Study objectives: This study aimed to determine the consequences of snoring independent of obstructive sleep apnea (OSA) and hypothesized that snoring sound intensity, as assessed by mean tracheal sound (TS) energy (Leq), is related to morning blood pressure (BP).
Methods: A home-based TS monitoring study was performed for two nights on 191 workers in Japan using an IC recorder. Leq and the respiratory disturbance index (RDI) were calculated from the TS data. RDI was used as a marker of OSA severity. Systolic and diastolic BP measurements in the evening and morning (eSBP/eDBP and mSBP/mDBP, respectively) were done before and after TS recording. The data of the second night were analyzed.
Results: Leq was significantly related to both mSBP and mDBP (r = 0.32, p < 0.0001; r = 0.34, p < 0.0001, respectively). Leq was also significantly related to morning BP after adjustment for age, sex, and body mass index. However, the relationship was no longer significant when both RDI and Leq were included in the multiple regression model. In non-apneic, non-obese subjects, Leq was significantly related to both mSBP and mDBP (r = 0.38, p < 0.0001; r = 0.33, p = 0.0004, respectively). In this group, Leq was associated with mSBP after adjusting for all confounding factors (n = 106, p = 0.022).
Conclusions: The association between night TS intensity and morning BP suggests a pathological role of heavy snoring. To understand this association, a prospective cohort study in a general population is warranted.
Commentary: A commentary on this article appears in this issue on page 1581.
Keywords: acoustics; morning blood pressure; sleep apnea; snoring.
© 2016 American Academy of Sleep Medicine