ABSTRACT
Several studies have reported that zinc deficiency limited the growth in infants and young children. This study has been designed to determine the plasma and hair zinc levels in preadolescent children and adolescents with short stature and to search for an eventual correlation of their levels with insulin-like growth factor 1 [IGF-1] and growth hormone [GH]. Subjects and Methods This study was conducted on forty short stature children with apparent good health and with height measurements below the 3rd percentile for age and sex. They were divided into two groups: preadolescent children [n=20] and adolescents [n=20]. Twenty children of normal growth and of matched age and sex were included as controls. In all studied subjects, plasma GH levels were estimated under basal conditions and after applying two provocative tests [exercise for 20 minutes and clonidine stimulation after 30, 60, 90 and 120 minutes] using radio immunoassay technique [RIA], plasma IGF-I using RIA, plasma and hair zinc using atomic absorption spectrophotometry. revealed that both preadolescent and adolescent subjects had reduced levels of plasma zinc, hair zinc, plasma IGF-1 and plasma GH under basal conditions. After applying the two provocative tests [exercise and clonidine stimulation], preadolescents showed normal GH levels while adolescents were still having reduced GH levels. Plasma zinc levels in the adolescent group showed a significant positive correlation with height measurements and with IGF-1 levels of these subjects. From the results of this work, one can conclude that short stature preadolescent children and adolescents have decreased levels of zinc which could account for the limited growth in these subjects whether through indirect mechanisms or via hormonal mediation specially by lowering the levels of IGF-1