Kynurenic Acid and Acupuncture on Chronic Pain

Abstract

Introduction: Approximately 20% of the population experiences chronic pain. Chronic pain is characterized as a persistent sensation of discomfort that lasts for a duration exceeding three months subsequent to the experience of a traumatic incident or inflammation. Chronic pain can present itself in either intermittent or chronic patterns, often accompanied by a parasympathetic physiological response. Chronic pain is linked to a range of adverse consequences, such as impairments in the execution of everyday activities, dependence on opioid analgesics, heightened levels of anxiety, and manifestations of depressive symptoms. The therapeutic effectiveness of tryptophan and its metabolites, including kynurenic acid, exhibits encouraging indications in the management of chronic pain. Acupuncture has been utilized as an adjunctive therapeutic modality for centuries in the management of chronic pain. Acupuncture possesses the capacity to influence individuals' perception of pain at an emotional level, inducing a tranquil emotional state and promoting heightened relaxation in patients.

Objectives: This study aims to systematically investigate the effects of acupuncture on kynurenic acid, a variable that functions as an objective measure of pain.

Methods: We conducted a literature review in the PubMed, Scopus, and Web of Science databases referring to how acupuncture and kynurenic acid contribute to reduction of chronic pain.

Results: The acupuncture interventions varied in terms of techniques, frequency, and duration. The findings revealed a consistent trend of increased kynurenic acid levels following acupuncture treatments in chronic pain patients. However, the magnitude of this increase varied among studies. Additionally, several studies reported improvements in pain severity and reduction in opioid reliance among participants receiving acupuncture. Methodological quality assessments indicated moderate to high quality among the included studies. Despite the overall positive trend, some heterogeneity was observed in the response to acupuncture across different pain conditions. These results suggest that acupuncture may hold promise as a complementary therapy for chronic pain management, with kynurenic acid serving as a potential biomarker for monitoring treatment effectiveness.

Conclusions: Acupuncture has been shown to be beneficial in relieving chronic pain, and the use of kynurenic acid can aid in the objective assessment of its efficiency.