The KID Study VI: diabetic complications and associated diseases in younger type 2 diabetics still performing a profession. Prevalence and correlation with duration of diabetic state, BMI and C-peptide.

A sub-study evaluated 698 younger (54.5 +/- 6.9 years) type 2 diabetics of the KID Study participants to establish the prevalence of diabetic complications and associated diseases and their correlation with body mass index (BMI), duration of disease and to C-peptide levels. Only 19.8% of the type 2 diabetics had a normal weight. In all weight subgroups, the average age of diabetes manifestation were around age 45. In 46.6% of all type 2 diabetics we could already demonstrate microangiopathic complications. Strikingly, 15.9% of the patients already had proliferative retinopathies and 12.6% had albuminuria of more than 1000 mg/dl. 74.7% of our type 2 diabetics presented with the well-known risk cluster of the metabolic syndrome: In every other patient, we found hypertension and/or hyperlipoproteinaemia. Accordingly, the prevalence of the macroangiopathic diabetic complications, coronary artery disease and peripheral vascular disease was 17.8%, which is high for a relatively young population with a mean age of 53.9 years and goes conform with recent literature (Lowel et al., 1999). An increase in BMI correlated significantly with deterioration of HbA1, a decrease in HDL cholesterol, an increase in triglycerides and with a higher prevalence of hypertension. The frequency of nephropathy increase significantly up to a BMI of 30-35 kg/m2. Retinopathies and polyneuropathies were associated with BMI but increased significantly with the duration of the diabetic state. In contrast to microangiopathic diabetic complications, there was already a high prevalence of nephropathy after a comparatively short duration of disease. The prevalence of hyperlipoproteinaemia and hypertension did not depend from the duration of diabetes. These concomitant diseases already were frequent early in the disease and did not increase with the duration of disease. However, there was a strong correlation between increasing hyperlipoproteinaemia and hypertension and higher C-peptide levels. We found no coincidence between C-peptide levels and microangiopathic diabetic complications.