper quartile of TAC, who were likely to have hyperuricemia. Fifty (8.6%) men were frail. There was evidence that higher TAC levels were associated with increased likelihood of frailty ( OR 1.34, 95% confidence interval [CI 0.99, 1.80]), and this was attenuated after adjustment for age and body mass index (BMI OR 1.26, 95% CI [0.93,1.71]). No effect modifiers or other confounders were identified. The sensitivity analysis revealed a positive association between TAC and frailty, before and after accounting for age and BMI (adjusted OR 1.79, 95% CI [1.01, 3.17] p = .038). These results suggest a positive association between TAC levels and frailty, supporting the hypothesis that this biomarker could be useful in identifying in iduals at risk of frailty. We speculate that a milieu of heightened oxidative stress in frailty may elevate the oxidative stress regulatory set point, raising antioxidant activity. This warrants further investigation.
Publisher: Wiley
Date: 15-02-2020
DOI: 10.1002/JCSM.12544
Publisher: Springer Science and Business Media LLC
Date: 13-01-2022
DOI: 10.1007/S00223-021-00939-9
Abstract: Accumulation of fat in the liver and skeletal muscle is associated with obesity and poor health outcomes. Liver steatosis is a characteristic of non-alcoholic fatty liver disease (NAFLD) and myosteatosis, of poor muscle quality in sarcopenia. In this study of 403 men (33–96 years), we investigated associations between the fatty liver index (FLI) and muscle density, as markers of fat accumulation in these organs. We also investigated associations between the FLI and parameters of sarcopenia, including DXA-derived appendicular lean mass (ALM) and handgrip strength by dynamometry. Muscle density was measured using pQCT at the radius and tibia. FLI was calculated from BMI, waist circumference, and levels of triglycerides and gamma-glutamyltransferase. There was a pattern of decreasing muscle density across increasing quartiles of FLI. After adjusting for age and lifestyle, mean radial muscle density in Q4 was 2.1% lower than Q1 ( p 0.001) and mean tibial muscle density was 1.8% lower in Q3 and 3.0% lower in Q4, compared to Q1 ( p = 0.022 and 0.001, respectively). After adjusting for age and sedentary lifestyle, participants in the highest FLI quartile were sixfold more likely to have sarcopenia. In conclusion, our results suggest that fat accumulation in the liver co-exists with fat infiltration into skeletal muscle.
Publisher: MDPI AG
Date: 18-01-2021
DOI: 10.3390/JCM10020343
Abstract: Background: Prevalence estimates for sarcopenia vary depending on the ascertainment criteria and thresholds applied. We aimed to estimate the prevalence of sarcopenia using two international definitions but employing Australian population-specific cut-points. Methods: Participants (n = 665 323 women) aged 60–96 years old were from the Geelong Osteoporosis Study. Handgrip strength (HGS) was measured by dynamometers and appendicular lean mass (ALM) by whole-body dual-energy X-ray absorptiometry. Physical performance was assessed using gait speed (GS, men only) and/or the timed up-and-go (TUG) test. Using cut-points equivalent to two standard deviations (SDs) below the mean young reference range from the same population and recommendations from the European Working Group on Sarcopenia in Older People (EWGSOP), sarcopenia was identified by low ALM/height2 ( .30 kg for women .94 kg for men) + low HGS ( kg women kg men) low ALM/height2 + slow TUG ( .3 s) low ALM/height2 + slow GS ( .8 m/s). For the Foundation for the National Institutes of Health (FNIH) equivalent, sarcopenia was identified as low ALM/BMI ( .512 m2 women, .827 m2 men) + low HGS ( kg women, kg men). Receiver Operating Characteristic curves were also applied to determine optimal cut-points for ALM/BMI ( .579 m2 women, .913 m2 men) that discriminated poor physical performance. Prevalence estimates were standardized to the Australian population and compared to estimates using international thresholds. Results: Using population-specific cut-points and low ALM/height2 + HGS, point-estimates for sarcopenia prevalence were 0.9% for women and 2.9% for men. Using ALM/height2 + TUG, prevalence was 2.5% for women and 4.1% for men, and using ALM/height2 + GS, sarcopenia was identified for 1.6% of men. Using ALM/BMI + HGS, prevalence estimates were 5.5–10.4% for women and 11.6–18.4% for men. Conclusions: This study highlights the range of prevalence estimates that result from employing different criteria for sarcopenia. While population-specific criteria could be pertinent for some populations, a consensus is needed to identify which deficits in skeletal muscle health are important for establishing an operational definition for sarcopenia.
