Leptin affects infertility
1/13/2005 12:00 PM
By: Ivanhoe Broadcast News
About 6 million people in the United States are affected by infertility.
Fertility depends on several factors, including a man's production of healthy sperm, a woman's production of healthy eggs, unblocked fallopian tubes that allow the sperm to reach the egg, the sperm's ability to fertilize the egg when they meet, the ability of the fertilized egg to become implanted in the woman's uterus, and sufficient embryo quality.
For the pregnancy to continue to full term, the embryo must be healthy, and the woman's hormonal environment must be adequate for its development.
About one-third of infertility cases can be attributed to male factors, another third can be attributed to female factors, and the final third is linked to problems in both partners, or in about 20 percent of cases, is unexplained.
The most common male causes of infertility is no or too few sperm cells are produced. The most common female cause is an ovulation disorder.
Leptin was first discovered in 1994. It is known for being an appetite and weight regulation hormone. But leptin also functions to signal the brain and other organs about dangerous states of very low energy availability. Leptin is produced by the body's fat tissue and is secreted into the bloodstream in proportion to the amount of energy stored in fat. From there, it travels to the brain where it communicates exactly how much energy is available. It thereby regulates several key physiological functions that depend on adequate energy balance, including reproduction, metabolism and bone formation.
Researchers have found leptin plays a critical role in women's reproductive and neuroendocrine health. The hormone can potentially treat a number of conditions, including exercise-induced bone loss, eating disorders and infertility. Women who have very low body fat can have adversely affected reproductive and metabolic health. They may stop menstruating and develop hypothalamic amenorrrhea. Their ovaries stop functioning and their levels of estrogen and other reproductive hormones dramatically drop.
Researchers studied 14 female athletes who had stopped menstruating on average 5˝ 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.
Leptin is not yet FDA approved and is still being tested. More studies are needed to look at specific factors like dosage before leptin can be made available to the public.
The two centers conducting this research are The Beth Israel Deaconess Medical Center and Massachusetts General Hospital, both in Boston.
source:
http://www.news8austin.com/content/l...8&addvid=27599
Leptin affects infertility 
