Uyama H, et al. – The current study examined the impacts of arousal accompanying an apneic event on blood pressure and sympathetic nerve activity in severe obstructive sleep apnea (OSA). The results seemed to suggest that apnea–hypopneas terminated by arousal are more often present in those with current systemic hypertension but independent of sympathetic nerve activity, compared with those whose apnea–hypopnea events do not have as many arousals. One could target an elevation in arousal threshold as a pathway for decreasing daytime blood pressure.

Methods

• Participants were consecutive ninety-seven patients who had diagnostic polysomnography (PSG) and demonstrated severe OSA (apnea-hypopnea index ≥ 30).
• After that, the proportion of apnea-hypopneas with arousal among all apnea-hypopneas was calculated in each patient.
• Finally, the relationship among the proportion of arousal accompanying apnea-hypopneas and a diagnosis of hypertension or heart rate variability during the PSG were examined.

Results

• The analysis in this study showed that the proportion of apnea-hypopneas with arousal among all apnea-hypopneas was higher in hypertensive patients (n = 47) than that in normotensive patients (n = 50) (mean ± standard deviation; 80.0 ± 12.8% vs. 73.7 ± 13.0%, p < 0.01).
• Findings revealed that heart rate variability was not related to the proportion of apnea-hypopneas with arousal.