Determination of body composition in children with cerebral palsy

Nutrition Research Newsletter, June, 2005

Recent population-based studies, have shown that 30% to 40% of children with cerebral palsy (CP) have been assessed to be undernourished. Clinicians and researchers are hampered by the complexities of evaluating nutritional status in children with CP.

Height is an unreliable measure and children with CP have an altered body composition, with fat mass maintained more centrally as compared with able-bodied peers. DEXA is one method for assessing these nutritional compartments, while bioelectrical impedance (BIA) is a less-expensive and more portable method. A recent study published in JADA set out to determine whether BIA and DEXA can be used to determine body composition for clinical and research purposes in children with CP.

Eight children with cerebral palsy (2 female, 8 male) were recruited from an outpatient tertiary care setting. The children underwent measurement of FM, FFM, and percentage body fat using BIA, anthropometry (two and four skinfold equations), and DEXA. Correlation coefficients were calculated for FM, FFM, and percent body fat for these measures as determined by BIA, and anthropometry when compared with DEXA.

Correlation coefficients were excellent for determination of FFM for all methods (that is, all were above 0.9). Correlations were moderate for determination of FM and percent body fat (0.4 to 0.8). BIA performed best for determining FM and skinfold equations were best for determining percent body fat. For all assessments, there was no advantage in using anthropometric equations that factor in four skinfold measures over those that factor in only two skinfold measures.

The results are consistent with those of previous researchers aM confirm the high correlation of BIA with DEXA for determination of FFM. Because of the clinical trial they were in, the children in this study had been fasting for a period of time before BIA measurements. This may have affected results because assessment is dependent on total body water. The study is also limited because of the small numbers evaluated. Therefore, these data support the need for a larger trial to investigate these methods further.

Li-Fen Liu, Ryan Roberts, Laurie Moyer-Mileur, and Lisa Samson-Fang, Determination of Body Composition in Children with Cerebral Palsy: Bioelectrical Impedance Analysis and Anthropometry vs Dual-Energy X-Ray Absorptiometry. JADA; 105:794-797 (May, 2005). [Correspondence: Lisa Samson-Fang, MD, Department of Pediatrics, University of Utah School of Medicine, 50 North Medical Dr, Salt Lake City, UT 84132. E-mail: Lisa.SamsonFang@HSC.Utah.EDU]