Parenteral nutrition and bioelectrical impedance analysis estimated fat-free mass in adult patients with chronic intestinal failure: A descriptive cohort study

Background: In patients with chronic intestinal failure, the content and type of parenteral nutrition are individually determined based on various factors, including body composition. In clinical practice, bioelectrical impedance analysis is used to assess body composition using standardized protocols. However, these protocols lack specific recommendations for patients receiving parenteral nutrition. Therefore, this study described the effect of parenteral nutrition infusion on fat-free mass as evaluated by single-frequency bioelectrical impedance analysis. Methods: We performed a descriptive cohort study using bioelectrical impedance analysis to assess adult patients with chronic intestinal failure receiving parenteral nutrition. Measurements were performed at baseline (before parenteral nutrition infusion) and 0, 1, 2, and 4 h after (usually) 18-h parenteral nutrition infusion using hand-to-foot single-frequency bioelectrical impedance analysis (Bodystat 500). The primary outcome of fat-free mass was calculated using the Kyle equation. A linear mixed model was used to compare baseline values with other time points. A difference of >1 kg in fat-free mass compared with baseline was considered clinically relevant. Results: Twenty patients (70% female) with a mean age of 58 (SD, 14) years and a median body mass index of 22.3 (IQR, 21.2–24.8) kg/m2 were included in the analysis. No significant change in fat-free mass after parenteral nutrition infusion was observed, and 90% (69/77 measurements) of all fat-free mass outcomes after parenteral nutrition infusion remained within the ≤1-kg clinically relevant range. Conclusion: This study found that parenteral nutrition infusion does not affect fat-free mass estimation as assessed by hand-to-foot single-frequency bioelectrical impedance analysis.