Age at menopause, frailty, and risk of incident sarcopenia among middle-aged and older Chinese women: A longitudinal cohort study.

OBJECTIVES

To investigate the independent and joint associations of menopausal status and frailty with incident sarcopenia among middle-aged and older Chinese women, and to identify potential threshold effects.

STUDY

DESIGN

Prospective longitudinal cohort study using data from the China Health and Retirement Longitudinal Study (2011-2015).

MAIN OUTCOME MEASURES: Incident sarcopenia was ascertained according to the 2025 Asian Working Group for Sarcopenia criteria. Menopausal status was categorized as premature (<40 years), early (40-44 years), normal (45-55 years), and late (>55 years). Frailty was defined by a frailty index ≥25 based on 32 health deficits. Cox proportional hazard models were used to calculate the hazard ratio and 95% confidence interval; restricted cubic splines and additive/multiplicative interaction analyses were employed.

RESULTS

Among 4503 women, premature menopause was independently associated with increased risk of sarcopenia (hazard ratio 1.63, 95% confidence interval 1.22-2.18). Restricted cubic spline analysis identified a critical threshold at 46 years: below this age, each additional year of delayed menopause reduced risk by 6% (hazard ratio 0.94, 95% confidence interval 0.91-0.96). Frailty was linearly associated with sarcopenia (hazard ratio 1.32, 95% confidence interval 1.03-1.69). Women with both premature menopause and frailty exhibited the highest risk (hazard ratio 2.06, 95% confidence interval 1.08-3.92).

CONCLUSIONS

Menopause before age 46 represents a critical threshold for an elevated risk of sarcopenia. Premature menopause and frailty act as independent rather than synergistic risk factors.