Fumar antecipa a menopausa ? Evidências do Estudo Pró-Saúde

Abstract

The definition of menopause is the moment when the ovarian function stops definitively. Once occurred, there is an increased risk of cardiovascular disease, Alzheimer disease, osteoporosis and bone fractures. When anticipated, menopause is related with higher risk of all-cause mortality and several serious illnesses. Because of the increasing population life expectancy, women may spend between one third to one half of their lives after menopause, and that s why postmenopausal health condition studies are important. There are many studies of factors that influence the age at menopause which have many different results and few of them are Brazilian ones. Smoking has been associated with earlier menopausal age. This study s aims are to analyses different aspects of the associations between smoking and the age of menopause, considering possible effects of smoking dose. The Pró-Saúde study data base was utilized with sectional analyses and a parametric proportional hazard survival regression model with a Weibull distribution. Our results point to a reduction of the menopause risk related to current smoking about 32% with active smokers achieving menopause 2,5 years latter than nonsmokers, adjusted to education and parity. However among current smokers, this study suggests a higher risk of 132% and 192% to those women who smoke about 10 to 20 cigarettes a day and those who smoke more than 20 pack-years, respectively, compared to those smokers of less than 10 cigarettes a day and less than 10 pack-years. Those groups achieved menopause 3.3 and 4.4 years earlier than controls, respectively. There was no evidence of association relating age at menopause with age at start smoking, time since stopped smoking or smoking duration. In this study, considering possible dose-response effects, smoking is shown as a factor related to anticipation of menopausal age in some aspects, although not in others.