Effects of GH and Lirglutide on AgRP

This is a randomized, placebo-controlled, cross-over study with 4 arms. Healthy and GH deficient adults ages 18-45 years will be studied. Arms will consist of 21-day treatment periods and be separated by 8-week washout periods. Subjects will receive, in random order: i) GH alone, ii) GH with liraglutide, iii) liraglutide alone and iv) placebo. Each phase of the study will consist of a 7-day baseline period including 2 days of testing and 21 days on therapy with visits on days 2, 7, 14 and 21. Testing before, during and at the completion of each arm will include blood sampling and assessments of insulin resistance, energy expenditure and body composition.