Relationship between serum vitamin D levels in diabetic patients with and without diabetic retinopathy

Abstract

Aim: To study the relationship between serum Vitamin D levels and severity of Diabetic Retinopathy. Materials and Methods: This cross-sectional study was conducted on 346 subjects. The cases were divided into three groups, group A comprised of 180 type 2 diabetic patients with retinopathy, group B comprised of 86 type 2 diabetic patients without retinopathy (no DR) and group C comprised of age and gender matched 80 healthy non diabetic controls. Group A further divided into group A1 consisting 84 proliferative diabetic retinopathy (PDR) patients and group A2 consisting of 96 non proliferative diabetic retinopathy patients (NPDR). Results: The difference in the levels of serum Vitamin D between group A1 and group B and group A1 and group C were statistically significant with p value and Confidence Interval (CI) being (<0.001, -10.35 to -4.66) and (<0.001, -11.45 to -5.54) respectively. There was statistically significant negative correlation between HbA1c and serum Vitamin D in diabetic patients with PDR (r=-0.464, p=0.002), diabetic patients with NPDR (r=-0.399, p=0.005) and diabetic patients with no DR(r=-0.397, p=0.011). Conclusions: Serum vitamin D level decreases significantly with increasing severity of Diabetic Retinopathy and increasing levels of HbA1c.