Apolipoproteins A-1 and B and the likelihood of non-fatal stroke and myocardial infarction data from the Third National Health and Nutrition Examination Survey

Background: The measurement of plasma apolipoproteins (APO) has been proposed for predicting the risk of cardiovascular diseases. However, the association between APOs and stroke is not well defined. Material/Methods: We evaluated the association between plasma concentrations of APO A-1 and APO B with a physician diagnosis of stroke (n = 153), and electrocardiogram evidence or physician diagnosis of myocardial infarction (n=379), in a nationally representative sample of 3,696 US adults aged ≥40 years who participated in the Third National Health and Nutrition Examination Survey. Multivariate logistic regression analyses were used to investigate these relationships. Results: After adjusting for differences in age, gender, race/ethnicity, education, hypertension, cholesterol, body mass index, and cigarette smoking, the upper quartile of APO A-1 (≥ 161 mg/dl) when compared with the lowest quartile (< 126 mg/dL) was inversely associated with the likelihood of myocardial infarction (Odds Ratio [OR], 0.6; 95% Confidence Interval [CI] 0.4-0.9) but not stroke. APO B concentrations were not associated with either myocardial infarction or stroke. However, an APO A-1 to B ratio ≥ 1.59 when compared with a ratio ≤ 1.04 was associated with a decreased likelihood of myocardial infarction (OR, 0.3; 95% CI, 0.2-0.6); and stroke (OR 0.4, 95% CI, 0.2-1.0). Conclusion: Higher APO A-1 concentrations were associated with a decreased likelihood for myocardial infarction but not for stroke. The APO A-1 to B ratio was inversely associated with both myocardial infarction and stroke and may be an important protective clinical marker for atherosclerosis.