Early breast development in overweight girls: does estrogen made by adipose tissue play a role?

Background: Girls who are overweight/obese (OB) develop breast tissue but do not undergo menarche (the first menstrual period) significantly earlier than girls of normal weight (NW). It has been proposed that estrogen synthesized by adipose tissue may be contributory, yet OB do not have higher serum estrogen levels than NW matched on breast stage. We hypothesized that estrogen synthesized locally, in mammary fat, may contribute to breast development.