21 March, 2016:
Paula and colleagues in 2013 conducted a cross-sectional study to investigate the association between smoking and early onset of menopause . The study included 1222 female employees on the campuses of Rio de Janeiro university. All participants were aged over 35 years. Smoking status was determined by questioning whether the participant had smoked at least 100 cigarettes during her lifetime, and whether she currently smoked. Women were classified as current smokers, former smokers or women who had never smoked. The researchers used a Cox proportional hazards model to investigate the data and the correlations between smoking status and age at the onset of menopause.
Among current smokers, there was an increase of 56% (hazard ratio 1.56; 95% confidence interval 1.06-2.31) in the risk of menopause, when compared with those who had never smoked (p = 0.02), while former smoking was not associated with the outcome. The results obtained from the study revealed that women who smoke are 1.8 years younger at the onset of menopause when compared to non-smoking women. There was no significant difference between the survival curves for former smokers and women who had never smoked, adding a very interesting conclusion: once a woman gives up smoking, her age at onset of menopause may be roughly equivalent to that of women who have never smoked. The results obtained from the study emphasize the importance of efforts to control cigarette smoking.