Circulating adipokine levels associate with COVID-19 severity in hospitalized patients

Purpose: Obesity is a risk factor for adverse outcomes in COVID-19, potentially driven by chronic inflammatory state due to dysregulated secretion of adipokines and cytokines. We investigated the association between plasma adipokines and COVID-19 severity, systemic inflammation, clinical parameters, and outcome of COVID-19 patients.
Methods: In this multi-centre prospective cross-sectional study, we collected blood samples and clinical data from COVID-19 patients. The severity of COVID-19 was classified as mild (no hospital admission), severe (ward admission), and critical (ICU admission). ICU non-COVID-19 patients were also included and plasma from healthy age, sex, and BMI-matched individuals obtained from Lifelines. Multi-analyte profiling of plasma adipokines (Leptin, Adiponectin, Resistin, Visfatin) and inflammatory markers (IL-6, TNF, IL-10) were determined using Luminex multiplex assays. 
Results: Between March and December 2020, 260 SARS-CoV-2 infected individuals (age: 65 [56-74] BMI 27.0 [24.4-30.6]) were included: 30 mild, 159 severe, and 71 critical patients. Circulating adipokine and inflammatory cytokine levels associated with COVID-19 severity, i.e., the need for hospitalization and admission to the ICU, but not mortality. Visfatin levels were higher in critical COVID-19 patients compared to non-COVID-ICU, mild and severe patients (4.7 vs 3.4, 3.0, and 3.72ng/mL respectively, p<0.05). Lower Adiponectin levels, but higher Resistin levels were found in severe and critical patients, compared to those that did not require hospitalization (3.65, 2.7 vs 7.9µg/mL, p<0.001, and 18.2, 22.0 vs 11.0ng/mL p<0.001). 
Conclusion: SARS-CoV-2 infection can induce adipose tissue dysfunction resulting in altered circulating adipokine levels in COVID-19 patients which appears to be more pronounced in critically ill patients.