Is there a relationship between body mass index and diabetic retinopathy in type II diabetic patients? A cross sectional study.

Background: Type 2 diabetes mellitus (T2DM) is one of the most important leading causes of disability, premature mortality and Diabetic Retinopathy (DR) that is one of the diabetes-related complications in diabetic patients and the most common cause of vision loss in diabetic patients. The aim of the study was to evaluate the association between DR and body mass index (BMI) in those patients with T2DM.

Methods: This was a central-based, cross-sectional study on 518 diabetic patients. Their medical history and the laboratory data were collected. All the patients received examination of diabetic retinopathy by professional ophthalmologist. Based on their optic fundi findings, they were classified into five groups: No retinopathy, Mild Non-proliferative Diabetic Retinopathy (NPDR), Moderate NPDR, Severe NPDR, Proliferative diabetic retinopathy (PDR). To analysis data SPSS v18 software used. Frequency, percent, mean and standard deviation were used for population description. t test, spearman correlation, partial correlation, analysis of variance (ANOVA) and Chi-square test (χ2) were used for analytic analysis. Multivariate logistic regression was used to estimate the odds ratio.

Results: 518 patients with T2DM 198 male (38%), 320 female (62%) included in this study. The mean age of patients was 61.02 ± 10.18 years. The mean age at onset was 49.06 + 10.52 years and the mean duration of diabetes was 12.09 ± 7.81 years. There was a strong relationship between duration of diabetes and DR ( P  = 0.001). There were strong significant association between the development of DR and Insulin therapy (OR = 5.975). Correlation analysis between Retinopathy and BMI showed that BMI had inverse relationship with DR when BMI considered as a continuous variable ( p -value = 0.009 and correlation coefficient = -0.467).

Conclusion: BMI in diabetic patient is one of the most important clinical parameter for their health and disease progression. We conclude that BMI had inverse relationship with DR when BMI considered as a continuous variable.