How Does Obesity Cause Diabetes?

Although it has been discovered that obesity plays a role in the onset of type 2 diabetes, scientists aren't certain how the excess weight triggers the disease.

What scientists do know is that obesity causes stress in the endoplasmic reticulum (ER), a system of cell membranes found inside cells. This stress results in the suppression of the signals of insulin receptors, leading to insulin resistance. Insulin is a hormone that converts blood sugar to energy.

The ER has been compared to a synthetic machine of a cell, responsible for processing proteins and fats. Scientists have also referred to the ER as a factory for producing protein, as well as the site where excess blood fats are processed.

When the body is bombarded with nutrients the following occurs:

• Nutrients must be processed, stored and utilized
• The ER factory becomes overworked and starts sending SOS signals
• SOS signals tell the cells to dampen their insulin receptors
  The ER restrains normal responses to insulin
• Insulin can no longer clear sugar from the body
  

Another downfall of ER stress, besides obesity, is that it triggers inflammation in cells. This inflammation can be linked to heart disease.

Studies have revealed that if people can find a way to reduce ER stress, generate less ER stress or find a way for the body to handle stress more efficiently, type 2 diabetes might be easier to manage.

Science October 15, 2004;306(5695):425-6