Type-2 insulin resistance studied

NEW HAVEN, Conn., Aug 15, 2005 (United Press International via COMTEX) -- Yale scientists say they've uncovered new clues about development of insulin resistance in type-2 diabetics and why such patients easily gain weight.

Nearly all patients with type-2 diabetes -- the most frequently encountered metabolic disorder in the world, -- have insulin resistance, or IR. But how IR develops and why it leads to diabetes is not well understood.

Yale scientists Kitt Petersen, Sylvie Dufour, and Gerald Shulman studied children of diabetic parents, some of whom are insulin-resistant, while they are still young and lean.

They compared seven such individuals with lean, healthy, non-smoking control participants who were matched for age and weight. They found while insulin increases energy production in the muscles of the control participants by approximately 90 percent, it had very little effect in the insulin-resistant individuals.

They also found in control individuals, insulin results in an increase of muscle cell phosphate, and that's also much reduced in insulin-resistant individuals.

The researchers said the results provide more support for the idea that insulin resistance compromises proper functioning of energy generation in the mitochondria of muscle cells.

The study appears in the open access international medical journal PLoS Medicine.