NEW HAVEN, CT — Low respiratory arousal threshold (ArTH) is common among veterans with obstructive sleep apnea and appears to be linked to underuse of CPAP therapy, according to a new study.
The report in the Journal of Clinical Sleep Medicine notes that low ArTH is more frequent among VA patients who are older and nonobese, as well as those using antidepressants. The condition is less frequent among patients taking antihypertensive medications, pointed out the Yale University School of Medicine researchers.1
“A marked reduction of long-term CPAP use in nonobese patients with low ArTH highlights the importance of understanding a patient’s physiologic phenotype for OSA management, and suggests potential targets to improve CPAP adherence,” study authors emphasized.
The investigators sought to determine the prevalence of ArTH among OSA patients, clinical features associated with it and how low ArTH correlates to reduced long-term CPAP use.
To do that, the researchers performed cross-sectional and longitudinal analyses in an observational study conducted among 940 male veterans with OSA, obtaining from clinical records data on clinical characteristics, polysomnography characteristics, and long-term (5 ± 2 years) CPAP use.
With a low ArTH observed in 38% of participants overall, a key finding was that the condition was more common among nonobese veterans, defined as a body mass less than 30 kg/m2. Normal weight or lower patients made up about 55% of the sample.
Results in adjusted analyses indicated that increasing body mass index (per 5 kg/m2) and antihypertensive medication use were negatively associated with low ArTH, with odds ratio (OR) (95% confidence interval [CI]) of 0.77 (0.69, 0.87) and 0.69 (0.49, 0.98), respectively.
Positively associated with low ArTH, on the other hand, were increasing age (per 10 years) and antidepressant use-OR (95% CI) 1.15 (1.01,1.31) and 1.54 (1.14,1.98), respectively. In fact, nonobese patients with low ArTH were notably less likely to be regular CPAP users-OR (95% CI) 0.38 (0.20, 0.72)-in an adjusted model.
“A marked reduction of long-term CPAP use in nonobese patients with low ArTH highlights the importance of understanding a patient’s physiologic phenotype for OSA management, and suggests potential targets to improve CPAP adherence,” study authors concluded.
1Zinchuk A, Edwards BA, Jeon S, Koo BB, Concato J, Sands S, Wellman A, Yaggi HK. Prevalence, Associated Clinical Features, and Impact on Continuous Positive Airway Pressure Use of a Low Respiratory Arousal Threshold Among Male United States Veterans With Obstructive Sleep Apnea. J Clin Sleep Med. 2018 May 15;14(5):809-817. doi: 10.5664/jcsm.7112. PubMed PMID: 29734986; PubMed Central PMCID: PMC5940432.