Effectiveness and safety of Ginkgo biloba extract (GBE50) in the treatment of dizziness caused by cerebral arteriosclerosis: a multicenter,double-blind,randomized controlled trial

SHA Rina,TANG Lu,DU Yawei,WU Shengxian,SHI Huawei,ZOU Hongxin,ZHANG Xuran,DONG Xinglu，ZHOU Li

SHA Rina,ZOU Hongxin,ZHANG Xuran,the First clinical medical college,Beijing University of Chinese Medicine,Beijing 100029,China

TANG Lu,DU Yawei,WU Shengxian,SHI Huawei,DONG Xinglu,ZHOU Li,Department of Neurology,Dongzhimen Hospital,Beijing University of Chinese Medicine,Beijing 100700,China

Abstract OBJECTIVE: To evaluate the effectiveness and safety of Ginkgo biloba extract (GBE50) in the treatment of dizziness caused by cerebral arteriosclerosis.METHODS: This was a multi-center,double-blind,double-dummy,positive -controlled,parallel randomized controlled clinical trial with 1∶1 allocation.We recruited 404 patients with dizziness caused by cerebral arteriosclerosis (blood stasis symptom pattern) in 10 hospitals in China.GBE50 group received GBE50 and Naoxinqing tablet (NXQ) of mimetic agent,control group received NXQ and GBE50 of mimetic agent.The main outcome was Traditional Chinese Medicine (TCM)symptom pattern score of blood stasis after 6 weeks.The secondary outcomes were changes in the dizziness handicap inventory (DHI) score,vertigo visual analogue scale (VAS) score,the university of California vertigo questionnaire (UCLA-DQ) score and single-item symptom score of TCM from baseline to 2,4 and 6 weeks.Safety indicators included the incidence of adverse events,severe adverse events and laboratory examination including blood routine,liver function,renal function,and so forth.RESULTS: The total effective rate of TCM symptom pattern score in the GBE50 group after 6 weeks of treatment was higher than that in the control group,the difference in rate was statistically significant (92.67% vs 83.07%,P=0.004).Compared with the control group,there was no difference in the incidence of adverse reactions (9.95% vs 14.85%,P=0.136).CONCLUSION: The treatment of dizziness caused by cerebral arteriosclerosis with GBE50 is effective,safe and reliable.

Keywords: Ginkgo biloba;intracranial arteriosclerosis;dizziness;treatment outcome;randomized controlled trial

1.INTRODUCTION

Dizziness is a common neurological disease affecting 15%-30% of adults each year.1The probability of developing dizziness increases linearly with advanced age,and the survey data have shown that vascular dizziness accounting for a higher proportion of the elderly.2,3Cerebral arteriosclerosis is the main cause of vascular dizziness.4The treatment of dizziness caused by cerebral arteriosclerosis in modern medicine is mostly limited to improving the blood supply of inner ear and secondary prevention of cerebral arteriosclerosis.5Betahistine,a common used drug for improving blood supply of the inner ear6with current data favoring a peripheral mode of action,has no definite evidencebased basis to confirm its curative effect on dizziness caused by cerebral arteriosclerosis.Meanwhile the secondary preventive drug of cerebrovascular disease can only delay the progression of arteriosclerosis,and the effect of improving dizziness is not significant.Blood stasis are the basic pathogenesis of dizziness caused by cerebral arteriosclerosis.The concept of dizziness caused by blood stasis was first described by Yang Renzhai during the Song Dynasty.In the Qing Dynasty,Wang Qingren further developed this point.7In recent years,promoting blood circulation for removing blood stasis therapy for dizziness caused by cerebral arteriosclerosis has obvious effect.Ginkgo biloba extract (GBE50) is a Traditional Chinese Medicine (TCM) extract with the effect of promoting blood circulation and removing blood stasis.It is widely used in cardiovascular and cerebrovascular diseases at home and abroad.However,confirmatory studies to validate the curative effect of dizziness caused by cerebral arteriosclerosis are yet lacking.The objective of this current project was to evaluate its effectiveness and safety for dizziness caused by cerebral arteriosclerosis.

2.METHODS

2.1.Study design

This was a multi-center,double-blind,double-dummy,positive-controlled,parallel randomized controlled clinical trial with 1∶1 allocation.And registered on the Chinese Clinical Trial Registry with registration number ChiCTR1900020572.

The study protocol was approved by the Ethics Committee of Dongzhimen Hospital,Beijing University of Chinese Medicine,and followed the tenets of the Declaration of Helsinki.

