A clinical staging system incorporating neck circumference, body mass index, baseline apnea-hypopnea index, and comorbidity burden may help stratify response to hypoglossal nerve stimulation among patients with obstructive sleep apnea, according to a retrospective cohort study.
The study included 119 patients with obstructive sleep apnea who underwent hypoglossal nerve stimulation implantation at Washington University in St Louis between April 2019 and October 2023 and completed a postimplant sleep study. Response was defined using modified Sher criteria: more than 50% reduction in apnea-hypopnea index (AHI) and a postimplant AHI below 15.
Overall, 83 patients, or 69.7%, met response criteria. Median AHI decreased from 30.7 before implantation to 6.9 after implantation, a median difference of −20.65 events per hour (95% CI, −24.50 to −17.45).
Four baseline factors were associated with response: smaller sex-specific neck circumference, BMI below 30, preimplant AHI below 30, and absence of comorbidities. Small neck circumference was defined as 14 inches or less for women and 16 inches or less for men. Patients with AHI below 30 were 17.7 percentage points more likely to respond than those with higher values, and patients without comorbidities were 17.4 percentage points more likely to respond than those with at least one comorbidity.
Comorbidity burden was treated as a binary variable encompassing hypertension, diabetes, congestive heart failure, stroke or transient ischemic attack, and ischemic heart disease, without weighting individual conditions.
Using conjunctive consolidation, the investigators developed a four-category clinical severity staging system. The highest-response group included patients with small neck circumference, BMI below 30, and AHI below 30, regardless of comorbidity status; 10 of 11 patients in this group responded, for a response rate of 90.9%. However, the subgroup included only 11 patients, limiting precision around that estimate — a single additional nonresponder would have dropped the rate to 82%.
The lowest-response group included patients with large neck circumference, BMI of 30 or higher, AHI of 30 or higher, and at least one comorbidity; 6 of 16 patients responded, for a response rate of 37.5%.
The staging system demonstrated moderate discrimination, with a C statistic of 0.68, better than chance but well short of the 0.80 threshold commonly associated with strong predictive performance. The response gradient increased from 22.5 percentage points in the model using neck circumference and BMI alone to 53.4 percentage points in the final model incorporating neck circumference, BMI, AHI, and comorbidities.
Drug-induced sleep endoscopy findings were analyzed but were not independently associated with response in the final model, despite prior literature suggesting some endoscopic features may predict hypoglossal nerve stimulation outcomes.
The authors cautioned that the findings require validation in an independent cohort. The study was retrospective and single-center, and 75 of 194 implanted patients, or 38.7%, were excluded because they had not yet completed postimplant sleep testing at the time of data collection. Because many excluded patients underwent more recent implantation, the findings may not fully reflect outcomes under evolving implantation and titration practices.
The cohort was predominantly male and White, with women comprising 30.3% of participants and White patients 92.4%, potentially limiting generalizability to more diverse populations. Patient-reported outcomes, including Epworth Sleepiness Scale scores, were not assessed, and BMI was measured only at baseline.
These variables may be used to divide patients into discrete prognostic categories, the authors wrote. While being in the group with the worst response rate does not necessarily mean the patient should not receive an HGNS, it may allow physicians to better counsel patients on their chance of response.
The article was corrected online April 16, 2026, after the authors clarified that FDA materials do not identify BMI greater than 40 as a formal contraindication to hypoglossal nerve stimulation implantation, but instead state that safety and effectiveness in that population have not been adequately studied.
Disclosures: Ji reported National Institutes of Health funding during the study. Jackson reported honoraria from Intuitive outside the submitted work. Kallogjeri reported payments from Washington University in St Louis related to licensing of the NOSE HHT instrument. Piccirillo reported grants from the National Center for Advancing Translational Sciences and royalty payments related to licensed instruments outside the submitted work. The study was supported by the National Center for Advancing Translational Sciences of the National Institutes of Health.
Source: JAMA Otolaryngology–Head & Neck Surgery