Association of Anemia and Diabetic Retinopathy Among Patients With Type 2 Diabetes Mellitus: Retrospective Cross-Sectional Study.

Abstract

Introduction Type 2 diabetes mellitus (T2DM) is a common metabolic disorder characterized by the combination of defective insulin secretion and the inability of insulin-sensitive tissues to respond appropriately to insulin. Diabetic retinopathy (DR) is a common microvascular complication that can result in a preventable cause of blindness. Research to determine the prevalence of anemia among diabetic patients is necessary to assess whether treatment practices should be changed. Anemia is a common complication in patients with T2DM and has been associated with the progression of DR. In this study, our aim is to determine the prevalence of DR and its association with hemoglobin levels in patients diagnosed with T2DM in Dubai, UAE. Methods In this retrospective cross-sectional study, we extracted the data using electronic medical records. The study was performed over a span of three years in Dubai from 2019 to 2022. A total of 368 T2DM patients were included based on retinal exam findings classified into mild, moderate, severe non-proliferative retinopathy, and proliferative retinopathy. Descriptive statistics were used for categorical (frequency, percentage) and continuous variables (mean, SD), with chi-square/Fisher exact tests for categorical associations, ANOVA for continuous variables, and multiple logistic regression to identify DR risk factors, using OR, 95% CI, and p < 0.05 for significance. Results The prevalence of anemia (defined as hemoglobin levels ≤13 mg/dL for men and ≤12 mg/dL for women) was observed in 39.4% of individuals with DR aged between 40 and 88 years; 60.6% of the patients had normal hemoglobin, while 91 individuals (24.7%) exhibited mild anemia, 53 individuals (14.4%) showed moderate anemia, and only one individual (0.3%) had severe anemia. DR grading was as follows: mild non-proliferative DR (16.8%), moderate non-proliferative DR (30.2%), severe non-proliferative DR (13.3%), and proliferative DR (39.7%). Macular edema was present in 59.2% of patients, showing a statistically significant association with more severe DR stages (p < 0.0001). No significant association was found between hemoglobin levels and DR severity (p = 0.568). However, among males, a significant difference in mean hemoglobin levels across DR grades was observed (p = 0.009), with higher hemoglobin levels associated with lower odds of severe DR (OR = 0.775, p = 0.036). Macular edema strongly predicted DR severity, with significant odds ratios across all stages (p < 0.0001). Conclusions There is a significant prevalence of anemia among the examined population. DR severity was notably associated with lower hemoglobin levels in males, and macular edema was significantly linked to more severe stages of DR. Vigilant monitoring and integrated care for both anemia and DR are crucial to optimize patient outcomes and mitigate complications. Regular retinopathy screening is essential for early detection and timely intervention, particularly considering the challenges posed by anemia, such as delayed wound healing and increased infection risk post-screening.