Researchers have found that continuous positive airway pressure (CPAP) treatment of obstructive sleep apnea (OSA) can improve depression symptoms in patients suffering from cardiovascular diseases.
Using data from the Sleep Apnea Cardiovascular Endpoints (SAVE) trial led by Flinders University, the new study has found a significant decrease in cases of depression after patients received CPAP treatment for their sleep apnea.
This is by far the largest trial of its type and one of very few studies reporting such an effect, says Professor Doug McEvoy from Flinders University.
From detailed analysis of the SAVE data, Flinders University experts and collaborators at the George Institute have found that CPAP for moderate-severe OSA in patients with cardiovascular disease has broader benefits in terms of preventing depression, independent of improved sleepiness.
Prior studies investigating the effect of CPAP on mood with various experimental designs and length of follow-up periods have yielded heterogenous results.
“Patients who have had a stroke or heart attack are prone to suffer from low mood and are 2 to 3 times more likely to develop clinical depression, which then further elevates their risk of future heart attacks and strokes,” says SAVE principal investigator Professor McEvoy, a senior author in the paper just published by The Lancet in EClinicalMedicine.
With up to 50% of patients with CV disease likely to have OSA, the study is “welcome news that treatment of OSA substantially relieves cardiovascular patients’ depressive symptoms and improves their wellbeing”.
The paper’s first author, Dr. Danni Zheng, from the George Institute for Global Health (UNSW), says the 2687 OSA patients enrolled in the SAVE trial were based solely on their history of cardiovascular disease and not on their current mood status.
“After following them for an average of 3.7 years, we found that CPAP provided significant reductions in depression symptoms compared with those who were not treated for OSA.
The improvement for depression was apparent within six months and was sustained.”
As expected, those with lower mood scores to start with appeared to get the greatest benefit.
“Our additional systematic review which combined the SAVE study findings with previous work provided further support of the treatment effect of CPAP for depression,” Dr. Zheng says.
Obstructive sleep apnea (OSA) is a type of sleep-disordered breathing that involves recurrent upper airway collapse leading to repetitive episodes of hypoxemia and arousal during sleep [1].
Cross-sectional and longitudinal studies have shown an association between OSA and hypertension [2,3], cardiovascular disease [4,5,6], and cerebrovascular events [7].
In patients with coronary artery disease (CAD), the prevalence of at least moderate OSA is approximately 50% [8,9,10], and OSA has been shown to be a significant predictor of incident CAD in males ≤70 years old after adjustment for other risk factors [4].
Therefore, OSA is an important comorbidity in patients with CAD.
Continuous positive airway pressure (CPAP) is the gold standard treatment for OSA.
Treatment with CPAP has been shown to have positive effects on cardiovascular outcomes, including in studies conducted in patients with CAD [11,12,13,14].
However, the beneficial effects of treating OSA with CPAP in patients with CAD have not been confirmed in the recent studies [15,16,17,18].
OSA has also been linked with depression and anxiety, although the correlation between objective measures of OSA severity and subjective symptoms such as anxiety and depression is not consistent [19,20,21].
There is also a reported link between depression and several aspects of heart disease [22].
In addition, CAD outcomes appear to be worse in the presence of anxiety and/or depression [22,23,24].
Treatment of OSA with CPAP has been shown to improve anxiety and depression symptoms [25,26].
However, less is known about the effects of CPAP treatment on anxiety and depression in patients with both OSA and CAD.
More information: Danni Zheng et al. Effects of continuous positive airway pressure on depression and anxiety symptoms in patients with obstructive sleep apnoea: results from the sleep apnoea cardiovascular Endpoint randomised trial and meta-analysis, EClinicalMedicine (2019). DOI: 10.1016/j.eclinm.2019.05.012
