Long-Term Systemic Outcomes Following Hypoglossal Nerve Stimulation for Obstructive Sleep Apnea: Systematic Review and Meta-Analysis

Introduction: Hypoglossal nerve stimulation (HNS) has emerged as an alternative therapy for patients with moderate to severe obstructive sleep apnea (OSA) who cannot tolerate continuous positive airway pressure (CPAP). Although HNS’s efficacy in reducing apnea-hypopnea index (AHI) and improving quality of life is established, its long-term impact on systemic health outcomes has not been comprehensively evaluated. Our objective is to systematically review and meta-analyze existing evidence on the long-term systemic health outcomes of HNS in adults with OSA.

Methods: A systematic search was conducted in five databases (PubMed, EMBASE, CENTRAL, Scopus, Web of Science) from inception to October 22, 2024. Eligible studies reported on long-term systemic outcomes of HNS, including cardiovascular, metabolic, and mental health measures. Two reviewers independently screened and extracted data. Meta-analyses of systolic (SBP) and diastolic (DBP) blood pressure changes were performed using random-effects models.

Results: Eleven studies met inclusion criteria. HNS consistently reduced AHI into the mild range and improved patient-reported outcomes (Epworth Sleepiness Scale, Functional Outcomes of Sleep Questionnaire). Four studies contributing to meta-analysis revealed a significant pooled reduction in SBP (mean difference: −5.12 mmHg; 95% CI, −10.89 to −1.45), with high heterogeneity (I²=85%), while DBP reduction was not statistically significant. Limited evidence also suggests potential benefits in mental health and glucose metabolism, although findings were inconsistent.

Conclusions: HNS for OSA appears to confer systemic health benefits, particularly in reducing systolic blood pressure. Preliminary evidence also indicates positive effects on metabolic and mental health outcomes; however, most studies were small and heterogeneous. Larger, high-quality randomized controlled trials with longer follow-up and standardized outcome assessments are warranted to confirm and expand on these findings.