Novel Insight Into the Relationship of Vitamin D Hydroxylase and Vitamin D With Obesity in Patients With Type 2 Diabetes Mellitus.

Background: In patients with type 2 diabetes mellitus (T2DM) and obesity, there is often a vitamin D deficiency, which is crucial for many physiological processes. The enzyme 25-D hydroxylase activates vitamin D, and its status has been linked to glucose and lipid metabolism in these patients. This study investigates the correlation between the levels of 25-D hydroxylase and 25-hydroxyvitamin D, and their impact on glucose and lipid metabolism in Saudi patients with T2DM and obesity.

Methods: This study involved 150 Saudi participants (ages 35-70) of both genders from King Faisal Medical Complex in Taif. The participants were divided into control, type 2 diabetic, and obese diabetic patient groups, with 50 subjects in each group. Serum levels of 25(OH) vitamin D and 25-D hydroxylase were measured using ELISA. In contrast, an automatic analyzer for chemistry tests was used to measure fasting blood glucose (FBG), aspartate transaminase (AST), alanine transaminase (ALT), and lipid profile levels. Hemoglobin A1c (HbA1c)% was analyzed using the automatic glycosylated hemoglobin analyzer. In addition, the body mass index (BMI) value was calculated using the equation (BMI = weight in kilograms/height in meters squared).

Results: In obese with T2DM and T2DM patient groups, there were significant increases (p < 0.0001) in BMI, FBG, HbA1c%, total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), AST, and ALT levels and significant decreases (p < 0.0001) in 25(OH) vitamin D, 25-D hydroxylase, and high-density lipoprotein cholesterol (HDL-C) levels compared to the control group. There were significant positive correlations between vitamin D with 25-D hydroxylase and HDL-C and negative correlations with HbA1c%, FBG, TC, TG, LDL-C, ALT, AST, and BMI in the studied patient groups.

Conclusions: This study shows that lower levels of the enzyme 25-D hydroxylase are linked to reduced vitamin D levels in people with T2DM and obese diabetic patients. Additionally, there was a notable correlation between vitamin D levels and BMI, lipid profile, FBG, HbA1c%, AST, and ALT levels.