Acupuncture for the treatment of overactive bladder: A systematic review and meta-analysis

This study represents an important contribution to understanding the role of acupuncture in the treatment of overactive bladder, a condition that affects millions of people around the world. Overactive bladder is characterized by sudden, uncontrollable urge to urinate, frequently accompanied by increased daytime and nighttime urinary frequency, with or without urinary incontinence. This syndrome, defined mainly by patient-reported symptoms, results from involuntary contractions of the bladder detrusor muscle during the filling phase, although only about 64% of patients show this detectable change on specific tests.

Conventional treatment of overactive bladder follows a stepped approach, starting with conservative measures such as behavioral modifications and pelvic floor exercises. When these measures prove insufficient, anticholinergic medications are introduced; they block the muscarinic receptors responsible for involuntary bladder contractions. However, these medications produce significant side effects, including dry mouth, blurred vision, constipation, and fatigue, leading many patients to discontinue treatment. Studies show that only 17% to 35% of patients continue taking the medication after one year of use.

In more severe cases, invasive procedures such as neuromodulation or botulinum toxin injections may be required, which leads many patients to seek alternative therapies.

To address this gap in scientific knowledge, the researchers conducted a comprehensive systematic review and meta-analysis, rigorously following established protocols for this type of research. The study was prospectively registered in the international PROSPERO database and followed PRISMA guidelines to ensure methodological quality. The search was performed in twelve different databases, including Western databases such as PubMed and EMBASE, and Eastern ones such as Chinese and Korean databases, covering publications from inception to February 2022. Only randomized clinical trials comparing acupuncture with placebo, conventional medications, or usual care in adult patients with non-neurogenic overactive bladder of any cause were included.

The results of this research, based on 30 studies involving more than 2,000 patients, offer promising evidence about the efficacy of acupuncture. When compared with sham acupuncture (placebo), true acupuncture demonstrated significant superiority in reducing overactive bladder symptom scores and urinary frequency. Even more impressive was the finding that acupuncture proved as effective as conventional anticholinergic medications in improving symptoms but with a significantly lower incidence of adverse events. This finding is particularly relevant given the tolerability problems that lead many patients to discontinue drug treatment.

In addition, when acupuncture was combined with medications, the results were superior to medication alone, suggesting a beneficial synergistic effect.

The clinical implications of these results are substantial for both patients and clinicians. For patients, acupuncture emerges as a viable and safe therapeutic option, particularly attractive for those who experience unacceptable side effects with medications or prefer more natural approaches. The technique proved to be well tolerated, with adverse events limited to minor local reactions such as pain at the insertion site, mild bleeding, or bruising. For clinicians, these findings suggest that acupuncture could be incorporated into the treatment algorithm for overactive bladder, either as a single therapy or in combination with medications, especially in patients who do not respond adequately or who do not tolerate conventional pharmacological treatment.

However, it is essential to acknowledge important limitations of this study that temper the initial enthusiasm with the results. The methodological quality of the included studies was predominantly low or very low, as assessed by the GRADE system, considered the gold standard for evaluating the certainty of scientific evidence. Many studies showed significant methodological problems, including inadequate randomization and allocation concealment methods, lack of adequate blinding of participants and assessors, and small sample sizes. Additionally, high heterogeneity was observed among the studies, reflecting substantial differences in the acupuncture protocols used, populations studied, and outcome measures evaluated.

The predominance of studies conducted in China (26 of 30 studies) also raises questions about the generalizability of the results to other populations and cultural contexts.

The inherent challenges of acupuncture research must also be considered. The development of an adequate placebo control for acupuncture remains a complex and controversial methodological issue in the field. Unlike medications, where a truly inert placebo can easily be created, sham acupuncture can produce its own physiological effects, making it difficult to distinguish the specific effects of acupuncture from placebo effects. In addition, complete blinding is virtually impossible in acupuncture studies, especially when compared with oral medications, because patients can easily identify which treatment they are receiving.

In conclusion, although this study represents the most comprehensive evaluation of acupuncture for overactive bladder to date, offering encouraging evidence about its efficacy and safety, future studies of greater methodological rigor are needed to definitively establish the role of acupuncture in the treatment of this condition. Future research should focus on large-scale multicenter studies, with rigorous methodology, standardized acupuncture protocols, and uniform outcome measures. It would also be valuable to investigate which patient populations benefit most from acupuncture, determine optimal treatment protocols, and explore the mechanisms by which acupuncture exerts its effects on bladder function. While we await more definitive evidence, current results suggest that acupuncture can be considered a promising and safe therapeutic option for patients with overactive bladder, especially those who do not respond adequately or do not tolerate conventional treatments.