Study design
This is a parallel group randomized superiority clinical trial comparing JTW to placebo for efficacy in treating insomnia. Eligible participants will be randomly assigned to either the JTW or placebo group in an equal proportion. The drug intervention will last for 1 week. Fig. 1 briefly shows the study flow chart, and Fig. 2 enumerates the treatment schedule and outcome measures. The study adheres to the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT 2013) checklist [14] (additional file 1).
Participants
Study population
Patients suffering from insomnia symptoms caused by the disharmony of the heart and kidney will be recruited from the Traditional Chinese
Medicine Department and Sleep Centre of the First Affiliated Hospital of Wenzhou Medical University in Wenzhou, Zhejiang Province, China. To recruit target subjects, advertisements will be distributed using flyers, Wechat, online and offline bulletin boards of the hospital.
Inclusion criteria
- Participants are 18-60 years of age, either male or female, and with a level of education above junior high school.
- Insomnia is almost the only symptom, including difficulty sleeping, deep sleep, dreaminess, early-morning awakening, trouble going back to sleep, feeling tired after waking up, or daytime sleepiness (excluding secondary insomnia).
- A Pittsburgh sleep quality index score of 7 or higher according to the Chinese Classification and Diagnostic Criteria of Mental Disorders-3 Version, CCMD-3[15].
- A Disharmony of Heart and Kidney Scoring System score of 9 or higher.
- Signed the informed consent before treatment.
Exclusion criteria
- Insomnia caused by physical diseases or lifestyle changes or environmental disturbances.
- Affective disorders, anxiety disorder, depression, schizophrenia and any other serious mental disorders.
- Suffering from somatic diseases that affect the central nervous system
- Serious heart, liver, kidney and hematopoietic system diseases, abnormal liver and kidney function.
- Regular use of antipsychotic drugs in the last month.
- Use of medicine to treatment sleeping disorders in the past week.
- Allergic to a certain ingredient of the drug involved in this trial or suffering from allergies.
- Alcohol abuse or (and) psychotropic drug addiction.
- Pregnancy or lactation.
Randomization and allocation concealment
We will apply block randomization to generate a sequence of labels (A or B) at 1:1 ratio, numbered from 001 to 124. This randomization approach forces balance between treatment and placebo groups over time as the recruitment proceeds. The pharmaceutical company will prepare the trial intervention packages according to the labeled sequence (A or B), numbered from 001 to 124, all in uniform plastic packages. The study coordinator will be blinded to the group assignment and will give participants the numbered package of intervention according to their visiting time sequence at baseline visit (e.g., the first participant will get the package numbered 001, the second participant will get packaged 002, and so on). Thus, the allocation concealment will be maintained throughout the study. The generated sequence of the group assignment and numbers will be sealed in opaque envelopes and stored in double-locked cabinets. Allocation concealment will be maintained throughout the entire study.
Blinding
This study will use a double-blind method. The placebos and JTW will have the look and will be packaged in uniform plastic bags. Then, the study coordinator will assign JTW or placebo according to the randomization codes and place them in special containers. The participants, outcome assessors, study coordinators, data managers, and statisticians will be blinded to the group allocation and numbered drug containers throughout the entire study. At the end of the study, the blinding codes will be revealed.
Intervention
These eligible participants will ingest 2 g granules of JTW or placebo, twice a day at 4 PM and 9 PM for 1 week and present themselves at the termination of medication, followed by a scheduled examination.
Both JTW and placebo are manufactured by the Kangren Pharmaceutical Factory according to good manufacturing practice standards. JTW will be produced in the form of granules with a yellowish-brown color. The medication will be 2 g, containing 1.1 g JTW soft extract with 0.37 g of lactose hydrate and 0.88 g of corn starch as the excipient. The JTW soft extract will be made of a water extract of a mixture of two herbal medicines, as follows: Rhizome Coptidis (10 g) and Cortex Cinnamomi (1 g). The placebo will consist of corn starch, lactose hydrate, citric acid, and caramel color. The placebo and JTW will have the same appearance and color.
Medication compliance monitoring
To ensure compliance with the medication, participants will be asked to count the actual intake, and return the empty wrapping papers for the medication and any remaining medicine.
Prohibition and permission for concomitant treatment
- The use of any sedative hypnotics to help sleep will be prohibited during the study.
- The use of any traditional medicine designed to treat insomnia, except for the intervention of this trial, will be prohibited during the study.
- The use of functional foods or other medications intended to improve the symptoms of insomnia will be prohibited during the study.
