| 1. |
- Goedecke, Julia H, et al.
(författare)
-
Reduced gluteal expression of adipogenic and lipogenic genes in black south african women is associated with obesity-related insulin resistance
- 2011
-
Ingår i: Journal of Clinical Endocrinology and Metabolism. - Philadelphia : Lippincott Williams & Wilkins. - 0021-972X .- 1945-7197. ; 96:12, s. E2029-E2033
-
Tidskriftsartikel (refereegranskat)abstract
- Context: Black South African women are less insulin sensitive than their White counterparts, despite less central and greater peripheral fat deposition. We hypothesized that this paradox may be explained, in part, by differences in the adipogenic capacity of sc adipose tissue (SAT). Objective: Our objective was to measure adipogenic and lipogenic gene expression in abdominal and gluteal SAT depots and determine their relationships with insulin sensitivity (S(I)) in South African women. Participants and Design: Fourteen normal-weight [body mass index (BMI) <25 kg/m(2)] Black, 13 normal-weight White, 14 obese (BMI >30 kg/m(2)) Black, and 13 obese White premenopausal South African women participated in this cross-sectional study.Main outcomes:S(I) (frequently sampled iv glucose tolerance test) in relation to expression of adipogenic and lipogenic genes in abdominal and gluteal SAT depots. Results: With increasing BMI, Black women had less visceral fat (P = 0.03) and more abdominal (P = 0.017) and gynoid (P = 0.041) SAT but had lower S(I) (P < 0.01) than White women. The expression of adipogenic and lipogenic genes was proportionately lower with obesity in Black but not White women in the gluteal and deep SAT depots (P < 0.05 for ethnicity × BMI effect). In Black women only, the expression of these genes correlated positively with S(I) (all P < 0.05), independently of age and fat mass. Conclusions: Obese Black women have reduced SAT expression of adipogenic and lipogenic genes compared with White women, which associates with reduced S(I). These findings suggest that obesity in Black women impairs SAT adipogenesis and storage, potentially leading to insulin resistance and increased risk of type 2 diabetes.
|
|
| 2. |
- Mendham, Amy E., et al.
(författare)
-
Sarcopenic Obesity in Africa: A Call for Diagnostic Methods and Appropriate Interventions
- 2021
-
Ingår i: Frontiers in Nutrition. - : Frontiers Media S.A.. - 2296-861X. ; 8
-
Tidskriftsartikel (refereegranskat)abstract
- This perspective aims to highlight the lack of current knowledge on sarcopenic obesity in Africa and to call for diagnostic methods and appropriate interventions. Sarcopenic obesity has been defined as obesity that occurs in combination with low muscle mass and function, which is typically evident in older adults. However, there has been no clear consensus on population-specific diagnostic criterion, which includes both gold-standard measures that can be used in a more advanced health care system, and surrogate measures that can be used in low-income settings with limited resources and funding. Importantly, low and middle-income countries (LMICs) across Africa are in an ongoing state of economic and social transition, which has contributed to an increase in the aging population, alongside the added burden of poverty, obesity, and associated co-morbidities. It is anticipated that alongside the increased prevalence of obesity, these countries will further experience an increase in age-related musculoskeletal diseases such as sarcopenia. The developmental origins of health and disease (DOHaD) approach will allow clinicians and researchers to consider developmental trajectories, and the influence of the environment, for targeting high-risk individuals and communities for treatment and/or prevention-based interventions that are implemented throughout all stages of the life course. Once a valid and reliable diagnostic criterion is developed, we can firstly assess the prevalence and burden of sarcopenic obesity in LMICs in Africa, and secondly, develop appropriate and sustainable interventions that target improved dietary and physical activity behaviors throughout the life course.
|
|
| 3. |
- Mendham, Amy E., et al.
