Graft function and arterial stiffness: can bioimpedance analysis be useful in renal transplant recipients?

We aimed to determine the total body water (TBW) by means of bioimpedance analysis (BIA) and to analyze the association of TBW, graft function, and arterial stiffness by means of pulse-wave velocity (PWV) and echocardiographic measurements in renal transplant (RT) recipients.

Eighty-two RT recipients (mean age, 38.7 ± 11.5 y; 58 male) who were using ≥1 antihypertensive treatment were enrolled in the study. Biochemical parameters, 24-hour urinary protein loss, estimated glomerular filtration rate (eGFR), transthoracic echocardiography, bioimpedance analysis according to systolic blood pressure, TBW, lean tissue index (LTI), extracellular water (ECW), intracellular water (ICW), lean tissue mass (LTM), phase angle (Phi50) levels, and renal resistive index (RRI) were evaluated.

TBW and ECW were significantly correlated with systolic blood pressure. Urinary protein loss, pulmonary artery pressure, frequency of overhydration, systolic blood pressure, TBW, LTI, ECW, ICW, LTM, and Phi50 values were significantly higher in patients with estimated glomerular filtration rate (eGFR) 15-49 mL/min but similar in patients with eGFR 50-70 mL/min.

Hypertensive RT recipients have increased TBW, LTI, ICW, FTI, LTM, and Phi50 values. Graft function is positively correlated with systolic blood pressure and BIA parameters. Therefore, hypertensive RT recipients should be closely followed with the use of BIA for an early diagnosis of loss of graft function.