Lipoprotein (a) is associated with endothelial function in healthy postmenopausal women

Background. Lipoprotein (a) (Lp(a)) is an independent risk factor for ather osclerotic cardiovascular disease. The atherogenic potential of Lp(a) may b e by impairment of endothelial function. Objectives. We investigated the re lation of Lp(a) plasma levels to endothelium dependent and independent dila tation of the brachial artery in healthy postmenopausal women. Methods. One hundred and five healthy postmenopausal women aged 52-67 years were includ ed in the study. Endothelial function was assessed non-invasively by measur ing percent lumen diameter change in the brachial artery after reactive hyp eremia and sublingual nitroglycerine spray. Results. Flow mediated dilatati on was inversely related to the plasma log Lp(a) level. Mean change per uni t log Lp(a) increase: -2.83% (95% CI: -5.22 - -0.43). Elevated Lp(a) (> 239 mg/l) (upper quartile) was associated with an impaired flow mediated vasod ilatation (2.4% +/- 1.2) compared to Lp(a) less than or equal to 239 mg/l ( 5.2% +/- 0.7). Adjustment for other cardiovascular risk factors did not cha nge the magnitude of the association. Nitroglycerine-induced vasodilatation was not significantly lower in the high Lp(a) level group, compared to the group with normal levels of Lp(a) (less than or equal to 239 mg/l) (8.0 +/ - 1.2 vs 11.4% +/- 0.8). Conclusion. Elevated lipoprotein (a) levels are as sociated with an impaired endothelial function in healthy postmenopausal wo men, independent of conventional risk factors for cardiovascular disease. S ince Lp(a) may be pathogenetically important for early vascular damage, ele vated Lp(a) levels might contribute to the increased cardiovascular risk se en in postmenopausal women. (C) 2000 Elsevier Science Ireland Ltd. All righ ts reserved.