Ghrelin and Beta Cell Function in Diabetes

Inclusion Criteria: T2DM study subjects to be considered for the study must meet the following inclusion criteria: 1. Established T2DM with good to moderate glycemic control 2. HbA1c \< 8.5% 3. Diabetes treatment with metformin, sulfonylurea, thiazolidinediones or combination of these medications; with no use of insulin during the study period 4. BMI ≤ 45.0 kg/m2 Control study subjects will be matched for age- (± 2 years), BMI (± 1.5 kg/m2) and gender and must meet the following inclusion criteria: 1. HbA1c ≤ 5.7% 2. Fasting plasma glucose ≤ 95 mg/dL 3. BMI ≤ 45.0 kg/m2 Exclusion Criteria: All subjects will be excluded for the following reasons: 1. History of myocardial infarction or arrhythmia within the past year, abnormal electrocardiogram (ECG) with evidence of ischemia or arrhythmia, history or symptoms of congestive heart failure 2. Uncontrolled hypertension 3. History or active liver or renal disease (AST or ALT \>2x upper limits of normal, calculated glomerular filtration rate \[eGFR\] \<60 at screening) 4. History of pituitary or adrenal disorders or neuroendocrine tumor 5. Anemia defined as hematocrit \<33% at screening 6. Active cancer diagnosis or currently undergoing cancer treatment 7. History of anorexia nervosa or previous gastrointestinal tract surgery 8. Pregnancy or lactation Control subjects will be excluded for the following reasons: 1. History or clinical evidence of impaired fasting glucose or impaired glucose tolerance on a 75 g OGTT, established diabetes mellitus, or taking medications prescribed for diabetes 2. Use of medications that alter insulin sensitivity (i.e. niacin, glucocorticoids, metformin)