Risk Factors Associated with Diabetic Retinopathy and Thalassemia Prevalence Survey in Diabetes Mellitus Patients at Six Primary Care Units of Naresuan University Hospital: A Cross-sectional Study

Abstract

Objective: To evaluate the risk factors and prevalence of diabetic retinopathy (DR) in both medical and socioeconomic aspects and find prevalence of thalassemia which associated hemoglobin A1c (HbA1c) measurement in diabetes mellitus (DM) patients at six primary care units (PCU) of Naresuan University Hospital (NUH). Materials and Methods: A cross-sectional survey of DM patients participated in annual proactive DR screening program at six PCU of NUH between December 2016 and March 2017 was conducted. Medical data were retrieved from medical records at PCU. Patients were also interviewed to gather socioeconomic information. Fundus examination was done by indirect ophthalmoscope. Three milliliters of blood was collected from each patient on the same day for Hb analysis. Results: Four hundred and eighty-eight DM patients participated in the present study. Mean age, duration of DM, fasting blood sugar (FBS) level, and HbA1c level were 61.2±9.8 years, 8 years (4 to 12), 124 mg/dL (108 to 151.5), and 7.1% (6.5 to 8.1), respectively. Prevalence of overall DR was 2.9% (14 patients) and proliferative DR was 0.2% (1 patient). Risk factors of DR were HbA1c at 7% or more [adjusted OR 4.7 (95% CI 1.4 to 13.5) and p=0.011] and emotional stress [adjusted OR 3.3 (95% CI 1.1 to 9.8) and p=0.033). Thalassemia screening found 116 patients had abnormal hemoglobin. Ninety-three patients were HbE trait, eight were HbE, ten were alpha-thalassemia trait, two were beta-thalassemia trait, one was HbH, one was alpha- and beta-thalassemia trait (α/β), and one was alpha-thalassemia trait and HbE trait (α/E), and all of them were thalassemia minor or intermedia. Only four patients from HbE trait group had DR. The mean HbA1c in all groups of patients with either normal or abnormal hemoglobin were not statistically significant different. Conclusion: The present study showed that HbA1c and emotional stress might have played an important role in association with DR development. Thalassemia minor and intermedia seemed not to associate with HbA1c measurement. Keywords: Diabetic retinopathy; Thalassemia; Primary care unit; Naresuan university; Risk factors