2.2.Randomization and blinding

This study used a center-based stratification and block a randomization method.The drugs of each center were coded according to the random numbers,and were assigned sequentially.The study set up Two-level blind method: the drugs for GBE50 and control groups were uniformly packaged and had no differences in appearance;code of packaging cassette of drugs was blinded with the help of opaque envelopes.The emergency letters were sent to each of the center with drugs until the end of the trial.The participants and investigators (including statisticians) were blinded to the treatment and group throughout the study.

2.3.Participants

Totally 404 patients were enrolled from January 2019 to December 2019 who came from 10 hospitals in China(Dongzhimen Hospital of Beijing University of Chinese Medicine,the Xi′an TCM Hospital,Fenyang Hospital in Shanxi province,the second affiliated Hospital of Shandong University of TCM,the second affiliated Hospital of Shanxi University of TCM,the Weifang TCM Hospital,the Luoyang first TCM Hospital,the Kaifeng TCM Hospital,the Luohe TCM Hospital,the Affiliated Hospital of Yanan University.

2.4.Diagnostic criteria

Western medicine diagnostic criteria referred to the diagnostic criteria for mild cerebral arteriosclerosis revised by the third national conference of neuropsychiatric surgery and cerebral atherosclerosis screening and diagnosis and treatment standard (2014).8In TCM,the main symptoms of blood stasis symptom pattern are defined as dizziness,dazzling and blurring of vision,the secondary symptoms include headache,tinnitus,insomnia,amnesia,numbness of the limbs,the tongue is dark or dark purple,or has ecchymosis or has sublingual varices,the pulse is uneven pulse or pulselessness,or deep and string-like pulse or string-like and late pulse.Patients with main symptoms,accompanied by the two or more secondary symptoms and tongue pulse could be defined as blood stasis symptom pattern.9-11

2.5.Inclusion criteria

(a) All the patients fulfilled the Criteria for the diagnosis of mild cerebral arteriosclerosis with dizziness;(b) all the patients fulfilled the TCM symptom pattern differentiation criteria of blood stasis symptom pattern;(c) all the patients were 40-70 years old,gender unlimited;(d) all the patients had recent no-fertility plan(A negative pregnancy test within 72 h of the start of treatment was required for all women of reproductive age) and agreed to use effective non-drug contraception during the study;(e) all the patients agreed to participate in this clinical trial and signed the informed consent voluntarily.

2.6.Exclusion criteria

(a) Vertigo caused by other causes,including nonvascular central vestibular vertigo,benign paroxysmal positional vertigo,vestibular neuronitis,labyrinthitis,Meniere′s disease,vertigo caused by intracranial tumors,vestibular migraine vertigo,vertigo caused by hypotension or hypertension,hypoglycemia,psychotic vertigo,motion sickness or medicated vertigo;(b)combined with heart failure,or advanced tumors,persons with severe or progressive diseases of the blood,central nervous system (such as history of epilepsy) or other systems;(c) combined with severe liver and kidney disease or abnormal liver and kidney function examination (ALT,AST ≥ 1.5 times upper normal limit,Cr ＞ upper normal limit);(d) poor control of hypertension,Patients with system antihypertensive treatment who blood pressure still ＞ 140/90 mm Hg;(e)patients had other diseases requiring medications which have similar main function to the experimental drug;(f)complicated with neurological or mental disorders and unable to cooperate with the researchers;(g) confirmed or suspected history of alcohol or drug abuse;(h)Pregnant,planning to become pregnant,or lactating;(i)participated in a clinical intervention trial within the past 3 months;(j) allergy to the test drugs or composition in the test drugs.

2.7.Interventions

After the screening period,eligible patients were randomly assigned to either the GBE50 group or the control group.GBE50 group received GBE50 (produced by Zhejiang Jiu Xu Pharmaceutical Co.,Ltd.,Jinhua,China.SFDA approval number: Z20050393,40 mg,three times daily for 6 weeks) and NXQ of mimetic agent,control groups received NXQ (produced by Hutchison Whampoa Guangzhou Baiyunshan Chinese Medicine Company Limited,Guangzhou,China,SFDA approval number Z44021765,1.23 g,three times daily for 6 weeks)and GBE50 of mimetic agent.GBE50 and NXQ of mimetic agent were produced by Zhejiang Jiu Xu Pharmaceutical Co.,Ltd.,Jinhua,China.

2.8.Outcome indicators

The primary outcome was TCM symptom patterns score of blood stasis after 6 weeks.Evaluation of clinical effectiveness based on reduction rate,treatment was ineffective if the symptoms and signs were not significantly improved and symptom scores decrease less than 30%.Reduction rate=(pre-treatment score-posttreatment score)/ pre-treatment score × 100%.The secondary outcomes were changes in the the dizziness handicap inventory (DHI) score,vertigo visual analogue scale (VAS) score,the university of California vertigo questionnaire (UCLA-DQ) score and single-item symptom score of TCM from baseline to 2,4 and 6 weeks.

