View clinical trials related to Puberty, Precocious.
Filter by:Increasing bone mass during puberty can ultimately decrease the risk of developing osteoporosis, which causes bones to weaken and break more easily later in life. The purpose of this study is to compare calcium absorption and bone growth in boys and girls on diets including either a nondigestible oligosaccharide (NDO) or simple sugar.
This study will test the safety and effectiveness of letrozole in treating precocious (early) puberty in girls with McCune-Albright syndrome (MAS). The physical changes of puberty, such as breast enlargement, menstruation and growth spurt, as well as the emotional changes of this developmental stage, usually begin in girls between the ages of 8 and 14. Girls with MAS, however, often begin puberty before age 7. In MAS, large ovarian cysts produce high levels of estrogens (female hormones) that cause the changes of puberty. Children with MAS also have polyostotic fibrous dysplasia (PFD), a disease of bones that, depending on what parts of the skeleton are affected, can lead to broken bones or disfigurement of the head, face, arms and legs, or can cause pressure on nerves and blood vessels. Many children with MAS have cafe-au-lait spots (increased pigmentation) on areas of their skin as well. Letrozole is an estrogen-lowering drug that has been approved for treating women with breast and other cancers. Although the drug has not been tested or approved for use in children, some pediatric specialists have given it to girls with precocious puberty and MAS and found that it improves their condition without harmful side effects. This study will examine whether letrozole can lower estrogen in girls with MAS and arrest puberty. It will also study the drug's effects on substances involved in bone growth, including calcium, phosphate and amino acids. Girls 1 to 8 years old with MAS may be eligible for this study. Patients who were enrolled in NIH protocol 98-D-0145 (Screening and Natural History of Patients with Polyostotic Fibrous Dysplasia and the McCune-Albright syndrome) are also eligible. Participants will be admitted to the hospital for 2 to 3 days every 3 months for 15 months, for a total of 6 visits. They will undergo a complete history and physical examination and routine blood and urine tests every visit, as well as evaluations of their general health, growth and bone development, endocrine system (hormone-secreting glands) status and PFD status. A hand X-ray will be taken at the first visit and every 6 months to measure bone age advance. The children will begin taking letrozole at the second visit and continue the drug for 6 months. They will be evaluated after 3 months and 6 months on the drug (visits 3 and 4), and again after 3 months and 6 months after stopping treatment (visits 5 and 6). Parents of children who weigh more than 18 kilograms (about 40 pounds) may be asked if extra blood may be drawn after 3 months (visit 3) and 6 months (visit 4) of treatment to measure letrozole levels. The blood will be drawn before the morning dose and at 0.5, 1, 1.5, 2, 3, 4, 6, 8, and 24 hours after the dose through an indwelling needle placed in the vein for 8 to 24 hours. Parents will keep a record of all episodes of menstrual bleeding and any other symptoms or complaints. Children who respond well to therapy (decreased menses, slowed breast development, slowed growth and bone age advance) will be offered another 12 months of letrozole treatment.
OBJECTIVES: Purify and characterize a testis-stimulating factor in the blood of adult volunteers who had precocious puberty as boys.
OBJECTIVES: I. Evaluate the sleep-entrained patterns of gonadotropin-releasing hormone (GnRH) and sex steroid secretion in normal and hypogonadal children. II. Examine the acute effects of sex steroids on the sleep-entrained patterns of GnRH secretion in pubertal children and normal adults, either by stimulation of endogenous production with pulsatile injection or by intravenous infusion of GnRH. III. Examine the role of endogenous opioids by means of opioid receptor blockade in the sex steroid regulation of GnRH secretion in pubertal children and normal adults.
This study is a continuation of two previous studies conducted at the NIH. The first study , "Treatment of True Precocious Puberty with a Long-Acting Lutenizing Hormone Releasing Hormone Analog (D-Trp(6)-Pro(9)-Net-LHRH)" had less than optimal results. Some patients, all of whom were diagnosed with familial isosexual precocious puberty, had an inadequate response to the medication and were observed to have high levels of testosterone, advanced bone aging, and other complications of the disease. As a result these patients were enrolled in a second study In the second study, "Spironolactone Treatment for Boys with Familial Isosexual Precocious Puberty", - the patients received another medication, spironolactone (Aldactone). The drug blocked the effects of testosterone, -but bone age advancement did not improve. Some patients began experiencing gynecomastia (an abnormal growth of the male breasts). Researchers believe these may be the effects of elevated levels of estrodiol (a form of the female hormone, estrogen). In the present study, testolactone is added to the drug regimen to block the production of estrogen. The study therefore uses spironolactone to prevent the action of the male hormones (androgen) and testolactone to block the production of female hormones (estrogen). Deslorelin, an LHRH analog which works by turning off true (central) puberty, is added to the drug regimen once true puberty begins. This is because it is know that boys with familial male precocious puberty go into true puberty too early (despite treatment with spironolactone and testolactone), and when that happens, the spironolactone and testolactone are no longer as effective. The goal of the treatment is to delay sexual development until a more appropriate age and prevent short adult stature (height).
The normal changes of puberty, such as breast enlargement, pubic hair and menstrual periods, usually begin between the ages of 9 and 15 in response to hormones produced in the body. Some children's bodies produce these hormones before the normal age and start puberty too early. This condition is known as precocious puberty. The hormones responsible for the onset of puberty come from the pituitary gland and the ovaries. The hormones from the pituitary gland act on the ovaries to produce different hormones that cause the breasts to grow, pubic hair to develop, and menstruation. Many children with precocious puberty can be treated with a medication known as lutenizing hormone-releasing hormone analog (Lupron, Histerelin, Deslorelin). This drug is made in a laboratory and is designed to act like the natural hormone LHRH, which is made in the pituitary gland. The drug causes the pituitary gland to decrease the amount of hormones it is releasing and thereby decrease the amount of hormones released by the ovaries. However, some girls already have low levels of pituitary hormones and yet their ovaries still produce hormones. Researchers do not believe that LHRH analog therapy will work for these children. Testolactone is a drug that acts directly on the ovary. It works by preventing the last step of estrogen production in the ovary. The goal of this treatment is to stop estrogen production and delay the onset of puberty until the normal age. Researchers will give patients with LHRHa resistant precocious puberty Testolactone for six months. If the initial treatment is successful and patients do not experience very bad side effects, they will continue to receive the medication until puberty is desired. Throughout the therapy patients will receive frequent monitoring of their general state of health, hormone levels, and medication levels.