Oral glucose, oral lipid and mixed-meal tolerance tests are widely used in metabolic research and diabetes drug development. They provide an integrated assessment of the β-cell response to an intestinally-delivered insulin secretory stimulus that includes activation of the incretin axis.
- Oral glucose tolerance test (OGTT) – Clinicians use the 75 g test to diagnose forms of glucose intolerance and type 2 diabetes.
- Mixed-meal tolerance test (MMTT) – This provides a more comprehensive physiological stimulus to insulin secretion as β-cells are responsive to certain amino acids and fatty acids in addition to glucose.
- Oral lipid tolerance test (OLTT) – Used to measure postprandial triglyceride levels and whole body lipid homeostasis after consumption of a standardized meal.