Low-cost and fast-performing indicators of muscle mass loss are good predictors of clinical outcomes in hospitalized patients: A longitudinal observational study

Background: "Gold standard" methods for muscle mass (MM) assessment are expensive and difficult to use in clinical practice. The present study aimed to evaluate the association between easy-to-apply and low-cost indicators of MM and clinical outcomes in hospitalized patients.

Methods: In this cohort study, calf circumference [CC], adductor pollicis muscle thickness [APMT], midarm muscle circumference [MAMC], and arm muscle area [AMA] were measured within 48 h of admission to detect MM loss, and it was also evaluated by physical examination. Patients were followed up until discharge for collection of in-hospital death and length of hospital stay (LOS) data, and they were contacted by phone to assess hospital readmission and mortality at 6 months after discharge.

Results: We evaluated 601 patients (55.8 ± 14.8 years). Moderate/severe loss of MM (hazard ratio [HR], 4.12; 95% CI, 1.26-13.49), low CC (HR, 3.67; 95% CI: 1.07-12.55), low MAMC (HR, 5.20; 95% CI, 1.48-18.35), and low AMA (HR, 14.28; 95% CI, 1.80-113.14) were predictors of in-hospital mortality. Moderate/severe loss of MM was a predictor of prolonged LOS (odds ratio [OR], 2.27; 95% CI, 1.53-3.36), hospital readmission (OR, 4.14; 95% CI, 1.26-13.55), and mortality at 6 months (OR, 3.20; 95% CI, 1.71-6.01). Low CC (OR, 2.49; 95% CI, 1.27-4.85) and low APMT (OR, 3.22; 95% CI, 1.56-6.66) were associated with death 6 months after discharge.

Conclusion: Easy-to-apply and low-cost indicators of MM were associated with negative clinical outcomes and should be part of nutrition assessment in hospitals.