Down syndrome-specific growth charts fall short in comparative analysis

By Megan Brooks

NEW YORK (Reuters Health) - Body mass index (BMI) growth charts specific for children with Down syndrome may need revising, a new study hints.

The study found that the Centers for Disease Control and Prevention (CDC) 2000 BMI charts are a better indicator of excess adiposity in children with Down syndrome than DS-specific BMI charts.

"These findings provide solid evidence to support the use of the CDC 2000 BMI charts to screen for excess adiposity in children, ages 10 to 20 years, with Down syndrome," Dr. Babette S. Zemel, of The Children's Hospital of Philadelphia in Pennsylvania, told Reuters Health.

"This information will help families and health care providers identify children who may be at risk for health complications of excess adiposity. However, we still need more information about the health consequences of excess adiposity in children with Down syndrome, as this may differ from typically developing children," Dr. Zemel said by email.

The study appeared online September 14 in Pediatrics.

Last year in Pediatrics, Dr. Zemel and colleagues published new growth charts for children with Down syndrome, including charts for length/stature, weight, head circumference and BMI. "In that publication, we commented that more information was needed in order to determine how to use and interpret the BMI charts for children with Down syndrome, given the high rate of obesity in that population," Dr. Zemel said.

In their new paper, they compared the ability of the CDC BMI 85th percentile and the DS-specific BMI 85th percentile to identify excess adiposity in 121 children (age 14.8 +/-3.3 years; 57% girls) with Down syndrome. These data were compared to more than 7900 typically developing children (age 15.0 +/- 3.0 years, 51% girls) enrolled in the Bone Mineral Density in Childhood Study.

"Our results indicate that for children and adolescents with DS, the 85th percentile on the CDC BMI growth charts is a better indicator of excess adiposity than the 85th percentile on the DS-specific BMI growth charts," the authors report in their article.

Dr. Zemel added, "The study found a close correspondence between the 50th percentile for the Down syndrome BMI charts, and the 85th percentile of the CDC 2000 BMI charts at most ages in boys and some ages in girls. This means that the entire distribution of BMI for contemporary children with Down syndrome is shifted towards higher BMI ranges, compared to the CDC 2000 charts."

In addition, using fat mass index (FMI), a measure of body fat relative to height, "the analysis showed that the CDC 2000 BMI chart 85th percentile was a better indicator of excess adiposity, defined by FMI, than the new DS-specific BMI charts," Dr. Zemel told Reuters Health.

The authors conclude, "Although the DS-specific charts are still an excellent method to compare patients with DS to their DS peers, the CDC BMI charts should be the preferred method for the early identification of obesity in children with DS."

SOURCE: http://bit.ly/2cmTlL9

Pediatrics 2016.

(c) Copyright Thomson Reuters 2016. Click For Restrictions - http://about.reuters.com/fulllegal.asp