The Growth Hormone-Insulin-like Growth Factor Axis in Glycogen Storage Disease Type 1: Evidence of Different Growth Patterns and Insulin-like Growth Factor Levels in Patients with Glycogen Storage Disease Type 1a and 1b

Patients with GSD1a have an impaired GH secretion associated with reference range serum IGF-I levels and normal stature, whereas in patients with GSD1b, the impaired GH secretion, probably because of the presence of APA, was associated with reduced IGF-I levels and increased prevalence of short stature. The ncreased IGF-II levels, probably caused by increased insulin levels, in patients with GSD1 are presumably responsible for the improved growth pattern observed in patients receiving strict dietary treatment.