Menopausal age in relation to smoking.

A population study of women revealed more smokers among 50-year-old postmenopausal women than among women of the same age who still menstruated. The difference was statistically significant. The postmenopausal smokers had on average smoked as long as or longer than the smokers who still menstruated. The higher number of smokers among postmenopausal women could thus not be explained by these women starting to smoke in connection with the menopause. Non-smoking women were on average heavier than smoking women. Previous studies indicate that an increased amount of adipose tissue might delay the menopausal age. It is therefore possible that the difference in menopausal age between smoking and non-smoking women might be explained either by a delayed menopause in non-smoking women due to an increased amount of adipose tissue in these women, or by a precocious menopause in smokers due to toxic effects from smoking. Probably both factors are of importance, but our results indicate that smoking per se is the main factor. The increased number of smokers among women with precocious menopause can probably explain part of the overrepresentation of women with precocious menopause among those who have myocardial infarction.