title: Changes in circadian rhythm of prolactin in short children are dependent on growth hormone secretion.
abstract: OBJECTIVE
  Taking into consideration the common ontogenic origin of prolactin (Prl) and growth hormone (GH), the Prl circadian pattern was analysed in children with different degrees of GH deficiency (GHD).
  
  
  METHODS
  The analysis comprised 100 short children (31 girls and 69 boys), aged: 10.1±3.51 years. Based on maximal GH secretion (GHmax) during two stimulating tests multiple hormone deficiency (MPHD), severe isolated GHD (SIGHD), partial isolated GHD (PIGHD) or idiopathic short stature (ISS) were diagnosed. Non-inferential chronobiometry (macroscopic analysis) of the circadian Prl rhythm, based on serum Prl measured every 3 hours during 24 hours, was performed. In this analysis, mesor, the area under curve (AUC), peak and trough level, dispersion, mean nocturnal and diurnal concentration, night/day ratio, amplitude and regression index were estimated.
  
  
  RESULTS
  In the study group, the positive correlations between GHmax and Prl concentrations at 02:00 and at 05:00 were observed, as well as between GHmax and mesor, amplitude, mean nocturnal concentration, night/day ratio and AUC. The nocturnal rise of Prl secretion was blunted in 100% MPHD and 50% SIGHD children, whereas in most children with PIGHD and ISS, the circadian Prl rhythm was normal.
  
  
  CONCLUSIONS
  1) In short children, the lower the concentration of GH is, the more blunted nocturnal Prl secretion becomes. 2) In the majority of MPHD and SIGHD children (but not PIGHD), the circadian Prl rhythm was disturbed; namely, reduced nocturnal Prl secretion was noticeable.
authors: Department of Endocrinology and Metabolic Diseases, Polish Mother's Memorial Hospital - Research Institute, Lodz, Poland, Department of Paediatric Endocrinology, Medical University, Lodz, Poland.
authors: Renata
authors: R
authors: Stawerska
authors: Department of Endocrinology and Metabolic Diseases, Polish Mother's Memorial Hospital - Research Institute, Lodz, Poland.
authors: Joanna
authors: J
authors: Smyczyńska
authors: Department of Endocrinology and Metabolic Diseases, Polish Mother's Memorial Hospital - Research Institute, Lodz, Poland, Department of Paediatric Endocrinology, Medical University, Lodz, Poland.
authors: Maciej
authors: M
authors: Hilczer
authors: Department of Endocrinology and Metabolic Diseases, Polish Mother's Memorial Hospital - Research Institute, Lodz, Poland, Department of Endocrinology and Metabolic Diseases, Medical University, Lodz, Poland.
authors: Andrzej
authors: A
authors: Lewiński
mesh_terms: D000293:Adolescent; D049628:Body Size / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D002940:Circadian Rhythm; D005260:Female; D006130:Growth Disorders / Q000097:blood; D019382:Human Growth Hormone / Q000172:deficiency / Q000378:metabolism*; D006801:Humans; D008297:Male; D011044:Poland; D011388:Prolactin / Q000097:blood*
chemical_list: D019382:Human Growth Hormone; D011388:Prolactin