Age at natural menopause and physical functioning in postmenopausal women: the Canadian Longitudinal Study on Aging

The aim of this study was to evaluate the association between categories of age at natural menopause (ANM) and gait speed (slowness) and grip strength (weakness), common measures of physical functioning in older women.

We analyzed data from the Canadian Longitudinal Study on Aging, which included participants from seven cities across Canada collected in 2012. The sample was restricted to women who reported to have entered menopause (N = 9,920). Women who had a hysterectomy before menopause were excluded since the age at which this surgical procedure was performed was not available. ANM was categorized into five groups: less than 40 (premature), 40 to 44 (early), 45 to 49, 50 to 54, and more than 54. We conducted linear regressions to assess the association between ANM and gait speed (m/s) and grip strength (kg) adjusting for participant age, education, body mass index, smoking, use of hormone therapy, height, and province of residence.

Mean ANM was 49.8 (95% confidence interval [CI]: 49.7-50.0), with 3.8% of women having a premature menopause; the average gait speed was 0.98 m/s (standard deviation: 0.22), the average grip strength was 26.6 kg (standard deviation: 6.39). Compared to women with ANM of 50 to 54, women with premature menopause had 0.054 m/s (95% CI -0.083, -0.026) lower gait speed when adjusting for age and study site. In the fully adjusted model, the association was attenuated, 0.032 m/s (95% CI -0.060, -0.004). ANM was not associated with grip strength.

Our study suggests that premature menopause (<40 years) may be associated with lower gait speed (slowness) among Canadian women. No association was observed between ANM and grip strength. Future studies should include a life course approach to evaluate whether social and biological pathways modify the association between age at menopause and physical function in populations from different contexts.