Metabolic Improvements Following Upper Airway Surgery in Obstructive Sleep Apnea: Association of Airway Improvement with Insulin Resistance

Background: Obstructive sleep apnea (OSA) is increasingly recognized as a systemic disorder associated with insulin resistance and elevated risk of type 2 diabetes. While continuous positive airway pressure (CPAP) is the standard therapy, its long-term metabolic benefits remain inconsistent. The metabolic impact of upper airway surgery is less well defined. Methods: In this retrospective study, 49 patients with polysomnography-confirmed OSA who underwent upper airway surgery were evaluated. Respiratory and metabolic parameters—including apnea–hypopnea index (AHI), fasting plasma glucose, fasting insulin, glycated hemoglobin (HbA1c), and homeostatic model assessment for insulin resistance (HOMA-IR)—were assessed preoperatively and at 6 months postoperatively. Associations between changes in AHI (ΔAHI) and insulin resistance (ΔHOMA-IR) were analyzed using correlation and receiver operating characteristic (ROC) analyses. Results: Significant improvements were observed in both respiratory and metabolic parameters. AHI decreased from 46.6 ± 25.8 to 20.7 ± 14.1 events/h (p < 0.001). Fasting plasma glucose, insulin levels, and HOMA-IR were significantly reduced postoperatively (all p < 0.05), while HbA1c showed a downward trend. Reduction in AHI was moderately correlated with improvement in insulin resistance (r = 0.527, p < 0.001). ROC analysis demonstrated modest discriminative ability of ΔAHI for identifying normalization of insulin resistance (AUC = 0.62). Conclusions: Upper airway surgery was associated with significant improvements in insulin resistance and glycemic parameters in patients with OSA. The correlation between airway improvement and metabolic change supports a physiological link between upper airway obstruction and insulin sensitivity. These findings suggest that upper airway surgery may represent a clinically relevant adjunct within multimodal strategies for metabolic risk reduction, particularly in patients unable to tolerate CPAP therapy.