Measurement of body composition should become routine in nutritional assessment of children with cerebral palsy PETER SULLIVAN Children’s Hospital Oxford, University of Oxford – Paediatrics, Oxford, UK. doi: 10.1111/dmcn.12751 This commentary is on the original article by Finbr aten et al. on pages 858–864 of this issue.
In the last two decades paediatricians have come to appreciate the nutritional consequences of cerebral palsy (CP) in children and researchers have provided a range of tools for the assessment of nutritional status. We have learned that the standard growth charts and dietary requirements of typically developing children do not apply to those with CP. We know that weight-for-age, height-for-age, and body mass index (BMI) are inappropriate measures of nutritional status in CP and that measurement of body composition is a more appropriate guide to nutritional management. The tools used to assess body composition range from stable isotope techniques (D2O dilution) to dual-energy X-ray absorptiometry (DXA) and bioelectrical impedance analysis (BIA). These tools have been developed predominately in research settings and have obvious limitations for routine clinical application. This has led to a search for reliable clinical estimates of body composition derived from measurements of skinfold thicknesses. Despite the relative ease of measurement of skinfold thicknesses, this technique has yet to be established as a part of routine clinical practice and controversies exist in relation to the derivation of body composition data from these measurements. Originally, Slaughter et al.1 created equations for use in typically developing children from which to estimate body composition from skinfold thicknesses. These equations do not take account of the different body composition (less bone and muscle mass) in children with CP and so they tend to underestimate their percentage body fat. Van den Berg-Emons found that the percentage body fat derived from skinfold measurements was substantially lower than that derived from the ‘criterion standard’ measure of body composition using D2O dilution and attributed this to a larger internal deposit of fat and a different distribution of subcutaneous fat in the limbs in children with CP.2 In an
attempt to improve on the standard Slaughter equation, Gurka et al.3 derived new equations with a correction factor based on sex, race, size, pubertal status, and GMFCS level. When using DXA as a standard, Gurka’s CP-specific equation seemed to provide a closer estimate of percentage body fat in children with CP than did the standard Slaughter equation. Similarly, Oeffinger et al.4 found that percentage body fat derived from skinfolds using Gurka’s CP-specific equation was not significantly different from that measured by DXA. Reiken et al.,5 however, using BIA and D2O dilution found that Gurka’s CP-specific equation tended to overestimate percentage body fat. Into this controversy comes the paper in this issue by Finbr aten et al.6 who confirmed that Gurka’s CP-specific equation for skinfold thickness measurement reliably estimated percentage body fat when compared those estimates derived from DXA. Does this put an end to the controversy? Probably not. The important point to remember, however, is not how nicely the different comparison between equations and ‘criterion standards’ stand up to statistical testing but how reliable they are as a measure of nutritional status in a way that is clinically meaningful. A difference of a few percentage points here and there between different estimates is not clinically relevant; what matters to the clinician is to find an answer to the question ‘Is this child in energy balance?’. If the child is in positive energy balance then they will lay down fat and one can pragmatically assume that the nutritional intake is sufficient to meet the metabolic, activity, and growth needs of the child. Recognition that this is so can avert the need for gastrostomy tube feeding in a child referred just because they are below the 0.4th centile of a standard growth chart. Conversely, recognition of low fat stores and negative energy balance can prompt the need for more effective nutritional intervention (including the possibility of gastrostomy) in a child who may not appear ‘from the end of the bed’ to be malnourished. The important fact emerging from all these studies is that measurement of body composition must become a routine component of the nutritional management of children with CP.
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Predicting extremely preterm children’s school performance by transient abnormal neurology? CORNELIEKE S H AARNOUDSE-MOENS Department of Pediatrics, Amsterdam Medical Centre, Amsterdam, the Netherlands. doi: 10.1111/dmcn.12833 This commentary is on the original article by Harmon et al. on pages 865–871 of this issue.
With the increase in survival amongst children born extremely preterm (gestational age