Determine the prevalence of, and clinical features associated with, a low respiratory arousal threshold (ArTH) among patients with obstructive sleep apnea (OSA), and to assess whether a low ArTH is associated with reduced long-term CPAP use.
Cross-sectional and longitudinal analyses were performed in an observational study conducted among 940 male Veterans with OSA. Data for clinical characteristics, polysomnography characteristics, and long-term (5 ± 2 years) CPAP use were obtained from clinical records. Logistic regression was used to assess the associations between low ArTH and clinical features, including regular CPAP use.
A low ArTH was observed in 38% of participants overall, and was more common among nonobese (body mass index < 30 kg/m2) patients (55%).
In adjusted analyses, 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. Conversely, 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—were positively associated with low ArTH. Nonobese patients with low ArTH were less likely to be regular CPAP users—OR (95% CI) 0.38 (0.20, 0.72)—in an adjusted model.
Low ArTH is a common trait among Veterans with OSA and is more frequent among those who are older and nonobese and those taking antidepressants, but is less frequent among patients taking antihypertensive medications. 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.
A commentary on this article appears in this issue on page 713.
Zinchuk 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;14(5):809–817.