We analyzed cross-sectional data from 1758 women aged 40-69 years who were enrolled in the baseline surveys of the Japan Multi-institutional Collaborative Cohort (J-MICC) Study.
Associations of timing of natural menopause with its probable covariates and with target gene variants were evaluated by univariate and multivariate Cox proportional hazards models.
Lower body mass index and later age at menarche were significantly associated with earlier natural menopause. Women with minor alleles at T-48444C in PPARD showed a significantly higher adjusted hazard ratio of 1.57 (95%confidence interval: 1.18-2.10) for earlier natural menopause. In contrast, women with minor alleles at Thr394Thr in PPARGC1A showed a significantly lower adjusted hazard ratio of 0.86 (0.76-0.97) for earlier natural menopause. These associations did not substantially alter when re-analyzed after excluding the subjects who self-reported a history of diabetes or the subjects whose age was more than 65 years.
Gene variants in PPARD and PPARGC1A might be associated with timing of natural menopause, probably through direct actions on the ovaries, among the general Japanese population.