The Association Between Low Body-Mass Index and Serious Post-endoscopic Adverse Events.

Background: Low body mass index (LBMI) was associated with longer colonoscopy procedure time and procedural failure, and commonly considered to be a risk factor for post-endoscopic adverse events, but evidence is lacking.

Aim: We aimed to assess the association between serious adverse events (SAE) and LBMI.

Methods: A single center retrospective cohort of patients with LBMI (BMI ≤ 18.5) undergoing an endoscopic procedure was matched (1:2 ratio) to a comparator group (19 ≤ BMI ≤ 30). Matching was performed according to age, gender, inflammatory bowel disease or malignancy diagnoses, previous abdomino-pelvic surgery, anticoagulation therapy and type of endoscopic procedure. The primary outcome was SAE, defined as bleeding, perforation, aspiration or infection, following the procedure. The attribution between each SAE and the endoscopic procedure was determined. Secondary outcomes included each complication alone and endoscopy-attributed SAEs. Univariate and multivariate analyses were applied.

Results: 1986 patients were included (662 in the LBMI group). Baseline characteristics were mostly similar between the groups. The primary outcome occurred in 31/662 (4.7%) patients in the LBMI group and in 41/1324 (3.1%) patients in the comparator group (p = 0.098). Among the secondary outcomes, infections (2.1% vs. 0.8%, p = 0.016) occurred more frequently in the LBMI group. Multivariate analysis revealed an association between SAE and LBMI (OR 1.76, 95% CI 1.07-2.87), male gender, diagnosis of malignancy, high-risk endoscopic procedure, age > 40 years, and ambulatory setting.

Conclusion: Low BMI was associated with higher post-endoscopic serious adverse events. Special attention is required when performing endoscopy in this fragile patient population.