How does obesity influence incretin effect and insulin resistance?

• A. Obesity is associated with reduced incretin effect and increased insulin resistance.
• B. Obesity increases incretin effect, improving insulin sensitivity.
• C. Obesity has no impact on incretin effect.
• D. Obesity reduces insulin production only.

Answer: (A)

In obesity, two connected changes happen in how the body handles glucose: the gut-driven boost to insulin secretion (the incretin effect) tends to be reduced, and the body's tissues become more resistant to insulin.

The incretin effect comes from hormones like GLP-1 and GIP released after eating, which amplify insulin release in response to oral glucose. In obesity, this incretin signal is blunted—either because the hormones are produced less, their receptors don’t respond as well, or the beta cells become less responsive to them. At the same time, obesity is a state of increased insulin resistance in muscle, liver, and fat tissue, so more insulin is required to achieve the same glucose control.

Putting those together, obesity is associated with a reduced incretin effect and increased insulin resistance, which helps explain why glucose regulation worsens in this condition. The idea that obesity would boost incretin effect or leave it unchanged isn’t supported, and saying it only reduces insulin production ignores the common reality of compensatory, often increased, insulin secretion in obesity.