A fascinating study in Korea1 published this August looked at the effects of acupuncture on endothelial dysfunction in patients with hypertension.
What exactly is endothelial dysfunction?
The endothelium is the inner lining of our veins and arteries and normally secretes substances that, amongst many other things, help to regulate blood flow and blood clotting2. Endothelial dysfunction is the term used where there is a reversible imbalance between these substances which can lead to high blood pressure and which plays an important role in the development of cardiovascular disease3. Testing for endothelial dysfunction has therefore become of great importance for predicting the risk of a patient developing cardiovascular problems such as high blood pressure, atherosclerosis, stroke and heart attacks. One such technique is called Flow-Mediated Dilation (FMD) which is used in the study reported below4.
What did the study aim to show?
The study looked at:
a) whether or not acupuncture improves endothelial dysfunction in patients with hypertension
b) if the above was true, which acupuncture points presented with the most benefit.
What kind of trial was this?
The trial was:
The patients are randomly assigned to treatment groups which ensures that both groups remain comparable at the beginning of the trial.
This means that neither the investigator nor the patient are aware of which of the treatments were being administered, although this is difficult to achieve in acupuncture trials from the investigator perspective. It is unclear from the details how the investigator was blinded in this trial.
The patients were aware that as well as the acupuncture on ‘true acupuncture’ points, they could be offered an inactive treatment on ‘placebo points’ which would have no effect on their symptoms.
The patients received a sequence of different treatments for the duration of the study.
What treatments did patients receive?
15 patients suffering with hypertension received a randomised sequence of four acupuncture treatment phases consisting of needling the following points:
Phase 1: Zu San Li ST36
Phase 2: Nei Guan PC6
Phase 3: Zu San Li ST36 and Nei Guan PC6
Phase 4: Placebo points
Points were needled on both sides for 15 minutes. The Flow-Mediated Dilation (FMD) and blood pressure were assessed before and after each acupuncture treatment. A 7 day break was given before the next acupuncture treatment was offered.
What were the results?
The researchers observed significant improvements in FMD in patients who received acupuncture at Zu San Li ST36 and at both Zu San Li ST36 and Nei Guan PC6 compared with patients who received acupuncture at Nei Guan PC6 and at placebo points.
What do the results from the trial mean?
The researchers concluded that ‘this study demonstrates that acute treatment of acupuncture in hypertensive patients improves endothelial dysfunction.’
This was a pilot study which is designed to be a small scale test study and despite the relatively small number of participants, the results are both encouraging and fascinating. Using objective outcome measures such as FMD means that results are not dependent on the judgement of the researcher or the patient and therefore provides more clinically valid and reliable results. However, due to limited access to the paper, it cannot be commented as to how adequate the placebo treatment was in the trial nor how successfully the double blinding was carried out.
The overall conclusions drawn from the study support the need for this research to be carried out on a larger scale. Further studies should look also into the long-term effects that acupuncture has on endothelial dysfunction in order to explore the role in which acupuncture could potentially play in reducing cardiovascular risk.
- Park JM, Shin AS, Park SU, Sohn IS, Jung WS, Moon SK. The acute effect of acupuncture on endothelial dysfunction in patients with hypertension: A pilot, randomized, double-blind, placebo-controlled crossover trial. J Altern Complemen Med. 2010 Aug 1. Available from http://www.ncbi.nlm.nih.gov/pubmed/20673141 [Accessed 3 August 2010].
- Puddu P, Puddu GM, Zaca F, Muscari A. Endothelial dysfunction in hypertension. Acta Cardiol. 2000 Aug;55(4):221-32.
- Sitia S, Tomasoni L, Atzeni F, Ambrosio G, Cordiano C et al. From endothelial dysfunction to atherosclerosis. Autoimmun Rev. 2010 Jul 30. Available from: http://www.ncbi.nlm.nih.gov/pubmed/20678595. [Accessed 3 August 2010].
- Korkmaz H, Orhan O. Evaluation of endothelial dysfunction: flow-mediated dilation. Endothelium-J Endoth. 2008 Jul;15(4):157-163.