Abstract
Background: Motoric cognitive risk syndrome (MCR), characterized by slow gait speed (GS) and subjective cognitive complaints, is a simple way to screen older adults at high risk of dementia. In primary care service, however, assessing GS may still be a challenge due to the short consultation time and space constraints common in general practice. Therefore, there is a need to explore alternative MCR subtypes with motor domains that can be measured conveniently. This study aimed to explore a new subtype of MCR, using low handgrip strength (HGS) as the motoric phenotype, and examined its association with the incidence of cognitive impairments among the Chinese community-dwelling older adults.
Methods: We used four-wave data (2011-2018) of participants (≥60 years) in the China Health and Retirement Longitudinal Study. We investigated two MCR subtypes. First, MCRg was defined in the literature as the coexistence of slow GS and cognitive complaints without dementia or morbidity disability. Then, we defined a new subtype, MCRh, by replacing slow GS with low HGS. Cox proportional hazards models were used to examine the association between baseline MCR subtypes (MCRg and MCRh) and incident cognitive impairment, controlling for sociodemographic characteristics, lifestyle behaviors and health conditions.
Results: Of 3325 participants (Mean age: 66.7±5.7, males: 54.9%), 5.2% had MCRg and 5.4% MCRh. Based on Cox models, both MCR subtypes were associated with the increased risk of cognitive impairment, with adjusted hazard ratios (95% CI) of 1.821 (1.402 to 2.368) for MCRg and 2.008 (1.567 to 2.574) for MCRh.
Conclusion: Low HGS, which can be quickly measured and requires no additional space, may be considered as a promising motoric phenotype of MCR subtypes. This study preliminarily supports the potential utilization of the HGS-based MCR subtype for early risk identification of cognitive impairment in primary care settings.