Effect of nephropathy on the composition of apolipoprotein-containing particles in NIDDM

We investigated the effect of nephropathy on the composition of apolipoprotein-containing particles in non-obese NIDDM patients with normocholesterolemia. Sixty-seven normal control subjects (group A), 48 NIDDM patients without nephropathy (group B) and 36 NIDDM patients with nephropathy (group C) were studied. Apolipoprotein AI or B100 containing particles (Apo AI or Apo B100) were isolated by immunoaffinity columns prepared with monoclonal antibodies. The total cholesterol (CH), esterified cholesterol (EC) and free cholesterol (FC) content in these particles was analyzed. Both the EC/FC ratio levels in Apo AI and in Apo B100 in group C were significantly higher than those in group A or B. Both the CH in Apo AI/apolipoprotein AI ratio and in Apo B100/apolipoprotein B100 ratio levels in group C were significantly lower than those in group A or B. The insulin resistance index showed significant positive correlation with the EC/FC ratio levels in Apo AI and in Apo B100, and showed significant negative correlation with the CH levels in Apo AI/apolipoprotein AI ratio and the CH levels in Apo B100/apolipoprotein B100 ratio levels in group C. Those compositional changes of lipoproteins in NIDDM patients with nephropathy may reflect partial insulin resistance and deteriorating atherosclerosis.