4.0 Discussion
4.1 Findings in the Context of the Broader Literature
As shown in the previous section, the six randomised controlled trials selected for inclusion in this review were inconclusive about whether acupuncture, in comparison to sham acupuncture, is effective at reducing systolic and/or diastolic blood pressure in people with hypertension. Based on these findings, it seems reasonable to conclude that acupuncture may, but will not necessarily, have a positive effect on hypertension. It also seems reasonable to conclude that acupuncture is unlikely to cause harm to those who choose to use it. However, this must be understood in the context of the broader literature on acupuncture and hypertension.
Half of the trials (n=3, 50.0%) concluded that active acupuncture is more effective than sham acupuncture for reducing blood pressure in people with hypertension (Flachskampf et al., 2007; Yin et al., 2007; Zheng et al., 2018). Across these three studies, the blood pressure of people receiving acupuncture decreased by an average of 7.0mmHg. It is uncertain whether this can be considered a ‘significant’ reduction in clinical or physiological terms. This is particularly true considering the research which shows that treatment with anti-hypertensive medications reduces blood pressure by an average of 13.6mmHg (systolic, for single medications) to 17.3mmHg (systolic, for combination medications) (Bronsert et al., 2013). Law et al. (2009) suggests that a reduction of ≥10mmHg (systolic) must be achieved if the person’s risk of hypertension-related cardiovascular disease is to be significantly reduced.
This review has shown that not only are the effects of acupuncture on a person’s blood pressure small, these effects are also variable: although half of the trials concluded that active acupuncture is more effective than sham acupuncture for reducing blood pressure in people with hypertension, the other half (n=3, 50.0%) returned less-positive results (Macklin et al., 2006; Kim et al., 2012; Zheng et al., 2016). If a patient were to choose to undergo acupuncture for their hypertension, it therefore seems reasonable that a nurse recommends they continue with their prescribed anti-hypertensive medication – that is, that acupuncture is used as an adjunctive treatment. However, it must be emphasised that this review did not consider the effects of acupuncture alone versus acupuncture in combination with anti-hypertensive medications (though half of the trials selected for review permitted patients to take anti-hypertensive medications while receiving acupuncture [Flachskampf et al., 2007; Yin et al., 2007; Zheng et al., 2016]). As two or more anti-hypertensive medications may have a cumulative effect on lowering a person’s blood pressure (Bronsert et al., 2013), it is possible that anti-hypertensives plus acupuncture may have the same effect. Further research on acupuncture in combination with anti-hypertensive medications is important to inform practice.
Another important finding from this review is that the effects of acupuncture on hypertension are unlikely to be sustainable beyond the intervention period (Macklin et al., 2006; Flachskampf et al., 2007). This is problematic because essential hypertension is a chronic disease and one, therefore, which requires effective long-term management (Chen, 2012). If a patient were to choose to undergo acupuncture for their hypertension, it therefore seems reasonable that a nurse recommen
