Photobiomodulation Therapy in Hypertension Management-Evidence from a Systematic Review and Meta-Analysis.

Background: Hypertensive patients have difficulties in controlling blood pressure (BP), resulting in high mortality rates. There is a growing number of lab and human studies investigating the effects of photobiomodulation (PBM) therapy on hypertension. This motivated the current work to systematically assess existing literature and group evidence on the utility of PBM in BP management. Methods: A systematic review with meta-analysis was performed on randomized clinical trials (RCTs) and experimental animal studies assessing PBM treatments in hypertensive patients/animals. Five primary databases were assessed by two reviewers. Descriptive and quantitative analyses were performed separately for clinical and experimental studies. Results: A total of 197 articles were screened that identified four RCTs and five experimental studies for final inclusion. The clinical trials noted that PBM treatments reduced systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR), but with very low certainty. Experimental lab studies corroborated that PBM treatments reduced SBP, DBP, and mean arterial pressure (MAP) while increasing nitric oxide levels, again with very low certainty. Overall, RCTs had a high risk of bias, and experimental studies had an unclear risk of bias. Conclusions: PBM treatments have the potential to be an adjunct therapy for the treatment of hypertension, with studies showing a possible reduction in SBP, DBP, MAP, and HR, but the evidence is of very low certainty, coming from RCTs with a high risk of bias and experimental studies with an unclear risk of bias. The current evidence needs to be significantly improved with rigorous, well-designed experimental and clinical studies.