- Any psychotherapy for accelerating sleep quality will be prohibited during the study.
- Medications used to treat other chronic diseases at the beginning of this trial will be allowed.
- Routine physical training prior to the start of this clinical trial will be allowed.
- Any change in medications or physical exercise during the study will be recorded in a clinical report form.
Outcome measurement
Primary Outcome
We chose 1 week to assess the curative effect of JTW based on i) our previous experimental results and findings on animal sedation and hypnosis [17]; and ii) our clinical experience with patients using JTW.
Pittsburgh Sleep Quality Index (PSQI)
The Pittsburgh Sleep Quality Index will be used at the baseline and the end of the drug intervention. The PSQI version used in this study is a 19-item self-reported retrospective questionnaire to access the quality of sleep in the past 7 days, and it is designed to measure 7 domains called component scores: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleep medications, and daytime dysfunction[16,17]. Component scores range from 0 (no difficulty) to 3 points (severe difficulty), and when summed, produce a global score ranging from 0 to 21. A higher score denotes worse sleep. These syndromes are categorized as mild (0-1), moderate (2-7), or severe (8 or more)[18]. Then, the scores the participants obtained at baseline will be recorded as score 0, and the scores obtained at the end of drug intervention will be recorded as score 1. The recorder will calculate the reduction rate (RR) according to the following formula: RR＝( score 1-score 0)/score 0*100%. Finally, we will assess the clinical curative effect of every participant based on the results of the RR. RR values greater than 75% will be regarded as a clinical cure, RR values between 50%-75% will be considered as a clinical effective, RR values between 25%-50% will be recognized as a clinical success and RR values less than 25% will be considered ineffective. The primary outcome is defined to have a value of 0 if RR is below 25% (ineffective) and 1 if RR is above 25% (clinical cure, clinically effective or clinical success). The proportion of 1’s (i.e. RR≥25%) will be compared between the treatment and placebo groups.
In addition, Xiancheng Liu,et al. [18] presented their opinion that the PSQI is suitable for Chinese patients after they conducted reliability and validity tests [19].
Secondary outcomes
Polysomnography
Polysomnography (PSG) will be taken twice both at the baseline and the end of drug intervention. On the first night, participants will adapt themselves to the laboratory environment. On the second night, participants will be placed on polysomnography monitoring to record the multiple physiological sleep parameters. The parameters [20,21] will include total sleep time, sleep efficiency, sleep latency, REM stage latency, wake after sleep onset and the time duration of the particular sleep stages (such as N1, N2, N3). The mean changes of all the parameters from the baseline to the end of drug intervention will be used to measure the changes in sleep quality.
PSG is considered the gold standard for scoring sleep disorders. The scoring of sleep and arousals relies on visual inspection of continuous surface electroencephalography (EEG), electromyography (EMG), and electrooculography (EOG) during PSG and then divides human sleep into 5 stages: wakefulness(W), rapid eye movement(REM), nonrapid eye movement (NREM), including N1, N2 and N3[22]. The American Academy of Sleep Medicine (AASM) defined the quantitative reference standard in PSG for adult insomnia as follows[23]: sleep latency ≥ 30min; total sleep time < 390 min; number of wake after sleep onset (WASO) ≥ 2 or time of WASO ≥ 40 min; time in N1/total sleep time > 60%; time in N2 / total sleep time > 60% or time in N3/total sleep time < 10%, or time in REM / total sleep time < 20%. A higher or lower score corresponds to more severe symptoms.
1H-magnetic resonance spectroscopy(1H-MRS)
1H-magnetic resonance spectroscopy (1H-MRS) will also be taken at the baseline and the end of drug intervention. 1H-MRS, with its unique noninvasive advantages, is able to detect and quantify the important metabolites of living brain tissue, including N-acetylaspartate(NAA), choline(Cho), creatine(Cr), gamma-aminobutyric acid(GABA) and myo-intositol(mI)[24]. In this study, single voxel hippocampus and thalamus metabolite ratios of GABA with Cr will be measured. The altered ratios of GABA with Cr between baseline and the end of drug intervention will be the second outcome measure.
Studies have revealed that the GABA/Cr ratio in the frontal lobe is significantly lower[25], and the average brain GABA levels are nearly 30% lower in patients with primary insomnia[26].
