Maximal exercise capacity in patients with obstructive sleep apnoea syndrome: a systematic review and meta-analysis.

Maximal aerobic capacity is a strong health predictor and peak oxygen consumption (') is considered a reflection of total body health. No systematic reviews or meta-analyses to date have synthesised the existing data regarding ' in patients with obstructive sleep apnoea (OSA).A systematic review of English and French articles using PubMed/MEDLINE and Embase included studies assessing ' in OSA patients either in mL·kg·min compared with controls or in % predicted. Two independent reviewers analysed the studies, extracted the data and assessed the quality of evidence.Mean ' expressed in mL·kg·min was significantly lower in patients with OSA than in controls (mean difference -2.7 mL·kg·min; p<0.001; n=850). This reduction in ' was found to be larger in non-obese patients (body mass index <30 kg·m). Mean ' % pred was 89.9% in OSA patients (n=643).OSA patients have reduced maximal aerobic capacity, which can be associated with increased cardiovascular risks and reduced survival in certain patient subgroups. Maximal exercise testing can be useful to characterise functional limitation and to evaluate health status in OSA patients.