Prospective study on the incidences of cardiovascular-renal complications in Chinese patients with young-onset type 1 and type 2 diabetes.

OBJECTIVE We examined metabolic profiles and cardiovascular-renal outcomes in a prospective cohort of Chinese patients with young-onset diabetes defined by diagnosis age <40 years. Patients with type 1 diabetes and normal-weight (BMI <23 kg/m(2)) and overweight (BMI ≥23 kg/m(2)) patients with type 2 diabetes were compared. RESEARCH DESIGN AND METHODS Between 1995 and 2004, 2,323 patients (type 1 diabetes, n = 209; normal-weight type 2 diabetes, n = 636; and overweight type 2 diabetes, n = 1,478) underwent detailed clinical assessment. Incident cardiovascular disease (CVD) including coronary heart disease, stroke, and peripheral vascular disease were identified using hospital discharge diagnoses. End-stage renal disease (ESRD) was defined by glomerular filtration rate <15 mL/min/1.73 m(2) or dialysis. RESULTS Overweight patients with type 2 diabetes had the worst metabolic profile and highest prevalence of microvascular complications. Over a median follow-up of 9.3 years, incidences of CVD were 0.6, 5.1, and 9.6 per 1,000 person-years in patients with type 1 diabetes, normal-weight patients with type 2 diabetes, and overweight patients with type 2 diabetes. The respective figures for ESRD were 2.2, 6.4, and 8.4 per 1,000 person-years. Compared with type 1 diabetes, the overweight type 2 diabetes group had a greater hazard of progression to CVD (hazard ratio [HR] 15.3 [95% CI 2.1-112.4]) and ESRD (HR 5.4 [95% CI 1.8-15.9]), adjusted for age, sex, and disease duration. The association became nonsignificant upon additional adjustment for BMI, blood pressure, and lipid. CONCLUSIONS Young patients with type 2 diabetes had greater risks of developing cardiovascular-renal complications compared with patients with type 1 diabetes. The increased risk was driven primarily by accompanying metabolic risk factors.