Lipoprotein(A) and coronary heart disease risk factors in a racially mixed population: the Johns Hopkins Sibling Study.

OBJECTIVES

To determine if heart disease risk factors differentially affect lipoprotein(a) concentration by race, we assessed the association of lipoprotein(a) with heart disease risk factors in healthy Caucasians and African Americans with family histories of premature heart disease.

METHODS

Participants (403 Caucasian and 148 African American), all less than 60 years old and free of heart disease, were recruited through a brother or sister diagnosed with coronary heart disease before age 60. Risk factor information was elicited through an interview and medical examination.

RESULTS

As expected, lipoprotein(a) was significantly higher among African Americans than among Caucasians. Mean lipoprotein(a) concentrations were positively associated with smoking status and age, and negatively associated with hypertension in African Americans. Smokers had lipoprotein(a) levels 38% higher than nonsmokers. Conversely, lipoprotein(a) concentrations were unrelated to heart disease risk factors among Caucasians.

CONCLUSION

While this study confirms that lipoprotein(a) concentration is independent of CHD risk factors in Caucasians, lipoprotein(a) appears to be related to several CHD risk factors in African Americans at high risk for premature heart disease. Given the high levels of lipoprotein(a) in people of African descent and lipoprotein(a)'s link to cardiovascular diseases, more research is needed to understand the relationship of lipoprotein(a) to heart disease risk factors and the subsequent disease in African-American populations.