Body Composition Assessment After Pediatric Liver Transplant

Background and Objectives Children with chronic liver disease experience altered growth and development due to the disruption of metabolic function. Pediatric liver transplantation generally restores metabolic function and results in growth recovery; yet, some children who have undergone liver transplant continue to be malnourished, have increased adiposity and may develop obesity as a long-term outcome. Increases in fat mass are associated with adverse developmental and metabolic outcomes that could be addressed through nutritional intervention. The ability to describe weight gain post-transplant would allow clinicians to assess nutritional status beyond anthropometrics. Several body composition assessment technologies are applicable to children, including air displacement plethysmography, dual x-ray absorptiometry and total body potassium, but are not portable or suitable for the clinic setting. A cross-sectional study was conducted to describe the quality of weight gain in post liver transplant children between the ages of 2 and 17 using multiple assessment tools and to determine whether multiple-frequency bioelectrical impedance analysis and ultrasound will accurately describe body composition and quality of weight gain. Methods Ten children (n=10) with a median age of 9.5 years were recruited from the liver transplant program at the University of Minnesota Masonic Children’s Hospital. Anthropometric measurements, multiple-frequency bioelectrical impedance analysis, air displacement plethysmography, and ultrasound measurements were conducted. Comparisons of z-scores for weight, height and BMI at the time of transplant and 6 and 12 months post-transplant were made by paired t-tests. The relationship between body composition methods was assessed using Wilcoxon signed rank test of the differences. The relationship between body composition methods and ultrasound measurements of muscle and adipose thickness was estimated by Spearman’s rank correlation rho. Intra-rater reliability was evaluated using deviance (absolute difference from mean). Results Mean percent body fat by air displacement plethysmography was 18.4% (±3.3) and 19.0% (±3.9) by multiple-frequency bioelectrical impedance analysis (p > 0.99). Positive differences in mean z-score comparisons from transplant indicate an increase over each time period: mean change in weight z-score at 6 months was 0.08 and 0.38 at 12 months; mean change in height z-score at 6 months was -0.56 and 0.09 at 12 months; mean z-score change in BMI at 6 months was 0.24 and 0.31 at 12 months. The combined muscle and adipose thickness measures by ultrasound were not a significant predictor for percent body fat determined by air displacement plethysmography or multiple-frequency bioelectrical impedance analysis. Ultrasound measures for biceps and quadriceps were not a significant predictor for segmental mass measures determined by multiple-frequency bioelectrical impedance analysis. Conclusions Percent body fat, fat mass and fat free mass measures determined by air displacement plethysmography and multiple-frequency bioelectrical impedance analysis were similar, which suggests the stand-on device used in this study is a useful body composition assessment tool for the pediatric population. There was no observed correlation between body composition variables by ultrasound, and air displacement plethysmography or multiple-frequency bioelectrical impedance analysis in children who have undergone a liver transplant. Including additional measurement sites and more study participants may improve the utility of ultrasound measurements.

Author dc:creator

• Perteet-Jackson, Alissa

Language dc:language.iso

en

Handle dc:identifier.uri

http://hdl.handle.net/11299/216062

OAI identifier oai:identifier

oai:conservancy.umn.edu:11299/216062