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

European Journal of Clinical Nutrition (2004) 58, 853–859 & 2004 Nature Publishing Group All rights reserved 0954-3007/04 $30.00 www.nature.com/ejcn ORIGINAL COMMUNICATION Body composition in patients with short bowel syndrome: An assessment by bioelectric impedance spectroscopy (BIS) and dual–energy absorptiometry (DXA) E Carlsson1*, I Bosaeus2 and S Nordgren1 1 Department of Surgery, University of Göteborg, Sweden; and 2Department of Clinical Nutrition, University of Göteborg, Sweden 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/M¼11/8). Mean BMI was 21.5 kg/m2. 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 (–7.805.40). 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), Göteborgs Läkarsällskap and IB and A Lundbergs forskningsstiftelse. European Journal of Clinical Nutrition (2004) 58, 853–859. doi:10.1038/sj.ejcn.1601886 Keywords: body composition; short bowel syndrome; Crohn’s disease; bioelectric impedance spectroscopy; dual-energy X-ray absorptiometry Introduction In current clinical practice, patients with short bowel syndrome (SBS) are mostly monitored by clinical examination, general well-being, weight and simple biochemical tests. Body weight (BW) and observed weight changes are important parameters, but do not provide information of the distribution of fat-free mass (FFM) and fat mass (FM) (Kyle et al, 2001). Although anthropometric variables remain *Correspondence: E Carlsson, Department of Surgery, Colorectal Unit, Sahlgrenska University Hospital, Goteborg 416 85, Sweden. E-mail: Received 15 April 2003; revised 26 August 2003; accepted 8 September 2003 constant, a shift between the main compartments of the body may occur. Simple and accurate body composition methods are required to evaluate to what extent patients with SBS are malnourished or dehydrated. Such methods are also important to monitor the efficacy of nutritional and rehydration treatment. Kyle et al (2001) in a study on 995 patients at hospital admission found that a low FFM was present in almost one-third of patients with a normal BMI of 20–24.9 kg/m2. They claimed that a body composition analysis based on bioelectrical impedance (BIA) was more sensitive than BMI to identify patients who were FFM depleted (Kyle et al, 2001). Methods for the determination of total body water (TBW) and assessment of fluid compartments as used in research are dominated by dilution Body composition in patients with sort bowel syndrome E Carlsson et al 854 techniques (Van Marken Lichtenbelt et al, 1994; Deurenberg et al, 1995; Heymsfield et al, 1996; Gudivaka et al, 1999). These techniques are cumbersome, require time for equilibration and involve extended laboratory facilities and calculations. Moreover, the patient has to be in a stable condition with minimal fluid turnover. For these reasons, they are not suitable for monitoring the dynamic clinical course in the management of patients with a rapid fluid turnover and in dehydrated patients. Dilution methods may be inaccurate in patients with SBS due to rapid fluid changes and high stoma output, resulting in inadequate equilibration of the isotope (Chambrier et al, 2001). The development of BIA measurements for clinical determination of TBW represents an interesting innovation. Particularly, with the use of the multiple-frequency technique (bioelectric impedance spectroscopy, BIS), allowing for a detailed analysis of water compartments, the potential clinical usefulness appears considerable (Van Loan and Mayclin, 1992; Van Marken Lichtenbelt et al, 1994; Gudivaka et al, 1999). Changes in the extracellular water/intracellular water (ECW/ICW) ratio may give important information about body water distribution and fluid shifts (Geerling et al, 1999). A supposed stability of tissue hydration makes it possible to use body fluid investigations for estimation of other compartments, such as FFM and further on FM (Wang et al, 1999a, b). The aim of the present study was to describe body composition in patients with SBS, as obtained by the use of BIS, and with data from DXA measurements and anthropometrically derived estimates. Patients and methods Patients (Table 1) In all, 19 consecutive patients (F/M¼11/8) with a mean (s. d.) age of 54 y (10.2), range 36–79, were recruited from the Short Bowel clinic. Among them, 16 patients had Crohn’s disease (CD), one had ulcerative colitis (UC), one had been operated for mesenteric vascular occlusion and one for intestinal strangulation. All patients lived in the Western region of Sweden. All had undergone massive intestinal resections; the length of the remaining small intestine is depicted in Table 1. Details regarding diagnosis, type of operations and remain- ing length of the small intestine were collected from the medical records. Eight of the patients were on home parenteral nutrition (HPN) at the time of the study. The median time on HPN was 74 months, range 61–201 months. None of the patients had any inflammatory activity, as indicated by clinical history, physical examination and plasma CRP. Three patients were on steroids, prednisolone, 5–10 mg/day. One patient was treated with azathioprine. Two of the women menstruated. The menstrual cycle phase was not taken into consideration for the study. One of the women had oestrogen supplementation. No other drugs were taken by the patients during the study. Urinary and sodium output differed between those with an ileostomy and those with a remaining colon. The ileostomy patients had a mean daily urine volume of 1.0 (0.47) l and those with remaining colon 2.2 (0.64) l. Urinary sodium output in patients with an ileostomy was 87 (51) mmol/24 h an (...truncated)