Ghrelin Regulation and Structure: Effect of Thiazolidinedione Therapy on Ghrelin

Ghrelin Regulation and Structure: Effect of Thiazolidinedione Therapy on Ghrelin

The purpose of this study is to learn more about how insulin resistance (inability to process glucose correctly resulting in mildly elevated glucose levels) affects the hormone ghrelin.

Insulin resistance suppresses fasting ghrelin levels and impairs postprandial ghrelin suppression. Improved insulin sensitivity with a thiazolidinedione will raise ghrelin levels, enhance meal-related suppression, but not change the ratio of total to active ghrelin or result in an alteration of ghrelin structure.

Inclusion Criteria:

• Age 18 to 80, weight stable for at least 3 months

• At lifetime maximal body weight and impaired glucose tolerance (ICT) by the World Health ORganization criteria:

  • fasting plasma glucose level of 100- 125mg/dL or
  • plasma glucose level between 140 to 149mg/dL following a 75gram oral glucose load

Exclusion Criteria:

• Actively losing weight
• Smokers
• Alcohol consumption > 2 drinks/day
• Prescription drug use
• Recreational drug use
• Type 2 Diabetes
• Conditions that contraindicate treatment with pioglitazone such as CHF, impaired liver or kidney function or known sensitivity to pioglitazone