Correlation between pituitary growth hormone reserve and degree of growth failure in children with short stature.

The correlation between a releasable pituitary growth hormone (GH) pool and degree of growth failure was examined in 30 children with GH deficiency (group I) and 19 children with normal short stature (group II). Based on the responsiveness of GH to GH-releasing hormone (GHRH), group I, with low GH responses (below 7 ng/ml) to both insulin and arginine, was classified into three subgroups; Ia (peak value less than 10 ng/ml, n = 19), Ib (10-20 ng/ml, n = 5) and Ic (above 20 ng/ml, n = 6). Group II, with a GH response above 10 ng/ml to either insulin or arginine, was also divided into IIa (below 20 ng/ml, n = 5) and IIb (above 20 ng/ml, n = 14). Body length and growth velocity in Ia and Ib were significantly reduced vs Ic; bone age in Ia was retarded vs Ic; plasma somatomedin C (Sm-C) levels in Ia and Ib were decreased vs Ic, who had almost normal levels (0.90 +/- 0.55 U/ml). The incidence of other combined pituitary hormone deficiencies and previous perinatal distress was definitely high in Ia and Ib, but zero in Ic. In group II also, body length and growth velocity were significantly decreased in IIa vs IIb (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)