Objective:

2

To evaluate the efficacy and safety of blood-letting therapy (BLT) in treatment of hypertension.

Methods:

2

A comprehensive electronic and manual bibliographic searches were performed in Cochrane Central Register of Controlled Trials

Excerpt Medica Database (EMBASE)

PubMed

China National Knowledge Infrastructure

Chinese Scientific Journal Database

Chinese Biomedical Literature Database

and Wanfang Database to identify randomized controlled trials (RCTs) in which hypertensive patients were treated with BLT or BLT plus antihypertensive drugs (BPAD) against placebo

no treatment or antihypertensive drugs. The Cochrane Risk Assessment Tool was used to assess the methodological quality of trials. The Review Manager 5.3 software was used for meta-analysis.

Results:

2

A total of 7 RCTs with 637 hypertensive patients from 1989 to 2017 were identified. Compared with antihypertensive drugs

blood pressure was significantly reduced by BLT (RR=1.21

95% CI: 1.01 to 1.44

P

=0.03; heterogeneity:

P

=0.06

I

2

=60%) and BPAD (RR=1.25

95% CI

1.02 to 1.53

P

=0.03; heterogeneity:

P

=0.01

I

2

=71%). Moreover

a significant improvement in Chinese medicine syndrome by BLT (RR=1.32; 95% CI: 1.14 to 1.53

P

=0.0002; heterogeneity:

P

=0.53

I

2

=0%) and BPAD (RR=1.47; 95% CI: 1.06 to 2.04

P

=0.02; heterogeneity:

P

=0.13

I

2

=56%) was identified. The reported adverse effects were well tolerated.

Conclusions:

2

Although some positive findings were identified

no definite conclusions regarding the efficacy and safety of BLT as complementary and alternative approach for treatment of hypertension could be drew due to the generally poor methodological design

significant heterogeneity

and insufficient clinical data. Further rigorously designed trials are warranted to confirm the results.