Co-Administration of Vitamin E and Atorvastatin Improves Insulin Sensitivity and Peroxisome Proliferator-Activated Receptor-γ Expression in Type 2 Diabetic Patients: A Randomized Double-Blind Clinical Trial.

Background: Negative effects of statins on glucose metabolism have been reported. The present study aimed to investigate the effects of co-administration of vitamin E and atorvastatin on glycemic control in hyperlipidemic patients with type 2 diabetes mellitus (T2DM). Methods: A randomized double-blind clinical trial was conducted at Vali-e-Asr Teaching Hospital (Zanjan, Iran) from July 2017 to March 2018. A total of 30 T2DM female patients were allocated to two groups, namely atorvastatin with placebo (n=15) and atorvastatin with vitamin E (n=15). The patients received daily 20 mg atorvastatin and 400 IU vitamin E or placebo for 12 weeks. Anthropometric and biochemical measures were recorded pre- and post-intervention. Peroxisome proliferator-activated receptor-γ (PPAR-γ) expression was measured in peripheral blood mononuclear cells (PBMCs). Independent sample t test and paired t test were used to analyze between- and within-group variables, respectively. The analysis of covariance (ANCOVA) was used to adjust the effect of baseline variables on the outcomes. P<0.05 was considered statistically significant. Results: After baseline adjustment, there was a significant improvement in homeostatic model assessment for insulin resistance (HOMA-IR) (P=0.04) and serum insulin (P<0.001) in the atorvastatin with vitamin E group compared to the atorvastatin with the placebo group. In addition, co-administration of vitamin E with atorvastatin significantly upregulated PPAR-γ expression (OR=5.4, P=0.04) in the PBMCs of T2DM patients. Conclusion: Co-administration of vitamin E and atorvastatin reduced insulin resistance and improved PPAR-γ mRNA expression. Further studies are required to substantiate our findings. Trial registration number: IRCT 20170918036256N.

Association of Serum Zinc and Vitamin A Levels with Severity of Retinopathy in Type 2 Diabetic Patients: a Cross-Sectional Study.

Diabetic retinopathy (DR) is a common microvascular disorder which occurs in type 2 diabetes mellitus (T2DM) patients due to chronic hyperglycemia. Previous studies reported that serum zinc (Zn) and vitamin A levels were associated with certain diabetic microvascular complications. However, the relationship between Zn and vitamin A levels with the severity of DR in type 2 diabetic patients is not clear. We aimed to analyze the relationship between serum Zn and vitamin A levels with the severity of DR in T2DM. Sixty T2DM patients were selected from whom attending to the ophthalmology center of hospital from June 2017 and Feb 2018. Patients were categorized as controls, non-proliferative DR (NPDR), and proliferative DR (PDR). Anthropometric, dietary, and physical activity data were gathered. Fasting blood samples were taken to measure biochemical parameters. Serum Zn and vitamin A levels were measured via enzymatic-calorimetric and HPLC methods, respectively. Results showed that serum Zn and vitamin A levels were significantly lower in the PDR group than the controls (p = 0.03 and p = 0.008, respectively). Serum low-density lipoprotein (LDL.C) was significantly higher in the PDR than the control group (p = 0.02). Adjusting for the other variables, increase in serum Zn and vitamin A levels reduced risk of DR by 25.7% and 31.1%, respectively (p = 0.02 and p = 0.007). Higher serum LDL.C increased DR severity by 28.7%, adjusted for the variables (95% CI = 0.002, 0.02; p = 0.01). Lower serum Zn and vitamin A levels, as well as higher LDL.C in the T2DM patients, are related to DR severity.