Age at Menopause and Mortality in Japan: the Jichi Medical School Cohort Study

Abstract

Communications. The people who moved out of the communities during the observation period were followed up until the date of the emigration. Data on emigration of the study subjects were obtained every year from their municipal governments.Age at menopause was categorized into <40 years, 40-44 years, 45-49 years, 50-54 years, and 55+ years. The reference group was females who were 45-49 years at menopause.Statistical analysis was performed using the SPSS ® software version 11.0. Descriptive parameters are shown as mean, standard deviation or proportion (%). We compared characteristics between the groups by one-way analyses of variance or the chisquare tests. Cox's proportional hazard models were used to calculate hazard ratios of mortality for age at menopause after adjusting for age, SBP, serum total cholesterol level, HDL cholesterol level, history of diabetes mellitus, BMI, smoking habits, alcohol drinking habits, marital status, study area, and type of menopause, which were considered to be potential confounding factors. Among the potential confounding factors that we obtained as the baseline data about blood pressure, we used SBP only in the multivariate analyses to avoid the co-linearity.This study was approved by the Institutional Review Board of Jichi Medical School for ethical issues.

The Epidemiology of Longevity and Exceptional Survival

“…Another study of 68,154 American women found that early menopause was associated with several causes of death, including predominantly coronary heart disease death but also respiratory disease, genitourinary disease, and external causes of death (59). Similar associations have been reported for other cohort studies in the United States (60), as well as in Japan (61,62) and South Korea (63).…”

Association between serum ferritin concentrations and depressive symptoms in Japanese municipal employees

“…The association between depressive symptoms and serum ferritin concentrations was examined separately among men and women. In women, because serum ferritin concentrations considerably increases after menopause (Whitfield et al, 2003), we further analyzed the data separately for those aged b 50 years and ≥ 50 years, with reference to data regarding the mean age of menopause in Japanese women (48.3 years old) (Amagai et al, 2006). Multivariate logistic regression analyses were then used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) of depressive symptoms for the quartiles of serum ferritin concentrations, taking the highest quartile category as a reference.…”

Type and Timing of Menopause and Later Life Mortality among Women in the Iowa Established Populations for the Epidemiological Study of the Elderly (EPESE) Cohort

“…10,19 We did not find a relationship between age at surgical menopause and mortality, similar to some studies of women of a broader age range. 3,4 However, some other studies found a …”

“…However, characteristics of menopause may indicate later life health risks, related to hormonal exposures or other processes that may influence the risk for cardiovascular mortality in particular. 1,2 Most previous analyses have found relationships of moderate strength between early age at natural menopause and increased risk of all-cause 1,[3][4][5][6][7][8][9][10][11] and cardiovascular mortality. 1,5,7,9,10,[12][13][14] Surgical menopause may also be related to the overall intrinsic rate of biological aging.…”

“…However, studies have not detected differences in all-cause or cardiovascular mortality between women with natural versus surgical menopause. 10,19 Some studies have shown no relationship between age at surgical menopause and all-cause mortality between women with natural or surgical menopause, 3,4 but the majority have demonstrated a relationship between early surgical menopause and increased cardiovascular and all-cause mortality risks. menopause and mortality may be stronger in women with younger rather than older attained age.…”