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Background: Excess visceral fat (VF) or high body mass index (BMI) is risk factors for severe COVID-19. The receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is expressed at higher levels in the VF than in the subcutaneous fat (SCF) of obese patients. Aim: To show that visceral fat accumulation better predicts severity of COVID-19 outcome compared to either SCF amounts or BMI. Methods: We selected patients with symptomatic COVID-19 and a computed tomography (CT) scan. Severe COVID-19 was defined as requirement for mechanical ventilation or death. Fat depots were quantified on abdominal CT scan slices and the measurements were correlated with the clinical outcomes. ACE 2 mRNA levels were quantified in fat depots of a separate group of non-COVID-19 subjects using RT-qPCR. Results: Among 165 patients with a mean BMI of 26.1 ± 5.4 kg/m 2 , VF was associated with severe COVID-19 (p = 0.022) and SCF was not (p = 0.640). Subcutaneous fat was not different in patients with mild or severe COVID-19 and the SCF/VF ratio was lower in patients with severe COVID-19 (p = 0.010). The best predictive value for severe COVID-19 was found for a VF area ≥128.5 cm 2 (ROC curve), which was independently associated with COVID-19 severity (p < 0.001). In an exploratory analysis, ACE 2 mRNA positively correlated with BMI in VF but not in SCF of non-COVID-19 patients (r 2 = 0.27 vs 0.0008). Conclusion: Severe forms of COVID-19 are associated with high visceral adiposity in European adults. On the basis of an exploratory analysis ACE 2 in the visceral fat may be a trigger for the cytokine storm, and this needs to be clarified by future studies.

BackgroundPatients liberated from invasive mechanical ventilation are at risk of extubation failure, including inability to breathe without a tracheal tube (airway failure) or without mechanical ventilation (non-airway failure). We sought to identify respective risk factors for airway failure and non-airway failure following extubation.MethodsThe primary endpoint of this prospective, observational, multicenter study in 26 intensive care units was extubation failure, defined as need for reintubation within 48 h following extubation. A multinomial logistic regression model was used to identify risk factors for airway failure and non-airway failure.ResultsBetween 1 December 2013 and 1 May 2015, 1514 patients undergoing extubation were enrolled. The extubation-failure rate was 10.4% (157/1514), including 70/157 (45%) airway failures, 78/157 (50%) non-airway failures, and 9/157 (5%) mixed airway and non-airway failures. By multivariable analysis, risk factors for extubation failure were either common to airway failure and non-airway failure: intubation for coma (OR 4.979 (2.797–8.864), P < 0.0001 and OR 2.067 (1.217–3.510), P = 0.003, respectively, intubation for acute respiratory failure (OR 3.395 (1.877–6.138), P < 0.0001 and OR 2.067 (1.217–3.510), P = 0.007, respectively, absence of strong cough (OR 1.876 (1.047–3.362), P = 0.03 and OR 3.240 (1.786–5.879), P = 0.0001, respectively, or specific to each specific mechanism: female gender (OR 2.024 (1.187–3.450), P = 0.01), length of ventilation > 8 days (OR 1.956 (1.087–3.518), P = 0.025), copious secretions (OR 4.066 (2.268–7.292), P < 0.0001) were specific to airway failure, whereas non-obese status (OR 2.153 (1.052–4.408), P = 0.036) and sequential organ failure assessment (SOFA) score ≥ 8 (OR 1.848 (1.100–3.105), P = 0.02) were specific to non-airway failure. Both airway failure and non-airway failure were associated with ICU mortality (20% and 22%, respectively, as compared to 6% in patients with extubation success, P < 0.0001).ConclusionsSpecific risk factors have been identified, allowing us to distinguish between risk of airway failure and non-airway failure. The two conditions will be managed differently, both for prevention and curative strategies.Trial registrationClinicalTrials.gov, NCT 02450669. Registered on 21 May 2015. Electronic supplementary materialThe online version of this article (10.1186/s13054-018-2150-6) contains supplementary material, which is available to authorized users.