title: Increased melatonin concentrations in children with growth hormone deficiency.
abstract: A relationship between melatonin and growth hormone (GH) is poorly understood. We compare circadian melatonin rhythms in short children with normal and decreased GH secretion. The analysis included 22 children (20 boys and 2 girls) aged 11.1-16.9 yr (mean +/- S.E.M. = 14.1 +/- 0.3 yr) with short stature (height SDS below -2.0). Based on the GH peak in stimulation tests patients were divided into two groups: idiopathic short stature (ISS, n = 11; GH peak > or = 10 ng/mL) and GH deficiency (GHD, n = 11; GH peak < 10 ng/mL). In all patients the circadian melatonin rhythm was assessed on the basis of nine blood samples, collected in 4-hr intervals during the daytime and 2-hr intervals at night, with dark period lasting from 22:00 to 06:00 hr. Magnetic resonance imaging examination excluded organic abnormalities in central nervous system in all patients. Melatonin concentration at 24:00, 02:00 and 04:00 hr as well as the area under curve of melatonin concentrations (AUC) were significantly higher in the patients with GHD than in individuals with ISS. Significant correlations between GH secretion and melatonin concentrations at 24:00, 02:00 and 04:00 hr, and AUC were also observed. On the basis of these data it seems that the assessment of nocturnal melatonin secretion might be a valuable diagnostic tool used for the improvement of the difficult diagnosis of short stature in children.
authors.affiliation: Department of Neuroendocrinology, Medical University of Lodz, Lodz, Poland. karasek@csk.umed.lodz.pl
authors.forename: Michal
authors.initials: M
authors.lastname: Karasek
authors.forename: Renata
authors.initials: R
authors.lastname: Stawerska
authors.forename: Joanna
authors.initials: J
authors.lastname: Smyczynska
authors.forename: Andrzej
authors.initials: A
authors.lastname: Lewinski
mesh_terms: D000293:Adolescent; D001827:Body Height / Q000502:physiology; D002648:Child; D005260:Female; D013006:Growth Hormone / Q000097:blood* / Q000172:deficiency*; D006801:Humans; D008297:Male; D008550:Melatonin / Q000096:biosynthesis* / Q000097:blood
chemical_list: D013006:Growth Hormone; D008550:Melatonin