The Impact of Obesity on Crohnʼs Disease Outcomes: A Nationwide Analysis

Abstract

Introduction: Obesity is associated with worse outcomes in various medical conditions. Smaller studies have suggested a negative impact on perioperative mortality in patients with Crohn's disease (CD). However, since the overall impact of obesity on CD outcomes has not been explored at a national level, it became the aim of this study. Methods: This was a retrospective cohort study using the 2013 National Inpatient Sample, the largest publically available inpatient database in the US. All patients with a principal ICD-9 CM diagnosis code for CD were included in the study. There were no exclusion criteria. The primary outcome was in-hospital mortality. Secondary outcomes were morbidity measured by development of fistulae, bowel obstruction from strictures, ileus, need for colectomy, intensive care unit (ICU) admission, shock and multi-organ failure; resource utilization measured by balloon dilation, colonoscopy, abdominal CT scan, abdominal ultrasound (US), total parenteral nutrition (TPN) use, length of hospital stay (LOS) and total hospitalization charges. Patients were classified as non-obese or obese using ICD-9 CM codes. Using multivariate regression analysis, odds ratios and means were adjusted for presence of diabetes, age, sex, race, median income in the patient's zip code, Charlson Comorbidity Index, hospital region, urban location, size and teaching status. Results: 115,270 patients with CD were included in the study, 8,620 (7.5%) of whom were obese. Mean age was 45 years and 57% were female. The overall in-hospital mortality rate was 0.14% (0.3% in the obese subgroup). Table 1 shows all adjusted odds ratios, means and p-values. On multivariate analysis, obese patients did not have a significantly different odds of mortality (OR:2.17,95%CI:0.81-7.69,p=0.12) compared to the non-obese. Looking at morbidity, there was no difference between the two groups. Obese patients had higher odds of an abdominal CT scan and ultrasound, while similar odds of colonoscopy and bowel dilation when compared to the non-obese. Further, total charges were higher for obese patients, while LOS was similar between the two groups.Table 1: Adjusted Odds Ratios, Means and p-values for the evaluated parameters for patients with Crohn's disease who have obesity versus patients who do not have the diagnosis of obesity.Conclusion: Obesity in general is not associated with increased mortality in patients with Crohn's disease. However, obesity affects resource utilization to different degrees, as measured by increased odds of abdominal imaging use and total hospitalization charges. Obesity does not affect in-hospital morbidity in patients with Crohn's disease.