Objective: To draw attention to the implications of smoking in the pathogenesis of osteoporosis and for the effectiveness and safety of hormone therapy. DESIGN Summary of own research and a MEDLINE search of English-language literature on the antiestrogenic effect of smoking in pre- and postmenopausal women published during the past two decades.
Results: Numerous observations suggest that part of the detrimental effect of smoking on bone metabolism is mediated by an adverse influence on sex-steroid metabolism, and in particular by an estrogen-lowering effect. Furthermore, in smokers, serum concentrations of estradiol and estrone during oral, but not parenteral, hormone therapy (HT) reach only half the concentrations of nonsmokers. Thus, cigarette smoking may reduce the favorable effects of HT significantly and may even negate the protective effects. In such cases, the failure of preventive therapy is a failure of dosing rather than of HT per se.
Conclusions: We urge colleagues to take the antiestrogenic effect of smoking into account when drawing conclusions from population-based trials, as well as when prescribing HT to their patients for the prevention of menopause-related health problems.