The outcomes of the obesity paradox in pulmonary embolism: a study of the national inpatient sample database from 2016 to 2020

The "obesity paradox" suggests that, despite a higher baseline risk for adverse health outcomes, obese patients can experience a lower complication and mortality rate in conditions such as pulmonary embolisms (PE). This study aims to examine the association between obesity and inpatient outcomes of PE patients, utilizing the data from the National Inpatient Sample (NIS) database. We conducted a retrospective study analysis of obese adult PE patients (aged ≥ 18) using the NIS database from 2016 to 2020. Patients were categorized as either obese (body mass index (BMI) ≥ 30) or non-obese, excluding those with cancer diagnosis and age > 75 years to reduce confounding factors. Multivariable logistic regression, adjusted for confounders, compared the inpatient outcomes, including mortality, length of stay, need for mechanical invasive ventilation (MIV), incidence of shock requiring vasopressor use and use of reperfusion therapies. Our results showed obese patients had a lower in-hospital mortality and reduced risk for certain adverse outcomes when compared to non-obese patients. Limitations in our data, such as the lack of imaging confirmation and inability to track certain risk indicators in real time, affected precision in outcome severity classification. Our findings support the existence of an obesity paradox, particularly in PE patients, with obese patients experiencing better inpatient outcomes relative to their non-obese counterparts. This study advances the understanding of obesity's complex role in PE outcomes. However, further research is needed to further elucidate potential protective mechanisms to address our study limitations.