Differences in lipoprotein (a) and apolipoprotein (a) levels in men and women with advanced coronary atherosclerosis.

BACKGROUND

This study was designed to evaluate whether differences between sexes exist in serum-lipoprotein (a) [Lp(a)] and arterial-wall-apolipoprotein (a) [Apo(a)] levels in patients with advanced coronary artery disease.

METHODS

The concentrations of Lp(a) in serum and Apo(a) in aortic biopsies were studied in 76 men and 20 women undergoing coronary artery bypass graft surgery. The severity of coronary artery disease was determined by a coronary atherosclerosis score that used quantitative coronary angiography.

RESULTS

Serum-Lp(a) and tissue-Apo(a) do not correlate with the severity of coronary artery disease as expressed by the coronary atherosclerosis score (r = 0.09 and r = 0.14, respectively). Women were older (65 +/- 8 versus 57 +/- 8 years, P < 0.001) and had higher mean Lp(a) and higher mean Apo(a) levels (47 +/- 41 versus 32 +/- 40 mg/dl and 33 +/- 34 versus 19 +/- 24 micrograms/g wet weight, P < 0.05) than men with identical coronary atherosclerosis score (35 +/- 8 versus 33 +/- 8, P > 0.05). The serum levels of cholesterol, triglycerides, and high-density lipoprotein were similar in both groups.

CONCLUSIONS

Men and women undergoing coronary artery bypass graft surgery had very similar severity of coronary artery disease as expressed by the coronary atherosclerosis score. Women were 8 years older and had 1.5 times higher mean serum-Lp(a) levels and 1.75 times higher mean tissue Apo(a) levels higher than the men. Sixty per cent of the women but only 39% of the men had serum Lp(a) levels higher than 25 mg/dl. Lp(a) level seems to be an additional risk factor for coronary artery disease confined to postmenopausal women.