(författare)
-
Understanding factors associated with sarcopenic obesity in older African women from a low-income setting : a cross-sectional analysis
- 2021
-
Ingår i: BMC Geriatrics. - : BioMed Central. - 1471-2318 .- 1471-2318. ; 21:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background: High rates of food insecurity, obesity and obesity-related comorbidities in ageing South African (SA) women may amplify the risk of developing sarcopenic obesity. This study aimed to investigate the prevalence and correlates of sarcopenic obesity and its diagnostic components [grip strength, appendicular skeletal muscle mass (ASM) and body mass index (BMI)] in older SA women from a low-income setting.Methods: This cross-sectional study recruited black SA women between the ages of 60–85 years (n = 122) from a low-income community. Testing included a fasting blood sample (markers of cardiometabolic risk, HIV), whole body and regional muscle and fat mass (dual-energy absorptiometry x-ray), anthropometry, blood pressure, functional movement tests, current medication use, demographic and health questionnaires, physical activity (PA; accelerometery), household food insecurity access scale, and a one-week quantified food frequency questionnaire. Foundation for the National Institutes of Health (FNIH) criteria (grip strength and ASM, adjusted for BMI) were used to classify sarcopenia. Participants with sarcopenia alongside a BMI of > 30.0 kg/m2 were classified as having sarcopenic obesity. Prevalence using other criteria (European Working Group on Sarcopenia in Older People, Asian Working Group for Sarcopenia and the International Working Group for Sarcopenia) were also explored.Results: The prevalence of sarcopenia was 27.9%, which comprised of sarcopenia without obesity (3.3%) and sarcopenic obesity (24.6%). Other classification criteria showed that sarcopenia ranged from 0.8–14.7%, including 0.8–9.8% without obesity and 0–4.9% with sarcopenic obesity. Using multivariate-discriminant analysis (OPLS-DA) those with sarcopenic obesity presented with a descriptive profile of higher C-reactive protein, waist circumference, food security and sedentary time than women without sarcopenic obesity (p = 0.046). A similar profile described women with low BMI-adjusted grip strength (p < 0.001).Conclusions: The majority of women with sarcopenia were also obese (88%). We show a large discrepancy in the diagnostic criteria and the potential for significantly underestimating the prevalence of sarcopenia if BMI is not adjusted for. The main variables common to women with sarcopenic obesity were higher food security, lower PA and chronic inflammation. Our data highlights the importance of addressing obesity within these low-income communities to ensure the prevention of sarcopenic obesity and that quality of life is maintained with ageing.
|
|
| 4. |
- Mendham, Amy, et al.
(författare)
-
Osteoporosis in older black South African women and relationships with body composition, dietary intake and physical activity
- 2020
-
Ingår i: 13th European Nutrition Conference, FENS 2019, 15–18 October 2019, Malnutrition in an Obese World: European Perspectives. - : Cambridge University Press. ; , s. E441-E441
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Introduction: Osteoporosis was not a public health concern in black South African (SA) women, until recently when it was reported that the prevalence of vertebral fractures was 9.1% in black compared to 5.0% in white SA women. Accordingly, this study aimed to measure bone mineral density (BMD) of older black SA women and to investigate its association with risk factors for osteoporosis, including strength, muscle and fat mass, dietary intake and objectively measured physical activity (PA).Methods and materials: Older black SA women (age, 68 (range; 60–85 years) n = 122) completed sociodemographic and quantitative food frequency questionnaires (QFFQ), fasting venous blood samples (25-hydroxycholecalciferol: Vitamin D-25), 24 h urine collection (estimate protein intake), grip strength and PA monitoring (activPAL). Dual-energy x-ray absorptiometry (DXA) scans of the hip (femoral neck and total) and lumbar spine determined BMD and whole-body scans for fat and fat-free soft tissue mass (FFSTM). WHO classifications were used to determine osteopenia (t-score -2.5 to -1), and osteoporosis (t-score < -2.5).Results: At the lumbar spine 34.4% of the women (n = 42) had osteopenia and 19.7% (n = 24) had osteoporosis. Osteopenia at the left femoral neck was 32% (n = 40) and osteoporosis was 13.1% (n = 16) of participants. The total left hip BMD indicated osteopenia in 27.9% (n = 34) and osteoporosis in 13.1% (n = 16) of participants. Multinomial regression revealed no differences in age (y) or frequency of falls in the past year between all groups (p = 0.727). Compared to those with normal BMD, participants with osteoporosis at the hip neck and lumbar spine were shorter, weighed less and had a lower body mass index (BMI) (all p < 0.05). When adjusted for height, the osteoporotic group (hip neck and lumbar spine) had lower trunk fat (% whole body), FFSTM (kg) and grip strength (kg), compared to those with normal BMD (p < 0.05). Only protein intake (g; 24 h urine analyses) was lower in women with osteoporosis (all sites) compared to those with normal BMD. Fat, carbohydrate and micronutrient intakes (relative to total daily energy intake), and vitamin D concentrations were not associated with BMD (all sites). Number of daily step count and stepping time (min) were inversely associated with BMI (p < 0.05), but not with BMD (all sites; p > 0.05).Discussion: A high prevalence of osteopenia and osteoporosis was evident at the lumbar spine and hip in older black SA women. This study highlights the importance of strength, body composition, and protein intake in maintaining BMD and preventing the development of osteoporosis in older women.
|
|
| 5. |
- Dlamini, Siphiwe N., et al.
(författare)
-
Targeted proteomics of appendicular skeletal muscle mass and handgrip strength in black South Africans : a cross-sectional study
- 2022
-
Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 12:1
-
Tidskriftsartikel (refereegranskat)abstract
- Although appendicular skeletal muscle mass (ASM) and handgrip strength (HGS) are key components of sarcopenia, their underlying biological mechanisms remain poorly understood. We aimed to investigate associations of circulating biomarkers with ASM and HGS in middle-aged black South Africans. This study consisted of 934 black South Africans (469 men and 465 women, aged 41–72 years) from the Middle-aged Soweto cohort. Linear regression models were used to examine relationships between 182 biomarkers (measured with proximity extension assay) and dual-energy X-ray absorptiometry-measured ASM and dynamometer-measured HGS. Age, height, sex, smoking, alcohol, food insecurity, physical activity, visceral adipose tissue, HIV and menopausal status were included as confounders. Regression models showing sex-interactions were stratified by sex. The Benjamini–Hochberg false discovery rate (FDR) was used to control for multiple testing, and FDR-adjusted P values were reported. In the total sample, 10 biomarkers were associated with higher ASM and 29 with lower ASM (P < 0.05). Out of these 39 biomarkers, 8 were also associated with lower HGS (P < 0.05). MMP-7 was associated with lower HGS only (P = 0.011) in the total sample. Sex-interactions (P < 0.05) were identified for 52 biomarkers for ASM, and 6 for HGS. For men, LEP, MEPE and SCF were associated with higher ASM (P < 0.001, = 0.004, = 0.006, respectively), and MEPE and SCF were also associated with higher HGS (P = 0.001, 0.012, respectively). Also in men, 37 biomarkers were associated with lower ASM (P < 0.05), with none of these being associated with lower HGS. Furthermore, DLK-1 and MYOGLOBIN were associated with higher HGS only (P = 0.004, 0.006, respectively), while GAL-9 was associated with lower HGS only (P = 0.005), among men. For women, LEP, CD163, IL6, TNF-R1 and TNF-R2 were associated with higher ASM (P < 0.001, = 0.014, = 0.027, = 0.014, = 0.048, respectively), while IGFBP-2, CTRC and RAGE were associated with lower ASM (P = 0.043, 0.001, 0.014, respectively). No biomarker was associated with HGS in women. In conclusion, most biomarkers were associated with ASM and not HGS, and the associations of biomarkers with ASM and HGS displayed sex-specificity in middle-aged black South Africans. Proteomic studies should examine ASM and HGS individually. Future research should also consider sexual dimorphism in the pathophysiology of sarcopenia for development of sex-specific treatment and diagnostic methods.
|
|
| 6. |
- Dugas, Lara R., et al.
