Analysis of serum apolipoprotein A-I in elderly non-insulin-dependent diabetic patients

Quantitative and qualitative modifications of plasma apolipoproteins could provide additional information in predicting coronary heart disease (CHD) in non-insulin-dependent diabetes mellitus (NIDDM). We examined 17 men and 15 women aged over 65 years affected by NIDDM. Alcohol intake, smoking habits, antidiabetic therapy, body weight, stature, and body mass index were considered. Furthermore, serum lipids and apolipoprotein A-I and B levels were determined. Apo A-I was characterized by isoelectric focusing (IEF) and immunoblotting. The men were heavier and taller than the women. The women had significantly higher serum levels of total cholesterol, HDL-cholesterol, and apo A-I than the men. The levels of HDL-cholesterol, apo A-I and B were significantly influenced by an interaction between sex and the duration of diabetes. An invariant pattern was observed for apo A-I isoforms in samples from diabetic subjects of both sexes. The percentage distribution of serum apo A-I isoforms determined by densitometry is quite different from that previously reported in the literature for the general population. Quantitative modification in apo A-I isoforms could be due to the specific pathology and these variations could partly explain reduced levels of HDL-cholesterol in diabetic patients.