Obstructive Sleep Apnea, Oxidative Stress, and Cardiovascular Disease: Evidence from Human Studies.
Level 5 - mechanism / opinion, no new human data
Narrative review of human mechanistic, biomarker, and biopsy studies without systematic review methodology.
PubMed 26167241 · doi:10.1155/2015/608438
What was done
This narrative review evaluated published human studies examining the mechanisms linking obstructive sleep apnea (OSA) and nocturnal intermittent hypoxia to oxidative stress and cardiovascular disease. It summarized findings from circulating biomarker studies, vascular biopsy studies, surrogate markers of vascular disease, and interventional studies assessing continuous positive airway pressure (CPAP) and antioxidant therapies.
What was found
No quantitative effect sizes or statistics were reported in the abstract. Qualitatively, human studies demonstrated that OSA is associated with increased reactive oxygen species production from leukocytes, elevated lipid peroxidation, decreased plasma nitrite and nitrate levels, and reduced total antioxidant capacity. Vascular biopsy studies showed decreased endothelial nitric oxide synthase expression and increased nitrotyrosine immunofluorescence. These oxidative stress markers correlated with surrogate cardiovascular disease endpoints, including endothelial dysfunction, carotid intima-media thickness, and elevated blood pressure. CPAP was reported to reverse oxidative stress markers, while evidence regarding antioxidant supplementation remained inconclusive.
Why it matters
The review synthesizes human evidence identifying oxidative stress as a primary mechanistic pathway connecting sleep-disordered breathing to vascular damage and cardiovascular morbidity. It highlights CPAP's role in mitigating oxidative injury while outlining the need for further clinical research on antioxidant therapies.
Limits
The abstract provides no numerical data, confidence intervals, sample sizes, or study selection criteria. As a narrative review, it lacks systematic screening and risk-of-bias assessment. Findings rely primarily on surrogate biomarkers rather than hard cardiovascular clinical outcomes.
Cited by
- supports Intermittent hypoxia in sleep apnea causes cells to release reactive oxygen species, generating chronic oxidative stress.