Obstructive sleep apnoea syndrome and endothelial function: potential impact of different treatment strategies-meta-analysis of prospective studies

Purpose Previous studies have shown an association between obstructive sleep apnoea syndrome (OSAS) and cardiovascular events. Whether this association is mediated by an impairment of endothelial function, which is itself a driver of elevated cardiovascular risk, has yet to be clarified, as it is the eventual protective role of several OSAS treatments. The aim of our meta-analysis is to evaluate the effect of various OSAS treatments on endothelial function calculated by means of flow-mediated dilatation (FMD). Methods: We conducted a meta-analysis of prospective studies including patients affected by mild to severe OSAS treated with continuous positive airway pressure (CPAP), surgery, oral appliance and medical treatments. FMD was measured before and after treatment Results: After pooling results from different treatment strategies, OSAS treatment showed a positive impact on endothelial function (Mean Difference [MD]=2.58; 95% CI 1.95-3.20; p<0.00001). Conclusions: Our study supports the hypothesis that several modalities of treatment for OSAS positively impact endothelial function. Whether this effect also associates with an improvement of clinical outcomes remains to be ascertained.