Effects of Smoking on Menopausal Age: Results From the Korea National Health and Nutrition Examination Survey, 2007 to 2012.
OBJECTIVE
Decreased fertility and impaired health owing to early menopause are significant health issues. Smoking is a modifiable health-related behavior that influences menopausal age. We investigated the effects of smoking-associated characteristics on menopausal age in Korean women.


METHODS
This study used data from the Korea National Health and Nutrition Examination Survey from 2007 to 2012. Menopausal age in relation to smoking was analyzed as a Kaplan-Meier survival curve for 11 510 women (aged 30 to 65 years). The risk of entering menopause and experiencing early menopause (before age 48) related to smoking were assessed using a Cox proportional hazards model.


RESULTS
The menopausal age among smokers was 0.75 years lower than that among non-smokers (p<0.001). The results of the Cox proportional hazards model showed pre-correction and post-correction risk ratios for entering menopause related to smoking of 1.26 (95% confidence interval [CI], 1.09 to 1.46) and 1.27 (95% CI, 1.10 to 1.47), respectively, and pre-correction and post-correction risk ratios for experiencing early menopause related to smoking of 1.36 (95% CI, 1.03 to 1.80) and 1.40 (95% CI, 1.05 to 1.85), respectively.


CONCLUSIONS
Smokers reached menopause earlier than non-smokers, and their risk for experiencing early menopause was higher.
Department of Preventive Medicine and Public Health, Ajou University School of Medicine, Suwon, Korea.
Hee Jung
HJ
Yang
Department of Preventive Medicine and Public Health, Ajou University School of Medicine, Suwon, Korea.
Pae Sun
PS
Suh
Department of Preventive Medicine and Public Health, Ajou University School of Medicine, Suwon, Korea.
Soo Jeong
SJ
Kim
Department of Preventive Medicine and Public Health, Ajou University School of Medicine, Suwon, Korea.
Soon Young
SY
Lee
D000328:Adult; D000367:Age Factors; D000368:Aged; D003430:Cross-Sectional Studies; D003710:Demography; D005260:Female; D006801:Humans; D008593:Menopause; D008875:Middle Aged; D009749:Nutrition Surveys; D016016:Proportional Hazards Models; D056910:Republic of Korea; D012307:Risk Factors; D012907:Smoking
Age; Menopause; Proportional hazard models; Smoking