Muscle strength is associated with COVID-19 hospitalization in adults 50 years of age and older

Background. Muscle strength has been associated with a wide range of health outcomes. Yet, whether individuals with weaker strength are more at risk for severe COVID-19 is still unclear. The objective of this study was to investigate the independent association between muscle strength and COVID-19 hospitalization. Methods. Data from 3600 adults 50 years of age and older were analyzed using logistic models adjusted for several chronic conditions, body mass index, age, and sex. Hand grip strength was repeatedly measured between 2004 and 2017 using a handheld dynamometer. COVID-19 hospitalization during the lockdown was self-reported in summer 2020 and was used an indicator of COVID-19 severity. Results. Results showed that higher grip strength was associated with a lower risk of COVID-19 hospitalization (adjusted odds ratio [OR] per increase of 1 SD in grip strength = .64, 95% confidence interval [95% CI] = .45-.87, p = .015). Results also showed that age (OR for a 10-year period = 1.70, 95% CI = 1.32-2.20, p < .001) and obesity (OR = 2.01, 95% CI = 1.00-3.69, p = .025) was associated with higher risk of COVID-19 hospitalization. Sensitivity analyses using different measures of grip strength and robustness analyses based on rare-events logistic regression and COVID-19 patients were consistent with the main results. Conclusions. Muscle strength is an independent risk factor for COVID-19 severity in adults 50 years of age and older.