PS-C17-5: HYPOBILIRUBINEMIA AND HYPERTENSION AS RISK FACTORS FOR DIABETIC RETINOPATHY OF TYPE 1 AND TYPE 2 DIABETES MELLITUS

Abstract

Objective: Previously, we reported that hypobilirubinemia is an important risk factor for diabetic retinopathy. On the other hand, high systolic blood pressure (SBP) is reported to be a risk factor for this condition. Therefore, we conducted this retrospective study to evaluate a significance of hypobilirubinemia and hypertension as risk factors for diabetic retinopathy of type 1 and type 2 diabetes mellitus (DM). Design and Methods: One hundred and thirty-one patients (59 men) with type 1 and 293 patients (159 men) with type 2 DM were included in this cross-sectional study. We compared serum total bilirubin concentration (TBC) between the patients with and without diabetic retinopathy, and compared it according to the severity of retinopathy. Logistic regression analysis was used to examine the effects of various factors on retinopathy, and the following factors were considered as independent variables: SBP, TBC, gender, age, diabetes duration, HbA1c, eGFR, and BMI. Results: The age, diabetes duration, BMI, HbA1c and TBC of the subjects with type 1 and type 2 DM were 54.9 + 15.0 years, 17.4 + 12.2 years, 21.9 + 3.6 kg/m2, 7.9 + 1.5%, 0.70 + 0.24 mg/dL and 64.1 + 12.8 years, 14.4 + 9.5 years, 25.4 + 5.4 kg/m2, 9.2 + 1.8%, 0.75 + 0.29 mg/dL, respectively. Forty-three (33%) patients with type 1 and 124 (42%) patients with type 2 DM patients were complicated by diabetic retinopathy, respectively. Sixty (46%) patients with type 1 and 211 (72%) patients with type 2 DM were complicate by hypertension. Among type 1 and type 2 DM patients, SBP was higher and TBC was lower significantly in patients with retinopathy than in those without retinopathy. It was shown that serum TBC was negatively associated with increasing severity of retinopathy in patients with both type 1 and type 2 DM. The results of logistic regression analysis showed that TBC was an independent explanatory factor for retinopathy of both type 1 (p = 0.001) and type 2 (p < 0.001) DM. Among type 1 diabetics, systolic blood pressure was an independent risk factor (p = 0.001), but SBP was not (p = 0.067). Conclusions: Low TBC might have pathophysiological significance in the onset of retinopathy for both type 1 and type 2 DM patients. On the other hand, the significance of hypertension might be higher for type 2 than type 1 DM.