Effect of irradiation with intravascular laser on the hemodynamic variables of hypertensive patients: Study protocol for prospective blinded randomized clinical trial.

Background: High blood pressure (HBP) is a multifactorial clinical condition, with a high morbidity and mortality rate and low rates of control. Due to its high prevalence, it is necessary to search for methods which aim to improve the quality of life of hypertensive patients. Studies have shown that low level laser therapy (LLLT) is capable of inducing a photobiological response within the cells which modifies the micro and macrovascular response; this accompanies evidence showing the systemic effects of intravascular laser irradiation of blood (ILIB). In the hypothesis that the use of LLLT can influence blood pressure levels, and perhaps facilitate adherence to treatment, this study aims to present a clinical research protocol with the goal of determining the effect of photobiomodulation in relation to changes in the hemodynamic parameters of hypertensive and normotensive patients.

Method: Forty-four participants, frequent attendees of an ambulatory university clinic, will be subdivided into 4 groups, and then submitted to protocol sessions of ILIB. The technique is noninvasive and consists of a laser which is attached to a bracelet which has been specifically developed for the light beam to be transcutaneously carried over the radial artery. Before the procedure, at the end of the photobiomodulation cycles, and 1 month after the end of therapy, blood samples will be collected for the evaluation of C-reactive protein, interleukin 6, and nitric oxide, to be analyzed by immunoturbidimetric, ELISA, and Griess reactions, respectively.

Analysis Of Results: Results will be analyzed using descriptive and inferential statistics and will be compiled into tables and/or graphs, with the help of SPSS version 24.0 with the adopted significance level for all tests being α = 0.05.

Discussion: The treatment of HBP involves both pharmacological and nonpharmacological therapy. Animal studies with photobiomodulation have previously shown hypotensive effects. Gaps in the literature exist regarding the applicability of this nonpharmacological therapy in humans. This study aims to consider the possibility of offering nonpharmacological therapy to hypertensive patients with the goal of increasing adherence to the treatment as well as minimizing morbidity and mortality caused by hypertension.