Drug administration
STERILE
Leiden University Medical Centre Research Pharmacy (Leiden, The Netherlands), delivered sterile, freeze-dried ghrelin powder (cGMP Human Acyl-Ghrelin) in individual 250 μg subject vials to the Hospital Pharmacy in Linköping. Each vial had study-specific labelling in Swedish. Infusion bags were prepared by the pharmacy as 200 mL of 0.9% NaCl (placebo) or 2.5 μg/mL ghrelin. The pharmacy dissolved each vial of 250 μg sterile, freeze-dried ghrelin powder in 5 mL of 0.9% NaCl, and then added the content of 2 vials (10 mL, 500 μg) to an infusion bag with 0.9% NaCl, to a final volume of 200 mL. The pharmacy added a blinded label to the infusion bag before distribution to the site. Participants and all study personnel were blinded. Monitoring of medication and randomization list handling was performed by an independent Good Clinical Practice (GCP) monitor.Ghrelin was administered continuously as an IV infusion of 5 pmol/kg/min (16.9 ng/kg/min) for up to 4 hours. The dose was based on body weight and multiple published studies, including a landmark study demonstrating that 5 pmol/kg/min (compared with placebo, or 1 pmol/kg/min) reproduced the physiological effects of ghrelin, including a robust induction of appetite (