In the large-scale, NIH-funded study, researchers from 104 institutions collected data from more than 100,000 women from the United States, Europe, and Australia. This includes women from the Twin Cities area enrolled in the Atherosclerosis Risk in Communities (ARIC) study. Not only were researchers able to identify these new genes, but they also found that many of them play a role in body weight regulation or biological pathways related to fat metabolism. The study findings also suggest that menarche is a result of a complex range of biological processes.

Today, girls are menstruating earlier than ever before. In the mid-1900s, the average age of menarche was 14-15 years. The average age today is 12-13 years.

"We now know that hormone regulation, cell development, and other mechanisms are related to menarche," said Demerath.

According to Demerath, the next step for researchers is to examine whether some of these genes also influence sexual development in males, whether the genes are related to general growth in size as well as development, the points in the life cycle when the genes are most powerfully expressed, and how environmental factors such as diet and physical activity can modify their effects.

Source: University of Minnesota