The association of vitamin D levels and insulin resistance.

OBJECTIVE: Vitamin D deficiency and insulin resistance have great prevalence in society. The latest studies indicate an inverse association between Vitamin D levels, insulin resistance, and Type 2 diabetes. The objective of this study was to investigate the effect of vitamin D status on insulin resistance. METHODS: In a cross-sectional study, 2160 participants were randomly recruited from a nutrition clinic in Tehran, Iran, 1057 (48.9%) were female and 1103 (51.1%) male. Information was gathered by a questionnaire. Following 12-h fasting, fasting plasma glucose (FPG) and insulin levels, as well as 25-hydroxy vitamin D levels were measured. 2-H glucose and insulin levels measured after consumption of 75 g glucose, HOMA2-IR, and HOMA-ß indices were then calculated. RESULTS: The average serum Vitamin D was 22.3 + 8.9 nmol/L and the prevalence of Vitamin D deficiency was 100%. There was an inverse relationship between Vitamin D levels and age, BMI, waist circumference, and all metabolic parameters (p < 0.001 in all) and a direct association with levels of exercise. Two logistic regression models were used to adjust for confounding variables; firstly, for age, gender, and smoking and secondly, additionally for BMI and energy intake. Both models showed a significant inverse relationship between Vitamin D levels and FPG and insulin levels, 2-h glucose and insulin levels, and HOMA2-IR. The optimum cut point for vitamin D was calculated at about 25 nmol/L for preventing insulin resistance. CONCLUSION: This study illustrated that there is a statistically significant inverse relationship between Vitamin D levels and insulin resistance.

Investigating the relationship between insulin resistance and adipose tissue in a randomized Tehrani population.

OBJECTIVES: Insulin resistance is the most common metabolic change associated with obesity. The present study aimed to investigate the relationship between insulin resistance and body composition especially adipose tissue in a randomized Tehrani population. METHODS: This study used data of 2,160 individuals registered in a cross-sectional study on were randomly selected from among subjects who were referred to nutrition counseling clinic in Tehran, from April 2016 to September 2017. Insulin resistance was calculated by homeostasis model assessment formula. The odds ratio (95% CI) was calculated using logistic regression models. RESULTS: The mean age of the men was 39 (±10) and women were 41 (±11) (the age ranged from 20 to 50 years). The risk of increased HOMA-IR was 1.03 (95% CI: 1.01-1.04) for an increase in one percent of Body fat, and 1.03 (95% CI: 1.00-1.05) for an increase in one percent of Trunk fat. Moreover, the odds ratio of FBS for an increase in one unit of Body fat percent and Trunk fat percent increased by 1.05 (adjusted odds ratio [95% CI: 1.03, 1.06]) and 1.05 (95% CI: 1.02, 1.08). Also, the risk of increased Fasting Insulin was 1.05 (95% CI: 1.03-1.07) for an increase in one unit of Body fat percent, and 1.05 (95% CI: 1.02-1.08) for an increase in one unit of Trunk fat percent. CONCLUSIONS: The findings of the present study showed that there was a significant relationship between HOMA-IR, Fasting blood sugar, Fasting Insulin, and 2 h Insulin with percent of Body fat, percent of Trunk fat.

Inhibition of neointimal formation and hyperplasia in vein grafts by external stent/sheath.

Synthetic and to a lesser extent vein graft failure is still a major problem in the treatment of peripheral arterial disease, with neointimal hyperplasia being the main cause for graft occlusion in the medium and long term. This review aims to establish the current status of external stents or sheaths in the prevention of intimal hyperplasia in small diameter (< 6 mm) vein grafts.