Enhanced External Counterpulsation Improves Sleep Quality in Chronic Insomnia: A Pilot Randomized Controlled Study.

Purpose: To investigate the short-term efficacy of enhanced external counterpulsation (EECP) on chronic insomnia. Methods: This is a pilot randomized, participant -blind, and sham -controlled study. Forty-six participants with chronic insomnia were randomly assigned in a 1:1 ratio to receive EECP or sham EECP intervention (total of 35 sessions with 45 min each). The primary outcome was Pittsburgh Sleep Quality Index (PSQI). The secondary outcomes included sleep diary, Hospital Anxiety and Depression Scale (HADS), Short -Form Health Survey (SF12), flow mediated dilation (FMD), serum biomarkers of melatonin, cortisol, interleukin-6, and high sensitivity C -reactive protein. Outcomes were assessed after treatment and at 3 -month follow-up. Results: The PSQI was significantly decreased in both EECP and sham groups after 35 -session intervention (13.74 to 6.96 in EECP and 13.04 to 9.48 in sham), and EECP decreased PSQI more than sham EECP (p = 0.009). PSQI in two groups kept improved at 3 -month follow-up. After treatment, the total sleep time, sleep efficiency, FMD value and SF12 mental component of EECP group were significantly improved, and group differences were found for these outcomes. At follow-up, total sleep time, sleep efficiency and SF12 mental component of EECP group remained improved, and group difference for SF12 mental component was found. Post -treatment and follow-up HADS-A significantly decreased in both groups, with no differences between groups. Post -treatment serum biomarkers showed no differences within and between groups. Limitation: Lack of objective sleep measurement. Conclusion: EECP could improve sleep quality and mental quality of life in chronic insomnia and the therapeutic effect maintained for 3 months.