Early natural menopause and the duration of postmenopausal life. Findings from a mathematical model of life expectancy.
Menopause marks the beginning of a stage of life characterized by an increased susceptibility to diseases such as coronary heart disease and osteoporosis. It was therefore hypothesized that early age at natural menopause would lengthen the duration of the postmenopausal stage of life and thereby result in an earlier age at death. This study investigated the relations between age at natural menopause, duration of postmenopausal life (ie, life expectancy at menopause), and age at death (ie, age at menopause plus life expectancy at menopause). Data were derived from a study of 5,287 naturally postmenopausal Seventh-day Adventists observed during 1976-1982. Life expectancy was estimated by a mathematical model that used mortality ratios from the study and mortality rates from the US general population. For natural menopause before the age of 47 years, each one-year decrease in age at menopause was associated with a 0.53-year increase in postmenopausal life (P = .04) and a 0.47-year decrease in the age at death (P = .04). For natural menopause at the age of 47 years and older, however, each one-year decrease in age at menopause was associated with a 0.99-year increase in postmenopausal life (P = .03) and only a 0.01-year decrease in the age at death (P = .85). Overall, these findings argue against the possibility that the association between age at menopause and age at death in this study was due to the relation of age at menopause to the duration of postmenopausal life.
Snowdon
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Division of Epidemiology, School of Public Health, University of Minnesota, Minneapolis 55455.
D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008017:Life Expectancy; D008593:Menopause / Q000502:physiology*; D008594:Menopause, Premature / Q000502:physiology*; D008875:Middle Aged; D008954:Models, Biological; D009026:Mortality; D012016:Reference Values