2.9.Safety assessment

Incidence of adverse events,serious adverse events and laboratory examination including blood routine,liver function,renal function,and so forth.

2.10.Statistical analysis

All data were performed using SAS 9.4 statistical software (NCSU,Raleigh,NC,USA).We used two sets of analyses: per protocol set and safety set.Measurement data were expressed as mean ± standard deviation,and the counting data were reported as frequencies and percentages.For comparison within the groups,paired ttest or Wilcoxon rank-sum test was applied.Comparison between groups was performed using the Wilcoxon ranksum test or independent samplet-test as indicated.Measurement data were evaluated using the independent samplet-test or Fisher’s exact test.Pvalue ＜ 0.05 was considered statistically significant,whilePvalue ＜ 0.01 was considered extremely significant.

3.RESULTS

3.1.Subjects

During the period from January 2019 to September 2019,a total 439 participants of dizziness caused by cerebral arteriosclerosis were initially screened.An additional,22 participants did not meet the inclusion criteria,13 participants satisfied the exclusion criteria.After screening,404 participants were randomly assigned in 1∶1 ratio to GBE50 group and control group.During the study,24 of 404 participants did not complete the trial.Among the participants,11 participants were in the trial group (5 were not completed,5 violated the trial program and 1 was poor medication compliance).13 were in the control group (6 were not completed,6 were violation of test program and 1 did not return for follow-up at the specified time).All the data from these 24 participants were excluded from the statistical analysis.The trial flow diagram is presented in Figure 1.

Figure 1 Study flowchart

3.2.Baseline characteristics

There were no significant differences in Baseline characteristics between the two groups (P＞ 0.05)(Table 1).

3.3.Evaluation of the effectiveness of TCM symptom patterns

Compared with the control group,the total effective rate of the GBE50 group at 2 and 4 weeks was not significant,and after 6 weeks of treatment was significantly higher than that of the control group,and the difference was statistically significant (P＜ 0.01) (Table 2).

Table 1 Baseline characteristics in GBE50 and control group ()

Table 1 Baseline characteristics in GBE50 and control group ()

Notes: SBP: systolic blood pressure;DBP: diastolic blood pressure;HR: heart rate;NXQ: Naoxinqing tablet.GBE50 Group received GBE50(40 mg,three times daily for 6 weeks) and NXQ of mimetic agent,control group received NXQ (1.23 g,three times daily for 6 weeks) and GBE50 of mimetic agent.P＞ 0.05 vs the control group.

Table 2 Comparison of Evaluation of the effectiveness of Traditional Chinese Medicine symptom patterns between two groups after 2,4 and 6 weeks

3.4.DHI score

There were no statistical differences between the GBE50 group and the control group at 2,4 and 6 weeks (P＞0.05).The difference between the DHI score and baseline score in the 6th week of treatment was higher than that in the control group (－33 ± 15vs－30 ± 15,P=0.0188) (Figure 2).

3.5.VAS score

There were no significant differences in VAS score on severity of dizziness symptoms the GBE50 group after 0,2 or 4 weeks of treatment compared with the control group (P＞ 0.05).After 6 weeks of treatment,the VAS score was significantly different from that of the control group (P=0.0008).The difference between the VAS score and baseline score in the 6th week of treatment was higher than that in the control group(－3.8 ± 1.6vs－3.2 ± 1.7,P=0.0001) (Figure 3).

3.6.UCLA-DQ score

There were no significant differences between the GBE50 and the control group after 0,2 or 4 weeks of treatment (P＞ 0.05).After 6 weeks of treatment,the UCLA-DQ score was significantly different from that of the control group (P=0.0056).The difference betweenthe UCLA-DQ total score and baseline score in the 6th week of treatment was higher than that in the control group (－9.46 ± 4.34vs－7.93 ± 4.39,P=0.0007)(Figure 4).

Figure 2 Comparison of the DHI score of two groups after 2,4 and 6 weeks of treatment

Figure 3 Comparison of severity VAS scores of dizziness symptoms at 2,4 and 6 weeks of treatment

Figure 4 Comparison of UCLA-DQ scores at 2,4 and 6 weeks of treatment

3.7.Single-item symptom score of TCM

There were no significant differences between the two groups before using medicine (P＞ 0.05).Compared with the control group,the difference between the single-item symptom score of TCM in the 4th week of treatment(dizziness,amnesia) was statistically significant (P＜0.05).Compared with the control group,the difference between the single-item symptom score in the 6th week of treatment (dizziness,dazzling and blurring of vision,headache,amnesia) was statistically significant (P＜ 0.01)(Table 3).

