Body composition in patients with short bowel syndrome: An assessment by bioelectric impedance spectroscopy (BIS) and dual-energy absorptiometry (DXA)

Objective: To describe body composition in patients with short bowel syndrome (SBS) by using bioelectric impedance spectroscopy (BIS), dual-energy X-ray absorptiometry (DXA) measurements and anthropometrical-derived estimates. Subjects: In all, 19 patients were included, mean age 54 y, range 36 - 77 (F/M = 11/8). Mean BMI was 21.5 kg/m(2). Eight patients were on home parenteral nutrition (HPN). Methods: Total body water (TBW), intracellular water and extracellular water were assessed by BIS. TBW were derived from DXA. Fat-free mass (FFM) was assessed by BIS and DXA. TBW and FFM were predicted according to an empirical formula. Differences were analysed using the Bland - Altman method. Results: The mean difference between TBW ( DXA) and TBW ( BIS) was - 1.1 l in women and - 1.8 l in men. For FFM, the mean difference between FFM ( DXA) and FFM ( BIS) was - 1.7 kg in women and - 2.5 kg in men. The mean difference between TBW ( DXA) and TBW ( BIS) for all patients was - 1.2 l and limits of agreement were ( - 7.80 - 5.40). Hydration of FFM assessed by BIS gave a mean of 0.75 (0.08). Conclusion: The limits of agreement ( Bland - Altman) between DXA and BIS were wide, indicating that methods are not interchangeable, which limits its clinical utility. Most of our patients with SBS were maintained in a stable clinical condition within normal limits of body weight and BMI. FFM and TBW did not appear to be altered in ileostomates or those on HPN. Sponsorship: The study was supported by grants from the Swedish Medical research Council (17X- 03117), Goteborgs Lakarsallskap and IB and A Lundbergs forskningsstiftelse.