The protective effect of endogenous sex hormones is commonly believed to explain the gender gap in the risk of coronary heart disease and the diminished protection in women when menopause occurs. Recent reports indicate that iron overload, due to cessation of menstrual bleeding, may be an important factor. We therefore investigated iron stores by serum ferritin measurements in healthy premenopausal (n=113) and postmenopausal (n=46) women. Ferritin levels were higher in postmenopausal than in premenopausal women, both in blood donors (43.4 versus 23.1 /xg/L, f<.001) and in nondonors (71.7 versus 32.8 fig/L, P<.001). Serum ferritin was positively correlated with age (r=.36, P<.001). After age adjustment, serum ferritin was positively correlated with hemoglobin, hematocrit, serum total cholesterol, and C oronary heart disease (CHD) is an uncommon disease in premenopausal women. 1 Most often, this has been attributed to the endogenous sex hormones, although the effects of age and menopause are difficult to separate.The benefits of estrogens have hitherto been related to the effects on serum lipids, as postmenopausal women experience elevation of serum low-density lipoprotein (LDL) cholesterol and trigh/ceride concentrations, 2 factors associated with an increased risk of CHD.
3It has been speculated that factors other than serum lipids are influenced by the menopause. Data from the Framingham Study suggested that removal of the uterus was as important as oophorectomy or a natural menopause in regard to the risk of CHD. 4 This led Sullivan 5 to propose regular menstrual blood loss as the protective factor and related the postmenopausal risk of CHD to an accumulating iron overload, reflected in raised levels of the iron storage protein, ferritin. The mechanisms, he suggested, might involve oxidant activity of iron-dependent enzymes. 6 Recently, Lauffer 7 reported a positive correlation between CHD mortality and the amount of iron in the liver. Similarly, Salonen et al 8 found an increased risk of myocardial infarction in men with elevated serum ferritin, and the association was even stronger in subjects with high serum LDL cholesterol levels.The aim of the present study was to investigate the cross-sectional relation between serum ferritin, sex hor- low-density lipoprotein (LDL) cholesterol. Total cholesterol was correlated with age (r=.66, / > <.001), as were LDL cholesterol (r=.6O, P<.01) and high-density lipoprotein cholesterol (r=.32, P<.01). Neither ferritin nor serum lipids were directly associated with female sex hormone levels. The mutual relation between ferritin, hemoglobin, and hematocrit probably only indicates their usefulness as measures of body iron. The parallel rise in serum ferritin, total cholesterol, and LDL cholesterol might contribute to the increased risk of coronary heart disease among postmenopausal women. {Arteriosder Thromb. 1994;14:857-861.)
Key Words• women cholesterol ferritin menopause mones, and cardiovascular risk factors in healthy women.
MethodsThe present investigation was p...