Anthropometric measurements to identify undernutrition in children with cerebral palsy

Abstract

Aim: To evaluate the diagnostic performance of anthropometric indicators to identify undernutrition in children with cerebral palsy (CP). Method: The present study was a monocentric retrospective analysis of prospectively collected data among children and adolescents with CP participating in a rehabilitation program. Undernutrition was defined as a z-score for dual-energy X-ray absorptiometry (DXA) determined body fat percentage less or equal to −2.0. The cut-off values for body mass index (BMI) of the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC), and the cut-off values for BMI and height for age of the Robert Koch Institut (RKI) were evaluated. Results: In total, 329 children with CP (181 males, 148 females, Gross Motor Function Classification System levels I–V) were eligible for analysis. The mean age was 12 years 4 months (SD 2y 9mo). The BMI cut-off values showed the following sensitivities and specificities: WHO, sensitivity of 0.474 (95% confidence interval [CI] 0.244–0.711), specificity of 0.897 (95% CI: 0.857–0.928); CDC, sensitivity of 0.632 (95% CI: 0.384–0.837), specificity of 0.819 (95% CI: 0.772–0.861); RKI, sensitivity of 0.789 (95% CI: 0.544–0.939), specificity of 0.732 (95% CI: 0.679–0.781); and for height for age, sensitivity of 0.263 (95% CI: 0.091–0.512), specificity of 0.668 (95% CI: 0.612–0.720). Interpretation: BMI had a high specificity but very low sensitivity in identifying undernutrition in children with CP. Z-scores for height for age had even lower specificity and sensitivity and seemed not to be appropriate for predicting undernutrition in children with CP. What this paper adds: Body mass index (BMI) z-scores had a high specificity but very low sensitivity in identifying undernutrition in children with cerebral palsy (CP). Height z-scores were not appropriate for predicting undernutrition in children with CP. Undernutrition assessed by BMI was overestimated in children with CP versus when assessed by dual-energy X-ray absorptiometry (DXA).