Overhydration measured by bioimpedance analysis and the survival of patients on maintenance hemodialysis: a single-center study

Increased plasma level of catestatin might be associated with poor prognosis in hemodialysis patients

PURPOSE

Cardiac complication is a major cause of death in hemodialysis patients. The aim of the study was to determine the relationship between plasma catestatin level and cardiac death in those people.

METHODS

A total of 330 maintenance hemodialysis patients were included. Blood samples were collected. Plasma catestatin level was detected by enzyme-linked immunosorbent assay. Fluid status of each patient was expressed by overhydration to total body weight ratio and daily diuresis. Each patient was followed-up for 36 months, unless some of them died in the follow-up period.

RESULTS

In the follow-up period, only one hemodialysis patient was lost, 29 patients were died of cardiovascular diseases, 28 patients were died of other diseases and remaining 272 patients survived. Logistic multivariate regression analysis revealed that patients with plasma catestatin level ≥1.9 ng/ml were associated with increased cardiac death risk (RR 6.13, 95% CI 2.54, 18.45), and survival analysis also showed that cardiac death rate in patients with plasma catestatin level ≥1.9 ng/ml was elevated than that in patients with plasma catestatin level <1.9 ng/ml (P < 0.001). In addition, overhydration to total body weight ratio and daily diuresis both had significant linear correlations with plasma catestatin level (r = 0.502, P < 0.001 and r = -0.338, P < 0.001).

CONCLUSION

Circulating catestatin concentration might be an independent cardiac prognostic indicator in hemodialysis patients. Fluid status might be involved in the prognostic forecasting process.

Extracellular Fluid/Intracellular Fluid Volume Ratio as a Novel Risk Indicator for All-Cause Mortality and Cardiovascular Disease in Hemodialysis Patients

Background

In hemodialysis patients, fluid overload and malnutrition are accompanied by extracellular fluid (ECF) expansion and intracellular fluid (ICF) depletion, respectively. We investigated the relationship between ECF/ICF ratio (as an integrated marker reflecting both fluid overload and malnutrition) and survival and cardiovascular disease (CVD) in the context of malnutrition-inflammation-arteriosclerosis (MIA) complex.

Methods

Seventy-seven patients from a single hemodialysis unit were prospectively enrolled. The ECF/ICF volume was measured by segmental multi-frequency bioimpedance analysis. MIA and volume status were measured by serum albumin, C-reactive protein (CRP), pulse wave velocity (PWV) and plasma B-type natriuretic peptide (BNP), respectively.

Results

The mean ECF/ICF ratio was 0.56±0.06 and the cut-off value for maximum discrimination of survival was 0.57. Compared with the low ECF/ICF group, the high ECF/ICF group (ratio≥0.57, 42%) had higher all-cause mortality, CVD, CRP, PWV, and BNP, but lower serum albumin. During the 5-year follow-up, 24 all-cause mortality and 38 CVD occurred (18 and 24, respectively, in the high ECF/ICF group versus 6 and 14 respectively in the low ECF/ICF group, P<0.001). In the adjusted Cox analysis, the ECF/ICF ratio nullifies the effects of the MIA and volume status on survival and CVD and was an independent predictor of all-cause mortality and CVD: hazard ratio (95% confidence interval); 1.12 (1.01–1.25) and 1.09 (1.01–1.18) for a 0.01 increase in the ECF/ICF ratio. The degree of malnutrition (albumin), inflammation (CRP), arteriosclerosis (PWV), and fluid overload (BNP) were correlated well with the ECF/ICF ratio.

Conclusions

Hemodialysis patients with high ECF/ICF ratio are not only fluid overloaded, but malnourished and have stiff artery with more inflammation. The ECF/ICF ratio is highly related to the MIA complex, and is a major risk indicator for all-cause mortality and CVD.