대한수면의학회

Background and Objectives: Insomnia is the most prevalent sleep disorder in the general population and is considered to be a disorder of hyperarousal. The aim of this study was to measure the psychophysiological responses in insomnia patients using a biofeedback system, and to compare them with results from normal healthy subjects. Materials and Methods: Eighty patients with primary insomnia (35 males and 45 females, average age $49.71{pm}12.91years$) and 101 normal healthy controls (64 males and 37 females, average age $27.65{pm}2.77$) participated in this study. Electromyography (EMG), heart rate (HR), skin conductance (SC), skin temperature (ST), and respiratory rate (RR) were recorded using a biofeedback system during 5 phases (baseline, stress 1, recovery 1, stress 2, recovery 2) of a stress reactivity test, and average values were calculated. Difference in values between the two groups in each corresponding phase was analyzed with independent t-test, and change in values across phases of the stress reactivity test was analyzed with paired t-test (all two-tailed, p<0.05). Results: Compared to normal controls, insomnia patients had higher EMG in all 5 phases (baseline : $7.72{pm}3.88{mu}V$ vs. $4.89{pm}1.73{mu}V$, t = -6.06, p<0.001 ; stress 1 : $10.29{pm}5.16{mu}V$ vs. $6.63{pm}2.48{mu}V$, t = -5.84, p<0.001 ; recovery 1 : $7.87{pm}3.86{mu}V$ vs. $5.17{pm}2.17{mu}V$, t = -5.61, p<0.001 ; stress 2 : $10.22{pm}6.07{mu}V$ vs. $6.98{pm}2.98{mu}V$, t = -4.37, p<0.001 ; recovery 2 : $7.88{pm}4.25{mu}V$ vs. $5.17{pm}1.99{mu}V$, t = -5.27, p<0.001). Change in heart rate across phases of the stress reactivity test were higher in normal controls than in insomnia patients (stress 1-baseline : $6.48{pm}0.59$ vs. $3.77{pm}0.59$, t = 3.22, p = 0.002 ; recovery 1- stress 1 : $-5.36{pm}0.0.59$ vs. $-3.16{pm}0.47$, t = 2.91, p = 0.004 ; stress 2-recovery 1 : $8.45{pm}0.61$ vs. $4.03{pm}0.47$, t = 5.72, p<0.001 ; recovery 2-stress 2 : $-8.56{pm}0.65$ vs. $4.02{pm}0.51$, t = -5.31, p<0.001). Conclusion: Psychophysiological profiles of insomnia patients in a stress reactivity test were different from those of normal healthy controls. These results suggest that the sympathetic nervous system is more highly activated in insomnia patients.

Insomnia;Psychophysiology;Biofeedback;Physiological stress reactivity;Electromyography;