Study setting
Six hospitals in mainland China participate in this study, listed as follows: Guang’ anmen Hospital of China Academy of Chinese Medical Sciences, Beijing Shijitan Hospital, Capital Medical University, Beijing Changping District Hospital of Chinese Medicine, Beijing Shunyi District Hospital of Chinese Medicine, Beijing Miyun District Hospital of Chinese Medicine, and Beijing Pinggu District Hospital of Chinese Medicine.
Eligibility Criteria
Diagnostic criteria
Diagnostic criteria for type 2 diabetes (T2DM) are based on the guideline for the prevention and control of T2DM in China (2017 Edition) [20], which is defined as: (1) In patients with classic symptoms of hyperglycemia, a random plasma glucose ≥ 11.1 mmol/L; or (2) Fasting plasma glucose ≥ 7.0 mmol/L; or (3) Two-hour plasma glucose ≥ 11.1 mmol/L after an oral glucose tolerance test.
Diagnostic criteria for DR are based on Proposed International Clinical Diabetic Retinopathy and Diabetic Macular Edema Disease Severity Scales by American Academy of Ophthalmology.Diagnosis and classification of type 2 diabetic retinopathy is defined as: (1) Mild NPDR: microaneurysm only; (2)Moderate NPDR: More than just microaneurysms but less than severe NPDR; (3)Severe NPDR: Any of the following: more than 20 intraretinal hemorrhages in each of 4 quadrants; definite venous beading in 2+ quadrants; Prominent intraretinal microvascular abnormalities in 1+ quadrant; And no signs of proliferative retinopathy; (4) Proliferative DR: One or more of the following: neovascularization, vitreous/preretinal hemorrhage [21-23].
TCM syndrome pattern differentiation
Traditional Chinese medicine syndrome pattern differentiation type indicating deficiency of dual qi and yin combined with blood stasis are based on Traditional Chinese medicine Clinical Pathway of Xiaoke disease and Traditional Chinese medicine Diagnosis and Treatment Scheme of Xiaoke disease [24]. The diagnostic criteria are listed:
1.Primary symptoms and signs include lack of strength, dry throat and mouth, shortness of breath, reddish yellow urine, heat in the palms and soles; and numbness or pain in the limbs.
2. Secondary symptoms and signs include palpitations, vexation, lumbago, chest pain, hypochondriac pain, back pain, insomnia, forgetfulness, encrusted skin, or wind-stroke hemiplegia, or blurred vision, facial ecchymosis, thin white fur, or dark tongue, purple mouth and tongue or purpura, the sublingual vein is purple and tortuous, string-like and fine pulse.
If participants have two terms of primary symptoms or signs, two terms of the secondary symptoms or signs, they will be diagnosed with this syndrome. A symptom scores survey will be conducted.
Inclusion criteria
1. Participants should be between 30 and 70 years old;
2. Participants should meet the diagnostic criteria for T2DM.
3. Participants should meet the diagnostic criteria for diabetic retinopathy and the stage of NPDR.
4. Participants should meet the diagnostic criteria of deficiency of dual qi and yin combined with blood stasis syndrome.
5. Participants should sign informed consent forms.
Exclusion criteria
1. Participants suffer with the stage of PDR, type 1 diabetic retinopathy, other ocular complications, such as glaucoma, severe cataracts, poor vision, retinal detachment, ophthalmic nerve disease, uveitis and retinopathy not related to DM.
2. Participants with severe cardiovascular and respiratory disease, or severe complications of liver, kidney, brain or other primary diseases.
3. Participants that serum transaminase level is two times higher than the upper limit of normal value; serum creatinine is two times higher than the upper limit of normal value.
4. Participants with recurrent hypoglycemia, diabetic ketoacidosis and severe infection within one month.
5. Participants with systolic blood pressure ≥160 mmHg or diastolic blood pressure ≥100 mmHg.
6. Pregnant, pregnant or lactating women, or have a history of drug allergy.
7. Participants with psychiatric conditions.
Drop-out criteria
1. Participants who experience some complications or physiological changes, which are not suitable for further study.
2. Participants whose fundus lesions progress to the PDR stage or received laser photocoagulation, participants should be withdrawn from the study, and the effect will be judged as invalid, which is a complete case.
3. Participants whose vision decrease by 3 lines or more, participants should be withdrawn from the study, and the effect was judged as invalid.
4. Participants with poor drug compliance.
5. Participants who break blinding or emergency unsealing of his/her information.
Interventions
Drug Treatment
Participants will be randomly assigned to receive any of the following four options: group 1: QZJC (2.5g three times per day) plus CaD(0.5g three times per day); group 2: QZJC placebo (2.5g three times per day) plus CaD (0.5g three times per day); group 3: QZJC (2.5g three times per day); group 4: QZJC placebo (2.5g three times per day). QZJC and QZJC placebo will be provided by Jilin Yi Zheng Pharmaceutical Co., Ltd. (Jinlin, China). The drugs are recommended to be taken after meals with boiled warm water. If the patient shows an intolerable adverse reaction related to the drug, the patient should discontinue the drugs. During the study, other drugs that could treat DR will be prohibited. These include TCMs that aim to fortifying qi and nourishing yin, activating blood and dissolve stasis, or drugs such as anti-VEGF therapy, fenofibrate, etc.
