The Influence of OSA Treatment on Muscle Sympathetic Nerve Activity: A Systematic Review and Meta‐Analysis

Abstract

Introduction Obstructive Sleep Apnea (OSA) is commonly treated with Continuous Positive Airway Pressure (CPAP) therapy, which reduces the number of airway obstructions while sleeping. Recently, diet and exercise interventions have been explored as a possible alternative treatment for OSA. Microneurography is a technique used to measure efferent postganglionic muscle sympathetic nerve activity (MSNA) via direct interneural recordings. CPAP therapy and diet and exercise interventions reduce disease severity, but their influence on MSNA is less clear. Purpose The present meta-analysis aims to examine the influence of type and length of treatment for OSA on MSNA. Methods A structured search of electronic databases was performed by a research librarian. Two reviewers independently assessed the titles of abstracts of articles; studies meeting eligibility criteria were selected for full-text review. Two reviewers independently extracted the data and assessed the quality of the studies using Joanna Briggs Institute Critical Appraisal of Evidence Effectiveness tool. Review Manager v5.3 was used to conduct the statistical analyses, and significance was set at P < 0.05. Results Evidence from 10 interventions (n=186) shows CPAP therapy significantly decreases MSNA burst frequency in individuals with OSA (Mean Difference, +12.6 bursts/min; 95% CI, 10.1-15.2 bursts/min; I2 = 39%). The same is shown for burst incidence in 6 studies (n=113) (MD, +21.5 bursts/100 hbs; 95% CI, 18.6-24.5 bursts/100 hbs; I2 = 0%). Reductions in MSNA (burst frequency and burst incidence) were seen for all time points of CPAP therapy: 1, 6, and 12 months. Data from 5 studies shows a significant decrease in burst frequency following diet and exercise intervention (n=68) (MD, +9.86 bursts/min; 95% CI, 5.37-14.35 bursts/min; I2 = 75%). A meta-regression analysis identified a relationship between CPAP therapy length and burst frequency (R2 = 0.329, p = 0.003). Conclusion CPAP therapy decreases MSNA in individuals with OSA, and a relationship exists between length of treatment and sympathetic activity. However, a significant reduction in sympathetic activity was also seen as a result of diet and exercise interventions; although, only burst frequency data was reported. More data is needed to determine optimal treatment type and length.