Publisher: Springer Science and Business Media LLC
Date: 20-12-2019
DOI: 10.1007/S00223-018-0506-1
Abstract: Recommendations from the FNIH Sarcopenia Project are that appendicular lean mass (ALM, kg) adjusted for body mass index (BMI, kg/m
Publisher: Springer Science and Business Media LLC
Date: 10-09-2023
Publisher: Springer Science and Business Media LLC
Date: 20-05-2021
Publisher: Springer Science and Business Media LLC
Date: 23-12-2022
Publisher: Elsevier BV
Date: 02-2022
DOI: 10.1016/J.BONE.2021.116268
Abstract: Bone material strength index (BMSi) is measured in vivo using impact microindentation (IMI). However, the associations between BMSi and other bone measures are not clear. This study investigated whether bone parameters derived by peripheral quantitative computed tomography (pQCT) are associated with BMSi. Participants were men (n = 373, ages 34-96 yr) from the Geelong Osteoporosis Study. BMSi was measured using an OsteoProbe (Active Life Scientific, USA). Bone measures were obtained at both the radius (n = 348) and tibia (n = 342) using pQCT (XCT 2000 Stratec Medizintechnik, Germany). Images were obtained at 4% and 66% of radial and tibial length. Associations between pQCT parameters and BMSi were tested using Spearman's correlation and multivariable regression used to determine independent associations after adjustment for potential confounders. Models were checked for interaction terms. Weak associations were observed between total bone density (radius 4% r = +0.108, p = 0.046, tibia 4% r = +0.115, p = 0.035), cortical density (tibia 4% r = +0.123, p = 0.023) and BMSi. The associations were independent of weight, height, and glucocorticoid use (total bone density: radius 4% β = 0.020, p = 0.006, tibia 4% β = 0.020, p = 0.027 and cortical density: radius 4% β = 4.160, p = 0.006, tibia 4% β = 0.038, p = 0.010). Associations with bone mass were also observed at the 66% radial and tibial site, independent of age, weight, and glucocorticoid use (β = 4.160, p = 0.053, β = 1.458, p = 0.027 respectively). Total area at the 66% tibial site was also associated with BMSi (β = 0.010, p = 0.012), independent of weight and glucocorticoid use. No interaction terms were identified. There were weak associations detected between some pQCT-derived bone parameters and BMSi.
Publisher: MDPI AG
Date: 20-05-2022
DOI: 10.3390/JCM11102906
Abstract: We aimed to examine associations between skeletal muscle deficits and indices of poor health. Cut-points for skeletal muscle deficits were derived using data from the Geelong Osteoporosis Study and definitions from the revised European Consensus on Definition and Diagnosis and the Foundation for the National Institutes of Health. Participants (n = 665 323 women) aged 60–96 year had handgrip strength measured by dynamometry and appendicular lean mass by whole-body dual-energy X-ray absorptiometry. Physical performance was assessed using the Timed Up and Go test. Sex-specific cut-points were equivalent to two standard deviations below the mean young reference range from the Geelong Osteoporosis Study. Indices of poor health included fractures, falls, and hospitalisations. Low trauma fractures since age 50 year (excluding skull, face, digits) were self-reported and confirmed using radiological reports. Falls (≥1 in the past 12 months) and hospitalisations (past month) were self-reported. Logistic regression models (age- and sex-adjusted) were used to examine associations. Receiver Operating Characteristic curves were applied to determine optimal cut-points for handgrip strength, Timed Up and Go, appendicular lean mass/height2, and appendicular lean mass/body mass index that discriminated poor health outcomes. There were 48 participants (6.9%) with hospitalisations, 94 (13.4%) with fractures, and 177 (25.3%) with at least one fall (≥1). For all cut-points, low handgrip strength was consistently associated with falls. There was little evidence to support an association between low appendicular lean mass, using any cut-point, and indices of poor health. Optimal cut-offs for predicting falls (≥1) were: handgrip strength 17.5 kg for women and 33.5 kg for men Timed Up and Go 8.6 s for women and 9.9 s for men appendicular lean mass/height2 6.2 kg/m2 for women and 7.46 kg/m2 for men and appendicular lean mass/body mass index 0.6 m2 for women and 0.9 m2 for men. In conclusion, muscle strength and function performed better than lean mass to indicate poor health. These findings add to the growing evidence base to inform decisions regarding the selection of skeletal muscle parameters and their optimal cut-points for identifying sarcopenia.
