Concerns about the application of resistance exercise with blood-flow restriction and thrombosis risk in hemodialysis patients.

• D-dimer may be a relevant molecule to screen for prior to prescribing physical exercise to avoid the risk of thrombosis in hemodialysis patients. • The application of blood-flow restriction to maximize the effects of physical exercise may not be a safe alternative for most hemodialysis patients with borderline (400–490 ng/mL) D-dimer levels. • Recent cardiovascular events, socioeconomic status, aging, vascular access, smoking, recent complications, type of anticoagulant used in hemodialysis, fasting glucose, blood pressure, and elevated C-reactive protein levels are all variables that should be part of the anamnesis of hemodialysis patients before starting intradialytic exercise with blood-flow restriction. Hemodialysis (HD) per se is a risk factor for thrombosis. Considering the growing body of evidence on blood-flow restriction (BFR) exercise in HD patients, identification of possible risk factors related to the prothrombotic agent D-dimer is required for the safety and feasibility of this training model. The aim of the present study was to identify risk factors associated with higher D-dimer levels and to determine the acute effect of resistance exercise (RE) with BFR on this molecule. Two hundred and six HD patients volunteered for this study (all with a glomerular filtration rate of <15 mL/min/1.73 m²). The RE + BFR session consisted of 50% arterial occlusion pressure during 50 min sessions of HD (intradialytic exercise). RE repetitions included concentric and eccentric lifting phases (each lasting 2 s) and were supervised by a strength and conditioning specialist. Several variables were associated with elevated levels of D-dimer, including higher blood glucose, citrate use, recent cardiovascular events, recent intercurrents, higher inflammatory status, catheter as vascular access, older patients (>70 years old), and HD vintage. Furthermore, RE + BFR significantly increases D-dimer after 4 h. Patients with borderline baseline D-dimer levels (400–490 ng/mL) displayed increased risk of elevating D-dimer over the normal range (≥500 ng/mL). These results identified factors associated with a heightened prothrombotic state and may assist in the screening process for HD patients who wish to undergo RE + BFR. D-dimer and/or other fibrinolysis factors should be assessed at baseline and throughout the protocol as a precautionary measure to maximize safety during RE + BFR. [Display omitted] [ABSTRACT FROM AUTHOR]