Diagnostic value of a ghrelin test for the diagnosis of GH deficiency after subarachnoid hemorrhage

OBJECTIVE To determine the diagnostic value of a ghrelin test in the diagnosis of GH deficiency (GHD) shortly after aneurysmal subarachnoid hemorrhage (SAH). DESIGN Prospective single-center observational cohort study. METHODS A ghrelin test was assessed after the acute phase of SAH and a GH-releasing hormone (GHRH)-arginine test 6 months post SAH. Primary outcome was the diagnostic value of a ghrelin test compared with the GHRH-arginine test in the diagnosis of GHD. The secondary outcome was to assess the safety of the ghrelin test, including patients' comfort, adverse events, and idiosyncratic reactions. RESULTS Forty-three survivors of SAH were included (15 males, 35%, mean age 56. 6 ± 11.7). Six out of 43 (14%) SAH survivors were diagnosed with GHD by GHRH-arginine test. In GHD subjects, median GH peak during ghrelin test was significantly lower than that of non-GHD subjects (5.4 vs 16.6, P=0.002). Receiver operating characteristics analysis showed an area under the curve of 0.869. A cutoff limit of a GH peak of 15 μg/l corresponded with a sensitivity of 100% and a false-positive rate of 40%. No adverse events or idiosyncratic reactions were observed in subjects undergoing a ghrelin test, except for one subject who reported flushing shortly after ghrelin infusion. CONCLUSION Owing to its convenience, validity, and safety, the ghrelin test might be a valuable GH provocative test, especially in the early phase of SAH.