Publisher: Springer Science and Business Media LLC
Date: 17-03-2020
DOI: 10.1007/S00198-020-05376-2
Abstract: Osteoporosis and sarcopenia share risk profiles, so we tested a fracture risk assessment tool (FRAX) as a screening tool for sarcopenia. FRAX probabilities without bone mineral density predicted sarcopenia with high sensitivity and reasonable specificity. There is potential to use this FRAX as a screening tool for sarcopenia. There is a need for simple screening tools for sarcopenia. As osteoporosis and sarcopenia share risk profiles, we tested the performance of a fracture risk assessment tool for discriminating in iduals at risk for sarcopenia. In this longitudinal study, FRAX (Australia) probabilities were calculated for 354 women (ages 40-90 years) in the Geelong Osteoporosis Study. Sarcopenia was assessed a decade later using DXA-derived low appendicular lean mass (Lunar ALM/height Baseline median (IQR) values for HF-FRAX without BMD were 0.4 (0.1-1.3) and for MOF-FRAX without BMD, 2.4 (1.2-5.2) comparable figures for HF-FRAX with BMD were 0.2 (0.0-0.7) and for MOF-FRAX with BMD, 2.1 (1.1-4.4). At follow-up, sarcopenia was identified for 11 (3.1%) women. When FRAX was calculated without BMD, the AUROC was 0.90 for HF-FRAX and 0.88 for MOF-FRAX. Optimal thresholds were 0.9 for HF-FRAX (sensitivity 90.9%, specificity 62.4%) and 5.3 for MOF-FRAX (sensitivity 81.8%, specificity 71.7%). Calculating FRAX with BMD did not improve the predictive performance of FRAX for sarcopenia. Here we provide preliminary evidence to suggest that FRAX probabilities without BMD might predict sarcopenia with high sensitivity and reasonable specificity. Given that FRAX clinical risk factors are identified without equipment, there is potential to use this or a modified version of the FRAX tool to screen for in iduals at risk of sarcopenia.
Publisher: Springer Science and Business Media LLC
Date: 02-07-2020
Publisher: Springer Science and Business Media LLC
Date: 27-09-2020
DOI: 10.1007/S00223-020-00759-3
Abstract: We aimed to investigate cross-sectional associations between skeletal muscle density, a proxy measure for fatty infiltration into muscle, and cognition. Contributions from body fat mass, systemic inflammation and lifestyle were explored, as these factors have been identified in both muscle and cognitive deterioration. For 281 men (60-95 year) from the Geelong Osteoporosis Study, radial and tibial muscle density were measured using peripheral quantitative computed tomography. Body fat and appendicular lean mass were measured using dual-energy X-ray absorptiometry. Cognitive function was assessed for psychomotor function (DET), visual identification/attention (IDN), visual learning (OCL) and working memory (OBK) (CogState Brief Battery). Composite scores signified overall cognitive function (OCF). Higher scores represent poorer performance except for OCL and OCF. Regression analyses examined associations between muscle density and cognition potential confounders included age, muscle cross-sectional area (CSA), body composition, lifestyle and serum markers of inflammation. Negative associations with age were evident for muscle density, all cognitive domains and OCF. Muscle density at both sites was positively associated with DET, OCL and OCF. After adjustment for age, the association persisted for DET (radius: B = - 0.006, p = 0.02 tibia: B = - 0.003, p = 0.04) and OCL (radius B = + 0.004, p = 0.02 tibia: B = + 0.005, p < 0.001). At the radius, further adjustment for serum TNF-α explained the association between muscle density (B = - 0.002, p = 0.66) and DET. Education and physical activity contributed to the model for radial muscle density and DET. There were no contributions from muscle CSA, appendicular lean mass, body fat mass, other markers of inflammation or other potential confounders. At the tibia, the association between muscle density and DET (B = - 0.003, p = 0.04) was independent of TNF-α. There was an age-adjusted association between muscle density and OCL at both sites (radius: B = + 0.004, p = 0.02 tibia: B = + 0.005, p < 0.001). None of the potential confounders contributed to the models. Muscle density was associated with cognitive function in the DET and OCL domains. However, there was little evidence that this was explained by inflammation or body fat mass. No associations were identified between muscle density and IDN or OBK.
