Total homocyst(e)ine concentration and the likelihood of nonfatal stroke - Results from the Third National Health and Nutrition Examination Survey, 1988-1994

Background and Purpose-Elevated serum total homocyst(e)ine [H(e)] is an independent risk factor for stroke. Few studies, however, have examined this association in blacks. Methods-Data from the Third National Health and Nutrition Examination Survey (n=4534), a nationally representative sample of US adults, were used to examine the relationship between H(e) and a physician diagnosis of stroke (n=185) in both black and white adults. Multivariate-adjusted logistic regression analyses were used to examine this relationship. Results-Serum vitamin B-12 and folate concentrations were significantly lower among participants in the highest H(e) quartile (greater than or equal to 12.1 mu mol/L) than among participants in the lowest quartile (less than or equal to 7.4 mu mol/L). Those in the highest quartile were older, had higher mean cholesterol and blood pressure levels, and were more likely to smoke and to have completed <12 years of education. After adjustment for age, the odds ratio (OR) for stroke was 2.9 (95% confidence interval [CI], 1.4 to 5.7; highest versus lowest quartile). Adjustment for gender, race/ethnicity, education, systolic blood pressure, cholesterol, diabetes mellitus, and smoking reduced the magnitude of the association (OR, 2.3; 95% CI, 1.2 to 4.6). The association between H(e) and stroke did not differ by race [P=0.265 for race-H(e) interaction term]. The multivariate adjusted OR for the highest quartile versus the lowest was 2.5 (1.1 to 5.5) among whites and 1.4 (0.4 to 4.7) among blacks. Conclusions-In this nationally representative sample of US adults, H(e) concentration was independently associated with an increased likelihood of nonfatal stroke. This association was present in both black and white adults.