Cigarette smoking, androgen levels, and hot flushes in midlife women.

Objective: To test the hypothesis that cigarette smoking is associated with hot flushes through a mechanism involving androgen levels, progesterone levels, sex hormone-binding globulin levels, or the ratio of androgens to estrogens.

Methods: Women with and without hot flushes were recruited from Baltimore, Maryland, and the surrounding counties. Women were between 45 and 54 years of age, with at least three menstrual periods in the previous 12 months, and were not postmenopausal. Study participants completed a questionnaire and gave a blood sample for hormone measurements.

Results: Current smokers had significantly higher androstenedione levels and a higher androgen-to-estrogen ratio than never smokers. Current smokers had significantly lower progesterone levels compared with never smokers. Former and current cigarette smokers had increased odds of experiencing hot flushes compared with never smokers (former: odds ratio [OR] 1.41, 95% confidence interval [CI] 0.99-2.01; current: OR 2.43, 95% CI 1.28-4.62). This association, however, was not attenuated by the addition of hormones to the smoking and hot-flush model.

Conclusion: Cigarette smoking is associated with hot flushes through a mechanism that may not involve alterations in hormone levels or their ratios.

Level Of Evidence: II.