Peripheral arterial tonometry monitors changes of autonomous nervous system in sleep apnea

The diagnosis of obstructive sleep apnea requires assessment of cardiovascular function because sleep apnea has been recognized as a risk factor for cardiovascular disorders. We tested a sensor which monitors autonomous nervous function by the measurement of peripheral arterial tone (PAT) on the finger. Twenty one patients with obstructive sleep apnea and arterial hypertension underwent polysomnography with parallel invasive blood pressure and PAT. The PAT signal allows us to track hemodynamic changes and it can recognize subcortical arousals which accompany apneas. Correlation between PAT attenuations and cortical arousal was significant (r=0.583; p<0.01). The PAT signal cannot replace invasive blood pressure but provides additional information which allows us to investigate changes of sympathetic and parasympathetic activities during sleep.