What's weight got to do with it? In-hospital outcomes in colorectal cancer patients with and without obesity: An NIS analysis.

e15667 Background: Obesity is a significant risk factor for various cancers, including colorectal cancer (CRC), the most common gastrointestinal malignancy in the United States. However, the impact of obesity on in-hospital outcomes for patients admitted with CRC remains insufficiently understood. This study aimed to assess the association of obesity with in-hospital mortality, length of stay (LOS), hospitalization costs, and related complications among hospitalized CRC patients. Methods: We analyzed data from the National Inpatient Sample (NIS) database between 2016 and 2021. Hospitalized adults with a primary diagnosis of CRC were identified using ICD-10 codes, excluding those with metastatic disease. Patients were stratified into two groups based on the presence or absence of obesity. Primary outcomes included in-hospital mortality, while secondary outcomes were LOS, total hospital charges (THC), and complications such as acute kidney injury (AKI), sepsis, and venous thromboembolism (VTE). Multivariable regression analyses, adjusted for demographics and clinical characteristics were conducted. Results: There was a total of 736,485 CRC hospitalizations of which 117,515 (15.9%) had obesity. Obese admissions with CRC had younger mean age (68.4 vs 66.7 years; p < 0.001), higher proportion of females (50.1% vs. 46.7%, p < 0.001) and non-Hispanic Whites (71.0% vs. 69.1%, p < 0.001). Clinically, CRC admissions with obesity had higher frequency of acute kidney injury and severe sepsis. On multivariable logistic regression, obesity was associated with a 39% decrease in in-hospital mortality (aOR 0.61; 95% CI: 0.55–0.69; p < 0.001) compared to non-obese CRC patients. Male gender, Black race, and higher Charlson comorbidity index were independent predictors of increased in-hospital mortality among obese CRC hospitalizations. Obese CRC admission had lower odd of prolong LOS (β-coefficient: 0.53; 95% CI: -0.42 to -0.63; p < 0.001) but higher odds of increased THC (β-coefficient: +$13,978; 95% CI: $12,388–$15,569; p < 0.001). Conclusions: Obesity was associated with paradoxical protective effects, including lower in-hospital mortality and shorter LOS, among hospitalized CRC patients. However, it also contributed to increased healthcare costs and a greater likelihood of complications such as AKI and sepsis. These findings underscore the complex relationship between obesity and CRC outcomes and highlight the need for tailored clinical and resource management strategies to optimize care for this patient population.