Hypertension is a wider and deeper problem than high blood pressure alone. It is not one problem, it is a set of problems. The value we read on the arm is only the number which reaches us at the end. Behind that number there is the autonomic nervous system, the vessel wall, the kidney, the hormonal balance, and the level which the brain has accepted as normal.
For this reason I follow closely the studies which examine acupuncture not as a replacement for medication but as something added on top of it. One of these was carried out at Kyung Hee University Hospital in Seoul between January and May 2004, and was published in Neurological Research in 2007. Below I explain what was done and what came out of it.
How was the study set up?
Forty-one volunteers were included. Systolic pressure of 120 mmHg and above, or diastolic pressure of 80 mmHg and above, was enough to enter. Those at 140/90 and above were taken only if they were already using medication. Those at 180/100 and above were not taken at all, in order not to create a risk during the study. Secondary hypertension, unstable risk factors, a weight-loss programme, any change of medication in the previous month, severe pain, atrial fibrillation and kidney insufficiency were reasons for exclusion.
The patients were divided into two groups by computer. One group received real acupuncture. The other received a sham application made with Park’s sham needle, which touches the skin but does not pass through it. Neither the patients nor the person who measured the pressure knew which patient was in which group. Everybody who was on antihypertensive medication continued it exactly as before, without any change of dose.
Both groups were asked to walk thirty minutes a day at an easy pace and to practise ten minutes of slow, deep breathing, and to keep a diary of this. Pressure was measured on the right upper arm with an automatic device, lying down, after five minutes of rest, as the average of three readings. At the beginning this measurement was repeated six times, and at the fourth and eighth weeks three times.
Which points were used?
The points were not the same for everybody, and this is the part of the study which interests me most. Four prescriptions were prepared according to Saam acupuncture, and the one suitable for the constitutional condition of the patient was chosen: ST36, LI11 and BL25 for the large intestine; SP3, LU9 and BL13 for the lung; KI7, KI2 and CV4 for the kidney; LI1, GV14 and GB20 for the bladder. When a psychological factor was in the foreground, PC6 and HT7 were added. Once the prescription was chosen for a patient it was not changed until the end. The needle was turned slowly until the Deqi sensation was obtained and was then withdrawn immediately, as in the classical application. Seventeen sessions were made over eight weeks, with three or four days between them.
What happened to the blood pressure?
Thirty of the forty-one patients finished the eight weeks, fifteen in each group. The leaving rate was 27 per cent, and the reasons were work, distance to the hospital, knee pain and personal reasons. The two groups were similar at the start: average age 52 and 54, eleven and ten women, body mass index 25.0 and 25.3, and every single patient was using medication, for 3.4 and 4.2 years on average.
In the real acupuncture group the average pressure was 136.8/83.7 mmHg at the beginning, 134.1/83.7 at the fourth week, and 122.1/76.8 at the eighth week. The fall over the whole period was 14.8 mmHg in systolic and 6.9 mmHg in diastolic pressure.
In the sham group the same values were 133.1/81.8 at the beginning, 130.5/80.7 at the fourth week and 129.1/80.7 at the eighth week. The fall was 4.0 and 1.1 mmHg, and it did not reach statistical meaning.
There is one point here which I find more important than the numbers themselves. Up to the fourth week the two groups were practically the same; the difference between them was not meaningful. The separation happened in the second half, between the fourth and the eighth week. This is exactly what we see in the clinic. The body does not give up the level it has accepted in one or two sessions.
What else was followed?
The general health feeling of the patients improved in both groups. The pain score fell only in the real acupuncture group. The expectation and satisfaction score also rose only in the real group, and again in the second half, in the same period when the pressure was coming down.
Alcohol, smoking, salt habit, body weight and the walking and breathing exercises did not change during the eight weeks. Attendance was almost equal in the two groups, around sixteen sessions each, and compliance with the exercises was above eighty-five per cent in both. Therefore the fall in pressure cannot be attributed to these. The blinding also held: not a single patient left the study because they understood that the needle was not entering.
The only adverse effect recorded was a small spot of bleeding at the needle site. It was seen in eight patients and in about five per cent of the sessions.
How is this effect explained?
The autonomic nervous system has a share in the formation of hypertension. When the sympathetic side works above its measure and the balance is disturbed for a long time, this is by itself a risk for the heart and the vessels. The explanation offered for acupuncture is that it reduces this excessive sympathetic activity, and the cholinergic system together with the opioid receptors in the brain stem are shown as the place where this happens. The change in heart rate variability after needling, which differs according to the region stimulated, supports the same idea.
The authors also note that the earlier work in this field was methodologically weak. In those studies the needle was inserted at wrong points, or the points were not chosen by a proper diagnosis, and the results were contradictory. The value of this study is that it used a sham needle which does not enter the skin, so that a real double-blind comparison became possible.
What the study does not say
The number of patients is small, the period is eight weeks, and there is no follow-up afterwards. We do not know what happened to these patients in the following months. Only the patients who completed the study were analysed, and every one of them was already on medication.
For this reason the result must be read exactly as it is written. Acupuncture gave an additional benefit on top of the treatment the patient was already receiving. This is not a study which shows that medication can be stopped, and it should not be presented in that way. What it does show is that the pressure can be brought down further while the medication stays the same, that this happens in the second half rather than immediately, and that it happens without any serious side effect. In a condition which is managed for a whole lifetime, this is not a small thing.
The study summarised above: Yin C, Seo B, Park HJ, Cho M, Jung W, Choue R, Kim C, Park HK, Lee H, Koh HG. Acupuncture, a promising adjunctive therapy for essential hypertension: a double-blind, randomized, controlled trial. Neurological Research 2007;29(Supplement 1):S98–S103. doi:10.1179/016164107X172220. The commentary belongs to Dr. Mehmet Salih Özaytürk; the study is the work of its own authors.
Why the brain accepts a raised blood pressure as its own normal level, and how hypertension is approached at the clinic, is explained on the hypertension treatment page.