1.
Hypovitaminosis D associations with adverse metabolic parameters are accentuated in patients with Type 2 diabetes mellitus: a body mass index-independent role of adiponectin?
Al-Daghri, NM, Al-Attas, OS, Alokail, MS, Alkharfy, KM, Al-Othman, A, Draz, HM, Yakout, SM, Al-Saleh, Y, Al-Yousef, M, Sabico, S, et al
Journal of endocrinological investigation. 2013;(1):1-6
Abstract
BACKGROUND Hypovitaminosis D has been associated with an increased prevalence of Type 2 diabetes mellitus (DMT2) and metabolic syndrome manifestations. The purpose of this study was to examine the association between 25-hydroxy-vitamin D (25-OH-VitD) levels and indices of insulin resistance (IR), including adipocytokines, in a Saudi population with or without DMT2. SUBJECTS AND METHODS A total of 266 subjects (153 DMT2 and 113 healthy controls) aged 26-80 yr were randomly selected from the existing Biomarkers Screening in Riyadh Program (RIYADH Cohort). Subjects were assessed clinically, anthropometry was performed, morning blood chemistries, including fasting glucose (FG), triglycerides, total cholesterol, LDL cholesterol (LDL-C), and HDL cholesterol were obtained. Homeostasis model assessment of IR (HOMA-IR) was calculated, and serum 25-OH-VitD, leptin, adiponectin, resistin, insulin, high sensitivity CRP (hsCRP), and tumor necrosis factor α concentrations were measured using specific assays. RESULTS In DMT2 subjects, negative correlations between 25-OH-vitD and body mass index (BMI), FG, insulin, HOMA-IR, cholesterol, LDL-C, and hsCRP were observed, while a positive correlation between 25-OH-VitD and adiponectin was detected. The later remained significant after controlling for BMI. Interestingly, only weak and nonsignificant associations between 25-OH-VitD and metabolic parameters were observed in the control group, whereas, when the entire population was examined, negative correlations were evident primarily between 25-OH-VitD and FG, HOMA-IR, total cholesterol, LDL-C. These associations remained significant after controlling for BMI. CONCLUSIONS These results suggest that hypovitaminosis D associations with metabolic disturbances are accentuated in DMT2. The BMIindependent positive correlation between 25-OH-VitD and adiponectin suggests a potential role for this adipocytokine as a link between 25-OH-VitD and IR in patients with DMT2.
2.
Vitamin D supplementation in patients with diabetes mellitus type 2 on different therapeutic regimens: a one-year prospective study.
Alkharfy, KM, Al-Daghri, NM, Sabico, SB, Al-Othman, A, Moharram, O, Alokail, MS, Al-Saleh, Y, Kumar, S, Chrousos, GP
Cardiovascular diabetology. 2013;:113
Abstract
BACKGROUND Little or no research has determined the effect of vitamin D3 supplementation in conjunction with pharmacological and non-pharmacological approaches in the diabetes mellitus type 2 (DMT2) patients. The objective of this study was to determine the effect of vitamin D3 supplementation in a cohort of Saudi DMT2 population on diet, insulin and/or different oral hypoglycemic agents and compare them with a non-DMT2 control cohort. METHODS A total of 499 randomly selected Saudi subjects divided into 8 groups [Non-DMT2 Control = 151; Rosiglitazone alone = 49; Diet = 15; Insulin alone = 55; Insulin + Orals = 12; Metformin alone = 121; Oral agents combination = 37; Sulphonylurea alone = 59] were included in this 12-month interventional study. All DMT2 patients were given 2000 IU vitamin D3 daily, while the control group received none but were advised to increase sun exposure. Anthropometrics, glucose, lipid profile and 25-hydroxyvitamin D (25-OHVitD) were measured at baseline, 6 and 12 months. RESULTS Circulating 25-OHVitD concentrations improved in all patient groups. The metformin group showed the highest change in circulating vitamin D levels both at 6 months (62.6%) and 12 months (50.6%) as compared to baseline (p < 0.001). No significant changes were observed in the BMI and glucose in any of the DMT2 groups. In contrast, the insulin + oral agents group showed more significant improvements in the metabolic profile, which included triglycerides and total cholesterol, as well as systolic blood pressure and HDL-cholesterol in males. Also, significant decreases in triglycerides were observed in the rosiglitazone and insulin + oral hypoglycemic agent groups both at 6 and 12 months of supplementation (both p-values <0.001). CONCLUSION While in all DMT2 groups circulating levels of 25-OHVitD increased after supplementation, in DMT2 patients on insulin in combination with other drugs benefitted the most in improving cardiovascular risk. Metformin improves 25-hydroxyvitamin D levels but did not seem to confer other added cardiometabolic benefits.