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A Randomized Placebo-Controlled Trial of Low- Versus Moderate-Dose Vitamin D3 Supplementation on Bone Mineral Density in Postmenopausal Women With HIV.
Yin, MT, RoyChoudhury, A, Bucovsky, M, Colon, I, Ferris, DC, Olender, S, Agarwal, S, Sharma, A, Zeana, C, Zingman, B, et al
Journal of acquired immune deficiency syndromes (1999). 2019;80(3):342-349
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Prevalence of fracture is 2 to 3-fold higher in women with HIV over age 50 than in the general population. The aim of this study was to compare the effects of two doses of vitamin D3 repletion (3000 IU Vs 1000 IU) on bone turnover and change in bone mass and microarchitecture in postmenopausal women with HIV. The study is a randomised placebo-controlled study which recruited women with HIV aged between 40 and 70 years. The participants were randomised to 3000 vs 1000 IU vitamin D3 daily together with 500mg calcium carbonate twice daily. Results indicate that moderate dose vitamin D3 (3000 IU) supplementation in minority postmenopausal women with HIV on established antiretroviral therapy (treatment for HIV) did not appear to have a greater impact on bone mineral density or bone turnover than low dose vitamin D3 supplementation (1000 IU). Authors conclude that further studies are required to determine whether vitamin D3 supplementation is beneficial in this patient population, and if so, what dose provides the maximum benefit in terms of musculoskeletal health in persons aging with HIV.
Abstract
BACKGROUND Prevalence of osteoporosis and fracture is increased among older people with HIV. We compared the effects of low (1000 IU) vs moderate (3000 IU) vitamin D3 (VitD) supplementation on areal bone mineral density (aBMD) and volumetric bone mineral density (vBMD) in African American and Hispanic postmenopausal women with HIV on antiretroviral therapy. METHODS We performed a 12-month prospective, randomized, double-blind, placebo-controlled study with primary outcomes of change in aBMD by dual-energy X-ray absorptiometry (DXA) and secondary outcomes of change in vBMD by quantitative computed tomography and bone turnover markers. An intent-to-treat analysis was performed on 85 randomized subjects (43 low and 42 moderate) for primary DXA outcomes, and complete case analysis was performed for secondary outcomes. RESULTS Mean age was 56 ± 5 years, median CD4 count was 722 cells/mm, and 74% had HIV RNA ≤ 50 copies/mL. Serum 25-OHD was higher in the moderate than low VitD group at 6 months (33.1 ± 10.3 vs 27.8 ± 8.1 ng/mL, P = 0.03) and 12 months, but parathyroid hormone levels remained similar. Percent change in aBMD, vBMD, and bone turnover markers did not differ between low and moderate VitD groups before or after adjustment for baseline aBMD. CONCLUSIONS VitD supplementation at 3000 IU daily increased mean total 25-OHD levels in postmenopausal women with HIV, but we did not find evidence of an effect on BMD beyond those observed with 1000 IU daily. Future studies are necessary to determine whether VitD supplementation is beneficial in this patient population, and if so, what dose is optimal for skeletal health.
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A whole-grain diet reduces peripheral insulin resistance and improves glucose kinetics in obese adults: A randomized-controlled trial.
Malin, SK, Kullman, EL, Scelsi, AR, Haus, JM, Filion, J, Pagadala, MR, Godin, JP, Kochhar, S, Ross, AB, Kirwan, JP
Metabolism: clinical and experimental. 2018;82:111-117
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Literature shows that dietary whole-grain intake is associated with a lower incidence of type 2 diabetes. The aim of the study was to investigate the association between a whole-grain diet and insulin resistance and glucose use in individuals at risk for type 2 diabetes. The study was a randomized, double-blind, controlled crossover trial involving fourteen middle-aged, obese adults at risk for diabetes. Randomisation was carried out prior to metabolic testing. Results indicate that whole-grain intake as part of a mixed-meal diet significantly improved post-prandial (after a meal) glucose metabolism in middle-aged obese adults. Furthermore, both whole-grain and refined-grain interventions induced about 3–6% weight and fat loss. Authors conclude that whole-grain intake effectively promotes glycaemic control by improving insulin action.
Abstract
BACKGROUND Whole-grain intake is associated with lower risk of type 2 diabetes but the mechanisms are unclear. PURPOSE We tested the hypothesis that a WG diet reduces insulin resistance and improves glucose use in individuals at risk for type 2 diabetes compared with an isocaloric-matched refined-grain diet. METHODS A double-blind, randomized, controlled, crossover trial of 14 moderately obese adults (Age, 38 ± 2 y; BMI, 34.0 ± 1.1 kg/m2). Insulin resistance and glucose metabolism was assessed using an oral glucose tolerance test combined with isotopic tracers of [6,6-2H2]-glucose and [U-13C]-glucose, and indirect calorimetry. Peripheral and hepatic insulin resistance was assessed as 1/(rate of disposal/insulin), and endogenous glucose rates of appearance (Ra) iAUC60-240 × insulin iAUC60-240, respectively. Both diets met ADA nutritional guidelines and contained either whole-grain (50 g per 1000 kcal) or equivalent refined-grain. All food was provided for 8 wk. with an 8-10 wk. washout period between diets. RESULTS Post-prandial glucose tolerance, peripheral insulin sensitivity, and metabolic flexibility (insulin-stimulated - fasting carbohydrate oxidation) improvements were greater after whole-grain compared to the refined-grain diet (P < 0.05). Compared to baseline, body fat (~2 kg) and hepatic Ra insulin resistance was reduced by both diets, while fasting glucose and exogenous glucose-meal were unchanged after both interventions. Changes in peripheral insulin resistance and metabolic flexibility correlated with improved glucose tolerance (P < 0.05). CONCLUSION Whole-grains reduced diabetes risk and the mechanisms appear to work through reduced post-prandial blood glucose and peripheral insulin resistance that were statistically linked to enhanced metabolic flexibility.