Efficacy of photobiomodulation associated with exercise in patients with fibromyalgia: A systematic review and meta-analysis.

PURPOSE: To conduct a literature review on the effects of photobiomodulation associated with exercise in patients with fibromyalgia. METHODS: The databases included were PubMed, Cochrane Library, the Physiotherapy Evidence Database (PEDro), Scopus, Web of Science, Embase and LILACS. Grey literature: Google Scholar, Open Grey and ProQuest. The risk of bias was assessed using the Cochrane RoB 2 tool. Outcomes of pressure pain threshold, pain intensity, functional capacity, symptoms of depression and quality of life were analysed. RESULTS: No statistically significant effects were observed in any of the outcomes studied: pressure pain threshold (MD = -0.36; 95% CI: -1.50 to 0.79; p = 0.54; I2 = 80%); pain intensity (MD = 1.07; 95% CI: -1.02 to 3.16; p = 0.32; I2 = 95%); objective functional capacity measured by the TUG (MD = 0.26; 95% CI: -0.13 to 0.65; p = 0.20) and the 6MWT (MD = -81.92; 95% CI: -236.21 to 72.37; p = 0.30; I2 = 93%). Similarly, subjective functional capacity (FIQ: SMD = 0.41; 95% CI: -1.36 to 2.18; p = 0.65; I2 = 0%), symptoms of depression (BDI: MD = 1.06; 95% CI: -6.29 to 8.42; p = 0.78; I2 = 53%) and quality of life (SF-36: MD = 6.29; 95% CI: -8.40 to 20.98; p = 0.40; I2 = 86%). Very low certainty means that the true effect is likely to be substantially different from the estimate. CONCLUSION: Based on very low certainty evidence (GRADE), this systematic review and meta-analysis found no statistically significant additional benefits of photobiomodulation combined with exercise compared to exercise alone for pain, function, depression, or quality of life. However, due to substantial heterogeneity, small sample sizes, and methodological limitations, the current evidence is insufficient to either confirm or definitively exclude a clinically meaningful additional effect. Further high-quality, adequately powered trials are needed.