Mediating effect of lower extremity muscle strength on the relationship between mobility and cognitive function in Chinese older adults: A cross-sectional study

Abstract

Aging is a multifactorial process associated with irreversible decline in mobility and cognitive function. However, the mechanisms underlying the relationship between mobility and cognitive function remain elusive. In specific, the mediating effect of muscle strength, which is essential to maintain mobility, on this relationship has yet to be clarified. Accordingly, we performed a cross-sectional study involving Chinese older adults to understand the role of muscle strength in the relationship between mobility and cognitive function. The cognitive function and physical performance of 657 community-dwelling participants aged over 65 years old were observed. Cognitive function was assessed using the Mini-Mental State Examination, whereas physical performance, including mobility and muscle strength, was measured via Timed Up-and-Go Test and knee extension strength measurement. Data were statistically analyzed using PROCESS Model 4 developed by Hayes, and 595 complete data were finally included. Physical performance (mobility and muscle strength) was significantly correlated with cognitive function (p < 0.01). Muscle strength was negatively correlated with mobility (r = −0.273, p < 0.001) and positively correlated with cognitive function (r = 0.145, p < 0.001). Muscle strength accounted for 20.1% of the total mediating effects on the relationship between mobility and cognitive function, which revealed the partial mediating role of lower extremity muscle strength in this relationship.

Sarcopenia in subjects with Alzheimer’s disease: prevalence and comparison of agreement between EGWSOP1, EGWSOP2, and FNIH criteria

“…Concerning the single-dimensional aspects of sarcopenia (i.e., reduced muscle mass and muscle strength), we did not find significant differences in the muscle mass metrics considered by sarcopenia diagnostic criteria (i.e., SMI, ASM and ASM/height 2 ) between AD patients and controls. Conversely, handgrip strength was significantly lower in AD patients compared to controls, consistent with findings from previous studies [19,27]. Finally, we found that the MQI was lower in AD patients than in controls but showed poor diagnostic accuracy (AUC ranging between 0.35 and 0.53) in identifying sarcopenia cases, regardless of the diagnostic criteria adopted.…”