The impact of continuous positive airway pressure therapy on circulating levels of malondialdehyde: a systematic review and meta-analysis

Background: Obstructive sleep apnea (OSA) is a highly prevalent sleep disorder which associated with increased oxidative stress and cardiovascular diseases. Malondialdehyde (MDA) is a reliable marker of lipid peroxidation and is elevated in patients with OSA. Studies reported inconsistent findings on the effect of continuous positive airway pressure (CPAP) therapy on MDA levels. As the study power maybe a reason for the inconsistent findings, we aimed to use meta-analysis to assess effect of CPAP therapy on MDA in patients with OSA. Method: Electronic search was performed to find out studies on the effect of CAPA on MDA levels in OSA patients. Search carried out in databases of PubMed, EMBASE, Scopus, Cochrane library and web of science. Results: Search resulted in 161 records of which 83 remained after removing duplicated records. Further, 51 articles were removed by title and abstract and 22 records evaluated by full text. Finally 13 articles were included in the intended meta-analysis. Pooled analysis demonstrated that CPAP therapy reduced MDA levels significantly [SMD (-1.51) (95% CI, -2.06 to -0.97) p < 0.05]. Subgroup analyses showed that CPAP therapy was effective in categories of age (<= 50 and > 50 years), BMI (<= 30 and > 30 kg/m(2)) and therapy duration (<= 12 week and >12 week). Conclusion: the results of the present study demonstrated considerable effect of CPAP therapy on MDA as independent risk factor for cardiovascular diseases and robust marker of lipid peroxidation. (c) 2020 Elsevier B.V. All rights reserved.