Bioimpedance spectroscopy for the detection of hypervolemia in peritoneal dialysis patients.

A practical, inexpensive, and reliable method is needed for the assessment of volume status in peritoneal dialysis (PD) patients. In the present study, we investigated the efficiency of bioimpedance spectroscopy (BIS) for detection of hypervolemia. The study enrolled 79 prevalent PD patients (mean age: 47 +/- 14 years; PD duration: 30 +/- 17 months; 55% men; 19% with diabetes) from a single center. Echocardiography and body composition analysis using the BIS technique [50 frequencies (Body Composition Monitor: Fresenius Medical Care, Bad Homburg, Germany)] were performed. Overhydration (OH) and extracellular water (ECW) in liters and OH/ECW ratio were used as volume indices. The mean left ventricular (LV) mass index was 117 +/- 37 g/m2, and 46% of patients had LV hypertrophy (LVH). Mean OH and OH/ECW ratio were 1.3 +/- 1.7 L and 7.6% +/- 9.3% respectively The OH/ ECW ratio correlated with LV mass index (r = 0.237, p < 0.036) and with left atrium index (r = 0.354, p < 0.001). Compared with patients not having LVH, patients with LVH had higher OH values (1.79 +/- 1.82 L vs 0.93 +/- 1.62 L, p = 0.003). In linear regression analysis, the OH/ECW ratio was an independent risk factor for LVH (t = 2.558, p = 0.01). In PD patients, BIS is a reliable method for evaluating volume status. The OH/ECW measured by BIS is a major determinant of LV mass. Control of hypervolemia and blood pressure is associated with better cardiac condition.