Use of body composition measurements to guide the assessment of dry weight in anuric dialysis patients: improvements in blood pressure control

PURPOSE: Fluid management using a body composition monitor (BCM) based on bioimpedance spectroscopy has been found to be beneficial for maintenance hemodialysis (MHD) patients. Our purpose was to provide a management procedure for the adjustment of post-dialysis overhydration (OH(post)) and to evaluate whether this approach could improve blood pressure. METHODS: Post-dialysis fluid status was assessed weekly using the BCM. The reference value of OH(post) and the flow procedure for post-dialysis target weight (PDTW) adjustment were established via measurements of OH(post) in 60 normotensive MHD patients. In the interventional study, we adjusted the PDTW of hypertensive patients to the optimal OH(post) range, with a 0.2–0.5 kg change in PDTW per week. RESULTS: This observational study included 130 anuric MHD patients, of whom 60 were in the pre-dialysis systolic blood pressure (sBP(pre)) < 140 mmHg group. On multivariate logistic regression analysis, we found that only OH(post) was significantly associated with sBP(pre) ≥ 140 mmHg (odds ratio = 2.293, p = 0.000). Patients in the OH(post) < −1.8 L group were mainly male and younger, and had higher post-dialysis diastolic blood pressure, ultrafiltration volume, levels of nutrition markers (serum albumin and creatinine), body mass index, and lean tissue index (LTI). On multiple stepwise regression analysis, only the change in LTI was found to be an independent predictor of OH(post) [R(2) 0.208, β = −0.196, 95% CI (−0.296, −0.095), p < 0.001]. The reference value of OH(post) was found to deviate by − 2.5–0.5 L from that of normotensive patients. At the end of the study, the systolic blood pressure of 38 patients was less than 140 mmHg after PDTW adjustment. The changes in OH(post) from the initial to last adjustment were significant (t = 5.431, p < 0.001), with a substantial decrease in the sBP(pre) (t = 11.208, p < 0.001). CONCLUSIONS: Assessment of OH(post) and LTI using a BCM with a patient-specific optimal PDTW adjustment flow can lead to significantly better control of hypertension in anuric MHD patients.