Effects of blood flow restriction resistance training on strength, vascular and motor function in persons with Parkinson's disease.

Abstract

Parkinson’s disease (PD) is a neurodegenerative disease that displays itself most notably through motor symptom disruptions. The first line of defense for persons with Parkinson’s disease (PwP) is carbidopa-levodopa (levodopa). While this drug therapy effectively treats motor symptoms, the deleterious effects to the vessels can lead to increased homocysteine, endothelial dysfunction, poor peripheral circulation, restless leg syndrome, autonomic dysfunction and cardiovascular disease. Homocysteine has been identified as a cardiovascular disease risk factor and has been associated with cognitive dysfunction. Resistance exercise is effective at lowering homocysteine and improving motor symptoms of PD. Resistance exercise, however, may cause increased arterial stiffness due to the increased hemodynamic load it causes and may not be complementary for the vessels of older individuals with present arterial stiffness. Blood flow restriction (BFR) resistance exercise has been shown to improve vascular function in healthy, older individuals. The effects of low-intensity BFR (LIRT-BFR) on the vascular and motor symptoms of PD has not been studied. Therefore, the purpose of this study was to determine if LIRT- BFR attenuates or improves endothelial function and homocysteine levels in PwP compared to high-intensity resistance exercise. Thirty-eight PwP on levodopa therapy were assigned LIRT-BFR, high-intensity resistance training (HIRT) or to a control group (CNTRL). The LIRT-BFR and HIRT groups participated in exercise three days per week for four weeks and the CNTRL group was asked to continue their normal routine. Hemodynamic loads and strength improvements were similar between the two exercise groups. There were significant improvements in homocysteine and endothelial nitric oxide synthase (eNOS) for LIRT-BFR and HIRT. Reactive hyperemia index (RHI), peripheral circulation and resting blood pressure only improved for LIRTBFR. HIRT showed worsening RHI, autonomic symptoms and resting blood pressure values. LIRT-BFR significantly improved vascular function in our participants with decreased endothelial function and circulation. This is the first intervention proposed to help attenuate the disruptive vascular effects of levodopa. More research is needed, however, to understand if these effects are lasting and will continue with LIRT-BFR intervention.