Most people tend to think of their skeleton as an inert, calcified framework, whose only function is to support the rest of the body.

However, you may be surprised to learn that bones are not just for structural support, but are also dynamic organs, containing active living cells and with blood vessels and nerves running through them.

Researchers at Columbia University Medical Center have discovered a surprising and important function of the skeleton. Their study shows that the skeleton plays an active and critical role in helping regulate sugar metabolism and fat storage; it may also play an important role in the development of type 2 diabetes, sometimes called "adult-onset diabetes."

The researchers found that certain bone cells, called osteoblasts, secrete a hormone called osteocalcin. Osteocalcin influences the way insulin works. Insulin is a hormone produced in the pancreas, which regulates the amount of sugar in your blood by helping the cells in your body take up glucose from your blood, and convert it into energy or store it. Either a lack of insulin or a reduced sensitivity to insulin results in diabetes.

Osteocalcin increases both the secretion of and the sensitivity to insulin. In addition, the researchers found that osteocalcin boosted the number of insulin-producing cells, and reduced storage of fat.

The researchers also found that increased osteocalcin activity prevented the development of type 2 diabetes and obesity in mice.

This discovery marks a significant advance in our understanding of skeletal function, and uncovered an important aspect of energy metabolism, which could help scientists to find new therapies for the treatment or prevention of obesity and type 2 diabetes.