Lack of increased coronary atherosclerotic risk due to elevated lipoprotein(a) in women >=55 years of age

Background Numerous studies have indicated that there is an association between lipoprotein(a) [Lp(a)] and coronary artery disease (CAD) in middle-aged men; however, few studies have addressed this issue in women or the elderly. Methods and Results Serum Lp(a) concentrations were determined in 354 women and 706 men with or without angiographically defined CAD (one or more coronary arteries with narrowing of greater than or equal to 75%). The age-specific impact of elevated Lp(a) (greater than or equal to 30 mg/dL) on CAD was examined in each sex. In the younger age group (<55 years old), elevated Lp(a) was independently associated with CAD in both sexes (adjusted odds ratio [OR]: women, 6.90, P<.01; men, 2.63, P<.05). The age-specific ORs declined with age, and elevated Lp(a) no longer conferred an increased CAD risk in either elderly men or women greater than or equal to 65 years old. In the age group of 55 to 64 years, elevated Lp(a) was positively associated with CAD for men (adjusted OR: 2.45, P<.05) but not fur women (adjusted OR: 0.56, P=NS). Conclusions For both sexes, elevated Lp(a) appears to be an independent risk factor for premature CAD and the importance of Lp(a) appears to decrease with age. However, for women, the risk estimate of Lp(a) began to decline at an age approximate to 10 years younger than for men. These data suggest that not only age- but also sex-specific factors such as menstrual status may interact with the association between Lp(a) and CAD.