Senior author Christos Mantzoros, M.D., director of the Human Nutrition Research Unit and clinical research overseer of the Department of Endocrinology at BIDMC and associate professor of medicine at Harvard Medical School explains that the three groups of women who can most benefit from this study are very thin women who are infertile, serious athletes and dancers in danger of bone loss, and women with eating disorders. What these women have in common is their extremely low levels of body fat.
Leptin functions to signal the brain and other organs about dangerous states of very low energy availability. In so doing, he adds, leptin regulates several key physiological functions that depend on adequate energy balance.
Consequently, Mantzoros adds, in situations in which body fat is severely diminished, a woman’s body enters a state harmful to her reproductive and metabolic health.
To test leptin’s ability to restore positive energy balance, the researchers recruited 14 competitive female athletes, all of whom had been diagnosed with amenorrhea.
Eight of the 14 subjects received doses of leptin that raised their levels to normal. Six subjects served as controls, receiving no treatment.
Mantzoros says the leptin therapy restored the women’s reproductive activity to normal and improved the women’s bone density. The control group showed no change in their condition.