STUDY ON RELATIONSHIP BETWEEN VITAMIN D DEFICIENCY/INSUFFICIENCY AND BELLY FAT AND INSULIN RESISTANCE IN PATIENTS WITH TYPE 2 DIABETES IN HUE CITY IN VIETNAM

Introduction: Recent studies show that Vitamin D deficiency/insufficiency is common in patients with type 2 diabetes, and Vitamin D is associated with pathogenic factors of type 2 diabetes, including obesity and insulin resistance. This study aims to clarify the relationship between Vitamin D and belly fat and insulin resistance in diabetic patients through their waist circumference (WC) and quantitative insulin sensitivity check index (QUICKI). Methods: A descriptive cross-sectional study was carried out on 110 diabetic patients examined and treated at Hue Central Hospital and Hue University of Medicine and Pharmacy Hospital. These patients underwent waist circumference measurement, fasting venous blood sampling, 25-hydroxy vitamin D (25 Oh vitamin D) test, fasting plasma glucose test, fasting insulin test and QUICKI calculation. Results: Percentage of participants with Vitamin D deficiency and insufficiency, belly fat and insulin resistance were 51.8%, 73.6% and 59.1%, respectively. Average concentration of 25 OH Vitamin D (ng/ml) in belly fat patients was 29.49±8.22, lower than in non-belly fat patients at 33.98±8.70 with p=0.014; Quicki in patients with and without belly fat were 0.31±0.03 and 0.33±0.04 respectively, with p=0.001; concentration of 25 OH Vitamin D in patients with insulin resistance was 29.16±8.12 and without insulin resistance was 32.85±8.76 with p=0.025; waist circumference (cm) in groups of patients with and without insulin resistance were 90.52±6.21 and 86.18±6.30 respectively, with p=0.001. The Chi-square test showed that percentage of Vitamin D deficiency and insufficiency in belly fat and non-belly fat groups were respectively 60.5% and 27.6% with p=0.003; this percentage in insulin resistance and non-insulin resistance groups were respectively 61.5% and 38.8% with p=0.020; insulin resistance rate in belly fat and non-belly fat groups were respectively 66.7% and 37.9% with p=0.009. The correlation analysis indicated that 25 OH Vitamin D concentration positively correlated with Quicki with r= 0.253, p=0.008; the waist circumference negatively correlated with Quicki, with r=-0.321 and p=0.001; there were no statistically significant correlation between 25 OH Vitamin D concentration and waist circumference. Conclusions: The diabetic patients with belly fat or insulin resistance had lower 25 OH Vitamin D concentration and higher Vitamin D deficiency and insufficiency ratio, and belly fat had a high statistically significant correlation with insulin resistance. There might be intercorrelations among Vitamin D, belly fat and insulin resistance. Key words: Diabetes, Vitamin D, insulin resistance, belly fat