Apolipoprotein A-I and B levels and the risk of ischemic heart disease during a five-year follow-up of men in the Québec cardiovascular study.
BACKGROUND
Results obtained largely from case-control studies have suggested that an elevated plasma concentration of apolipoprotein (apo) B may be considered an important risk factor for ischemic heart disease (IHD). Prospective data on the relevance of measuring apo A-I and apo B levels in the assessment of IHD risk, however, remain sparse as well as controversial.


RESULTS
Plasma lipid, apo B, and apo A-I levels as well as other risk factors were evaluated at baseline in 1985 in a sample of 2155 men (45 to 76 years old) who were followed for a period of 5 years for clinical signs of IHD. Proportional-hazards analyses indicated that plasma apo B concentrations measured at entry were strongly associated with onset of IHD (relative rate, 1.4; 95% confidence interval [CI], 1.2 to 1.7), independent of covariables such as age, smoking, diabetes mellitus, and systolic blood pressure. Controlling for triglycerides, HDL cholesterol, and total/HDL cholesterol ratio did not eliminate the relationship between plasma apo B levels and IHD. The association between apo A-I and IHD was of lower magnitude (relative rate, 0.85; 95% CI, 0.7 to 1.0), and adjustment for selected plasma lipid and lipoprotein levels eliminated this association. Stepwise logistic regression analysis revealed that, among metabolic variables, apo B was the strongest correlate of IHD.


CONCLUSIONS
These prospective results emphasize the importance of apo B as a risk factor for IHD. Apo B may be regarded as a relevant tool in the assessment of IHD risk in men, because it may provide information that would not be obtained from the conventional lipid-lipoprotein profile.
Lamarche
B
B
Lipid Research Center, Laval University Hospital Research Center, Ste-Foy, Canada.
Moorjani
S
S
Lupien
P J
PJ
Cantin
B
B
Bernard
P M
PM
Dagenais
G R
GR
Després
J P
JP
D000368:Aged; D016632:Apolipoprotein A-I / Q000097:blood*; D001055:Apolipoproteins B / Q000097:blood*; D008076:Cholesterol, HDL / Q000097:blood; D015331:Cohort Studies; D005500:Follow-Up Studies; D005544:Forecasting; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D016019:Survival Analysis
D016632:Apolipoprotein A-I; D001055:Apolipoproteins B; D008076:Cholesterol, HDL