PROSPECTIVE-STUDY OF THE DETERMINANTS OF AGE AT MENOPAUSE

The authors prospectively studied the effect of demographic, reproduct ive, stress-related, and health behavior factors measured at study ent ry on age of natural menopause in 185 healthy US women. At study entry , women were 42.5-47.5 years old and premenopausal. After a baseline e xamination (1983-1985), women were followed for 7-9 years, during whic h time they reported on a monthly basis their menstrual status and whe ther they were taking hormones. Menopausal age was defined as age at t he last menstrual period prior to stopping menstruation for 12 months (and not taking hormones). Estimated median age at menopause was 51.5 years for the whole sample. Median age at menopause was earlier for wo men who reported irregular menstrual cycles at study entry (50.2 years ), were African-American (49.3 years), were smokers (50.6 years), or w ere currently on a weight reduction diet (50.5 years). Psychosocial st ress was predictive of an even earlier median age at menopause in Afri can Americans (48.4 years) and in those with irregular cycles at basel ine (49.4 years). Results suggest that premenopausal women in their fo rties who are experiencing irregular menstrual cycles, are smokers, ar e dieting, or are African-American are likely to reach menopause earli er than their contemporaries. African-American women may have a differ ent ''biological clock'' than white women, especially when under stres s, or they may experience more stress of longer duration.