Bioelectrical impedance analysis to evaluate nutritional status in hemodialysis patients

Abstract

Objective To explore the value of bioelectrical impedance analysis in evaluating hemodialysis patients′ nutritional status. Methods Cross-sectional design was employed to evaluate 193 hemodialysis patients′ nutritional status in a Level 3 hospital in Zhuhai, with bioelectrical impedance analysis, modified quantitative subjective global assessment, physical and biochemical measurement. The correlation between each index and the predictive effect of bioelectrical impedance analysis on malnutrition of patients were analyzed. Results According to bioelectrical impedance analysis, hemodialysis patients′ average muscle mass was (44.06±8.84) kg, body fat rate was (19.81±8.89)%, fat free mass index was (17.70±2.45) kg/m2, presumed bone mass was (2.49±0.46) kg, and extracellular water rate was (40.54±3.75)%. The bioelectrical impedance analysis indexes were significantly correlated with most other nutritional evaluation indexes (P<0.05). The muscle mass and bone mass of the malnourished group were lower than that of the well-nourished group (P<0.01). Multivariable logistic regression analysis found that body fat rate (OR=0.94, 95%CI 0.89-0.99), fat free body mass index (OR=0.79, 95%CI 0.66-0.93) were associated with lower risk of malnutrition, age (OR=1.08, 95% CI 1.04-1.12), dialysis age (OR=1.02, 95%CI 1.01-1.04), high sensitive C reactive protein (OR=1.11, 95%CI 1.03-1.23) were associated with higher risk of malnutrition. Conclusion Bioelectrical impedance analysis is a valid measurement on evaluating maintenance hemodialysis patients′ nutritional status. There has a high prevalence of malnutrition in hemodialysis patients. The lower risk of malnutrition is associated with higher body fat rate and higher fat free mass index, and the higher risk of malnutrition is associated with older age, longer dialysis age and higher level of high sensitive C reactive protein. Key words: Electric impedance; Hemodialysis; Nutritional status