Effects of Sihogayonggolmoryeo-tang (Saikokaryukotsuboreito or Chai-Hu-Jia-Long-Gu-Mu-Li-Tang) for insomnia disorder with prehypertension or stage 1 hypertension: A study protocol for a randomized controlled trial

BACKGROUND: Insomnia and hypertension are diseases with a high prevalence and a known association with each other. Sihogayonggolmoryeo-tang (SYM) is an herbal medicine traditionally used for the treatment of insomnia disorder concurrent with hypertension. However, no scientific clinical evidence exists supporting the effects of SYM on these disorders. This study aims to explore the feasibility, effectiveness, and safety of SYM for the treatment of insomnia disorder with concurrent prehypertension or stage 1 hypertension. METHODS: A prospective, randomized, wait-list controlled, parallel, pilot clinical trial has been designed for a study to be conducted in Daejeon, Republic of Korea. Thirty insomnia disorder patients with prehypertension or stage 1 hypertension will be randomly assigned to a SYM or wait-list group at a 1:1 ratio. The SYM group will be administered SYM granules twice a day for 4 weeks and followed-up for 2 weeks while the wait-list group will not receive SYM granules. All participants in both groups will be given brochures with instructions for maintaining sleep hygiene and lifestyle modifications to reduce hypertension. Data will be collected at baseline and at 2, 4, and 6 weeks after allocation. The primary outcome is the Insomnia Severity Index score at 4 weeks post-treatment. The secondary outcomes will consist of the Pittsburgh Sleep Quality Index, sleep diary, systolic and diastolic blood pressure, brachial-ankle pulse wave velocity, ankle-brachial index, atherosclerosis biomarkers, the Hospital Anxiety and Depression Scale, the 5-level EuroQol-5 dimensions, and the Patient Global Impression of Change. Adverse events and laboratory test results will be monitored to assess the safety. Data will be recorded in electronic case report forms and analyzed using SPSS Statistics, Version 24.0. DISCUSSION: This is the first clinical trial to explore the effectiveness and safety of SYM for the treatment of insomnia disorder concurrent with prehypertension or stage 1 hypertension. The results of this study can form the foundation for a future multicenter, large-scale, confirmatory clinical trial. TRIAL REGISTRATION: Clinical Research Information Service, KCT0005001 (registered on May 8, 2020).