Effect of obesity on postoperative complications in ulcerative colitis: A systematic review and meta-analysis

Abstract

Background

The prevalence of ulcerative colitis (UC) is around 200/100 000 people. Colectomy is required in 7.5%–40% of patients and 58.8%–94% of these operations are elective. Approximately one in two adults with UC are overweight or obese.

Objective

Our aim was to compare postoperative complications between obese (defined by a body mass index (BMI) over 30 kg/m²) and non-obese UC patients who underwent total proctocolectomy with ileal pouch-anal anastomosis (IPAA).

Methods

Our preregistered protocol can be found on PROSPERO (CRD42022377761). We conducted our search in three databases on the 26th of November 2022. PRISMA 2020 guideline and the Cochrane Handbook were applied. We used the GRADEpro program and the QUIPS tool. We applied a random-effects model to pool effect sizes. We included cohort and case–control studies investigating UC patients undergoing colectomy with IPAA and reported information on postoperative complications in obese and non-obese patients. We used mean difference (MD) for continuous variables and calculated odds ratio (OR) with a 95% confidence interval (CI) for dichotomous variables.

Results

Of the 6870 hits of our systematic search, we included three retrospective cohort studies for analyses involving 4929 patients in our research. Neither the incidence of complications at 30 days after surgery [OR = 1.08; CI: 0.65–1.79] nor the incidence of septic complications [OR = 1.11; CI: 0.85–1.46] had any clinical relevance, except for the length of hospital stay [MD = 0.36; CI:0.04–0.69]. When we assessed the risk of bias, we found that most of the aspects examined had a moderate overall risk. Our results have very low certainty of evidence.

Conclusions and Relevance

Our findings suggest that obesity defined as BMI over 30 kg/m² may not associated with an increased risk of higher rates of overall postoperative complications compared to non-obese patients. Obesity with a cut-off value of 30 kg/m² does not appear to be a primary reason for prehabilitation.