The insulin profiles of the IDDM patients were flat with low post-prandial peaks, corresponding to only one-third of the peaks of the non-diabetic girls. The integrated insulin levels, both during 24-h sampling and during daytime, were significantly lower in the diabetic group. There were no differences during night-time. The diabetic patients had elevated mean baseline levels of serum GH (IDDM 2.8 +/- 0.5 mU/l, controls 0.7 +/- 0.2; P<0.001), a higher 24-h mean serum GH level (9.8 +/- 1.7 mU/l vs. 4