Journal Article

Effect of serum 25-hydroxyvitamin D sub(3) on insulin resistance and beta -cell function in newly diagnosed type 2 diabetes patients

Xian, Yang, Yang, Yan, Bao, Mingjing, Li, Pengqiu, Zhang, Xuejun, Wu, Jichuan, Liu, Limei

2016

Overview

Aims/Introduction To evaluate serum 25-hydroxyvitamin D sub(3) (25(OH)D sub(3)) in newly diagnosed type 2 diabetes patients and to explore the associations of 25(OH)D sub(3) with insulin resistance and beta -cell function. Materials and Methods A total of 97 newly diagnosed type 2 diabetes patients and 69 healthy controls were recruited. Serum 25(OH)D sub(3) was determined using high-pressure liquid chromatography. Insulin resistance was measured using a homeostasis model assessment of insulin resistance (HOMA-IR). beta -Cell function was determined using the HOMA beta -cell function index (HOMA- beta ), early-phase insulin secretion index ( Delta I30/ Delta G30) and area under the insulin curve (AUCins). Correlation analysis was carried out using Pearson's correlation and multiple stepwise regression analysis. Results Serum 25(OH)D sub(3) was much lower in patients with newly diagnosed type 2 diabetes (t = -13.00, P < 0.01), and the prevalence of hypovitaminosis 25(OH)D sub(3) was 62.9% (61/97) in diabetic patients. Among the diabetic patients, patients with hypovitaminosis 25(OH)D sub(3) showed higher glycosylated hemoglobin and AUCglu (P < 0.01) as well as lower HOMA- beta , Delta I30/ Delta G30 and AUCins. Serum 25(OH)D sub(3) was independently positively correlated with Delta I30/ Delta G30 and AUCins (P < 0.05), but was not significantly correlated with either HOMA-IR or HOMA- beta . Only triglycerides, glycosylated hemoglobin and Delta I30/ Delta G30 emerged as independent factors associated with serum 25(OH)D sub(3) in both diabetes patients and the health control group. Conclusions The present results further showed a low serum 25(OH)D sub(3) concentration in patients with newly diagnosed type 2 diabetes. 25(OH)D sub(3) deficiency is associated with disturbances in glucose metabolism and lipid metabolism. Serum 25(OH)D sub(3) is not correlated with basal insulin resistance or beta -cell function, but is significantly positively correlated with glucose-stimulated insulin secretion and beta -cell function.