Long-term nasal CPAP in patients with obstructive sleep apnea significantly reduced the asleep LF/HF ratio from 1.21 to 1.11 (P<0.001), indicating reduced cardiac sympathetic tone.
Observational (n=14)
p-value: p=<0.001
The increased sympathetic activation that occurs in obstructive sleep apnoea (OSA) may play an important role in associated morbidity. We investigated the effect of long-term (3 month) nasal continuous positive airway pressure (CPAP) on the autonomic nervous system assessed by heart rate variability (HRV). Fourteen patients (12 men), mean age 61.4 +/- 8.1 years, with OSA underwent continuous synchronized electrocardiographic and polysomnographic monitoring. The apnoea/hypopnoea index (AHI) decreased from 50.6 +/- 13.7 to 2.2 +/- 2.5 events h-1 after CPAP. HRV analysis showed significant decreases in low frequency (LF; from 7.12 +/- 1.06 to 6.22 +/- 1.18 ln ms2 Hz-1; P < 0.001), high frequency (HF; from 5.91 +/- 0.87 to 5.62 +/- 0.92 ln ms2 Hz-1; P < 0.05) and LF/HF (from 1.21 +/- 0.12 to 1.11 +/- 0.15 ln ms2 Hz-1; P < 0.001) when the patients were asleep. The decrease in LF/HF was prolonged into the daytime (from 1.33 +/- 0.22 to 1.24 +/- 0.21 ln ms2 Hz-1; P < 0.001). Treatment of OSA by CPAP significantly reduced the parameters of cardiac sympathetic tone, a favourable effect.
Roche et al. (Mon,) conducted a observational in Obstructive sleep apnoea (OSA) (n=14). Nasal continuous positive airway pressure (CPAP) was evaluated on Autonomic nervous system assessed by heart rate variability (HRV) parameters including LF, HF, and LF/HF ratio (p=<0.001). Long-term nasal CPAP in patients with obstructive sleep apnea significantly reduced the asleep LF/HF ratio from 1.21 to 1.11 (P<0.001), indicating reduced cardiac sympathetic tone.