Upper airway stimulation for obstructive sleep apnea: Treatment outcomes by sleep position and sex

Obstructive sleep apnea (OSA) severity varies by sleep position and sex; however, it is unknown whether these factors affect hypoglossal nerve stimulation (HGNS) treatment effectiveness. Thus, this study evaluates HGNS control of OSA by sleep position and sex. To enhance real-world clinical applicability of results and address concerns regarding appropriate postoperative sleep study criteria to evaluate HGNS outcomes, our study also proposes and utilizes a standardized HGNS titration study scoring protocol to assess apnea-hypopnea index (AHI). A retrospective cohort of adult patients underwent device implantation at a tertiary care center between January 2018 and June 2021. Outcome measures included response rate by sleep position and sex using Sher criteria (reduction of AHI ≥50% to < 20/hr) and AHI normalization (<5/hr). Of 181 patients implanted, 113 patients met inclusion criteria. Patients were primarily older (median 65.0 years), overweight (BMI 30.0), white (91.2%) males (67.3%) with severe OSA (AHI 32.0/hr). HGNS success by Sher criteria and AHI normalization were 77.0% and 54.1%, respectively, in lateral sleep compared to 52.9% and 23.5% in supine sleep. Females attained a greater supine AHI reduction (p < 0.04, Wilcoxon rank-sum test) and success by both response criteria (both p < 0.03, chi-square tests of independence). Subgroup analyses using fixed-voltage home sleep apnea tests were underpowered and limited by low counts. Thus, HGNS more effectively controlled OSA in lateral sleep and for females, suggesting clinically meaningful differences by sleep position and sex that may help inform clinical decision making for patients with similar demographics.