Browsing by Subject "Body composition"

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    Changes in blood pressure, glucose levels, insulin secretion and anthropometry after long term exposure to antiretroviral therapy in South African women
    (2015-08-05) Abrahams, Zulfa; Dave, Joel A; Maartens, Gary; Levitt, Naomi S
    Abstract Background A number of metabolic abnormalities, such as dysglycaemia, insulin resistance, lipodystrophy and dyslipidaemia, are associated with the use of antiretroviral drugs. We aimed to assess the effects of long-term antiretroviral exposure on blood pressure, glycaemia, insulin secretion and anthropometric measures in black South African women. Methods A convenience sample of HIV-infected women on first-line ART for a median of 16 months at baseline, had the following evaluations twice, at baseline and after approximately 5 years: anthropometry, including skin fold thicknesses, blood pressure, oral glucose test, and insulin. Insulin sensitivity and secretion (HOMA-IR, IGI and DIo) were estimated. Results At baseline more than half the 103 women were using stavudine and efavirenz. The median interval between baseline and follow-up evaluation was 66 months. Weight, waist circumference, and waist-hip ratio increased over time, while limb skinfold thickness decreased over time. Systolic and diastolic blood pressure increased significantly and the proportion of participants with hypertension increased from 3.9 to 15.5% (p < 0.001). There were increases from baseline in plasma glucose concentrations at 30 and 120 min; insulin concentrations at 0 and 30 min; and IGI and DIo. The proportion of participants with diabetes increased from 1 to 7.5% (p = 0.070). Conclusion In black South African women with long-term exposure to ART, increases in hypertension and possibly diabetes were observed. Participants experienced an increase in central fat and a decrease in peripheral fat distribution. Early identification and management of these metabolic changes are important, especially in a region with the highest HIV-infected population in the world.
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    Comparison of body fatness measurements by near-infrared reactance and dual-energy X-ray absorptiometry in normal-weight and obese black and white women
    (2010) Jennings, Courtney L; Micklesfield, Lisa K; Lambert, Mike I; Lambert, Estelle V; Collins, Malcolm; Goedecke, Julia H
    The aim of the present study was to compare body fat percent (BF %) using single-site near-IR reactance (NIR) and dual-energy X-ray absorptiometry (DXA) in a cohort of normal-weight (BMI < 25 kg/m2) black (n 102) and white (n 71); and obese (BMI > or = 30 kg/m2) black (n 117) and white (n 41) South African women (18-45 years). NIR-derived BF % was significantly correlated with DXA-derived BF % in all groups: normal-weight black (r 0.55, 95 % CI: 0.40, 0.67, P < 0.001) and white (r 0.69, 95 % CI: 0.53, 0.79, P < 0.001) women; obese black (r 0.59, 95 % CI: 0.46, 0.70, P < 0.001) and white (r 0.56, 95 % CI: 0.30, 0.74, P < 0.001) women. NIR under-predicted BF% compared to DXA in black women (normal-weight, - 4.36 (sd 4.13) % and obese, - 3.41 (sd 3.72) %), while smaller mean differences were observed in white women (normal-weight, - 0.29 (sd 4.19) % and obese, - 0.81 (sd 3.09) %), irrespective of normal-weight or obese status (P < 0.001). In obese subjects, NIR-derived BF % did not measure values greater than approximately 45 %, while the maximum DXA-derived measure was 58 %. In conclusion, although there was a significant relationship between NIR- and DXA-derived BF %, NIR under-predicted BF % in normal-weight and obese black South African women compared to DXA, but to a greater extent in subjects with very high levels of adiposity (>45 %). The results of single-site NIR as a measure of BF % should therefore be interpreted with caution, particularly in women of African descent and in those with very high levels of adiposity.
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    Conjugated linoleic acid versus high-oleic acid sunflower oil: effects on energy metabolism, glucose tolerance, blood lipids, appetite and body composition in regularly exercising individuals
    (2007) Lambert, Estelle V; Goedecke, Julia H; Bluett, Kerry; Heggie, Kerry; Claassen, Amanda; Rae, Dale E; West, Sacha; Dugas, Jonathan; Dugas, Lara; Meltzer, Shelly; Charlton, Karen; Mohede, Inge
    The aim of this study was to measure the effects of 12 weeks of conjugated linoleic acid (CLA) supplementation on body composition, RER, RMR, blood lipid profiles, insulin sensitivity and appetite in exercising, normal-weight persons. In this double-blind, randomised, controlled trial, sixty-two non-obese subjects (twenty-five men, thirty-seven women) received either 3.9 g/d CLA or 3.9 g high-oleic acid sunflower oil for 12 weeks. Prior to and after 12 weeks of supplementation, oral glucose tolerance, blood lipid concentrations, body composition (dual-energy X-ray absorptiometry and computerised tomography scans), RMR, resting and exercising RER and appetite were measured. There were no significant effects of CLA on body composition or distribution, RMR, RER or appetite. During the oral glucose tolerance tests, mean plasma insulin concentrations (0, 30, 120 min) were significantly lower (P= 0.04) in women who supplemented with CLA (24.3 (SD 9.7) to 20.4 (SD 8.5) microU/ml) compared to high-oleic acid sunflower oil control (23.7 (SD 9.8) to 26.0 (SD 8.8) microU/ml). Serum NEFA levels in response to oral glucose were attenuated in both men and women in the CLA (P=0.001) compared to control group. However, serum total cholesterol and LDL-cholesterol concentrations decreased in both groups and HDL-cholesterol concentrations decreased in women over 12 weeks (P=0.001, P=0.02, P=0.02, respectively). In conclusion, mixed-isomer CLA supplementation had a favourable effect on serum insulin and NEFA response to oral glucose in non-obese, regularly exercising women, but there were no CLA-specific effects on body composition, energy expenditure or appetite.