Assessment of body composition by bioelectrical impedance in adolescent patients with celiac disease

Assessment of body composition is of primary importance in the management of celiac adolescents. We aimed to evaluate body composition by dual-energy x-ray absorptiometry and bioelectrical impedance in celiac adolescents on a gluten-free diet to investigate whether impedance may provide an alternative method to assess nutritional status in these patients.

We studied body composition in 43 adolescents affected by celiac disease on a gluten-free diet for > or = 1 yr and 30 healthy subjects. Fat, fat-free, and bone masses were assessed by dual-energy x-ray absorptiometry. Fat and fat-free masses were also assessed by bioelectrical impedance. All anthropometric measurements were performed according to standard procedures.

All patients had a significantly lower body weight, height, fat-free mass, bone mineral density (p < 0.001), and body mass index (p < 0.01) compared with controls. In contrast, parameters predicting fat compartment (sum of skinfolds and fat mass) did not differ from those of controls. No significant difference was found between patients strictly adherent to a gluten-free diet and patients partially compliant. Compared with dual-energy x-ray absorptiometry measurements, bioelectrical impedance showed a high accuracy to estimate fat-free mass (R2 = 0.97) and limited accuracy for fat mass (R2 = 0.75). Furthermore, impedance was more reliable for estimating hydration of soft tissue underlying the fat-free mass changes.

In adolescents with celiac disease, after a mean of 1 yr of gluten-free diet all the parameters assessing body compartments, except fat mass, were affected, compared with healthy controls. Bioelectrical impedance holds promise for routine assessment of body composition changes in celiac adolescents on a gluten-free diet.