3.8.Safety assessment

One patient in the trial group dropped out of the trial at the first follow-up,it was no safety evaluation after medication,and was not included in the SS.A total of 403 patients were included in the SS (201 in GBE50 group,202 in control group),Compared with the control group,there was no significant difference in the incidence of adverse reactions (9.95 %vs14.85%,P=0.136).There was one case of drug-related adverse events occurred in the experimental group,it showed that ALT,AST and GGT values were mildly increased,and resolved after concomitant medications (statins)discontinued.There was one case of severe adverse events occurred in the control group.After analysis,the severe adverse event was deemed unrelated to study medication.No serious adverse events occurred in the experiment group.No subjects discontinued the study due to adverse events during the trial (Table 4).

Table 3 Comparison of the single-item symptom score of TCM for 2,4 and 6 weeks of treatment ()

Table 3 Comparison of the single-item symptom score of TCM for 2,4 and 6 weeks of treatment ()

Notes: GBE50 group received GBE50 (40 mg,three times daily for 6 weeks) and NXQ of mimetic agent,control group received NXQ (1.23 g,three times daily for 6 weeks）and GBE50 of mimetic agent.aP ＜ 0.05,bP ＜ 0.01 vs the control group after 2,4 and 6 weeks.

Table 4 Adverse events in experiment and control groups [n (%)]

4.DISCUSSION

The result suggested that GBE50 can provide greater benefit at the sixth week after treatment with 92.67%effective rate compared with NXQ in 83.07%.In terms of safety,there was no significant difference in the incidence of adverse reactions between GBE50 group and the control group (9.95%vs14.85%,P=0.136).These findings were found to be in agreement with previous studies that used GBE50 to treatment dizziness caused by cerebral arteriosclerosis.12,13Furthermore,the deficiency in cerebral blood flow and the cerebral circulatory disturbance may induce other clusters of symptoms,such as headache,numbness of the limbs,forgetfulness and so on.14The contents of evaluation of the effectiveness of TCM symptom patterns largely align with the abovementioned theory.Based on the results of individual symptom scores of TCM between the baseline and 6 weeks after commencing drugs treatment,GBE50 provided significantly better outcomes than NXQ on dizziness,headache,and forgetfulness while the difference in tinnitus,insomnia,and numbness of the limbs between the two groups was insignificant.According to the record ofRenzhai Zhi Zhi Fangof Yang Shiying,15blood stasis is the cause of dizziness in the theory of Chinese medicine.In view of blood stasis,TCM adopts the method of activating blood and removing blood stasis.The clinical symptoms of dizziness caused by cerebral arteriosclerotic is similar to the blood stasis symptom pattern described by TCM so both can be treated with the drugs of promoting blood circulation and removing blood stasis such as GBE50.It was documented inTreatise on Febrile Diseases16that he who is forgetful must has blood stasis,which points out the relationship between forgetfulness and blood stasis.In addition,Wang Qingren,a famous doctor during the Qing Dynasty,stated that the importance of activating blood circulation and removing blood stasis in treating headache.17A major feature of the theoretical system of TCM is dialectical treatment,tinnitus,numbness of hands and feet,and insomnia is mainly caused by deficiency of kidney,heart and spleen rather than blood stasis.18-20Therefore,these diseases are mostly treated with only activating blood circulation and removing blood stasis with a low success rate.Emotional disturbances,reduced self-autonomy and increased fear of falling have been reported in patients with dizziness,these are adverse impacts on the social and professional life of patients,especially for elderly patients.21,22The most used scales to assess quality of life are DHI,UCLA-DQ and VAS.23-25Our study showed an improvement of functional,physical,and emotional aspects associated with dizziness,with a significant reduction of two subscales (DHI-P,DHI-F) of DHI at the end of treatment.Scores on the VAS and UCLA-DQ also indicated that superiority of GBE50 over NXQ regarding to restore quality of life in dizziness patients.

There were also some limitations in this trial.Due to lack of study on drugs of combination of disease and symptom pattern and no demonstrative guidelines,we have no suitable control drugs to choose.So we can only retrieve indications of Chinese patent medicines which has been on the market for years to find suitable control drugs.In the future we need to explore in this regard to study more reasonable and standardized.

In conclusion,EGB50 provide great effectiveness in dizziness caused by cerebral arteriosclerosis and significantly improved accompanying symptoms like headache and forgetfulness,further improve the patients’recovery and eventually enhance the patients′ activities of daily living and quality of life.And the clinical application of GBE50 is safe.