Effect of serum 25-hydroxyvitamin D3 on Insulin Resistance and β Cell function in newly diagnosed type 2 diabetes patients

Abstract

Aims/Introduction

To evaluate serum 25-hydroxyvitamin D₃ (25(OH)D₃) in newly diagnosed Type 2 diabetes patients and to explore the associations of 25(OH)D₃ with insulin resistance and β-cell function.

Materials and Methods

Ninety-seven newly diagnosed Type 2 diabetes patients and 69 health controls were recruited. Serum 25(OH)D₃ was determined using high pressure liquid chromatography. Insulin resistance was measured using a homeostasis model assessment of insulin resistance (HOMA-IR). Β-cell function was determined using the HOMA β-cell function index (HOMA-β), early-phase insulin secretion index (ΔI30/ΔG30), and area under the insulin curve (AUCins). Correlation analysis was performed using Pearson correlation and multiple stepwise regression analysis.

Results

Serum 25(OH)D₃ was much lower in patients with newly diagnosed Type 2 diabetes (t=-13.00, p<0.01), and the prevalence of hypovitaminosis 25(OH)D₃ was 62.9% (61/97) in diabetic patients. Among the diabetic patients, patients with hypovitaminosis 25(OH)D₃showed higher HbA1c and AUCglu (p<0.01) as well as lower HOMA-β, ΔI30/ΔG30, and AUCins. Serum 25(OH)D₃ was independently positively correlated with ΔI30/ΔG30 and AUCins (p<0.05) but was not significantly correlated with either HOMA-IR or HOMA-β. Only triglycerides, HbA1c, and ΔI30/ΔG30 emerged as independent factors associated with serum 25(OH)D₃ in both diabetes patients and the health control group.

Conclusions

Our results further demonstrated a low serum 25(OH)D₃ concentration in patients with newly diagnosed Type 2 diabetes. 25(OH)D₃deficiency is associated with disturbances in glucose metabolism and lipid metabolism. Serum 25(OH)D₃ is not correlated with basal insulin resistance or β-cell function but is significantly positively correlated with glucose-stimulated insulin secretion and β-cell function.

Full study: http://onlinelibrary.wiley.com/doi/10.1111/jdi.12381/pdf

Graham