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 rises soon after menopause in women, and hormone replacement therapy (HRT) has proved to be useful in preventing onset of clinical manifestations of the disease. However, it is not known how HRT affects sonographically determined atherosclerotic severity (AS) and number of atherosclerotic plaques (NAP) in large arteries. Furthermore, 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 determined AS and NAP in large arteries of 101 postmenopausal women compared to 40 controls without HRT. We also studied the interaction of HRT and antibodies against oxidized LDL on AS and NAP progression. Results: Estradiol valerate alone, combined estradiol valerate–levonorgestrel and combined estradiol valerate–medroxyprogesterone acetate therapy are each associated with lower NAP and AS as compared to controls without HRT. In a multiple regression model explaining NAP in the whole study population, the strongest predictors were HRT ( P =0.0006) and copper-oxidized LDL cholesterol autoantibodies ( P =0.0491). Discussion: Our findings indicate that postmenopausal HRT is associated with a lower total number of atherosclerotic plaques and less severe atherosclerotic lesions, as compared to controls without HRT, and that this outcome may be associated with the effect of HRT on LDL cholesterol oxidation.