Insulin is not only for controlling blood sugar, but also for muscle strengthening in older ages. Scientists have recognized that insulin resistance plays a major role in the loss of physical strength that occurs, as people grow older. The senior author of the research paper Dr. Elena Volpi, and her co-authors of University of Texas Medical Branch at Galveston researchers have demonstrated that by increasing insulin levels above the normal range in elderly test subjects, they can restore the impaired muscle-building process responsible for age-related physical weakness.

"When you give insulin intravenously and increase the blood insulin levels to the same amount produced after a meal, you see that in young people it stimulates protein synthesis and muscle growth, while in older people it really doesn't. But when we gave seniors double the insulin they would normally produce after eating, their muscles were stimulated like those of young people." said Dr. Elena Volpi.

Dr. Volpi and her team worked with 14 elderly volunteers to examine the response of thigh muscle to the two different blood insulin levels, established by infusion into the thigh's main artery to reach the conclusions, which were published in September issue of the Diabetologia. Blood samples taken from catheters inserted in the femoral artery and vein of each subject enabled the researchers to calculate blood flow and muscle protein synthesis, and muscle biopsies allowed them to measure levels of signalling molecules involved in muscle protein growth.

Source : University of Texas Medical Branch at Galveston (2009, September 27). Insulin Boost Restores Muscle Growth In Elderly.