Sex-specific association of lipoprotein(a) with presence and quantity of coronary artery calcification in an asymptomatic population

Background: Lipoprotein(a) (Lp(a)) is a potential risk factor for coronary artery disease (CAD). The relationship between serum Lp (a) and coronary artery calcification (CAC), a measure of subclinical coronary artery atherosclerosis, has not been extensively explored. Material/Methods: Electron beam computed tomography was performed on 616 asymptomatic, white individuals (285 men) from a community-based study. Mean age was 57.2 years. Serum Lp (a) levels were measured by an immunoturbidimetric assay. Tobit regression was used to determine the sex-specific association of Lp (a) levels with presence and quantity of CAC. Results: In women, Lp (a) was a significant predictor (P=0.0426) of presence and quantity of CAC after adjustment for age, hypertension status, waist circumference, presence of high low-density lipoprotein cholesterol (LDL-C), and history of smoking. In men, after adjusting for age, hypertension status, body mass index, presence of high LDL-C, and history of smoking, a positive interaction between Lp (a) and history of smoking (P=0.0387) was significantly associated with presence and quantity of CAC. Conclusions: Sex-specific relationships between Lp (a) and CAC provide evidence supporting sex-specific risk factor profiling for CAD. In women, Lp(a) alone may be an independent risk factor for coronary atherosclerosis, while in men, Lp (a) may confer higher risk conditional on the presence and level of other risk factors. The role of Lp (a) in the prediction and pathogenesis of subclinical coronary atherosclerosis needs to be further elucidated.