Comparative characteristics of auxological and hormonal parameters of small for gestational age children and patients with isolated somatotropic deficiency

Abstract

Purpose of the study — to conduct a comparative analysis of the auxological and hormonal parameters of patients with growth deficiency due to small for gestation age and growth hormone deficiency. Material and methods. We examined 84 prepubertal children (55 boys and 29 girls) with short stature. 50 of them were SGA children, other 34 children had growth hormone deficiency. All patients had two stimulation tests (insulin, clonidine) to check the growth hormone function. All patients were euthyroid on the basis of their TSH serum level within the normal range. They did not receive treatment with recombinant growth hormone (rGR) previously. Levels of GH, IGF‑1 were investigated by enzyme-linked immunosorbent assay using Immulate 2000 XPi kits. The levels of TSH, T4 free, IGF-BP‑3 were investigated by the immunoradiometric method using standard kits (Immunotech® kit, Chech Republic). Results. All SGA children with short stature had a significant decrease in length and body weight at birth compared to children with isolated somatotropic deficiency with the same gestational age. In all examined patients persisted the lack of growth and body weight. The degree of decreasing in growth, bone age, growth rate and stage of puberty in all examined patients did not significantly differ. In the majority (68,0%) of SGA patients without a «spontaneous catch-up growth», an adequate stimulated release of GH was recorded, however, such children remained significantly lack in growth and body weight. In others SGA patients (32%) and in isolated GH deficiency patients, a decrease in the stimulatory GH release was established, indicating a GH deficiency. In all examined children, a decrease in serum IGF‑1 and IGF-BP‑3 levels was observed. The decrease in the IGF-BP‑3 level was the same in patients of all groups, however, a significant decrease in the IGF‑1 level was observed in children with growth hormone deficiency compared to the SGA patients with GH deficiency (p<0.05). Conclusions. SGA patients who do not have a «spontaneous growth» can experience both normal and reduced rates of stimulated growth hormone and reduced IGF‑1 and IGF-BP‑3 levels. Deficiency of growth, body weight, decrease in the IGF‑1 and IGF-BP‑3 levels persist for a long time after the birth of the baby.