Concomitant treatment
Based on the guidelines for the prevention and control of type 2 diabetes in China (2017 Edition)[20], all participants will receive the standard intervention of blood glucose: fasting blood glucose (FBG) will be controlled to < 7.0 mmol/L and two hour plasma glucose (2h PG) will be controlled to < 10.0 mmol/L, and glycosylated hemoglobin (HbA1c) will be controlled to < 7%. The standard intervention will include achieving a blood pressure control target of < 130/80 mmHg, and paying close attention to other cardiovascular risk factors and giving appropriate intervention measures. Moreover, the participants will not change the drugs used to treat chronic diseases. The researchers will guide the participant to have a healthy lifestyle and keep detailed records in the CRFs, in order to maintain two groups in general balance.
Outcomes
Primary outcome
The primary outcome is the changes in grading of retinal microvascular injury before and after treatment. The stage is divided into the condition of exacerbated, stable, and improved. The exacerbated state is defined that the severity of retinal microaneurysm injury exacerbated > 1 grade after treatment. The stable state is defined that the severity of retinal microaneurysm injury is unchanged before and after treatment, while the improved state is defined that the severity of retinal microaneurysm injury is reduced by >1 grade after treatment. The grade is defined as the stage of DR that the same as the diagnostic criteria.
Secondary outcomes
Secondary outcomes are listed as the changes of vision, FBG and 2h PG, HbA1c, blood lipids [total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C)], urinary albumin excretion rate (UAER) and improvement in TCM symptoms (evaluated by TCM symptom score scale) from baseline to 24 week.
Safety assessment
Safety assessment outcomes are listed as vital signs (body temperature, blood pressure, respiration, heart rate), routine blood test, routine urine test and routine stool test, electrocardiogram, liver function [alanine aminotransferase (ALT) and aspartate aminotransferase (AST)], renal function [serum creatinine (SCr) and blood urea nitrogen (BUN)] will be performed at every 12 weeks from baseline.
Adverse events (AEs) will be documented at every visit, including the occurrence time, severity, duration, solution and transfer. Every AE will be classified as a mild, moderate, or severe AE, and its correlation with the intervention drugs will be evaluated. Severe AEs will be reported to the principal investigator and the Ethics Committee within 24 hours, and fill out the “Severe Adverse Event (SAE)” form. All the adverse events will be correctly recorded in the CRF, and treated until resolved.
Participant timeline
The study duration will last for 26 weeks, including a 2-week run-in period, the treatment will last for 24 weeks. After treatment begin, visits will conduct every 4 weeks. All data will be documented on the CRFs. Schedule of enrollment, allocation, visits, and assessments is listed in Table 1.
Table 1 Schedule of enrollment, allocation, visits, and assessments
|
Enrolment
|
Allocation
|
Post-allocation
|
Time of visits (weeks)
|
-2-0w
|
4w
|
8w
|
12w
|
16w
|
20w
|
24w
|
Collect basic medical history
|
Sign informed consent form
|
√
|
|
|
|
|
|
|
|
Determine inclusion and exclusion criteria
|
√
|
√
|
|
|
|
|
|
|
Determine withdrawal criteria
|
√
|
√
|
√
|
√
|
√
|
√
|
√
|
√
|
Fill in general information
|
√
|
√
|
|
|
|
|
|
|
History of diabetes and treatment
|
√
|
|
|
|
|
|
|
|
Comorbidity and symptom
|
√
|
|
|
|
|
|
|
|
Physical examination and consultation
|
√
|
√
|
√
|
√
|
√
|
√
|
√
|
√
|
Concomitant medication
|
√
|
√
|
√
|
√
|
√
|
√
|
√
|
√
|
Efficacy assessment
|
Fundus photography
|
|
√
|
|
|
|
|
|
√
|
Fluorescence fundus angiography
|
|
√
|
|
|
|
|
|
√
|
Routine ophthalmic examination, fundus
|
|
√
|
|
|
√
|
|
|
√
|
Vision
|
|
√
|
|
|
√
|
|
|
√
|
Fasting blood glucose
|
|
√
|
√
|
√
|
√
|
√
|
√
|
√
|
Two-hour plasma glucose
|
|
√
|
√
|
√
|
√
|
√
|
√
|
√
|
Blood pressure
|
|
√
|
√
|
√
|
√
|
√
|
√
|
√
|
Glycosylated hemoglobin
|
|
√
|
|
|
√
|
|
|
√
|
Blood lipids
|
|
√
|
|
|
√
|
|
|
√
|
Urinary albumin excretion rate
|
|
√
|
|
|
√
|
|
|
√
|
TCM symptoms
|
|
√
|
|
|
√
|
|
|
√
|
Safety assessment
|
Vital signs
|
|
√
|
√
|
√
|
√
|
√
|
√
|
√
|
Routine blood, urine and stool examination
|
|
√
|
|
|
√
|
|
|
√
|
Liver function
|
|
√
|
|
|
√
|
|
|
√
|
Renal function
|
|
√
|
|
|
√
|
|
|
√
|
Electrocardiogram
|
|
√
|
|
|
√
|
|
|
√
|
Adverse events
|
|
|
√
|
√
|
√
|
√
|
√
|
√
|
Other work
|
Randomization
|
|
√
|
|
|
|
|
|
|
Drug distribution and patient journal cards
|
|
√
|
√
|
√
|
√
|
√
|
√
|
√
|
Recovery drugs, quantity statistics
|
|
|
√
|
√
|
√
|
√
|
√
|
√
|
Recycle patient’s diary card
|
|
|
√
|
√
|
√
|
√
|
√
|
√
|
Research summary
|
|
|
|
|
√
|
|
|
√
|
Note: The follow-up time was within 3 days of the day appointed.
