Calf Bioimpedance Spectroscopy for Determination of Dry Weight in Hemodialysis Patients: Effects on Hypertension and Left Ventricular Hypertrophy

Abstract

Background/Aims: Dry weight estimation in hemodialysis patients is still a substantial problem. Despite meticulous clinical assessment, fluid overload is common, leading to hypertension and left ventricular hypertrophy (LVH). Segmental calf bioimpedance spectroscopy (cBIS) is a novel tool for dry weight assessment. Here we tested the hypothesis, that its clinical routine use reduces arterial hypertension and left ventricular mass. Methods: Left ventricular mass (determined by magnetic resonance imaging), blood pressure and antihypertensive medication (defined daily doses, ddd) were assessed at baseline (BL). Thereafter post-dialytic target weight was reduced until cBIS-defined dry weight was reached (DW). During a 6-month follow up, DW was re-evaluated monthly by cBIS and end-dialytic weight was adjusted correspondingly. At the end, left ventricular mass, blood pressure and antihypertensive medication were determined a 3^rd time (follow-up, FU). Results: Eleven out of 15 patients were available for analysis after 6 months. Left ventricular mass showed a declining trend during the study period (Mean±SD; BL 145±54g; DW 142±55g; FU 137±52g; p=0.61, linear mixed model). Comparable results were obtained for systolic blood pressure (BL 158±18mmHg; DW 144±19mmHg; FU 149±21mmHg; p=0.07), and antihypertensive medication (BL 3.28±2.82ddd; DW 2.86±2.81ddd; FU 3.36±3.05ddd; p=0.37). Conclusions: We conclude that attainment of dry weight assessed by cBIS tends to reduce left ventricular mass and blood pressure while antihypertensive medication remains unchanged. While the study was underpowered, its results provide an important hypothesis generating data basis for the design of larger studies.

The Effect of Preserved Residual Renal Function on Left Ventricular Structure in Non-Anuric Peritoneal Dialysis Patients

“…Furthermore, a recent study during a 6-month follow-up further supports the presumption of positive effect of volume control in dialysis patients using clinical routine by segmental calf bioimpedance spectroscopy (cBIS) for dry weight assessment. Also, myocardial mass and LVMi dropped constantly in that study [20].…”

Intra-Renal Hemodynamic Changes After Habitual Physical Activity in Patients with Chronic Kidney Disease

“…Although, hemodialysis procedure ameliorate clinical outcomes and survival in uremic patients, chronic exposure to hemodialysis seems to induce changes in HRV [94]. In addition autonomic neuropathy induce alterations in HRV and there is evidence that high fluid overload met in hemodialysis patients also impairs ANS activity, leads to hypertension and left ventricular hyperthrophy where enhances cardiac mortality [95]. It has been found that during the ultrafiltration procedure of the hemodialysis therapy an acute decrease in parasympathetic function and a relative hyperactivity of sympathetic nervous system takes place [96].…”

Calf Resistivity Values in Chronic Kidney Disease in a Caucasian Population

“…Systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate were measured in triplicate using a calibrated electronic blood pressure device (Dinamap ProCare, General Electric Healthcare, Munich, Germany, cuff sizes according to upper arm circumference, size 1: 198 27-35 cm, size 2: 34-43 cm). Electrode positions and resistivity measurements were carried out as described before [6,7,9] by one out of 2 trained investigators (S.G.M. and J.P.).…”

“…In recent years, bioimpedance analysis has gained more attention and different approaches have been developed to address fluid management in HD patients (reviewed in [4] ). We reported earlier on calf bioimpedance spectroscopy (cBIS) as a means for accurately determining DW (cBIS-DW) [5][6][7][8] and were able to demonstrate beneficial effects on left ventricular hypertrophy and antihypertensive medication needs [9] . cBIS does not require comparison of volumes (e.g., extracellular volume, ECV) to a normal population and is based on the flattening of the resistance curve of a segment of the calf that is continuously recorded during HD.…”

“…Flattening of the curve of calf extracellular resistance (R 0 /R t ≤ 0.01) over 20 min and ii . ρ N,5 is equal to or greater than the lower threshold of the gender-specific normal range (males: >18.5 × 10 -2 · Ωm 3 kg -1 ; females: >19.1 × 10 -2 · Ωm 3 kg -1 ) This concept has been extensively tested and validated [8][9][10][11] . It is a key advantage of the cBIS-DW concept in comparison to other BIS methods that criterion (i) is solely dependent on the fluid content and its removal by ultrafiltration during dialysis.…”