Bridging Pain and Motoric Cognitive Risk Syndrome: Mediating Effect of Handgrip Strength.

Abstract

Background: Motoric cognitive risk syndrome (MCR) is a preclinical stage of dementia that strongly predicts future cognitive deterioration and dementia development. Although research has advanced in exploring MCR's epidemiological aspects, the association between pain, handgrip strength (HGS), and MCR remain insufficiently studied.

Methods: This cross-sectional study analyzed baseline data from the 2015 China Health and Retirement Longitudinal Study (CHARLS), restricted to participants aged ≥45 years. MCR cases were identified through self-reported cognitive complaints combined with objectively measured gait slowing, excluding subjects with existing dementia. Using multivariable-adjusted logistic regression, we investigated associations between chronic pain, HGS, and MCR prevalence. Mediation analysis further assessed whether HGS mediated the pain-MCR relationship. Stratified analyses evaluated effect modification across key demographic strata.

Results: This research encompassed a cohort of 4,795 individuals, displaying an average age of 67.3 ± 6.5 years, comprising 4,648 non-MCR and 147 MCR individuals. In the non-MCR group, 70.3% had no pain, 4.8% had one pain, and 25.3% had two or more pains. In the MCR group, 51% had no pain, 10.2% had one pain, and 38.8% had two or more pains (p < 0.001). The mean HGS was 29.1kg ± 9.0kg in the non-MCR group, significantly higher than the MCR group's 21.7kg ± 8.4kg (p < 0.001). Pain was positively associated with MCR, increasing its likelihood by 1.9 times per unit increase (OR = 1.90, 95% CI: 1.29-2.80, p = 0.001). Conversely, HGS was negatively associated, reducing MCR likelihood by 9% per unit increase (OR = 0.91, 95% CI: 0.88-0.93, p < 0.001). HGS's indirect effect on the pain-MCR link was 2.58×10^-3 (p < 0.001), explaining 24.87% of the total effect variation.

Conclusion: The study found that pain is positively associated with MCR, while HGS is negatively associated with MCR, and HGS mediates the relationship between pain and MCR.