Comparison of physiologic and pharmacologic assessment of growth hormone secretion
S. F. Siegel, D. J. Becker, P. A. Lee, J. P. Gutai, T. P. Foley Jr and A. L. Drash
To determine if pharmacologic and physiologic tests are equally effective
in the assessment of growth hormone (GH) secretory status, serum GH levels
were measured during sequential tests with intravenous arginine infusion
and insulin-induced hypoglycemia (arginine-insulin tolerance test [ AITT ]
) and during sleep in 62 children, aged 2.1 to 17.3 years. Responses during
AITT and sleep were concordant in 53 patients and discordant in nine
patients. Arginine-insulin tolerance test results were consistent with the
subsequent clinical course in 80% of the patients while nocturnal sampling
was consistent with the subsequent clinical course in 93% of the patients.
Thus, the failure of a normal serum GH response to pharmacologic stimuli is
not always a diagnostic indicator of GH deficiency. Additional
investigation of discordant GH responses to pharmacologic and physiologic
stimuli may lead to a further understanding of the control mechanisms of GH
secretion.
