Related factors for skeletal muscle mass loss in patients before hip and knee replacement: analysis on 267 cases

Objective To investigate the incidence of preoperative skeletal muscle mass (SM) loss and related influencing factors in patients with hip or knee replacement. Methods A cross-sectional survey was performed on 267 patients who planned to undergo hip or knee replacement for first time from August 2020 to June 2021 in Army Medical Center. The demographic data, disease history and laboratory indicators were collected. Nutritional risk screening 2002 (NRS2002) scale was used to assess nutritional status, and chair test, 3-m reentry test and 6-min walking test were employed to evaluate lower extremity muscle strength and joint functional mobility. According to the screening criteria for bioelectrical impedance analysis (BIA) recommended by 2019 Consensus of Asian Working Group for Sarcopenia, the patients were divided into muscle mass reduction group (n=94) and normal muscle mass group (n=173). The related factors of muscle mass loss were analyzed. Results The detection rate of muscle mass loss was 35.21%. Statistical significances were seen in lower extremity joint function performance between the 2 groups by 3-m reentry test (Z=-4.744, P < 0.001) and 6-min walking test (Z=-4.889, P < 0.001). There were significant differences in age, BMI, results of nutritional risk screening, usage of walking aid, lymphocyte count, and levels of hemoglobin, serum albumin, serum prealbumin, and C-reactive protein between the 2 groups (P < 0.05). Multivariate logistic regression analysis showed that BMI (OR=0.640, 95%CI: 0.557~0.734) was an independent protective factor for muscle mass loss, and age (OR=1.093, 95%CI: 1.057~1.132) and usage of walking aid (OR=2.956, 95%CI: 1.179~7.410) were risk factors. Multiple linear regression analysis indicated that the influencing factors of muscle mass were sex (muscle mass of men larger than that of women, β=0.846, P < 0.001), age (β=-0.245, P < 0.001), history of smoking (β=-0.170, P=0.024), and hemoglobin (β=0.149, P=0.017), and age and smoking were negatively and hemoglobin was positively correlated with muscle mass. Conclusion Loss of muscle mass is more common in patients who choose hip or knee arthroplasty. Age, BMI, and use of walking aids may be related to the occurrence of muscle mass loss in them, and gender, age, and hemoglobin content may be used as predictors of preoperative skeletal muscle mass.