Interrelation between Histamine and Serotonin, Dopamine, GABA, IGF-1 in a Growth Hormone (GH) Deficient Group under rh-GH Replacement Therapy

Aim: To evaluate relationship between histamine (HIST), serotonin (5-HT), dopamine (DA), gamma-amino-butyric acid (GABA) and IGF-1 in 20 GH-deficient boys.                                   Research design and methods: This study included 20 boys (5-14 years) with GH deficit clinically established and a 10 matched normal group with no endocrine dysfunction. All of GH deficient patients underwent GH replacement therapy. In 2017, all subjects were tested by analytical methods for blood: HIST,GABA,DA,5-HT,IGF-1.                                                            Results: We divided this study group into a low HIST lot 1 (10 subjects): HIST median: 3.48 nM/L and a high HIST lot 2 (10 subjects): HIST median: 11nM/L. Median parameters in lot 1 vs. lot 2 were: 5-HT: 212.5 vs. 370ng/mL, DA: 30 vs. 45pg/ml, GABA: 30 vs. 56.5ng/mL, IGF-1: 373.5 vs. 200ng/mL. Median values in normal subjects were as it follows: HIST: 5.55nM/L; 5-HT: 235.5ng/mL; DA: 31.5pg/mL; GABA: 81ng /mL. T-Test revealed a statistical significance between HIST in lot 1 vs. lot 2 (P<0.001), HIST in lot 1 vs. normal group (P<0.01) or HIST in lot 2 vs. normal group (P<0.01).We can also underline a statistical significance between 5-HT in lot 1 vs. lot 2 (P<0.05) or in lot 2 vs. normal group (P=0.01).                                                                 Conclusion: Our study underlined a HIST/5-HT positive relationship in low HIST group vs. a negative relationship HIST/5-HT in high HIST group, with small IGF-1 increments under r-GH therapy.