Publisher: Springer Science and Business Media LLC
Date: 05-06-2020
DOI: 10.1186/S12877-020-01595-8
Abstract: Frailty is characterised by age-related declines in physical, psychological and social functioning. Features of frailty overlap with risk factors for fragility fractures. The aim of this study was to investigate the association between the fracture risk assessment tool (FRAX®) and frailty. In cross-sectional analysis, frailty status was determined for participants aged 60-90 yr at 15-year follow-up of the Geelong Osteoporosis Study, using a modified Fried frailty phenotype. Using the FRAX on-line tool, scores for hip and major osteoporotic fracture (MOF) were calculated with and without bone mineral density (BMD). Using the area under Receiver Operating Characteristic (AUROC) curves, and FRAX scores calculated at the baseline visit for these participants, we investigated the association of FRAX and frailty 15 years later. Forty-seven of 303 women (15.5%) and 41 of 282 men (14.5%) were frail at the 15-year visit. There was a gradient of increasing median FRAX scores from robust to frail. For ex le, for women, median MOF-FRAX without BMD increased from 5.9 for the robust to 7.5 for the pre-frail and 14.0 for the frail ( p 0.001). In secondary analyses, an association was observed between FRAX and frailty over 15 years, with the highest AUROC for women being 0.72 for MOF-FRAX with BMD, and for men, 0.76 hip-FRAX without BMD. An association was observed between FRAX and frailty where frail men and women had higher FRAX-scores compared to the other groups. Preliminary data suggest that FRAX, with or without BMD, may be useful in enhancing the information on frailty. Further research using larger datasets will be required to explore this.
Publisher: Springer Science and Business Media LLC
Date: 08-02-2020
DOI: 10.1186/S12891-020-3098-7
Abstract: The extent of muscle deterioration associated with ageing or disease can be quantified by comparison with appropriate reference data. The objective of this study is to present normative data for lower-limb muscle strength and quality for 573 males and 923 females aged 20-97 yr participating in the Geelong Osteoporosis Study in southeastern Australia. In this cross-sectional study, measures of muscle strength for hip flexors and hip abductors were obtained using a Nicholas manual muscle tester, a hand-held dynamometer (HHD kg). Leg lean mass was measured by dual energy x-ray absorptiometry (DXA kg), and muscle quality calculated as strength/mass (N/kg). For both sexes, muscle strength and quality decreased with advancing age. Age explained 12.9–25.3% of the variance in muscle strength in males, and 20.8–24.6% in females age explained less of the variance in muscle quality. Means and standard deviations for muscle strength and quality for each muscle group are reported by age-decade for each sex, and cutpoints equivalent to T-scores of − 2.0 and − 1.0 were derived using data from young males ( n = 89) and females ( n = 148) aged 20–39 years. These data will be useful for quantifying the extent of dynapenia and poor muscle quality among adults in the general population in the face of frailty, sarcopenia and other age-related muscle dysfunction.
Location: Australia
No related grants have been discovered for Monica Tembo.