Association of Age and Sex with Different Status of Serum Vitamin D Level among Different Grades of Diabetic Retinopathy: A Cross-sectional Study

Abstract

Introduction: Diabetes Mellitus (DM) is rapidly escalating globally as well as in India, affecting all age and sex groups. One of the dreaded microvascular complications of DM is Diabetic Retinopathy (DR). In parallel to increase in prevalence of DM and its complications, several reports of serum 25 hydroxy (OH) Vitamin D deficiencies have been documented in India. Aim: To establish the relation of different age and sex groups with different status of serum 25 (OH) Vitamin D level among different grading of Diabetic Retinopathy in patients of Type 2 Diabetes Mellitus. Materials and Methods: This cross-sectional and observational study was conducted in Calcutta National Medical College and Hospital, Kolkata, West Bengal, India, from May 2019 to May 2020. Total 107 type 2 DM patients aged 40 years and above including both males and females were taken. Direct ophthalmoscopy was done for examination of retina and venous blood was taken for Fasting Blood Sugar (FBS), Post Prandial Blood Sugar (PPBS), Glycated Haemoglobin (HbA1c) and serum 25 (OH) Vitamin D level estimation aseptically. Mean, median and standard deviation were compared across the groups using Mann-Whitney's U-Test/ Kruskal-Wallis's Test as appropriate. Spearman’s test was applied for assessing the correlation between age of diabetic patients and vitamin D levels. The p-value <0.05 was considered as statistically significant. Results: In this study, most of the participants were under the age group of 50-59 years. No significant relationship between the age and Vitamin D levels of the subjects was observed. The association between different status of serum Vitamin D level and different age groups among different grading of Diabetic Retinopathy is statistically significant out of entire sample size, not in individual grading. The association between different sex groups and different vitamin D status among different grading of DR was not statistically significant. There was no significant difference between serum Vitamin D level in males and females with DR. Correlation between serum Vitamin D level and age was linear and positive; but strength was low and p-value was not significant (correlation coefficient=0.100 , p-value=0.306). Conclusion: This present study showed that maximum subjects were under the age group of 6th decade. There was a significant association between different status of serum Vitamin D level and different age groups out of whole study population, however non significant difference was observed between different grades of DR. No association was observed between different sex groups and different Vitamin D status among different grading or severity of DR.