Effectiveness and safety of photobiomodulation therapy in diabetic peripheral neuropathy: Protocol for a systematic review and meta-analysis

Introduction: Diabetic peripheral neuropathy (DPN), a widely prevalent complication in patients with type 2 diabetes, exerts a significant influence on patients’ overall health and financial circumstances. Photobiomodulation therapy is one of the means of physical therapy for DPN. Although preliminary findings suggest the efficacy of photobiomodulation therapy in alleviating peripheral neuropathy, the existing literature lacks substantial evidence regarding its safety and effectiveness specifically in the context of diabetes-related peripheral neuropathy. Therefore, we plan to arrive at more distinct findings through systematic evaluation and meta-analysis. Methods: We will conduct a comprehensive search for studies published from the beginning until October 1, 2023, using various databases including Web of Science, Embase, Cochrane Library, PubMed, AMED, Wanfang database, VIP database, China National Knowledge Infrastructure, and the Chinese Biomedical Literature database. Simultaneously, we will also search for the WHO International Clinical Trial Registration Platform, China Clinical Trial Registration Platform, and Clinical Trials.gov. Gray literature will be retrieved using Google Scholar and opengrey.edu. Only randomized controlled trials in Chinese and English were included, with no restrictions on publication status. The primary outcomes will include change of symptom scores, change of nerve conduction velocity. Additional outcomes will encompass quality of life, change in pain, blood glucose levels after fasting and 2 hours after eating, levels of glycosylated hemoglobin, and any adverse events associated with photobiomodulation therapy. Reman V.5.4 and R language will be used for the meta-analysis. Assessment of potential bias will be conducted through Cochrane risk of bias 2 tool (RoB 2.0) and Physiotherapy Evidence Database (PEDro) scale. Registration: PROSPERO (registration number: CRD42023466586). Discussion: This meta-analysis aims to assess the efficacy and safety of photobiomodulation therapy as a potential treatment for diabetic peripheral neuropathy (DPN), and providing a straightforward and convenient therapeutic for patients. Additionally, it expands the range of treatment alternatives available to healthcare professionals managing DPN.