Short-term administration of pegvisomant improves hepatic insulin sensitivity and reduces soleus muscle intramyocellular lipid content in young adults with type 1 diabetes.

Context: Data on metabolic effects of Growth Hormone (GH) derived from studies using GH suppression by pharmacological agents may not reflect selective actions. Objective: To evaluate the effects of GH antagonism on glucose and lipid metabolism using pegvisomant, a selective GH receptor antagonist in patients with type 1 diabetes (T1D). Design & participants: In a randomised, placebo-controlled, crossover study, 10 young adults with T1D were evaluated at baseline, and after 4 weeks of treatment with either 10mg of pegvisomant or placebo. The assessments included an overnight euglycaemic steady state followed by a hyperinsulinaemic euglycaemic clamp, and employed glucose and glycerol cold stable isotopes. Outcome measures: Hepatic and peripheral insulin sensitivity (IS), lipid turnover and intramyocellular lipid (IMCL) Results: Compared with placebo, pegvisomant treatment resulted in lower IGF-I levels (p