Raised circulating fetuin-a after 28-day overfeeding in healthy humans.

Fetuin-A is a liver secretory glycoprotein that has been linked to the development of insulin resistance in animal models (1). Recent work suggests that free fatty acids (FFAs) and fetuin-A interact to induce insulin resistance in animal models (1) and humans (2). However, short-term overfeeding increases peripheral insulin resistance without significant increases in the levels of circulating FFAs in healthy humans (3,4). Thus, short-term overfeeding studies provide an ideal model with which to evaluate the relationships between fetuin-A and insulin resistance, independent of FFAs.