Insulin resistance can be detected 20 years before type 2 diabetes onset, researchers find

• A detectable decline in energy production by mitochondria -- the organelles that are the cell's furnace for energy production -- seems to be a key problem leading to insulin resistance, and thus to type 2 diabetes, according to studies by Howard Hughes Medical Institute researchers.
• The research team said that insulin resistance -- an impaired response to the presence of insulin -- is detectable as early as 20 years before the symptoms of diabetes become evident.
• In the new study examining how insulin interacts with the energy-producing mitochondria inside living cells, Shulman and his colleagues found that the rate of insulin-stimulated energy production by mitochondria is significantly reduced in the muscles of lean, healthy young adults who have already developed insulin resistance and who are at increased risk of developing diabetes later in life.
• The new research, which is published in the September 2005 issue of the open-access journal PLoS Medicine, indicates that a decreased ability to burn sugars and fats efficiently is an early and central part of the diabetes problem.
• The young adults studied by the research team are the offspring of parents who have type 2 diabetes, adding support to the idea that the risk can be inherited, and that the problem begins well before diabetes symptoms become evident.
• In an earlier research study published in the journal Science, Shulman and his colleagues had also found that healthy, lean older individuals have a major reduction in mitochondrial energy production that leads to accumulation of fat inside muscle cells resulting in insulin resistance.
• Normal mitochondria react to insulin by boosting production of an energy-carrying molecule, ATP, by 90 percent.
• Their work offers new insight into the early steps in the development of insulin resistance, and offers important clues to where the problem lies.