Comparison between insulin-induced hypoglycemia and growth hormone (GH)-releasing hormone + arginine as provocative tests for the diagnosis of GH deficiency in adults.

摘要: There is now wide consensus that, within an appropriate clinical context, GH deficiency (GHD) in adults must be shown biochemically by provocative testing of secretion and that cut-off limits have to defined for each test. Insulin-induced hypoglycemia (ITT) indicated as the test choice, severe GHD, treated with recombinant human replacement, a peak response ITT less than 3 micrograms/L. GHRH + arginine (GHRH ARG) one most promising tests alternative ITT. In fact, it has been reported potent, reproducible, age-independent able distinguish between GHD normal adults. The aim present study was compare ARG large group hypopituitary (n = 40; 29 male 11 female; age: 36.4 +/- 2.1 yr). third centile limit 5 micrograms/L, whereas our lab, 16.5 adults, mean (1.5 0.2 range: 0.1-8.5 micrograms/L) lower (P < 0.001) (3.0 0.4 range 0.1-12.0 micrograms/L), though there positive correlation (r 0.61, P responses 2 tests. ARG, but not ITT, positively (though weakly) associated insulin-like growth factor-I levels 0.35, 0.03). Childhood adult onset patients, well patients single multiple pituitary insufficiencies, had similar or ARG. Analyzing individual responses, 4/40 (10%) peaks higher micrograms/L after ITT; moreover, other (7%) peaks, On hand, all 21/40 (52.5%) Because arbitrary which we arbitrarily considered 9 point It noteworthy 37/40 (92.5%) peak, below this limit. conclusion, results confirm reliable diagnosis they show is, at least, sensitive (provided are considered). Note even demonstrated potency