Concentrations of apolipoprotein A-I-containing particles in patients with hypoalphalipoproteinemia.

This study was performed to determine relations among concentrations of high-density lipoprotein (HDL) apolipoprotein (apo) A-I and apoA-II and lipoproteins with apoA-I only (LpA-I) and with both apoA-I and apoA-II (LpA-I:A-II) in patients with low plasma levels of HDL cholesterol. Seventy-seven middle-aged men with low HDL cholesterol levels (< 40 mg/dL) were compared with 37 middle-aged men with normal HDL cholesterol levels (> 40 mg/dL). Low-HDL patients were divided into those with normotriglyceridemia (triglycerides < 250 mg/dL; n = 49) and hypertriglyceridemia (triglycerides > or = 250 mg/dL; n = 28). Total apoA-I and apoA-II concentrations and apoA-I levels in LpA-I were significantly lower in the two low-HDL groups compared with control subjects. Although low-HDL patients' apoA-I levels were numerically lower in LpA-I:A-II compared with control subjects' levels, the differences were not statistically significant. Thus, there is a preferential reduction in apoA-I levels of LpA-I compared with LpA-I:A-II in patients with low HDL cholesterol. This preferential reduction in LpA-I levels was observed in both normotriglyceridemic and hypertriglyceridemic patients. However, among low-HDL patients levels of apoA-I in LpA-I did not distinguish between those with and without coronary heart disease.