Risk Factors for Diabetic Complications in Juvenile-Onset Type 1 Diabetic Patients.

Abstract

We investigated the incidence of diabetic retinopathy and nephropathy in juvenile-onset type 1 diabetic patients and the impact of metabolic control and other risk factors on the incidence of retinopathy and nephropathy. A clinic-based observational longitudinal study was performed. Patients visited our outpatient clinic at the Diabetes Center, Tokyo Women's Medical University from 1980 to 1998. Participants for the study were 533 patients with type 1 diabetes. Fukuda's classification for fundoscopic findings grade (A1, A2, and B1) corresponded to non-proliferative retinopathy and the other grades to proliferative retinopathy. Incipient nephropathy was defined as that in which the albumine-creatinine ratio (ACR) was 30-300 mg/g.Cr, and overt nephropathy was defined as that in which ACR was over 300 mg/g.Cr. The predictive effect of independent variables was explored using Cox's proportional hazard regression analysis. Independent predictors were HbA1c, total-cholesterol, triglyceride, duration of diabetes, systolic blood pressure (BP) for non-proliferative retinopathy, HbA1c, diastolic BP, and total-cholesterol for proliferative retinopathy, HbA1c and duration of diabetes for incipient nephropathy, and HbA1c and onset age for overt diabetic nephropathy. Systolic BP was a significant independent risk factor for non-proliferative retinopathy, and diastolic BP was an independent risk factor for proliferative retinopathy. Once retinal vascular injury has been initiated, greater diastolic pressure may promote progression. Duration of diabetes was an independent risk factor for both non-proliferative diabetic retinopathy and incipient diabetic nephropathy, but was not a risk factor for either proliferative diabetic retinopathy or overt diabetic nephropathy. Strict control of blood glucose, BP, and lipid metabolism are mandatory for reducing the risk of progression of diabetic complications.