Sarcopenia trajectories and associated factors in older adults: evidence from the China health and retirement longitudinal study.

BACKGROUND: Sarcopenia is a dynamic and reversible condition, yet its longitudinal changes remain unclear. METHODS: Using three waves of data from the China Health and Retirement Longitudinal Study, sarcopenia status was assessed in 2,945 older adults based on the Asian Working Group for Sarcopenia 2019 criteria. Growth mixture modeling identified distinct sarcopenia trajectories, and multinomial regression examined associated factors. RESULTS: The stages of sarcopenia changed over 4 years with both possible worsening and improving transitions. Four trajectories were identified: persistent low risk (59.86%, n = 1763), persistent high risk (26.62%, n = 784), low but increasing risk (6.89%, n = 203), and high but decreasing risk (6.63%, n = 195). Respondents classified with persistent low risk trajectory were likely to be younger, male, and being overweight or obesity. Individuals who smoked were more likely to belong to the low but increasing-risk [Odds ratio (OR) = 1.635, 95% Confidence Interval (CI): 1.123–2.379] and persistent high risk trajectory (OR = 1.567, 95% CI: 1.176–2.088). Conversely, those with a drinking habit had lower odds of being in the low but increasing-risk trajectory and were more likely to remain in the persistent low-risk group (OR = 0.574, 95% CI: 0.395–0.834). Being underweight was strongly associated with the persistent high risk (OR = 87.339, 95% CI: 52.266–145.950) and high but decreasing risk trajectory (OR = 32.150, 95% CI: 18.613–55.532), while cognitive impairment showed a slight inverse association with persistent high risk trajectory (OR = 0.968, 95% CI: 0.944–0.992) compared with persistent low risk trajectory. DISCUSSION AND IMPLICATIONS: This study identified four trajectories of sarcopenia in Chinses older adults. Persistent high and low but increasing sarcopenia trajectories should be prioritized for intervention. It is necessary to develop tailored intervention strategies to improve cognitive function, especially for older adults with advancing age, female sex, smoking habit, and underweight to reduce the risk of worsening sarcopenia trajectories.