Low muscle mass and high visceral fat mass predict mortality in patients hospitalized with moderate-to-severe COVID-19: a prospective study.

The severity of coronavirus disease 2019 (COVID-19) has been positively correlated with several comorbidities. The primary outcome of the study was to assess the relationship between the mortality and severity of COVID-19 and obesity classes according to BMI, visceral adipose tissue (VAT) area, s.c. adipose tissue area, muscle area (MA), and leptin levels. In this prospective cohort study, 200 patients hospitalized with moderate-to-severe COVID-19 underwent an unenhanced CT of the thorax and laboratory tests, and leptin levels between June and August 2020 were obtained. Our study included 200 patients (male 52%; mean age: 62 (49-74) years; obesity (BMI > 30): 51.5%)). Fifty-eight patients (23.5%) were admitted to the intensive care unit and 29 (14.5%) died. In multivariate logistic regression (corrected for leptin, sex, age, and serum biomarkers) and receiver operating characteristic curve analyses, high VAT > 150 cm2 (odds ratio (OR): 6.15; P < 0.002), MA < 92 cm2 (OR: 7.94; P < 0.005), and VAT/MA ratio > 2 (OR: 13.9; P < 0.0001) were independent risk factors for mortality. Indeed, the Kaplan-Meier curves showed that patients with MA < 92 cm2 and without obesity (BMI < 30) had a lower survival rate (hazard ratio between 3.89 and 9.66; P < 0.0006) than the other groups. Leptin levels were not related to mortality and severity. This prospective study reports data on the largest number of hospitalized severe COVID-19 patients and pinpoints VAT area and MA calculated by CT as predictors of COVID-19 mortality.