Objectives: To evaluate the impact of smoking on the onset age of menopause.
Methods: From January of 1998 to January of 2001, 775 postmenopausal women, with ages ranging from 40 to 65 years, were evaluated by means of a questionnaire. They were asked about their birth date; last menstrual bleeding, number of children, smoking habits, use of hormone medication, number of cigarettes per day, and gynecological surgeries. The menopausal status was characterized by blood determinations of FSH (> 30 UI) and estradiol (< 13 pg/mL). Women with surgical menopause, premature menopause and users of hormone replacement therapy were excluded.
Results: Of the 775 women included 646 (83%) were not-smokers and 129 (17%) smokers. For the non-smoking group mean age at menopause was 48.6 (+/- 4.1) years and for smokers 47.8 (+/-3.9). Median ages at menopause were 49.2 (+/-3.7) and p=0.464; 47.6 (+/-4.3) and p=0.171); and 46.9 (+/-3.6) and p=0.016 years for women who smoked 1-5, 6-10 and 11 or more cigarettes per day, respectively.
Conclusion: Onset of menopause was anticipated by eight months for women who smoke. This finding suggests a greater susceptibility to earlier menopause in accordance with the number of cigarettes smoked per day.