The impact of obesity on COVID-19 outcomes in hospitalized patients

Background: Obesity is recognized as a risk factor for adverse outcomes in patients with COVID-19. However, a number of studies, including an analysis of the Federal Registry of Diabetic Patients (Russian Federation), have not identified any significant effect of obesity on mortality in COVID-19. Therefore, the role of obesity, assessed by body mass index (BMI) and waist circumference (WC), as a risk factor for an unfavorable course of coronavirus infection remains disputable. Aim: To assess the impact of obesity on the severity and outcomes of coronavirus infection in the Russian population of hospitalized patients. Materials and methods: This was a single center, retrospective, observational study in 367 patients with the polymerase chain reaction (PCR)-confirmed diagnosis of COVID-19 hospitalized to the in-patient department from April 2020 to November 2021. The first group included 185 patients with obesity (BMI 30.0 kg/m2); the second group consisted of 182 patients without obesity (BMI 30.0 kg/m2). Prevalence of comorbidities, clinical and laboratory parameters, and computed tomography results were assessed in both groups. WC was measured in 100 patients. Results: In this Russian population of hospitalized patients with COVID-19, obesity (BMI 30.0 kg/m2) didn't increase the probability of death both in the general sample (odds ratio (OR) = 1.31; 95% confidence interval (CI) 0.901.92, p = 0.164) and in the patients with type 2 diabetes (OR = 1.0; 95% CI 0.591.7, p = 0.997) or without diabetes (OR = 1.3; 95% CI 0.712.39, p = 0.392). However, obesity was associated with a 1,7-fold increase of the risk of severe COVID-19 (95% CI 1.132.59, p = 0.010). Morbid and abdominal obesity (according to World Health Organization and International Diabetes Federation criteria) had no significant impact on the death rate. WC of 101 cm, regardless of the patients gender, was associated with a 4,9-fold increase of the risk of death (95% CI 1.4516.42, p = 0.012). Conclusion: Obesity didnt show any significant effect on mortality, but increased the chance of severe course of COVID-19 infection. Abdominal obesity (WC 101 cm) was a more significant factor in predicting of a fatal outcome, than BMI.