Effect of renal sympathetic denervation on apnea-hypopnea index in patients with obstructive sleep apnea: a systematic review and meta-analysis.

ABSTRACT

PURPOSE: Recent evidence associates sympathetic tone with severity of obstructive sleep apnea (OSA). Renal sympathetic denervation (RDN), by decreasing sympathetic tone, has the potential to decrease OSA severity. Small observational studies that assessed this hypothesis lacked precision. Hence, in this meta-analysis, we have attempted to pool available data from studies that have assessed the effect of RDN on OSA severity in patients with OSA. METHODS: Medline, Embase, Cochrane central, Ovid, Cinahl, web of science, and conference abstracts were searched for eligible citations by two independent reviewers using key words "renal denervation," "hypertension," and "obstructive sleep apnea." From a total of 2,863 identified citations, using meta-analysis of observational studies in epidemiology method, five studies were assessed eligible and included in the meta-analysis. RESULTS: All five studies followed an observational study design, involved patients with OSA and HTN, and reported an apnea-hypopnea index (AHI) 6 months post-RDN. Four were "before and after" studies and one compared continuous positive airway pressure with RDN. In the pooled analysis, involving 49 patients, RDN was associated with a significant reduction in mean AHI [weighted mean difference -9.61 (95 % CI -15.43 to -3.79, P = 0.001)] 6 months post-RDN. One study also reported improvement in oxygen desaturation index and Epworth sleepiness scale score 6 months post-RDN. CONCLUSIONS: RDN is associated with significant improvement in OSA severity. However, our results need validation in RCTs that assess effect of RDN in patients with OSA, which can potentially broaden the clinical applicability of RDN.