Terapia com laser de baixa intensidade na reatividade vascular e na pressão arterial em policiais militares

Abstract

Police officers (PO) are exposed to a stressor environment, and stress has an indirect effect as a factor and risk for cardiovascular diseases and a prognostic factor on recurrent event and death. In addition, the stress has a direct effect on vascular pathophysiology, and could affect endothelial function, thus increasing cardiovascular risk. Arterial stiffness and endothelial dysfunction and impairment blood pressure response to exercise are markers of cardiovascular risk. Previous experimental studies have shown that low-level laser therapy (LLLT) promotes increase in flow-mediated dilation (FMD). Thus, we hypotetized that LLLT would improves endothelial function and decrease blood pressure in response to maximum exercise in police officers. METHODS: One group of PO was submitted to LLLT (PO / LLLT, n=11, 39.4±2 years; 91.9±5 kg) for 6 months, while a PO group matched for age and weight that remained without any therapy was characterized as a control group (PO / C, n=7, 38.2±3 years; 83.8±3 kg). LLLT was applied twice weekly in the sublingually, with a maximum of three days between one application and another. Endothelial function was evaluated by brachial artery FMD. Systolic and diastolic blood pressure (BP) Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were analyzed during cardiopulmonary exercise test. RESULTS: After 6 months, there was an increase in FMD in the PO / LLLT group, which did not occur in the PO / C group (increase Δ 8.34 ± 1 and 0.33 ± 1%, respectively, P = 0. 001. Interestingly, BP response to maximal exercise decreased only in the PO / LLLT group (pre vs. post, SBP = 202 ± 4 vs. 177 ± 4 mmHg, P = 0.02, DBP = 106 ± 2 vs. 90 ± 2 mmHg, P = 0.01, and there was no change in the PO / C group (P = 0.19). CONCLUSION: Our results demonstrate for the first time that low-intensity laser therapy is able to improve endothelial function and, in addition, decrease systolic and diastolic blood pressures in response to maximal exertion, that is, to physical stress. This important adaptation can confer a cardiovascular protection in the response to mental stress, a frequent condition in the function of the military police.