Lipoprotein(a) associated with coronary artery disease in older women: ageand gender analysis

Background: Lipoprotein (a) has been associated with increased coronary art ery disease (CAD) risk in men, but relatively little data exists in women. While age influences the cardiovascular risk associated with Lp(a) in men, little is known about this phenomenon in women. The impact of gender on Lp( a) has not been fully studied in an ongoing clinical practice. Methods and Results: Baseline Lp(a) values were measured in 918 CAD and 829 non-CAD pat ients (603 females, 1144 males) entering an outpatient prevention clinic. T he age-specific association of elevated Lp(a) ( > 30 mg/dl) with CAD was ex amined after adjustment for traditional risk factors. Lp(a) was a significa nt risk factor (OR = 1.9, CI, 1.4-2.6) in men and women (OR = 1.9, CI 1.3-2 .9). In men age less than or equal to 55 years the odds ratio for increased cardiovascular risk in high vs low Lp(a) was 2.5 (CI 1.6-3.9). In men less than or equal to 55, CAD increased from 32 to 61% as Lp(a) progressively r ose from less than or equal to 5 to greater than or equal to 45 mg/dl (P va lue for trend < 0.001). No significant increase was observed in men > 55 ye ars (OR = 1.3, CI 0.9-2.1). In women less than or equal to 55 years, the ri sk of CAD increased from 22 to 35% (OR 1.6, CI 0.8-3.2), and increased from 38 to 63% in women > 55 (OR 2.1, CI 1.3-3.5). Further, of high-risk patien ts (men I 55 and women > 55 years) with an Lp(a) in the range of 20-44mg/dl (third quartile), younger men showed a greater incidence of CAD (51%) than older women (43%). Both genders revealed substantial risk when the Lp(a) v alues were above 45 mg/dl. (OR = 3.7,CI = 2.0-6.8 in younger men; OR = 3.3, CI = 1.6-6.6 in older women). Conclusions: In this cross sectional study of both men and women, elevated Lp(a) was associated with a significantly inc reased risk of CAD in men and women. While we corroborate previous reports on the lack of association in older men, the determination of an enhanced L p(a)-related risk in older women was new and unanticipated. Further, in thi s population of high risk patients, substantial cardiovascular risk appeare d to be represented by higher concentrations of Lp(a) in women than observe d in men. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.