Lipoprotein(a) levels in relation to diabetic complications in patients with non-insulin-dependent diabetes.

The relationship between serum levels of lipoprotein(a) Lp(a)) and the presence of chronic diabetic complications was studied in 194 patients with non-insulin-dependent diabetes mellitus (NIDDM; 75 males, 119 females; age 66 +/- 11 years; duration of diabetes, 11 (range 1-35) years). They were taking various treatments (diet alone, oral hypoglycaemic agents and/or insulin). Metabolic status and prevalence of diabetic complications were assessed by detailed history, physical examination, laboratory analysis and ECG. Average metabolic control was moderate (HbA1c 8.2 +/- 1.7%). Median serum Lp(a) level was 183 U l-1 (range 8-2600 U l-1), which was significantly higher than in control subjects of comparable age (median 101; range 8-1747 U l-1; P < 0.05), while HDL-cholesterol levels were lower (1.14 +/- 0.38 vs. 1.35 +/- 0.35 mmol l-1; P = 0.001), and total cholesterol levels were comparable. No significant relationships between diabetes treatment or metabolic control and Lp(a) levels were observed. In the quartile of patients with the highest Lp(a) levels, total cholesterol and triglycerides were slightly higher (P < 0.05), whereas HDL-cholesterol was not different. With increasing Lp(a) levels, higher prevalences of preproliferative retinopathy and of coronary artery disease (CAD) were observed, but not of the other complications. No relationship was found between the degree of albuminuria and Lp(a) levels. We conclude that in NIDDM patients, Lp(a) levels are elevated compared with non-diabetic subjects, and that higher Lp(a) levels are associated with higher prevalences of CAD and of retinopathy.