Growth hormone responses following double pulse oral glucose administration in various clinical states

The 8-h double pulse oral glucose test is proposed as an alternative screening procedure for determining the adequacy of growth hormone (GH) release. The second pulse of glucose is timely in suppressing GH release and delaying it for a more predictable controlled elevation. Peak GH (mean plus or minus SD) values following the double pulse glucose test were 17 plus or minus 10.2, 16.5 plus or minus 2.2, and 1.3 plus or minus 0.5 ng/ml in normal controls, short stature patients and GH deficient patients, respectively. Peak GH values following insulin hypoglycemia were 36.9 plus or minus 13.8, 21.9 plus or minus 23.0 and 1.8 plus or minus 1.1 ng/ml in normal controls, short stature patients and GH-deficient patients. Peak GH values during a 5-h oral glucose tolerance test were 16.4 plus or minus 6.0 and 10.2 plus or minus 3.3 ng/ml in normal controls and short patients, respectively. These differences in peak GH values between the various clinical and control groups were not significantly different except for the greater GH peak values reached in short patients in the double pulse glucose test compared to the 5-h oral glucose tolerance test. The rise in GH following double pulse oral glucose is more timely predictab-e than after the 5-h oral glucose test and involves less professional time than the insulin tolerance test as it does not require close medical supervision.