Hospitalization for COVID-19 is associated with significant changes in body composition

COVID-19 is a severe viral infection of the respiratory tract and has become a worldwide pandemic. Months after the initial infection several people report persistent limitations in daily life. Previous studies have identified body composition as a predictor of clinical progression in cases of COVID-19. However, body impedance measurements were limited to baseline and not repeated in serial measurements. In this study we analyzed the impact of a moderate oxygen-dependent COVID-19 infection on body composition during hospitalization.

We enrolled 12 consecutive patients hospitalized due to an oxygen-dependent SARS-CoV-2 infection. Body impedance analysis was performed within 24 h of admission and repeated on day 3 ± 1 as well as on the day of discharge. Endpoints were any significant changes in body composition.

Median age of enrolled patients was 70.6 years with a BMI of 30.8 kg/m². Patients were hospitalized for 14 days. Median oxygen demand was 3 l/min, 2 patients required mechanical ventilation. Body water and fat remained unchanged during the study period. We observed a significant decrease of phase angle (-0.6, p < 0.01) and body cell mass (-2.3%, p < 0.01) with an increase in extracellular mass on day 3. Values returned to baseline along recovery.

We found a significant reduction in body cell mass and phase angle during the active infection with slow regression towards hospital discharge. Future studies are needed to clarify if nutrition and training programs during and after COVID-19 might limit these changes and have a positive impact on clinical course and rehabilitation.