Relative Association of Overhydration and Muscle Wasting with Mortality in Hemodialysis Patients: Assessment by Bioelectrical Impedance Analysis / 대한내과학회지

BACKGROUND/AIMS: Assessment of fluid status in hemodialysis patents is very important. Overhydration in hemodialysis is associated with generalized edema, cardiovascular complications, and hypertension. The aim of this study was to determine the factors correlated with mortality of hemodialysis patients, assessing body muscle mass and fluid status using bioelectrical impedance analysis (BIA). METHODS: This study enrolled 93 patients who underwent hemodialysis between January 2010 and May 2015 at CHA Bundang Medical Center. Medical records of enrollees up to June 2017 were reviewed retrospectively. These included laboratory results (serum albumin, C-reactive protein [CRP], lipid profile, etc.) and BIA data (extracellular water, intracellular water, total body water, soft lean mass, fat free mass, skeletal muscle mass, etc.). RESULTS: Eleven of 93 patients had expired by May 2017. Among the surviving subjects, mean age was younger, CRP levels were lower, albumin levels were higher, and extracellular water/total body water (ECW/TBW) ratios were lower than in the expired patient group. Kaplan-Meier survival analysis revealed that overhydration (ECW/TBW > 0.4) was associated with higher mortality. CONCLUSIONS: In hemodialysis patients, overhydration is an important factor in mortality, and BIA could be a reliable modality in its assessment. We suggest that, for hemodialysis patients, overhydration is more of a risk factor for mortality than is muscle wasting.

Changes in bioimpedance analysis components before and after hemodialysis

BACKGROUND: This study compared nutritional parameters in hemodialysis (HD) subjects and controls using bioimpedance analysis (BIA) and investigated how BIA components changed before and after HD. METHODS: This cross-sectional study included 147 subjects on maintenance HD from two hospitals and 298 propensity score-matched controls from one healthcare center. BIA was performed pre- and post-HD at mid-week dialysis sessions. RESULTS: Extracellular water/total body water (ECW/TBW) and waist-hip ratio were higher in the HD patients; the other variables were higher in the control group. The cardiothoracic ratio correlated best with overhydration (r = 0.425, P < 0.01) in HD subjects. Blood pressure, hemoglobin, creatinine, and uric acid positively correlated with the lean tissue index in controls; however, most of these nutritional markers did not show significant correlations in HD subjects. Normal hydrated weight was predicted to be higher in the pre-HD than post-HD measurements. Predicted ultrafiltration (UF) volume difference based on pre- and post-HD ECW/TBW and measured UF volume difference showed a close correlation (r 2 = 0.924, P < 0.01). Remarkably, the leg phase angle increased in the post-HD period. CONCLUSION: The estimated normal hydrated weight using ECW/TBW can be a good marker for determining dry weight. HD subjects had higher ECW/TBW but most nutritional indices were inferior to those of controls. It was possible to predict UF volume differences using BIA, but the post-HD increase in leg phase angle, a nutritional marker, must be interpreted with caution.

Study on the relevant factors affecting the hydration status in peritoneal dialysis patients / 上海交通大学学报（医学版）

Objective · To explore influencing factors associated with the hydration status in peritoneal dialysis (PD) patients.Methods · Eligible PD patients treated in Renji Hospital affiliated to Shanghai Jiao Tong University School of Medicine from September 2016 to January 2017 were enrolled.Demographic data of patients were collected and biochemical indexes were measured.Their peritoneal transport characteristics and dialysis adequacy were evaluated.Hydration status index overhydration (OH) value was measured with bioimpedance spectroscopy.Multivariate linear regression was used to analyze the independent factors associated with the OH.Results · A total of 147 PD patients with a median age of 58.52 years and a median PD duration of 43.03 months were enrolled.Of them,90 (61.2％) were male,21(14.3％) were accompanied by diabetes mellitus,and 107 (72.8％)were overhydrated (OH＞1.1L).Compared to those with normal hydration status (OH ≤ 1.1 L),the overhydrated patients had higher proportion of diabetes,BSA,Charlson comorbidity score,brain natriuretic peptide (BNP),4 h D/Pcr,and 24 h dialysate protein,and lower tKt/V,serum albumin than the normal hydrated patients (all P＜0.05).Multivariate linear regression showed that comorbid diabetes mellitus (P=0.000),higher 4h D/Pcr (P=0.000),and lower serum albumin level (P=0.001) were independent relevant factors for the increase of OH.Conclusion· Overhydration is common in PD patients.Comorbid diabetes mellitus,higher 4 h D/Pcr,and lower serum albumin are independent relevant factors for the hydration status in PD patients.