Muscle strength performed better than muscle mass in identifying cognitive impairment risk in maintenance hemodialysis patients

Objectives The association between muscle mass and cognitive impairment (CI) is conflicting. We aimed to evaluate and compare the associations of muscle strength, muscle mass and CI risk in maintenance hemodialysis (MHD) patients. Methods We conducted a multicenter, cross-sectional study. Cognitive function was assessed with the Mini-Mental State Examination (MMSE) score. Muscle strength was assessed by hand grip strength (HGS), muscle mass was assessed by lean tissue mass (LTM). Education status was divided into two groups: lower education status (senior middle school and below) and higher education status (high school and above). Multivariable logistic regression models and subgroup analyses were performed. Receiver-operating characteristic (ROC) analyses were conducted to compare their predictive power in discriminating CI. Results 2827 adult MHD patients were included in our final analysis. Patients in the lowest quartile of HGS was 2.82-fold as likely to have CI as compared to those in the highest quartile, while participants in the lowest quartile of LTM group were 1.52-fold as likely to have CI, when compared with the highest quartile group of LTM after adjusting for age, gender and education level. The association persisted in all subgroups except for women and well-educated participants. There was a significant interaction between HGS and education status on CI and age played an interactive role in the association between LTM and incident CI (P for interaction < 0.05). The AUC value of the HGS was significantly higher than that of LTM (0.69 VS 0.63, P < 0.001). Conclusions Muscle strength performed better than muscle mass in identifying individuals at high risk of CI, particularly in male and less educated Chinese MHD patients.