Prevalence of posttraumatic growth hormone deficiency is highly dependent on the diagnostic set-up - results from The Danish National study on posttraumatic hypopituitarism

ContextRecent international guidelines suggest pituitary screening in patients with moderate and severe traumatic brain injury (TBI). Predominantly isolated GH deficiency (GHD) was reported in the literature raising the question of potential methodological bias.ObjectiveTo assess the prevalence of GHD in patients admitted in 2008 with TBI, with concurrent assessment of methodological bias.DesignNationwide population based cohort studySettingTertiary referral University HospitalsParticipantsDanish patients with a head trauma diagnosis from Danish Board of Health diagnostic code registry; 439 patients and 124 healthy controls underwent dynamic assessment of GH secretion median 2.5 years after TBI.Main outcomePrevalence of GHD given use of 1) local versus guideline cut-offs, 2) insulin tolerance test (ITT), pyridostigmin-GHRH (PD-GHRH) or GHRH-arginine (GHRH-arg) test, 3) single versus repeated testing, and 4) GH-assessment by assays with different isoform specificity.ResultsThe prevalence of GHD was lower by local than guideline cut-offs (12% vs. 19% (PD-GHRH/GHRH-arg, P