Changes in arterial stiffness following dialysis in relation to overhydration and to endothelial function.

INTRODUCTION

Cardiovascular (CV) morbidity and mortality are greatly enhanced in patients with chronic kidney disease, partly due to increased arterial stiffness.

MATERIAL AND METHOD: The study included 63 stable HD patients. Stiffness parameters were evaluated by applanation tonometry before the mid-week HD sessions. Pre-HD bioimpedance parameters were measured. A phase angle <six degrees was previously reported as abnormal, reflecting extracellular overhydration. Fluid status was evaluated echocardiographic by measuring the inferior vena cava (IVC) diameter. Endothelium-dependent and endothelium-independent vascular reactivity were assessed by changes in Alx following sublingual nitroglycerin and inhaled salbutamol.

RESULTS

PWV directly correlated with patients' age and dialysis vintage. Patients with a phase angle <6°, were significantly overhydrated (larger IVC, increased ECW, and lower ICW), had stiffer arteries and greater left ventricle mass (LVM), compared with those with a phase angle >6°. Overhydration increases arterial stiffness, but has no influence on either EID or ED vascular reactivity.

CONCLUSION

In hemodialysis, volume overload is an important contributor to increased arterial stiffness and modifies cardiovascular status especially by LV hypertrophy. Achieving normohydration may significantly ameliorate cardiac abnormalities and arterial stiffness and may impact major clinical events and CV mortality.