Could Leptin be the next fertility medication?

Leptin is a hormone produced in adipose tissue (fat cells). It has been the subject of much study in recent years. Leptin was first discovered in 1994. It is primrily thought of as an appetite and weight regulation hormone. However, leptin also functions to signal the brain and other organs about dangerous states of very low energy availability. Leptin is secreted into the bloodstream in proportion to the amount of energy stored in fat. The leptin is detected by receptors in the brain where it signals how much energy is available. It thereby regulates several key physiological functions that depend on adequate energy balance, including reproduction, metabolism, and bone formation.

We have known for some time that women who have very low body fat and/or those who exercise vigorously, can stop ovulating. Once they stop ovulating, they no longer produce essential hormones like estrogen and their periods can also stop or become infrequent. This condition is called hypothalamic amenorrhea.

Traditionally, in order to acheive pregnancy in these women, we used one of several techniques. First, we might ask the woman to decrease or stop her exercise or try to gain weight. This is usually successful in getting ovulation to return. However, some women are reluctant to try this approach. for them, we would use fertility medications to induce ovulation. This is effective but requires monitoring and has a risk for multiple pregnancy.

Researchers in boston recently studied 14 female athletes who had stopped menstruating on average five-and-a-half years before the start of the study. They had about 40-percent less body fat than the average woman. Eight of the women received leptin, while the others served as controls. After just three months of treatment, women receiving twice-daily leptin supplements resumed menstrual periods, and their ovaries began to function normally. The hormone also significantly improved bone density bone markers in the blood. No change was observed in the control group.

This is pretty exciting stuff. If these results can be confirmed in larger studies and if a pharmaceutical compnay is wlling to put forth the financial risk to do the additional dosing and safety studies then Leptin could become a vialbe treatment option for this group of patients.

Could Leptin be used to treat other ovulation problems like polycystic ovary syndrome - PCOS? This is less certain. Many studies have been conducted trying to determine whether leptin levels are correlated with polycystic ovary syndrome - PCOS but with inconsistent results. Theoretically, however, polycystic ovary syndrome - PCOS patients may have too much Leptin and need a medication which blocks or reduces its effects.