Kids from poorer families may hit puberty early: study

Children who grow up in economically disadvantaged families are more likely to experience puberty early, which may lead to serious health complications later in life, scientists said today.

Researchers from the Murdoch Children's Research Institute (MCRI) in Australia found that boys who grew up in very disadvantaged households had more than four times the risk of starting puberty early, at 10 or 11 years of age, while girls had double the risk.

The factors determining early puberty have received greater attention recently as more kids are starting puberty at an earlier age than past generations.

Researchers surveyed about 3,700 children. Parents were asked to report on signs of children's puberty at age eight to nine and 10 to 11 years.

These signs included a growth spurt, pubic hair and skin changes, plus breast growth and menstruation in girls, and voice deepening and facial hair in boys.

Researchers found that at 10 to 11 years of age, about 19 per cent of boys and 21 per cent of girls were classified in the early puberty group.

Boys from very disadvantaged homes had 4.2 times the risk of developing early and the same factors increased the risk of early puberty for girls, researchers said.

"Ongoing exposure to extremely unfavourable household socioeconomic position in boys independently predicted a four-fold increase in the rate of early puberty," said Ying Sun, a visiting academic at MCRI.
"In girls, the increase was nearly two-fold, when compared with those from a favourable background," Sun said.

The disadvantage may be linked to early puberty for evolutionary reasons, researchers said.

In the face of hardship, (eg economic disadvantage, harsh physical environment, absence of a father etc), children may be programmed to start the reproductive process earlier to ensure their genes are passed on to the next generation, they said.

"Early maturation has links in girls with emotional, behavioural and social problems during adolescence including depressive disorders, substance disorders, eating disorders and precocious sexuality," said George Patton, professor at MCRI.

"Early puberty also carries risks for the development of reproductive tract cancers and cardio-metabolic diseases in later life," he said.

The study was published in the journal Pediatrics. `