Serum lipids and apolipoproteins in relation to glycaemic control and diabetic nephropathy in long-term survivors of diabetes: results of the Erfurt Study.

Follow-up data of all 208 long-term diabetics (duration of the disease at least 20 years) living in the closed area of the Erfurt district in 1970 had demonstrated the importance of lipoprotein pattern for longevity. Now the dependence of lipoprotein levels on both the diabetes-related conditions nephropathy and glycaemic control has been examined in 47 of them, still alive in 1985 that means 35 or more years after the onset of diabetes. Glycaemic control was assessed by measuring the glycosylated haemoglobin (n = 44). Diabetic nephropathy was assumed in case of persistent proteinuria. Poor glycaemic control (n = 16) was associated with increased levels of atherogenic lipoproteins as reflected by higher concentrations of total cholesterol, LDL cholesterol, apolipoprotein B, and triglycerides, as well as a changed HDL composition indicated by a decreased HDL cholesterol/apolipoprotein A--I ratio. Higher ratios of total cholesterol to HDL cholesterol and apolipoprotein B to apolipoprotein A--I point to an increased risk of developing atherosclerotic diseases in poorly controlled diabetics. 86% of the well controlled long-term diabetics had non-pathological values of LDL cholesterol, triglycerides, apolipoprotein B, HDL cholesterol, and apolipoprotein A--I but only 31% of the poorly controlled patients did so. Diabetic nephropathy in the absence of chronic renal failure (n = 10) was characterized by higher values of LDL cholesterol, triglycerides, total cholesterol/HDL cholesterol, and apolipoprotein B/apolipoprotein A--I. 80% of the subjects with a pathological lipoprotein pattern were proteinuric or in poor glycaemic control or both. Therefore, it is concluded that prevention of these two conditions might help to delay atherosclerosis via its beneficial influence on lipoprotein metabolism.