Swedish study reveals combined effects of smoking and early menopause on overall mortality

Women may now have yet another reason to quit smoking given the results of a new study that is being reported online today in Menopause, the journal of The North American Menopause Society (NAMS). The Swedish study involving 25,474 women is the first to quantify the combined effects of smoking and age at menopause on overall mortality in terms of survival time by investigating the role of smoking as a possible effect modifier.

A harmful association between younger age at menopause and overall mortality has already been documented. In this study that followed a large population of Swedish women over 16 years, the difference in median age at death between women with menopause at 40 years and women with menopause at 60 years was 1.3 years.

Cigarette smoking, which decreases age at menopause, has been identified as the only lifestyle factor modifying this association. Compared with current smokers, former smokers and never smokers had an older median age at death of 2.5 years. When the analysis was restricted to current smokers, the difference in age at death between women with menopause at age 40 years and women with menopause at 60 years increased from 1.3 years to 2.6 years.

The authors of the study concluded that not only does the age at menopause and smoking relate in predicting mortality, but also that smoking exaggerates the effects of estrogen deficiency on women with menopause at a younger age. However, differently from other studies, this study demonstrated a nonsignificant association between age at menopause and mortality among never smokers. Of note was the fact that the women with later menopause were more likely to be nonsmokers and more likely to use hormone therapy.

"This study provides credible evidence that women can proactively work to delay menopause through various lifestyle choices such as stopping smoking," says NAMS Medical Director Wulf Utian, MD, PhD, DSc. "The ultimate benefit to them is that they may well extend their life expectancy."

The article, "Differences in age at death according to smoking and age at menopause," will be published in the January 2016 print edition of Menopause.