Constitutional delay in growth: comparison of linear growth with serum growth hormone response to provocative tests in 26 children.

The peak levels of serum growth hormone (GH) obtained in response to administration of insulin and arginine in 26 children with constitutional delay in growth (CDG) are compared to similar test results in 7 normal children. Heights at the time of testing, and follow-up linear growth, are documented in all subjects. Most patients with constitutional delay in growth could be identified on the basis of history, physical examination, bone age radiograph, and yearly follow-up of growth. Only two patients exhibited growth of less than 4 cm per year; both had normal responses to provocative testing. In response to provocative testing, individual patients with constitutional delay in growth revealed peak levels of serum GH which were within the normal range, but the group mean peak value was less (p less than 0.05) than in normal children. One child with clinical constitutional delay in growth revealed a subnormal response to both provocative tests. The results suggest that children with constitutional delay in growth may have a diminished reserve for secreting growth hormone.