Effect of Body Mass Index on Long‐Term Outcomes After Endoscopic Sinus Surgery

OBJECTIVES: Whether body mass index (BMI) influences long-term clinical outcomes after endoscopic sinus surgery (ESS) for chronic rhinosinusitis (CRS) remains unclear. We investigated whether BMI is associated with baseline symptom severity, longitudinal postoperative symptom trajectories, and time to revision surgery or biologic use. METHODS: ), overweight (25.0-29.9), and obese (≥ 30.0). Outcomes were baseline 22-item Sinonasal Outcome Test (SNOT-22) scores, longitudinal SNOT-22 trajectories analyzed via multivariable linear mixed-effects models, and time to revision surgery or biologic use via multivariable Cox regression. RESULTS: Among 664 patients, 35.4% were normal weight, 35.5% overweight, and 29.1% obese. Obese patients had significantly higher baseline SNOT-22 scores (β, 6.70; 95% CI, 2.56-10.85). A significant BMI-by-time interaction (p = 0.033) revealed that obese patients' symptoms worsened at a greater rate over time, increasing by 0.82 points per year versus normal-weight patients. Elevated BMI predicted higher revision surgery risk (hazard ratio [HR], 2.41; 95% CI, 1.11-5.22), particularly in patients with nasal polyps (HR, 5.30; 95% CI, 1.45-19.35). Preoperative BMI was not associated with subsequent biologic use (HR, 1.67; 95% CI, 0.64-4.36). CONCLUSION: Elevated BMI was associated with worse baseline symptoms, progressive postoperative symptom deterioration, and increased revision risk. Although baseline SNOT-22 differences were below the minimal clinically important difference (MCID), cumulative longitudinal divergence exceeded the MCID by year 3, indicating that BMI should inform preoperative counseling and postoperative monitoring.