Is Acupuncture Effective for Hypertension? A Systematic Review and Meta-Analysis

This systematic review and meta-analysis represents an important milestone in the scientific evaluation of acupuncture for arterial hypertension. The researchers analyzed 23 randomized clinical trials involving 1,788 patients with essential hypertension, seeking to definitively answer whether acupuncture is effective in reducing blood pressure. The methodology was rigorous, including searches across seven electronic databases and careful assessment of study quality. The results revealed a nuanced picture of the efficacy of acupuncture.

When used as adjuvant therapy to antihypertensive medications, acupuncture demonstrated significant benefits. The meta-analysis of two studies showed that patients who received acupuncture combined with medication had additional reductions of 7.47 mmHg in systolic pressure and 4.22 mmHg in diastolic pressure, compared with those who received only sham acupuncture plus medication. In addition, four studies demonstrated that the acupuncture-medication combination was superior to medication alone in terms of efficacy rate, with an odds ratio of 4.19. However, the results were less convincing for acupuncture as monotherapy.

Seven studies with 510 patients showed no significant difference between acupuncture and conventional medications in reducing blood pressure. Similarly, ten studies with 963 patients did not demonstrate superiority of acupuncture over medications in terms of efficacy rate. The most frequently used acupuncture points were LR-3 (taichong), LI-11 (quchi), GB-20 (fengchi), and ST-36 (zusanli), reflecting the traditional Chinese approach to hypertension. Treatment duration ranged from 7 to 56 days, with a mean of 28.5 days, and most studies reported obtaining 'Deqi,' a sensation considered important for the efficacy of acupuncture.

The clinical implications of these findings are significant. For patients who are already taking antihypertensive medications but still have suboptimal blood pressure control, acupuncture may offer additional benefit. This is particularly relevant considering that many hypertensive patients do not achieve blood pressure goals even with multiple medications. Acupuncture could therefore be considered an integrative therapy in the management of resistant hypertension.

However, several limitations should be considered. The methodological quality of the included studies was variable, with many presenting unclear risk of bias for crucial aspects such as allocation concealment and blinding. Heterogeneity between studies was substantial, with I² values ranging from 0% to 94%, suggesting important differences in the methods and populations studied. In addition, most studies were conducted in China, raising questions about applicability in other populations.

The safety of acupuncture remained inadequately reported in most studies. Only four studies described adverse events, including punctate bleeding and, in rare cases, hypertensive emergencies. This gap in safety documentation is concerning, especially considering that hypertensive patients may be at greater risk for certain complications. The authors emphasize that, although the results suggest a benefit of acupuncture as adjuvant therapy, the current evidence may not be sufficiently robust against methodological shortcomings and significant heterogeneity.

They recommend future studies with better quality control, including adequate allocation concealment, blinding of outcome assessors, and standardized measurements such as 24-hour ambulatory blood pressure monitoring.