The relation of oxidized LDL autoantibodies and long-term hormone replacement therapy to ultrasonographically assessed atherosclerotic plaque quantity and severity in postmenopausal women

Background: In epidemiologic studies, the incidence of atherosclerosis rise s soon after menopause in women, and hormone replacement therapy (HRT) has proved to be useful in preventing onset of clinical manifestations of the d isease, However, it is not known how HRT affects sonographically determined atherosclerotic severity (AS) and number of atherosclerotic plaques (NAP) in large arteries. Further-more, it is not clear how HRT affects oxidation of low density lipoproteins (LDL), which obviously has an important role in the pathogenesis of atherosclerosis. Objectives: The purpose of the study was to determine whether HRT has a beneficial effect on sonographically det er-mined AS and NAP in large arteries of 101 postmenopausal women compared to 40 controls without HRT. We also studied the interaction of HRT and anti bodies against oxidized LDL on AS and NAP progression. Results: Estradiol v alerate alone, combined estradiol valerate-levonorgestrel and combined estr adiol valerate-medroxyprogesterone acetate therapy are each associated with lower NAP and AS as compared to controls without HRT. In a multiple regres sion model explaining NAP in the whole study population, the strongest pred ictors were HRT (P = 0.0006) and copper-oxidized LDL cholesterol autoantibo dies (P = 0.0491). Discussion: Our findings indicate that postmenopausal HR T is associated with a lower total number of atherosclerotic plaques and le ss severe atherosclerotic lesions, as compared to controls without HRT, and that this outcome may be associated with the effect of HRT on LDL choleste rol oxidation. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.