(författare)
-
Obesity-related metabolite profiles of black women spanning the epidemiologic transition
- 2016
-
Ingår i: Metabolomics. - New York : Springer-Verlag New York. - 1573-3882 .- 1573-3890. ; 12:3
-
Tidskriftsartikel (refereegranskat)abstract
- In developed countries, specific metabolites have been associated with obesity and metabolic diseases, e.g. type 2 diabetes. It is unknown whether a similar profile persists across populations of African-origin, at increased risk for obesity and related diseases. In a cross-sectional study of normal-weight and obese black women (33.3 +/- 6.3 years) from the US (N = 69, 65 % obese), South Africa (SA, N = 97, 49 % obese) and Ghana (N = 82, 33 % obese) serum metabolite profiles were characterized via gas chromatography-time of flight/mass spectrometry. In US and SA women, BMI correlated with branched-chain and aromatic amino acids, as well as dopamine and aminoadipic acid. The relationship between BMI and lipid metabolites differed by site; BMI correlated positively with palmitoleic acid (16: 1) in the US; negatively with stearic acid (18: 0) in SA, and positively with arachidonic acid (20: 4) in Ghana. BMI was also positively associated with sugar-related metabolites in the US; i.e. uric acid, and mannitol, and with glucosamine, glucoronic acid and mannitol in SA. While we identified a common amino acid metabolite profile associated with obesity in black women from the US and SA, we also found site-specific obesity-related metabolites suggesting that the local environment is a key moderator of obesity.
|
|
| 7. |
- Evans, Juliet, et al.
(författare)
-
Depot- and ethnic-specific differences in the relationship between adipose tissue inflammation and insulin sensitivity
- 2011
-
Ingår i: Clinical Endocrinology. - : Wiley. - 0300-0664 .- 1365-2265. ; 74:1, s. 51-59
-
Tidskriftsartikel (refereegranskat)abstract
- Objective It is unclear whether there are differences in inflammatory gene expression between abdominal and gluteal subcutaneous adipose tissue (SAT), and between black and white women. We therefore tested the hypotheses that SAT inflammatory gene expression is greater in the abdominal compared to the gluteal depot, and SAT inflammatory gene expression is associated with differential insulin sensitivity (S(I) ) in black and white women. Design and methods S(I) (frequently sampled intravenous glucose tolerance test) and abdominal SAT and gluteal SAT gene expression levels of 13 inflammatory genes were measured in normal-weight (BMI 18-25 kg/m(2) ) and obese (BMI >30 kg/m(2) ) black (n = 30) and white (n = 26) South African women. Results Black women had higher abdominal and gluteal SAT expression of CCL2, CD68, TNF-α and CSF-1 compared to white women (P < 0·01). Multivariate analysis showed that inflammatory gene expression in the white women explained 56·8% of the variance in S(I) (P < 0·005), compared to 20·9% in black women (P = 0·30). Gluteal SAT had lower expression of adiponectin, but higher expression of inflammatory cytokines, macrophage markers and leptin than abdominal SAT depots (P < 0·05). Conclusions Black South African women had higher inflammatory gene expression levels than white women; however, the relationship between AT inflammation and S(I) was stronger in white compared to black women. Further research is required to explore other factors affecting S(I) in black populations. Contrary to our original hypothesis, gluteal SAT had a greater inflammatory gene expression profile than abdominal SAT depots. The protective nature of gluteo-femoral fat therefore requires further investigation.
|
|
| 8. |
- Evans, Juliet, et al.
