Share This Page

More signs link obesity to puberty

| Monday, Nov. 4, 2013, 12:01 a.m.

The age at which puberty starts in some girls has continued to drop, finds the latest study to suggest obesity may be a key trigger.

The start of puberty — determined by a specific stage of breast development — was at a median age of 9.7 years old in white, non-Hispanic girls, four months earlier than in a landmark 1997 study that first documented early puberty in U.S. girls. The report is in December's Pediatrics, published online on Monday.

The new study tracked 1,200 girls enrolled at ages 6 to 8 over seven years. It found blacks continue to develop earlier than whites, reaching puberty at a median age of 8.8, versus 9.3 years for Hispanics and 9.7 for Asians.

But blacks matured at similar ages in the 1997 study; it was not clear why there was no change for blacks. For Hispanics and Asians, data was insufficient to know whether puberty age changed.

While previous studies found that race as well as body mass index played a role in predicting the onset of puberty, “BMI supplants race as the No. 1 factor” in the new analysis, according to lead author Frank Biro, director of adolescent medicine at Cincinnati Children's Hospital.

Girls with higher BMIs in all race and ethnic groups were progressively more likely to have started puberty.

Although this and other studies implicate weight as a “prime driver” of early puberty, Biro says the question remains, “Why are they more obese?” In addition to increased calorie consumption and less physical activity, researchers are looking at a number of other possible explanations, such as exposure to chemicals in the environment that may trigger hormonal changes, he says.

TribLIVE commenting policy

You are solely responsible for your comments and by using TribLive.com you agree to our Terms of Service.

We moderate comments. Our goal is to provide substantive commentary for a general readership. By screening submissions, we provide a space where readers can share intelligent and informed commentary that enhances the quality of our news and information.

While most comments will be posted if they are on-topic and not abusive, moderating decisions are subjective. We will make them as carefully and consistently as we can. Because of the volume of reader comments, we cannot review individual moderation decisions with readers.

We value thoughtful comments representing a range of views that make their point quickly and politely. We make an effort to protect discussions from repeated comments either by the same reader or different readers

We follow the same standards for taste as the daily newspaper. A few things we won't tolerate: personal attacks, obscenity, vulgarity, profanity (including expletives and letters followed by dashes), commercial promotion, impersonations, incoherence, proselytizing and SHOUTING. Don't include URLs to Web sites.

We do not edit comments. They are either approved or deleted. We reserve the right to edit a comment that is quoted or excerpted in an article. In this case, we may fix spelling and punctuation.

We welcome strong opinions and criticism of our work, but we don't want comments to become bogged down with discussions of our policies and we will moderate accordingly.

We appreciate it when readers and people quoted in articles or blog posts point out errors of fact or emphasis and will investigate all assertions. But these suggestions should be sent via e-mail. To avoid distracting other readers, we won't publish comments that suggest a correction. Instead, corrections will be made in a blog post or in an article.