| Girls' Body Fat at Age 5
Linked to Earlier Puberty
NEW YORK (Reuters Health) -
Girls who have more body fat at age 5 tend to be closer to puberty
at age 9 than other 9-year-olds who had less body fat, researchers
report. And girls showing large increases in body fat between
the ages of 5 and 9 also tend to show more signs of puberty at
age 9 compared with other youngsters.
The new findings suggest that weight
control efforts may need to start as early as preschool, according
to Dr. Kirsten Krahnstoever Davison and colleagues of Pennsylvania
State University, in University Park.
Some experts believe that the rising
rate of obesity among U.S. children has spurred early maturation.
On average, girls are starting to show the first signs of breast
development at ages 8 and 9, a year earlier than 20 years ago,
according to the report in the journal Pediatrics.
Both obesity and earlier puberty
can have health consequences.
Obesity puts young people at risk
for diabetes and raises their odds of heart disease and other
health problems down the road. For girls, early puberty increases
their lifetime exposure to estrogen, which may elevate the risk
for breast cancer and possibly ovarian cancer.
In the new study, Davison's team
evaluated 181 girls at the age of 5, 7 and 9 years. All the girls
underwent weight and body fat measurements, and at age nine had
pubertal development assessed. All the girls were white and from
families with a median annual income that ranged from $35,000
"Girls with higher percent body
fat at 5 years, and girls with higher percent body fat, higher
BMI (body mass index) percentile, or larger waist circumferences
at 7 years, were more likely to be classified with earlier pubertal
development at 9 years," the authors write.
Body mass index is a measurement
that takes into account a person's height and weight and is used
to identify people who are overweight.
Girls who gained the highest percentage
of body fat between the ages of 5 and 9, and those who saw the
largest increase in their waist size between the ages of 7 and
9 were also more likely to show signs of puberty onset at age
9, the study indicates. Overall, 30 percent of the girls were
overweight and 56 percent showed the first signs of breast development
by age 9.
"This study indicates that body
fat levels during middle childhood are causally implicated in
earlier timing of puberty among white girls," the authors conclude.
"The practical implications of
these findings emphasize the need for implementation of early
prevention and treatment programs for childhood overweight, beginning
as early as the preschool period," the authors conclude.
Further research will need to assess
the relationship between weight, body fat and early onset puberty
in girls of other ethnic groups, according to the report.
SOURCE: Pediatrics 2003;111:815-821.
Reference Source 89