Bioelectrical Impedance Analysis Before Versus After a Hemodialysis Session in Evaluation of Nutritional Status

Objective

The objective of our study was to evaluate whether bioelectrical impedance analysis (BIA) performed 15 minutes after a hemodialysis (HD) session is clinically useful in nutrition status assessment in comparison with BIA performed before HD. Because of better reliability, it is postulated in the literature that BIA measurements should be performed 1 to 5 hours after HD sessions. However, the measurements 1 to 5 hours after HD sessions are inconvenient in clinical practice. Furthermore, the currently published BIA reference values for the HD population are based on the measurements taken before HD sessions.

Methods

The study group consisted of 29 HD patients who were in a stable clinical condition. BIA measurements were performed by means of BIA 101 System (Akern RJL Systems, Florence, Italy). The correlation coefficients were surveyed between traditional indices of nutritional status, such as body mass index (BMI) and plasma concentrations of protein, albumin, and nonprotein nitrogen blood urea nitrogen (BUN) (measured before HD) on one hand, and BIA parameters (taken before and 15 minutes after HD) on the other hand.

Results

Statistically significant correlations occurred between such BIA parameters as (1) phase angle and BMI or albumin, or total protein or BUN and (2) body cell mass and BMI or BUN. The differences between correlation coefficients achieved either before or after HD were statistically nonsignificant.

Conclusions

BIA measurements in the studied group of patients did correlate with traditional indices of nutritional status. The correlation coefficients were not significantly influenced by the time of performing BIA measurements. The obtained correlations confirm that BIA performed 15 minutes after an HD session may be a useful tool in evaluation of nutritional status of stable HD patients in clinical practice.