Press Release

Body Mass Index Can Predict Infant's Risk of Becoming an Obese Child

Boston, MA April 02, 2016

Pediatricians can now identify infants who are at higher risk of early-childhood obesity, before obesity develops, using a simple measurement of body mass index (BMI), a tool not routinely used until children are 2 years old. This conclusion, from a new study of nearly 4,000 children, will be presented Friday at the Endocrine Society’s 98th annual meeting in Boston.

In the U.S., 17 percent of children and teens are obese, according to the Centers for Disease Control and Prevention. However, health care providers do not know when obese children develop an abnormal pattern of weight gain, said lead investigator Allison Smego, MD, a pediatric endocrinology fellow at Cincinnati Children’s Hospital Medical Center.

“Our study shows that growth patterns in children who become severely obese by 6 years of age differ from normal-weight children as young as 4 to 6 months of age,” Smego said.

The researchers found that a high BMI, measured between 6 and 18 months of age, accurately predicted which infants were prone to early-childhood obesity.

Children age 2 years or older are considered overweight if they have a BMI at or above the 85th percentile for their age and sex on standard growth charts, and are obese if their BMI is at the 95th percentile or higher. Although not typically done, infants’ BMI can be tracked on World Health Organization (WHO) growth charts for birth to 24 months.

In this study, Smego and colleagues looked at the electronic health records for two groups of patients who had growth data from birth through age 6 years. One group of 480 children was severely obese between ages 2 and 6 years, with a BMI above the 99th percentile on the WHO growth charts, and the other group of 783 kids was lean, with a BMI between the 5th and 75th percentiles during those ages. Looking back at the growth curves over time, the researchers found that BMI diverged between the two groups starting at only 4 months of age.

A BMI above the 85th percentile at 6, 12, or 18 months was a strong predictor of severe obesity by the age of 6 years, the investigators reported.

Most of the obese children were from low-income, African-American populations in Cincinnati, according to Smego. To validate their findings in a different ethnic and socioeconomic population, the researchers repeated the study in a third group: 2,649 children seen at Children’s Hospital Colorado in Aurora, Colo., which had a higher Hispanic population. Smego said that a BMI threshold above the 85th percentile increased the chance of severe obesity at age 6 years by threefold to nine-fold in this group.

“Based on our findings, we recommend that pediatricians routinely measure BMI at infant well-child assessments beginning at 6 months, identify high-risk infants with BMI above the 85th percentile, and focus additional counseling and education regarding healthy lifestyle toward the families of these children,” Smego said. “It might take the pediatrician a minute to look at BMI, yet it gives them a wealth of knowledge about how their patient is growing.”

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