A 5-YEAR FOLLOW-UP-STUDY ON THE INCIDENCE OF RETINOPATHY IN TYPE-1 DIABETES-MELLITUS IN RELATION TO MEDICAL RISK INDICATORS

Objectives. The aim of the present study was to describe the 5-year incidence of retinopathy in type 1 diabetes mellitus and to characterize risk indicators for the development and progression of retinopathy. Design. A cross-sectional study of type 1 diabetic patients taken care of at a medical department. Setting. All type 1 diabetic patients attending the Department of Internal Medicine, University Hospital, Lund, during a 2-year period were offered ophthalmological examination. Subjects. A total of 396 out of 461 (85.9%) initially examined type 1 diabetic patients formed the basis for this 5-year follow-up study. Main outcome measures. The degree of retinopathy was based on fundus photography or biomicroscopy. Degree of metabolic control was assessed by HbA(1c) levels, signs of nephropathy by albumin creatinine clearance ratio and urinary albumin levels. Blood pressure was measured in the supine position. Duration of diabetes, age, and insulin dosage were registered. Results. The incidence of retinopathy was 47.2%, and progression from background to severe retinopathy occurred in 41%. Risk indicators for the development of retinopathy were duration of diabetes (P < 0.001), degree of metabolic control (P < 0.001), insulin dosage (P < 0.05) and signs of nephropathy based on measurements of albumin creatinine clearance ratio (P < 0.01) and urinary albumin concentration (P < 0.05). Two risk indicators could be identified for progression of retinopathy, i.e. the degree of metabolic control (P < 0.01) and diastolic blood pressure (P < 0.05). Conclusions. The results suggest that apart from poor metabolic control, development of retinopathy in type 1 diabetes is associated with long diabetes duration and clinical signs of diabetic nephropathy. Progression of retinopathy is associated with poor metabolic control and elevated diastolic blood pressure levels.