Serum Vitamin D Levels and Vascular Endothelial Growth Factor in Patients with Type 2 Diabetes Mellitus: A Cross-sectional Study

Introduction: Diabetes Mellitus (DM) is the most common noncommunicable disease and the fifth leading cause of death worldwide. Recent research has demonstrated that low Vitamin D levels and high Vascular Endothelial Growth Factor (VEGF) in middle-aged and elderly populations represent a risk factor for Type 2 Diabetes Mellitus (T2DM). Aim: To estimate the Vitamin D and VEGF levels in study subjects with T2DM and healthy controls and to correlate the Vitamin D level and VEGF with HbA1c % in study subjects with T2DM. Materials and Methods: A cross-sectional study was undertaken from October 2014 to November 2016 at the Department of Medicine in collaboration with the Department of Biochemistry, Bangalore Medical College and Research Institute, Bangalore. The study included 50 T2DM subjects on oral hypoglycaemic agents for five years and 50 age and sexmatched healthy controls selected randomly from the general population. In all the study subjects, Random Blood Glucose (RBG), LFT, Renal Function Test (RFT), HBA1c, serum Vitamin D, and serum VEGF were estimated. Student t -test and Chi square/Fisher-Exact test were used to find the significance of study parameters between cases and controls. Multivariate logistic regression analysis was done to assess the risk factors for DM. Results: The mean age of the cases was 50.9 +/- 9.7 years and of controls was 49.76 +/- 7.7 years. Among the 50 cases, 19 (38%) were men and 31 (62%) were women. Among the 50 controls, 27 (54%) were men and 23 (46%) were women. The mean Body Mass Index (BMI) among cases was 27.21 +/- 4.59 and in controls was 24.82 +/- 2.63 (p-value=0.0016). The mean serum 25(OH) Vitamin D levels in cases were 11.39 +/- 3.32 ng/mL and in controls were 28.06 +/- 11.14 ng/mL (p -value <0.001). The mean serum VEGF levels in cases were 97.52 +/- 16.96 pg/mL and in controls were 56.37 +/- 17.74 pg/mL (p -value <0.001). Conclusion: The present study found that subjects with T2DM have lower serum 25(OH) Vitamin D levels and higher serum VEGF levels than those without T2DM. Serum Vitamin D decreases and serum VEGF-A levels increase with increasing HbA1c%, correlating with vascular complications.