The Tromsø Heart Study: serum apolipoprotein AI concentration in relation to future coronary heart disease.

The concentrations of apolipoprotein AI, a major peptide of high density lipoprotein (HDL), have been measured by immunoelectrophoresis in samples of serum from twelve subjects who subsequently developed a coronary event during 2 years of follow-up and compared with those in serum from sixteen matched control subjects. The mean apolipoprotein AI concentration in the cases was significantly lower than that in the controls, independently of the serum total cholesterol and triglyceride concentrations. There was no significant difference between the cases and controls in mean HDL cholesterol: apolipoprotein AI ratio. Within several case-control pairs, however, the difference in apolipoprotein AI concentration was proportionately much less than that in HDL cholesterol. On discriminant function analysis, apolipoprotein AI concentration was a less powerful predictor of coronary heart disease than was HDL cholesterol.