The Impact of Sleep Position on Hypoglossal Nerve Stimulation Outcomes

Introduction: There is interest in understanding factors predicting success following hypoglossal nerve stimulation (HGNS) for obstructive sleep apnea; however, the role of sleep position is not well understood. We examine how predominant sleep position (supine versus non-supine) relates to patient factors and treatment outcomes following HGNS.

Methods: This is a retrospective, single-institution study of patients (n = 222) who underwent unilateral HGNS implantation from 2018 - 2024. Complete sociodemographic information, pre- and post-operative polysomnography data, DISE scores, anatomic factors, and titration studies were available for 185 patients. Predominant sleeping position was determined based on the position maintained for at least 50% of total sleep time. Primary outcomes of interest include treatment success and minimum effective stimulation voltage (mEV).

Results: Approximately 66% of patients were successfully treated based on modified Sher criteria (minimum of 50% reduction with a post-operative AHI less than 15). Supine-predominant sleepers showed no significant differences from non-supine sleepers in anatomic factors, DISE scores, likelihood of treatment success, or mEV. Pre-operative positional AHI was significantly higher among supine sleepers (38.6 versus 27.7, p = 0.004) despite comparable treatment success rates. Among patients with preserved predominant sleep position across both sleep studies, supine sleepers had a significant decrease in positional AHI (mean difference = 15.9, p < 0.001), but this effect was not observed for non-supine sleepers (mean difference = 5.67, p > 0.05) and was independent of treatment success.

Conclusions: Supine-predominant sleepers derived a greater reduction in positional AHI following HGNS implantation than non-supine sleepers; however, treatment success rates by modified Sher criteria were similar. These findings suggest that unilateral HGNS offers clinical benefit irrespective of predominant sleep position. Results may inform pre-operative counseling and strategies to optimize treatment efficacy.