ABSTRACT
Background: Chronic low-grade inflammation associated with a dysregulated adipose tissue might contribute to amplifying the inflammatory response in severe COVID-19. The aim of this study was to examine the association between levels of circulating leptin and adiponectin and the severity and mortality of COVID-19. Methods: Serum levels of leptin and adiponectin were determined at admission in 123 individuals with confirmed COVID-19 and their association with 90-day mortality and respiratory failure was analyzed by logistic regression analysis and expressed as odds ratios (ORs) with 95% confidence intervals (CIs). Results: The median values of circulating leptin and adiponectin were 7.2 ng/mL (IQR 3.8-13.4) and 9.0 µg/mL (IQR 5.7-14.6), respectively. After adjustment for age, sex, body mass index, hypertension, diabetes, chronic obstructive pulmonary disease, and oxygen saturation at admission, a doubling of circulating adiponectin was associated with a 38% reduction in odds of 90-day mortality (OR 0.62, CI 0.43-0.89) and a 40% reduction in odds of respiratory failure (OR 0.60, CI 0.42-0.86). The association tended to be strongest in individuals below the median age of 72 years. Circulating leptin was not associated with outcomes. Conclusions: Circulating adiponectin at admission was inversely associated with mortality and respiratory failure in SARS-CoV-2 infection. Further studies are needed to elucidate how exactly adipokines, especially adiponectin, are linked to the progression and prognosis of COVID-19.