Vitamin D is negatively associated with triglyceride in overweight/obese patients with type 2 diabetes

Abstract

Purpose: Vitamin D has been identified to have a relation to the development of insulin resistance-related diseases, such as type 2 diabetes (T2D). T2D is often associated with obesity and dyslipidemia. Our study aimed to analyze the relationship between vitamin D and lipid profile in patients with T2D.

Methods: A total of 446 T2D patients who were hospitalized from January 2015 to December 2016 were recruited. Baseline characteristics were recorded, including body mass index (BMI), serum level of 25 hydroxy vitamin D (25(OH)D), and other biochemical indicators. T2D patients were divided into normal-weight group and overweight/obese group according to their BMI. Subgroup analysis was conducted after patients were subdivided using the quartet-method according to serum level of 25(OH)D. Differences in glucose and lipid metabolism indicators were analyzed. The correlation between serum 25(OH)D and lipid profiles was assessed by the multiple linear regression.

Results: The levels of serum 25(OH)D and high-density lipoprotein cholesterol in T2D patients of overweight/obesity group were significantly lower than those in normal-weight group, while the levels of triglyceride (TG) and HOMA-IR were significantly higher (P < 0.05). Subgroup analysis uncovered that total cholesterol (TC) and TG levels were lower with higher 25(OH)D in normal weight T2D patients. In overweight/obese T2D patients, TG level was lower in patients with higher 25(OH)D (P < 0.05). There were no significant differences in low-density lipoprotein cholesterol (LDL-C), fasting blood glucose (FBG), fasting insulin (FINS), and hemoglobin Alc (HbAlc) among Q1-Q4 in both normal weight and overweight/obese groups. Pearson test showed that serum 25(OH)D was positively correlated with high density lipoprotein cholesterol (HDL-C), and negatively correlated with TC and TG. Serum 25(OH)D was unrelated to low density lipoprotein cholesterol (LDL-C) in both groups. Multiple linear regression analysis only demonstrated an independent negative correlation between 25(OH)D and TG levels in the overweight/obese group (P < 0.01).

Conclusions: In overweight/obese patients with T2D, serum 25(OH)D was independently, negatively correlated with TG. Vitamin D supplementation should be guaranteed in patients with diabetes, especially with obese T2D.

Keywords: Insulin resistance; Lipid profile; Overweight/obese; Type 2 diabetes; Vitamin D.