BMC Public Health Research article Early menopause, association with tobacco smoking, coffee consumption and other lifestyle factors: a cross-sectional study Thea F Mikkelsen*1, Sidsel Graff-Iversen2, Johanne Sundby1 and Espen Bjertness1 BioMed Central Open Access Address: 1Institute of General Practice and Community Medicine, Faculty of Medicine, University of Oslo, Norway and 2Norwegian Institute of Public Health, Oslo, Norway Email: Thea F Mikkelsen* - theam@studmed.uio.no; Sidsel Graff-Iversen - sgri@fhi.no; Johanne Sundby - johanne.sundby@medisin.no; Espen Bjertness - espen.bjertness@medisin.no * Corresponding author Published: 7 July 2007 BMC Public Health 2007, 7:149 doi:10.1186/1471-2458-7-149 This article is available from: http://www.biomedcentral.com/1471-2458/7/149 Received: 25 October 2006 Accepted: 7 July 2007 © 2007 Mikkelsen et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Abstract Background: Early onset of menopause is a risk factor for several health problems. The objective was primarily to investigate the association between early menopause and current, past active and passive smoking. A second aim was to investigate the association between coffee and alcohol consumption and early menopause. Methods: The present population-based cross-sectional study included a sub-sample of 2123 postmenopausal women born in 1940–41 who participated in the Oslo Health Study. Early menopause was defined as menopause occurring at an age of less than 45 years. We applied logistic regression analyses (crude and adjusted odds ratio (OR)) to examine the association between early menopause and selected lifestyle factors. Results: Current smoking was significantly associated with early menopause (adj. OR, 1.59; 95% CI, 1.11–2.28). Stopping smoking more than 10 years before menopause considerably reduced the risk of early menopause (adj. OR, 0.13; 95% CI, 0.05–0.33). Total exposure to smoking (the product of number of cigarettes per day and time as a smoker) was positively related to early menopause and, at the highest doses, nearly doubled the odds (adj. OR, 1.93; 95% CI, 1.12–3.30). These data suggest a possible dose-response relationship between total exposure to smoking and early menopause, but no dose-response relationship was detected for the other variables examined. We found no significant association of coffee or alcohol consumption with early menopause. Of the lifestyle factors tested, high educational level (adj. OR, 0.50; 95% CI, 0.34–0.72) and high social participation (adj. OR, 0.60, 95% CI, 0.39–0.98) were negatively associated with early menopause. Conclusion: This cross-sectional study shows an association between current smoking and early menopause. The data also suggest that the earlier a woman stops smoking the more protected she is from early menopause. Early menopause was not significantly associated with passive smoking, or alcohol or coffee consumption. Page 1 of 8 (page number not for citation purposes)