In girls obesity is the largest predictor of earlier-onset puberty, which is affecting white girls sooner than previously reported, according to a study.
Published Nov. 4 on the website of the journal Pediatrics, the multi-institutional study strengthens a growing body of research documenting the earlier onset of puberty in girls of all races, the authors noted.
The impact of earlier maturation in girls has important clinical implications involving psychosocial and biologic outcomes, Frank Biro, MD, the studys lead investigator and a physician in the Division of Adolescent Medicine at Cincinnati Childrens Medical Center, said in a news release. The current study suggests clinicians may need to redefine the ages for both early and late maturation in girls.
Girls with earlier maturation are at risk for a multitude of challenges, including lower self-esteem, higher rates of depression, norm-breaking behaviors and lower academic achievement, according to the news release. Early maturation also results in greater risks of obesity, hypertension and several cancers, including breast, ovarian and endometrial.
Researchers at centers in the San Francisco Bay Area, Cincinnati and New York City examined the ages of 1,239 girls at the onset of breast development and the impact of body mass index and race or ethnicity. The girls ranged in age from 6 to 8 at enrollment and were followed at regular intervals from 2004 to 2011. Researchers used established criteria of pubertal maturation, including the five stages of breast development known as the Tanner Breast Stages.
The girls were followed longitudinally, which involved multiple regular visits for each girl. The researchers said this method provided a good perspective of what happened to each girl and when it occurred.
The researchers found the respective ages at the onset of breast development varied by race, BMI and geographic location. Breast development began in white, non-Hispanic girls at a median age of 9.7 years, earlier than previously reported. Black girls continue to experience breast development earlier than white girls, at a median age of 8.8 years. The median age was 9.3 years for Hispanic girls in the study and 9.7 years for Asian girls.
Body mass index was a stronger predictor of earlier puberty than race or ethnicity. Although the research team is working to confirm the exact environmental and physiological factors behind the phenomenon, they concluded the earlier onset of puberty in white girls likely is caused by greater obesity.
The study was conducted through the Breast Cancer and Environmental Research Program, established by the National Institute of Environmental Health Science. Pediatrics is the journal of the American Academy of Pediatrics.