Traditional Chinese Medicine Shows Improvements in Airway Remodeling Due to Asthma

Traditional Chinese medicine, alone or in combination with conventional medicine, helped to alleviate airway remodeling symptoms for patients with asthma, according to results of a study published in the European Journal of Integrative Medicine. However, investigators added that additional randomized trials are still needed to confirm the benefits of traditional Chinese medicine.

According to the study authors, airway remodeling is when the airway has irreversible structural changes and is one of the driving forces of asthma. It can affect the airway muscles, epithelium, blood vessels, and extracellular matrix. In previous studies, investigators found that traditional Chinese medicine might help to treat airway inflammation, airway hyperresponsiveness, and airway remodeling, the study authors said. However, they noted that the effects have not been systematically reviewed, so their aim was to conduct a systematic review of randomized control trials to evaluate traditional Chinese medicine on airway remodeling.

Investigators gathered peer reviewed publications in both Chinese and English using the search terms “asthma,” “airway remodeling,” “traditional Chinese medicine," and “randomized controlled trial” from inception to March 2022. The populations that were included were individuals with a primary diagnosis of asthma that was based on at least 1 standardized international or domestic diagnostic criteria, and a broad range of traditional Chinese medicine interventions, regardless of frequency, session duration, and modalities, were used. Further, investigators included traditional Chinese medicine in combination or without pharmaceutical treatment for asthma.

The primary outcomes were lung function and the levels of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinases-1 (TIMP-1) after treatment. Secondary outcomes included type, frequency, and severity of adverse effects, according to the study authors.

Investigators included 20 studies in the final systematic review, after excluding studies for no mention of airway remodeling, wrong outcomes, wrong study design, duplicates, wrong comparator, and wrong intervention, among other reasons. In total, 1790 individuals were included, with 899 in the treatment group and 893 in the control group. Patients ranged from 3 to 79 years of age and traditional Chinese medicine interventions were given for anywhere between 5 hours to 3 months. The interventions included Chinese herbal compounds (14 studies), Chinese herbal compounds combined with acupoint (2), Chinese patent medicine (2), moxibustion (1), and single herbs (1), according to the study authors.

According to the results, traditional Chinese medicine alone or in combination with pharmacotherapy did improve lung function and decreased the levels of MMP-9 and TIMP-1 in patients with asthma. The 5 trials that showed a statistically significant improvement in FEV1 and FVC had interventions including Xuanfei Jiejing decoction and conventional pharmacotherapy, Cordyceps sinensis, Wuhu decoction with acupoint application and comprehensive rehabilitation, Geze decoction with conventional pharmacotherapy, Yanghe Pingchuan granules with conventional pharmacotherapy, and Chuanben recipe and conventional pharmacotherapy, according to the study authors.

Two trials demonstrated statistically significant improvement in TIMP-1 expression, including Mailuoning injection and Jiawei Shegan Mahuang decoction. Additionally, 8 trials showed statistically significant improvements in MMP-9 levels and included interventions such as Mailuoning injection combined with conventional pharmacotherapy and comprehensive rehabilitation, Suhuang Zhike capsules, Xuanfei Jiejing decoction, Cordyceps sinensis, Wuhu decoction combined with acupoint, self-made Pingchuan decoction, and Geze decoction, according to the study authors.

Five trials reported on adverse events, which included nausea, headache, and vomiting.

The study authors reported that there was a very low to low range of certainty of evidence, and the trials had either unclear bias or high risk of bias.

Reference

Lv YI, Song JZ, Huang Y, et al. Traditional Chinese medicine for airway remodelling in patients with asthma: A systematic review of randomized controlled trials. Eur J Integr Med. 2024;102354. doi:https://doi.org/10.1016/j.eujim.2024.10235