WIN Notes
Spring 2000
Design of
Clinical Trial
Underway
Gorden
Continues
Distinguished
Research
Career
at NIH
Schools Instill
Healthier
Habits in
Youth
Weight
Concerns
May Trigger
Smoking in
Youth
Conference
Highlights
Obesity as a
Public Health
Crisis
Girl
Power and
You! Begins
Phase II
Materials
From Other
Organizations
NIDDK
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Genetics may play a greater role in childhood obesity than previously thought. A team of researchers at St. Luke's-Roosevelt Hospital Center, Columbia University, led by David B. Allison, Ph.D., estimate that genes account for 75-80 percent of the percent body fat (PBF) in children, while the remaining 20-25 percent is attributed to nonshared environmental influences. Previous studies into the heritability of fat mass in children, which have been few and have relied primarily on body mass index (BMI) measurements, have estimated approximately 70 percent of BMI differences to be genetically based.
Allison and his research team used structural equation modeling and multivariate analyses to predict genetic and nonshared environmental influences on PBF in 66 pairs of twins (41 monozygotic and 25 dizygotic) ages 3 through 17. Bioimpedance analysis was used to estimate PBF. The findings show that genes that influenced PBF but not BMI caused 62.5 percent of the total genetic variation in PBF. "This implies that BMI alone may be a useful but insufficient measure of fat mass for gene-mapping studies using pediatric samples," according to the study authors.
Recognizing that genetic predisposition may present a challenge to treating childhood and adolescent obesity, the investigators suggest that future studies focus on identifying the critical life experiences that may promote adiposity in children and adolescents.
Allison's study, which was funded by a grant from the National Institute of Diabetes and Digestive and Kidney Diseases, is reported in the July 1999 issue of Pediatrics and can be found on the Web at www.pediatrics.org.
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