Leptin solves hormone problems

A paper published in this week's New England Journal of Medicine reports that low doses of recombinant leptin, the fat-derived hormone, corrected hormonal deficiencies, and in some cases, restored ovulation and menstrual cycles in women with hypothalamic amenorrhea.

Hypothalamic amenorrhea is characterized by low levels of key reproductive hormones and the absence of menstruation, and often leads to infertility and bone loss. Those affected by the condition fall along a spectrum, senior author Christos Mantzoros, of Harvard University, told The Scientist. At one end are extremely thin women with anorexia nervosa or several hormonal abnormalities; at the other end are very thin women who only become aware of their less pronounced abnormalities when they try unsuccessfully to become pregnant.

"Our hypothesis, based on previous experiments in mice and in normal humans, was that leptin was regulating the [reproductive] hormones," Mantzoros said. He then reasoned: "If we restored...