Objective:
In December 2018, the Pharmaceutical Benefits Scheme subsidised growth hormone (GH) for the treatment of severe adult GH deficiency (GHD). The eligibility criteria requires documented GHD by one of three dynamic tests; therefore, the number of referrals for glucagon stimulation tests (GSTs) have increased significantly, preferred for its relative safety compared to the insulin tolerance test. This study aims to review the safety and adverse events (AEs) of the GST.
Research Methods:
A retrospective analysis was performed on all GSTs (n=30) undertaken at St Vincent’s Hospital, Melbourne from January–June 2019. All patients received a fixed dose of intravenous 1mg glucagon, and GH levels were measured every 30 minutes for 240 minutes. GHD was defined as peak GH level <3.0mcg/L. Due to protocol changes throughout the year, 20 cases had either venous or capillary blood glucose levels (BGL) checked throughout testing. Blood pressure (BP) was checked twice during the test and if cases were symptomatic. AEs were documented for each patient including significant hypotension (systolic BP (SBP) <90mmHg or >20mmHg decrease in SBP); hypoglycaemia (venous or capillary BGL ≤3.5mmol/L) and; nausea/vomiting.
Results:
Participants were aged between 20–66 years, 63% were female and 53% were previously on GH replacement. The GSTs confirmed GHD in 90% of cases. In total, 40% experienced one and 17% more than one AEs. Nausea/vomiting occurred in 6/30 (20%) and hypoglycaemia in 10/20 (50%) patients. Significant hypotension occurred in 8/30 (27%) patients, with hypotension occurring in 7/30 (23%) patients despite taking their usual cortisol replacement prior to testing.
Conclusion:
This audit demonstrates that AEs are common during the GST. As a result of these findings, protocol changes have been made at this centre to prevent these AEs occurring. Larger, prospective studies need to be conducted with a consistent protocol to examine these risks further.