Disharmony of Heart and Kidney Scoring System
The Disharmony of Heart and Kidney Scoring System will be used
at the baseline and the end of drug intervention. It is a checklist covering 1 indispensable and 7 accompanying items. These items are the symptoms and signs of the disharmony of heart and kidney pattern according to the theory of the pattern identification system in traditional East Asia medicine. The score of the indispensable item uses a four-point scale (0, 3, 6 and 9) depending on the severity of the insomnia (0=none, 9=very severe); the 7 accompanying items including palpitations, dizziness, spermatorrhea or menstrual irregularity, and night sweat and use 0-4-point scale based on their frequency. A total score of more than 9 out of 30 points is thought to demonstrate disharmony of the heart and kidney[27,28].
Although there is no accurate evidence to explain the validity and reliability of this questionnaire, no other methods are currently available to identify the disharmony of heart and kidney pattern.
Blood tests
The levels of adenosine (AD) and melatonin (N-acetyl-5-methoxytryptamine) in blood samples will be recorded at the baseline and the end of the drug intervention, will then be analyzed by the clinical lab.
Sleep homeostasis in adults is affected by the sleep-regulatory substances AD and melatonin[29,30]. AD is a product of brain metabolism, and is closely related to sleep parameters. A previous study[31] showed that AD levels were elevated as a consequence of sustained wakefulness. Melatonin is an endogenous hormone produced by the pineal gland and is released exclusively at night. Melatonin has been shown to synchronize the circadian rhythms, and improve the onset, duration and quality of sleep. Takaesu Y and his colleagues thought that reduced melatonin secretion may be involved in the mechanism of insomnia[32].
In this study, high-performance liquid chromatography (HPLC) will be developed to determine the levels of adenosine, and an enzyme-linked immunosorbent assay will be used to detect the concentration of melatonin.
Safety outcomes
At the end of this trial, participants will participate in a routine physical examination, including breath rate, heart rate, temperature, blood pressure, weight, routine urine test, routine blood test, liver, kidney function tests, and an electrocardiogram.
Adverse event reporting and treating
During the treatment period, the researchers will record any adverse events (AEs) that will be defined as unpredictable, undesirable symptoms, signs or diseases related to the treatment during daily telephone calls. Then, the researchers will comprehensively evaluate the correlation between these adverse events and the experimental drugs according to the recorded details about AEs, including the manifestation, occurrence time, duration, cause and treatment measures. Simultaneously, if any AE occurs, the investigator will take proper measures such as dose adjustment, drug withdrawal and symptomatic treatment to ensure the safety of participants, and all details will be written down carefully. Furthermore, continuous follow-up will be insisted upon until the condition of the participants returns to normal. What’s more, an insurance contract will be concluded to cover financial compensation to participants who might be injured during the study.
Sample size
The ratio of cases between the JTW group and the placebo group is set to 1:1, and this study is designed to achieve a statistical power of 80% (two-sided type-1 error of =5%， =20%). Based on previous clinical practice [33,34], we assume a treatment success rate of 40% in the placebo group and 70% in the JTW group over 7 days. The sample size is calculated using the following formula:
where is the cumulative distribution function of the standard normal distribution, and are the success rate in experimental and control group, respectively. Considering a 20% drop-out rate, a sample size of N=49/(1-0.2)=62 is needed for each group.
Thus, under the assumptions of a success rate of 70% for treatment and 40% for placebo, and a non-compliance rate of 20%, the sample size required to have at least 80% power of detecting a difference between the two groups at a two-sided alpha level of 5% is 124 participants.
Data management and monitoring
The experimental data will be carefully saved in Microsoft Access, which is a database management system (DBMS) from Microsoft. To guarantee the data quality, data will be input and checked twice by two researchers. Regular monitoring will be carried out to ensure the quality of the data by independent and eligible monitors.
Statistical analysis
We will use two-sided p-value for the primary outcome, and two sided p-values for all secondary outcomes and safety variables. For the primary outcome, we will use Fisher’s exact test to test the hypothesis at null: the treatment has the same efficacy as the placebo. For each secondary outcome, defined as the value difference between baseline and end-of-intervention, we will use the following tests: i) t-test for the continuous PSG variables; chi-square test for the categorical PSG variables; ii) t-test for the blood-level adenosine and melatonin; iii) t-test for GABA-to-Cr-ratio, and; iv) Wilcoxon rank sum test for the disharmony score of Heart and Kidney. For safety evaluation of JTW, two-sided t-test will be applied to each safety measurement after data normalization.
We define the analysis population as the enrolled participants who have successfully completed the trial. We will characterize the type of subjects who have missing data to better understand the nature the missing mechanisms. We will use statistical models to impute missing values if the assumption of missing at random is met. This can preserve and utilize the information of the non-missing values.