Multivariate identification of metabolic features in inflammatory bowel disease

Weight loss and malnutrition are commonly reported in inflammatory bowel di sease (IBD), but differences between Crohn's disease (CD) and ulcerative co litis (UC) patients have rarely been pointed out. In this regard, a sample of 102 consecutive patients with a diagnosis of either CD (n = 63, 33 males ) or UC (n = 39, 25 males) based on previously reported clinical, morpholog ic, and histopathologic criteria were studied. Twenty-six anthropometric an d metabolic variables were measured upon admission. Body composition was as sessed by both anthropometry and bioimpedance measurements, and energy expe nditure and substrate oxidation were assessed by indirect calorimetry. The data were subjected to principal-component analysis and to factor rotation to derive a set of a few basic independent descriptors of the metabolic fea tures of each subject. Six descriptors were found to be responsible for gre ater than 86% of the total sample variability and to associate very well wi th mutually disjoint subsets of the original variables. The six summarizing factors are listed in order of decreasing percentage of explained variatio n (size 41.8%, fatness 17.9%, fuel 12.2%, shape 5.4%, energy 5.2%, and ster oid 3.9%). CD and UC patients differed significantly with respect to fatnes s (CD lower, P = .004) and carbohydrate (CHO) fuel preference (CD lower, P = .030). Hence, CD patients showed a reduced fat mass (FM) compared with UC patients, and from a metabolic point of view, too, CD and UC are not super imposable. In fact, the lower CHO oxidation (CHOox) rate and consequent pre ferential lipid utilization found in CD patients may be taken into account as a contributing cause of lipid tissue wasting and in planning therapeutic enteral regimens. Copyright (C) 1999 by W.B. Saunders Company.