Researchers have identified a fat cell protein that may predict insulin resistance and help doctors to prescribe treatments to slow the development of type 2 diabetes.

In a healthy person the pancreas makes enough insulin to keep the supply and use of glucose in balance. In diabetes, the glucose balancing system is disrupted, either because too little insulin is produced or because the body’s cells do not respond to insulin normally -- a condition called insulin resistance. The result is an unhealthy rise in blood glucose levels.

If diabetes is left untreated, the two principal dangers are the immediate results of high blood glucose levels (which include excessive urination, dehydration, intense thirst, and fatigue) and long-term complications that can affect your eyes, nerves, kidneys, and large blood vessels.

A screening test to identify people with insulin resistance could allow doctors to prescribe treatments or lifestyle measures to stop or slow the development of type 2 diabetes. Researchers have taken a step toward such a screening test, according to a new study reported in The New England Journal of Medicine (Volume 354, page 2552 ).

In the study, the researchers identified increased blood levels of a protein produced and secreted by fat cells in people who become insulin resistant. The protein’s name: retinol-binding protein 4 (RBP4).

Scientists already know that people with insulin resistance have increased levels of RBP4. The new study found that levels of RBP4 rose in parallel with the severity of insulin resistance in people who were obese or had prediabetes or type 2 diabetes and in healthy people with a family history of the disease.

Researchers are trying to determine whether lowering RBP4 with medication makes cells more sensitive to insulin. However, the study also found that about two thirds of the participants were able to decrease their RBP4 levels and reduce insulin resistance with a tried-and-true lifestyle measure: exercise.