(författare)
-
Diagnostic ability of obesity measures to identify metabolic risk factors in south african women
- 2011
-
Ingår i: Metabolic Syndrome and Related Disorders. - New York : Mary Ann Liebert. - 1540-4196 .- 1557-8518. ; 9:5, s. 353-360
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Currently, guidelines for obesity thresholds relating to metabolic risk in South African women have not been established. Therefore, the aim of the study was to investigate the level and diagnostic ability of obesity measures [waist circumference (WC), waist-to-height ratio (WHtR), and visceral adipose tissue (VAT) area] to identify black and white South African women with elevated blood pressure, dyslipidemia, and insulin resistance. Methods: Blood pressure, fasting insulin, glucose, and lipids were measured in 241 black and 188 white South African women. Receiver operator characteristic (ROC) curve analyses were performed to determine the diagnostic ability of WC, WHtR, and computer tomography (CT)-derived VAT to identify subjects above metabolic risk thresholds. The Youden index was used to calculate obesity thresholds for metabolic risk variables. Results: WC, WHtR, and VAT were significant determinants of all metabolic risk variables (P < 0.05), and differences in the ROC area under the curve (AUC) between obesity measures were small (approximate to 0.08) for all metabolic risk variables, in both ethnic groups. However, the ROC AUC vales for all obesity measures were greater in white compared to black women (P < 0.01). WC and VAT thresholds were lower in black women compared to white women, whereas WHtR thresholds varied less between ethnicities. Conclusions: Due to the cost, access, and radiation exposure, CT-derived VAT is not recommended above the use of simple anthropometric measures (WC and WHtR) for the determination of metabolic risk. Furthermore, thresholds of WHtR, due to low variability between ethnicities, may be more useful than WC for ethnic comparisons of risk.
|
|
| 9. |
|
|
| 10. |
- Fortuin-de Smidt, Melony C., et al.
(författare)
-
Effect of exercise training on insulin sensitivity, hyperinsulinemia and ectopic fat in black South African women : a randomized controlled trial
- 2020
-
Ingår i: European Journal of Endocrinology. - : Bioscientifica. - 0804-4643 .- 1479-683X. ; 183:1, s. 51-61
-
Tidskriftsartikel (refereegranskat)abstract
- Objective: We investigated the effects of a 12-week exercise intervention on insulin sensitivity (SI) and hyperinsulinemia and associated changes in regional and ectopic fat.Research design and methods: Healthy, black South African women with obesity (mean age 23 ± 3.5 years) and of isiXhosa ancestry were randomised into a 12-week aerobic and resistance exercise training group (n = 23) and a no exercise group (control, n = 22). Pre and post-intervention testing included assessment of SI, insulin response to glucose (AIRg), insulin secretion rate (ISR), hepatic insulin extraction (FEL) and disposition index (DI) (AIRg × SI) (frequently sampled i.v. glucose tolerance test); fat mass and regional adiposity (dual-energy X-ray absorptiometry); hepatic, pancreatic and skeletal muscle fat content and abdominal s.c. and visceral adipose tissue volumes (MRI).Results: Exercise training increased VO2peak (mean ± s.d.: 24.9 ± 2.42 to 27.6 ± 3.39 mL/kg/min, P < 0.001), SI (2.0 (1.2–2.8) to 2.2 (1.5–3.7) (mU/l)−1 min−1, P = 0.005) and DI (median (interquartile range): 6.1 (3.6–7.1) to 6.5 (5.6–9.2) × 103 arbitrary units, P = 0.028), and decreased gynoid fat mass (18.5 ± 1.7 to 18.2 ± 1.6%, P < 0.001) and body weight (84.1 ± 8.7 to 83.3 ± .9.7 kg, P = 0.038). None of these changes were observed in the control group, but body weight increased (P = 0.030). AIRg, ISR and FEL, VAT, SAT and ectopic fat were unaltered after exercise training. The increase in SI and DI were not associated with changes in regional or ectopic fat.Conclusion: Exercise training increased SI independent from changes in hyperinsulinemia and ectopic fat, suggesting that ectopic fat might not be a principal determinant of insulin resistance in this cohort.
|
|
