RESUMEN
The current study was conducted to assess the effects of vitamin D supplementation on insulin metabolism, lipid fractions, biomarkers of inflammation, and oxidative stress in diabetic hemodialysis (HD) patients. This randomized double-blind placebo-controlled clinical trial was carried out among 60 diabetic HD patients. Subjects were randomly allocated into two groups to intake either oral vitamin D3 supplements at a dosage of 50 000 IU (n=30) or placebo (n=30) every 2 weeks for 12 weeks. After 12 weeks of intervention, subjects who received vitamin D supplements compared with the placebo had significantly decreased serum insulin concentrations (-3.4±3.7 vs. +2.0±4.2 µIU/ml, p<0.001), homeostasis model of assessment-estimated insulin resistance (HOMA-IR) (-1.2±1.8 vs. +0.9±2.3, p<0.001), and improved quantitative insulin sensitivity check index (QUICKI) (+0.02±0.03 vs. -0.01±0.02, p<0.001). In addition, compared with the placebo, vitamin D supplementation led to significant reductions in serum high-sensitivity C-reactive protein (hs-CRP) (-1.4±2.5 vs. +1.4±4.8 mg/l, p=0.007), plasma malondialdehyde (MDA) (-0.1±0.2 vs. +0.1±0.2 µmol/l, p=0.009) and a significant increase in plasma total antioxidant capacity (TAC) concentrations (+33.8±56.7 vs. -2.0±74.5 mmol/l, p=0.04). We did not see any significant effect of vitamin D supplementation on lipid profiles and other biomarkers of inflammation and oxidative stress compared with the placebo. Overall, we found that vitamin D supplementation had beneficial effects on serum insulin, HOMA-IR, QUICKI, serum hs-CRP, plasma MDA, and TAC levels among diabetic HD patients for 12 weeks. CLINICAL REGISTRATION:: http://www.irct.ir: IRCT201611155623N92.