Effect of disease localization on the anthropometric and metabolic features of Crohn's disease

We conducted this study to evaluate the effect of disease localization on the anthropometric and metabolic characteristics of inactive Crohn's disease (CD).

Forty-three patients with biopsy or radiology proven CD (23 men; age, 33.8 yr; range, 18-54 yr) in clinical remission (simplified Crohn's diseases activity index [SCDAI] < 3) and not receiving steroid therapy or nutritional support were enrolled in the study. Patients were separated into three subgroups according to disease localization: ileal (n = 16), ileo-colonic (n = 13), and colonic CD (n = 14). Sixty healthy volunteers (26 men; age, 32.0 yr; range, 18-60 yr), matched for age and height were used as control subjects. Body composition was assessed by both anthropometry and bioimpedance analysis and indirect calorimetry was performed to measure energy expenditure and substrate oxidation rates.

CD patients showed a lower body weight than controls, both as a whole (61.5 kg; range, 41.5-74.0 vs 66.9 kg; range, 55.0-86.0 kg; p < 0.001) and separated by disease localization (ileal; p < 0.001; ileo-colonic; p < 0.001; and colonic; p < 0.05 vs controls). Fat-free mass (FFM) did not differ between the groups, whereas fat mass was significantly lower in CD patients than in controls (p < 0.001), with the lowest values in ileal and ileo-colonic patients. Basal metabolic rate by kg of FFM was higher in CD patients than in healthy individuals (p < 0.01). Nonprotein respiratory quotient was significantly lower in CD than in controls as a whole (0.79; range, 0.73-0.84 vs 0.83; range, 0.79-0.89; p < 0.001) or separated by disease localization (p < 0.001 each subgroup vs controls), with a consequent higher lipid oxidation rate. A lower dietary lipid intake was found in patients than in controls (p < 0.01).

Regardless of disease localization, CD patients showed a lower fat mass and a higher utilization of lipids than control subjects. Patients with ileal and ileo-colonic disease showed the greater reduction in body weight, compared with control subjects, suggesting they were at a higher risk of malnutrition, probably as a consequence of the simultaneous occurrence of both malabsorption and decreased energy intake.