The Relationship of BMI to Menarche Differs by Race in Three Nationally Representative Samples of Girls in the United States
Authors: Amparo G. Gonzalez-Feliciano, Mildred Maisonet and Michele Marcus
Abstract: The age at which girls experience their first menstrual period, also known as menarche, is influenced by genetic and environmental factors. In the United States and in Europe, age at menarche has declined over time. This is of concern because earlier age at menarche has been associated with increased risk of breast cancer and adverse reproductive outcomes. Current data indicate that black girls attain menarche earlier than white girls, and overweight and obese girls attain menarche earlier than their normal weight peers. However, data from earlier time periods reveal that the racial difference in age at menarche is a recent phenomenon. Therefore, it is likely to be due to environmental factors. Using data from NHES II and III, NHANES III, and NHANES 2003-2006 we explored the associations between BMI and menarche among black girls and among white girls in each of the time periods. Race-specific analyses revealed a steeper decline in age at menarche with increasing BMI for black girls when compared to white girls. This apparent interaction has not been previously reported. Possible mechanisms for race-specific differences in the relationship between BMI and age at menarche should be explored.