Sample size
The sample size of clinical study will be estimated based on previously published studies [25]. The results showed that the rate of retinal microvascular disease decreased by 3.6% in the placebo group, and we deduce that QZJC could decrease the rate of retinal microvascular disease by 6.5%. The following sample size formula is used for calculation.
In this formula, assuming that α = 0.05 and β = 0.20 according to the one-sided test to obtain the tabular value, uα = 1.64485 and uβ = 0.84162; Take each value into the formula and get n = 42. Therefore, each group needs 42 participants. Considering that the drop-out rate is no more than 15%, finally 50 participants are needed in each group and a total of 200 participants is set as the sample size.
Assignment of interventions: Blinding and allocation
Participants will be randomly assigned to any of the four groups at an equal probability. The stratified block randomization will be adopted, a specific randomized sequence will be generated using SAS software. The clinical research coordinator enters participant information and will be acquired a random number. The allocation list file will not be available to any participant for the duration of the trial, and be uncovered after completion of the trial. If a medical emergency happens, the participant’s random number and group allocation list can be exposed. Considering the safety of the trial, research assistants may be aware of random distribution. However, the data evaluators and the statisticians of research results will not be involved in distribution situation.
Data collection and management
The researchers should document the data into the case report form (CRF) timely, completely, correctly and clearly according to original data. The clinical supervisor will confirm that all the CRFs are filled correctly and completely, and consistence with the original data. The errors and omissions must correct them in time, the original records should be kept clear and visible when modifying, and the correction should be signed and dated by the researcher. After checked and signed by the supervisor, the CRFs will be sent to the trial data administrator. The data administrator will check the data again before data entry. If any problem is found, they will notify the supervisor, and asks the researcher to respond. The exchange between them should be kept in the form of query table. The data administrator also should understand the content and coding of each item before data entry. The data entry personnel should input the data twice. After data entry, the quality and l logicality will be checked. The documents will be requested to conserve by every unit after the study. Researchers should preserve the documents of clinical trial for five years.
Statistical methods
Data will be collected and analyzed using SAS 9.3 software. Three analysis sets, the intention-to-treat set (ITT), the per-protocol analysis set (PPS) and the safety analysis set (SAS), will be used for assessing the data. FAS and PPS will be used for assessing baseline characteristics and clinical efficacy, SAS will be used for assessing the safety. All statistics will be two-sided tests, P < 0.05 is considered statistically significant. Quantitative data will be expressed as the mean, median, standard deviation, minimum, and maximum, and analyzed using the t-test or Wilcoxon rank-sum test, whereas qualitative data will be analyzed using the chi-square test and Fisher’s exact test. For the main outcome, the number of cases, mean, median, standard deviation, minimum, and maximum will be calculated, its changes relative to baseline after treatment will be compared within each group using a paired-samples t test or the Wilcoxon signed-rank test; changes relative to baseline after treatment will be compared between groups using an independent-samples t test or the Wilcoxon rank-sum test. For the secondary outcomes, the changes in vision, blood glucose, blood lipids, urinary albumin excretion rate, and TCM symptoms will be assessed, and their changes relative to baseline after treatment will be described, the number of cases, mean, median, standard deviation, maximum, and minimum will be calculated and compared within each group using a paired-samples t test or the Wilcoxon signed-rank test; changes relative to baseline after treatment will be compared between groups by an independent-samples t test or Wilcoxon rank-sum test. Statistical analysis will be completed by the third-party statisticians.
Oversight and monitoring
Quality control will run through the whole test process. Before the trial starts, the protocol will be sent to each center, and all research assistants will be trained according to a standardized operation practice (SOP). When the trial starts, the clinical research coordinator (CRC) will inspect and monitor the data collection process regularly, they will understand the progress of the trial, review the CRFs, confirm the informed consent form, inspect the selection of participants and the consistency of intervention drugs and protocols, the consistency of index filling and original data, and record of adverse events, etc. Whether the intervention drugs will be stored to meet the requirements or not will also be checked, drugs distribution and recovery should be recorded. When the trial ends, the CRFs and data will be kept intact and filed in time. The third-party quality control will be implemented.
Dissemination plans
The results will be disseminated through peer-reviewed journal articles and presented abstracts and posters at scientific conferences in the field of diabetes and TCM, as well as the general public through internet and newspaper.