(082) Vitamin D and the Microvascular Complications of Type 2 Diabetes in India: A Case-Control Study

Background: Numerous studies indicate that up to 80% of the Indian population is deficient in vitamin D. Given that India is recognized as the diabetes capital of the world, there is a growing interest in exploring potential factors contributing to the increased incidence and prevalence of Type 2 Diabetes Mellitus and its associated complications in this population.

Objectives: This study tries to investigate the possible association between vitamin D levels and the risk of development of microvascular complications of diabetes among the Indian population.

Methods: A case-control study was conducted at a tertiary care hospital in India. Medical records of type 2 diabetic patients with documented vitamin D levels, who were admitted to the general medicine department between 2019 and 2022 were reviewed. Patients with type 1 diabetes or malignancy, pregnant or lactating women, and patients who are already vitamin D supplements were excluded. After enrolment, patients were grouped as cases (with complications) and controls (without complications) based on the presence of diabetic complications like neuropathy, retinopathy and nephropathy. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the association between vitamin D levels and each complication using both univariate and multivariate logistic regression analyses.

Results: A total of 475 type 2 diabetic patients were included in the final analysis, where 49.7% were males, and the average age was 61.13 + 12.05 years. The vitamin D levels in the population are as follows: vitamin D deficiency (63.4%), vitamin D insufficiency (22.9%) and vitamin D sufficiency (13.7%). Univariate logistic regression revealed significant associations between vitamin D levels and complications, including neuropathy (OR: 3.268, 95% CI [1.260-8.478], p=0.042), retinopathy (OR: 2.678, 95%CI [1.106-6.483], p=0.003) and nephropathy (OR: 2.580, 95% CI [1.293-5.148], p=0.001). However, multivariate analysis did not show any correlation with any diabetic complication after adjusting for covariates like age, gender, diabetic duration and laboratory parameters.

Conclusions: Our study found no association between vitamin D levels and microvascular complications in diabetic patients after adjusting for potential confounders. Further long-term studies with larger sample sizes are needed to understand its association with other diabetic complications.