Comparative efficacy of electrical stimulation therapies for obstructive sleep apnea: A network meta-analysis of randomized controlled trials.

BACKGROUND

The objective of this study was to compare the efficacy of hypoglossal nerve stimulation (HNS), submental electrical stimulation (SMES), and transcutaneous electrical nerve stimulation (TENS) on key outcomes in obstructive sleep apnea (OSA).

METHODS

A network meta-analysis was conducted using data from 12 randomized controlled trials involving 677 OSA patients. Trials were identified through a systematic search of PubMed, Embase, and Cochrane Library databases up to June 2024. Effect sizes were calculated using standardized mean differences (SMDs) with 95% confidence intervals (CIs) for Apnea-Hypopnea Index (AHI), oxygen saturation, Oxygen Desaturation Index, lowest oxygen saturation during sleep (LSAT), and Epworth Sleepiness Scale. Random-effects models were used to synthesize the data and estimate both direct and indirect effects.

RESULTS

SMES exhibited the greatest reduction in AHI (SMD = -1.14, 95% CI [-1.51, -0.78]) and was most effective for improving oxygen saturation (SMD = 0.80, 95% CI [0.48, 1.12]) and ODI (SMD = -0.92, 95% CI [-1.27, -0.57]). TENS significantly improved LSAT (SMD = 0.68, 95% CI [0.30, 1.06]). HNS produced the largest improvement in Epworth Sleepiness Scale (SMD = -1.03, 95% CI [-1.53, -0.53]).

CONCLUSION

SMES, TENS, and HNS are effective treatments for OSA. SMES is physiologically superior for reducing AHI and improving oxygenation, owing to its ability to stimulate multiple upper-airway muscles and induce long-term neuromuscular adaptation. TENS improves LSAT by enhancing respiratory muscle performance, and HNS effectively reduces daytime sleepiness. These therapies offer modality-specific benefits that may support personalized OSA management.