Diabetic retinopathy and mortality in type 2 diabetic patients

BACKGROUND AND OBJECTIVE: This study was intended to assess the independent contribution of retinopathy to mortality in type 2 diabetic patients. PATIENTS AND METHOD: Prospective cohort study. Type 2 diabetic patients with available fundus were included. The clinical end-point was total mortality. The main independent variable was baseline presence of background or proliferative retinopathy. Cox regress on models were adjusted for age, sex, duration of diabetes, classical risk factors and baseline presence of nephropathy and cardiovascular disease. RESULTS: 458 patients were included (181 male, 277 females), with a median follow-up of 8 years (inter-cuartile range, 6.7-9). There were 125 patients (27.3%) with background retinopathy and 46 (10%) with proliferative retinopathy. Mortality incidence rates per 1,000 patients-year were 20/1,000 (non retinopathy), 36.8/1,000 (background retinopathy) and 45.9/1,000 (proliferative retinopathy) with p = 0.0021. In the multivariate analysis, background retinopathy (HR = 1.87; 95% CI, 1.1-3.1; p = 0.019) and proliferative retinopathy (HR = 2.6; 95% CI, 1.3-5.1; p = 0.0048) were independent predictors of mortality. Other independent predictors were age (HR [1 year] = 1.13; 95% CI, 1.1-1.17; p < 0.0001), total cholesterol (HR [1 mmol/l] = 0.76; 95% CI, 0.6-0.97; p = 0.026), baseline insulin treatment (HR = 1.9; 95% CI, 1,1-3.2; p = 0.017) and baseline proteinuria (HR = 4.1; 95% CI, 2-8.5; p = 0.0001). CONCLUSIONS: The presence of retinopathy increases the mortality risk in type 2 diabetic patients.