Cognitive Impairment and Long-Term Cognitive Trajectories in Relation to Incident Sarcopenia

Although sarcopenia is a well-known risk factor for cognitive impairment, the evidence regarding whether cognitive dysfunction may be associated with sarcopenia remains limited. This prospective cohort study aimed to evaluate the association between mild cognitive impairment (MCI), long-term cognitive trajectories, and the development of sarcopenia. We also examined whether a healthy lifestyle could modify this risk.

Using data from the China Health and Retirement Longitudinal Study, we conducted a four-year longitudinal study with 7,048 participants. We used Cox proportional hazards regression to assess the link between baseline cognitive function and incident sarcopenia. Generalized estimating equation models explored the role of specific cognitive domains. Latent mixture modeling was used to identify long-term cognitive trajectories and evaluate the modifying effects of lifestyles.

Among the 7,548 included participants, the mean age was 63.5 ± 6.6 years, and 44.7% were females. Over a four-year follow-up, we identified 502 new cases of sarcopenia. Baseline MCI was significantly associated with a 57% increased risk of developing sarcopenia (HR=1.57; 95% CI, 1.25-1.96; P<0.001). Specific cognitive domains including orientation, memory, and computation-were also significantly linked to sarcopenia. We identified three distinct cognitive trajectories: low (16.6%), moderate (45.6%), and normal (37.8%) function. Compared to the normal group, participants in the low and moderate cognitive function groups had a 2.02-fold and 1.51-fold higher risk of sarcopenia, respectively. A favorable lifestyle was found to significantly reduce the risk of sarcopenia.

Both MCI and a persistent low-level decline in cognitive function are strongly associated with an increased risk of sarcopenia, but implementing timely healthy lifestyle interventions can significantly mitigate this risk and promote healthy aging.