MORE MUSCLE MASS – and not just less body fat – is critical to lowering your risk for type 2 diabetes, a new UCLA study suggests. Reporting in the Journal of Clinical Endocrinology and Metabolism, the researchers suggest there is a correlation between greater muscle mass, relative to body size, and a substantially decreased risk of developing the metabolic changes that lead to diabetes.
“Our findings suggest that beyond focusing on losing weight to improve metabolic health, there may be a role for maintaining fitness and building muscle mass,” says Preethi Srikanthan, M.D., assistant professor of medicine in the Division of Endocrinology. “This is a welcome message for many overweight patients who experience difficulty in achieving weight loss, as any effort to get moving and keep fit should be seen as laudable and contributing to metabolic change.”
For the study, the researchers used data from the National Health and Nutrition Examination Survey III, which was collected between 1988 and 1994. They studied 13,644 adults who were not pregnant and had a BMI of at least 16.5 to examine the ratio of waist size to hip size – an indirect measure of abdominal fat relative to gluteal musculature – to see how this measure correlated between higher levels of muscle mass and lower levels of insulin resistance, a precursor to diabetes.
After controlling for age, race and ethnicity, gender, generalized obesity (high BMI) and central obesity (large waist), they found that for each 10-percent increase in the skeletal muscle index (SMI) – the ratio of muscle mass to total body weight – there was a corresponding 11-percent reduction in insulin resistance and a 12-percent reduction in pre-diabetes, a condition characterized by higher-than-normal levels of glucose in the blood.
The study was cross-sectional rather than interventional, so the researchers cannot say for certain that increasing one’s muscle mass will lower one’s risk of developing insulin resistance or pre-diabetes. But given the strong associations they found, the research demonstrates the importance of monitoring relative muscle mass to get an idea of a person’s risk for diabetes.