Effect of a GnRH Injection on Ghrelin Concentrations in Girls With Suspected Premature Puberty
Effect of a GnRH Injection on Ghrelin Concentrations in Girls With Suspected Premature Puberty
The purposes of the study is to investigate whether circulating levels of ghrelin decreases
 after an iv injection of GnRH in girls with suspected central premature puberty and to
 investigate the effects of different post sampling handling on the preservation of acylated
 ghrelin.
Patients with clinically suspected central premature puberty undergo a GnRH stimulation test
 to have an appropriate diagnosis. 20 such girls will be recruited to this study and a
 modified GnRH stimulation test will be done. The modification includes prolonged blood
 sampling time (0, 30, 60, 90, 120, and 150 min after the GnRH injection instead of the usual
 0, 30, 60, and 90 min). The girls will also be investigated twice. In randomised order they
 will be given either GnRH or placebo (isotone saline), on different days. One week to one
 month will separate the different investigation days.

 The proteinase inhibitor 4-(2-aminoethyl) benzene-sulfonyl fluoride hydrochlorid (AEBSF) will
 be added to some of the blood tubes, and hydrochloric acid will be added to some of the
 plasma. All plasma samples will be frozen and all analyses will be done at the same time.
 Acylated ghrelin will be analyzed by Millipore's specific ELISA kit and deacylated ghrelin
 will be analyzed by Cayman's specific ELISA kit.

 Anthropometric data as well as pubertal state will be collected. P-glucose, S-insulin,
 S-follicle stimulating hormone (FSH), S-luteinizing hormone (LH), and S-estradiol will also
 be analyzed.
Inclusion Criteria:

 -  Female gender.

 -  Clinical suspicion of central precocious puberty.

 -  A GnRH stimulation test is to be performed to make appropriate diagnosis.

 Exclusion Criteria:

 -  Age < 1 year.

 -  Weight < 10 kg.

 -  Untreated hypo- or hyperthyroidism.

 -  Diabetes of any kind.

 -  BMI > 3 z-score.

 -  Growth hormone treatment.

 -  Syndrome or suspected syndrome.

 -  Tumour or congenital malformation of the hypothalamus or the pituitary gland.
 (Neuroradiology does not have to be performed only because of the study.)

 -  On going ulcus ventriculi or the patient has gone through surgery that removed part of
 the ventricle or changed it markedly in any other way.