New Study Links Skeleton with Obesity and Diabetes

14/08/07 P.L. Thomas has announced a new study "Endocrine Regulation of Energy Metabolism by the Skeleton" published in the journal Cell that for the first time links the vitamin K-dependent protein osteocalcin to the endocrine system with significant potential benefits for obesity and diabetes.

The bones in the human body are constantly engaged in a process called remolding, with cells breaking down and rebuilding bone structure. Bones also produce red blood cells in their marrow. Now it is known that the skeleton is also an endocrine organ involved in energy metabolism, and may play a role in diabetes and obesity: Bones help regulate glucose (blood sugar) by producing the vitamin K-dependent protein called osteocalcin, which secretes a hormone that enhances insulin activity and was shown to reduce obesity and type 2 diabetes in mice.

According to Leon Schurgers, Ph.D., a vitamin K expert from the University of Maastricht: "This study shows that bone cells actually play a role in the regulation of fat cells. It is very interesting to consider the potential therapeutic benefits, including perhaps a new method to help regulate glucose. It again demonstrates new functions for vitamin K-dependent proteins, which thus exert a broader effect well beyond blood clotting."

The researchers identified the genes that operate primarily in the bone cells that are linked to glucose metabolism. By "knocking out" these genes in mice so that they could not function, the animals lacking a functional osteocalcin gene gained fat. Osteocalcin helps regulate the cells that produce insulin in the pancreas and release it into the bloodstream. These osteocalcin deficient mice also became glucose intolerant. Both conditions are considered "pre-diabetic"

Osteocalcin was also shown to signal fat cells to release a hormone called adiponectin that increases insulin sensitivity. Thus bone cells signaled fat cells. Osteocalcin also promotes insulin for use by the body by promoting the production of more pancreatic beta cells – the cells that make insulin.

Awareness of the roles of vitamin K-dependent protein, including osteocalcin, is growing as the body of research expands. Consider the paper published in Thrombosis and Haemostasis this July titled "Vitamin K: The Coagulation Vitamin That Became Omnipotent," that discusses the historic understanding of vitamin K and coagulation, as well as its newly recognized roles activating osteocalcin for bone health and matrix GLA protein for cardiovascular health.

The authors concluded that in healthy individuals, substantial fractions of the vitamin K-dependent proteins, including osteocalcin, are not fully activated, indicating subclinical vitamin K deficiency.

There are two forms of vitamin K. K1, found in leafy green vegetables which is primarily used by the liver, and K2 (menaquinones) which are found in fermented foods such as cheese and the Japanese soy food natto, which are used also outside of the liver.

Several clinical studies have shown benefits for K1 and synthetic vitamin K2 as menaquinone-4 (MK-4), however this has only been reported at pharmacological doses ranging between 1 and 45 milligrams per day. Natural vitamin K2 as Mk-7, due to its longer half-life in the blood and bioactivity, it is expected to be beneficial at nutritional levels, i.e. within recommended intake.

PL Thomas offers a natural vitamin K2 as menaquinone-7 under the tradename MenaQ7 in alliance with Natto Pharma, Norway.