Background: Coronavirus disease 2019 (COVID-19) has affected millions of people worldwide with worse outcomes demonstrated in those with certain co-morbid conditions such as diabetes and cardiovascular disease. The Rio Grande Valley (RGV), a four-county region along the Texas-Mexico border has been disproportionately affected by the pandemic. The case fatality ratio in the RGV from COVID-19 is 4.45%, compared with 1.77% and 2.01% in Texas and the United States, respectively. Additionally, the RGV has one of the highest rates of obesity in the country at 37%, which when combined with health disparities such as high prevalence of uninsured and undocumented residents likely contributes to the high mortality rate. The goal of the study is to evaluate if obesity affects outcomes in patients that were hospitalized for COVID-19.
Methods: A retrospective study at a university-affiliated hospital located in Cameron County was conducted on 814 COVID-19 positive patients admitted between 3/19/20 and 9/15/20. COVID-19 was diagnosed using antigen and polymerase chain reaction, in concordance with World Health Organization standards. Patients admitted and discharged within 24 hours were excluded from our study. Patient’s BMI were stratified based on obesity classification as delineated in Centers for Disease Control and Prevention guidelines. Patient outcomes of this study include total length of hospitalization, need for endotracheal intubation, and in-hospital death.
Results: Of the 814 COVID-19 positive patients in our dataset, 104 patients were categorized as normal weight (BMI 18.5-24.9), 255 as overweight (BMI 25-29.9), 206 as obesity class I (BMI 30-34.5), 114 patients as obesity class II (BMI 35-39.9), and 135 patients as obesity class III (BMI ≥ 40). When compared with patients in the normal BMI category, patients with increased BMI >25 had a relative risk (RR) of 1.577 (p = 0.048; 95% CI: [1.041-2.710]) of in-hospital mortality. Further statistical analysis demonstrated that when compared to patients of normal BMI, patients who were overweight or had obesity class I had RR of 1.679 (p=0.034; 95% CI: [1.041-2.710]) and 1.693 (p=0.034; 95% CI: [1.039-2.757]) for in-hospital death, respectively. When compared to the normal BMI category, patients in the obesity class I category had RR of 1.803 (p=0.034; 95% CI: [1.047-3.106]) of being intubated and RR of 1.903 (p=0.025; 95% CI: [1.082-3.345]) of being put on mechanical ventilation. Further statistical analysis with adjustment for age, race, and obesity-related comorbidities is currently in process.
Conclusions: Our preliminary data demonstrates a significant increase in relative risk of mortality and intubation in obese patients. Obesity is associated with hypertension and diabetes, both of which have been linked with worse COVID-19 outcomes. The molecular interactions of SARS-CoV-2 virus with host cells lead to endothelial damage and cytokine release. In patients with obesity, these pro-inflammatory states are already present, which can lead to physiologic disadvantages in mounting an adequate immune response against the virus. More analysis will be performed to evaluate other factors that may further potentiate the effects of obesity on COVID-19 outcomes.