QJM Advance Access originally published online on July 22, 2006
QJM 2006 99(8):545-553; doi:10.1093/qjmed/hcl074
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Effect of nCPAP therapy on heart rate in patients with obstructive sleep apnoea-hypopnoea
From the 1Department of Respiratory Medicine, Kyoto University Graduate School of Medicine, and2Department of Physical Therapeutics, Kyoto University Hospital of Medicine, Kyoto, Japan
Address correspondence to Dr K. Chin, Department of Physical Therapeutics, Kyoto University Hospital of Medicine, 54 Shogoin Kawahara-cho, Sakyo-Ku, 606-8507 Kyoto, Japan. email: chink{at}kuhp.kyoto-u.ac.jp
Received 2 February 2006 and in revised form 5 May 2006
Background: Elevated heart rate (HR) is a risk factor for cardiovascular disease. The effects of obstructive sleep apnoea-hypopnoea syndrome (OSAHS) on HR are controversial.
Aim: To investigate the effect of nasal continuous positive airway pressure (nCPAP) therapy on HR in OSAHS patients.
Methods: Sixty-two OSAHS patients underwent 24-h electrocardiographic recording, both before and 3 or 4 days after instigation of nCPAP.
Results: After nCPAP was started, HR significantly decreased (mean ± SD 71.8 ± 10.6 vs. 67.5 ± 9.4 bpm, p < 0.0001), both in the daytime (0600–2200 h, 76.3 ± 12.2 vs. 72.2 ± 10.2 bpm, p < 0.0001) and at night-time (2200–0600 h, 64.5 ± 9.1 vs. 60.0 ± 8.9 bpm, p < 0.0001). HR was significantly reduced in both periods in the 44 patients with hypertension and/or diabetes mellitus, but only during the night-time in the 18 with neither condition. Before nCPAP treatment, HR was positively correlated with percentage time of arterial O2 saturation <90% during sleep (p = 0.008) and with the apnoea-hypopnoea index during sleep (p = 0.003). In 15 patients undergoing HR for 2 days before starting nCPAP, the mean HRs for the two periods were similar (p = 0.95).
Discussion: nCPAP therapy appears to decrease HR in OSAHS patients, and may thereby reduce their risk of cardiovascular disease.