Researchers have identified 30 genes that play a role in the onset of menstruation in girls. Some of these puberty genes have previously been linked to body weight and fat metabolism, strengthening the connection between the obesity epidemic and the early onset of puberty in industrialized nations.
For the study, published in Nature Genetics, researchers analyzed 32 genome-wide association studies that included more than 87,000 women from the United States, Europe and Australia, and then replicated the results in a further 14,000 women. Of the 30 genes that they found play a role in the timing of women’s first periods, four genes are linked to body mass index, three play a role in metabolism, and three are involved in hormone regulation.
Study co-author, Dr Enda Byrne of the Queensland Institute of Medical Research says the results from this study show that many of the genes that increase risk for weight gain and obesity in adulthood, also influence the onset of puberty. “This supports the idea that the body launches into puberty once it reaches a certain level of nutrient stores and therefore children who are overweight are more likely to undergo early puberty,” says Byrne. [Australian Broadcasting Corporation]
Since its emergence in the early 1980s, the drug isotretinoin—used to treat severe acne and sold under a host of different brand names—has been subject to controversy over whether it increases the incidence of suicide attempts in those who take it. But sorting out whether the drug, the acne itself, or some other factor is driving increased suicide risk is quite difficult.
So for a study out in the British Medical Journal, a team of researchers in Sweden looked at a deluge of data for 5,756 people who took the drug. Their conclusion: Severe acne patients who took isotretinoin had an increased risk for suicide attempts both before and after taking it, so they can’t definitively link isotretinoin to suicide.
The drug, perhaps best known as the pharmaceutical company Roche’s Accutane, has been embraced by dermatologists and their suffering patients, but has also been dogged by controversy for its side effects.
While powerful at clearing acne, the drug has been linked to birth defects if taken during pregnancy and has also been suspected of causing mental side effects, although Roche has vigorously defended personal injury claims in this area. [Reuters]
Anders Sundstrom led the current research, which seems to support the theory that the pharmaceutical isn’t a threat to mental health. Said Sundstrom:
Girls around the country are starting puberty ever younger, says a new study out in Pediatrics.
Researchers led by Frank Biro studied more than a thousand girls between six and eight years old from New York, Cincinnati, and San Francisco. Their findings: By the age of 7, about 23 percent of black girls, 15 percent of Hispanic girls, and 11 percent of white girls showed enough breast development to be considered pubescent. Those numbers are even more extreme than the findings of a similar 1997 study that seemed to show the age entering puberty was dropping fast.
“In 1997, people said, ‘That can’t be right; there must be something wrong with the study’. But the average age is going down even further” [Los Angeles Times].
The starkness of Biro’s statistics has drawn plenty of attention. But just what it means is a difficult question, because there’s no “ideal” age for entering puberty.