A greater muscle to total abdominal area ratio was associated with lower odds of diabetes….
Skeletal muscle loss with diabetes onset is common and low muscle mass can be a potential risk factor for diabetes. Studies show that glucose storage and consumption by lean muscle are important factors when looking at glycemic regulation. One study has shown that a higher ratio of estimated muscle-to-total body weight predicted a lower prevalence of insulin resistance and pre-diabetes independent of central adiposity. But to date, most of the studies that assessed muscle area and metabolism have only focused on overweight or obese individuals. Despite the key role of muscle in glucose regulation, little is known about the relationship between muscle area and prevalence of metabolic disorders, or the role that decreased muscle may play when looking at normal weight metabolic obesity.
Researchers from University of California, San Diego, and the University of Pittsburgh, PA, assessed the independent associations between both abdominal muscle and fat depositions (measured by computed tomography) and the prevalence of type 2 diabetes, and examined the modifying role of weight category.
Researchers conducted a cross-sectional analysis of the 2001–2002 visit for the Rancho Bernardo Study, Filipino Women’s Health Study, and Health Assessment Study of African American Women. There were a total of 392 postmenopausal participants who are community-dwelling older women (mean age 64) who were found to be free of clinical cardiovascular disease. The main outcome was prevalence of type 2 diabetes, which was defined as any use of antidiabetes medication, fasting plasma glucose ≥126 mg/dL, and/or OGTT ≥200 mg/dL. Abdominal muscle and fat areas were measured from the 2001–2002 examination CT scans by three experienced CT analysts working on networked workstations running muscle segmentation software.
After adjusting for demographics, hypertension, estrogen use, lipids, smoking, physical activity, visceral fat area, and height, the researchers found that a greater muscle to total abdominal area ratio was associated with lower odds of diabetes [OR = 0.63 per standard deviation, 95% CI (0.43– 0.92), p = 0.02]. Higher visceral fat was associated with greater odds of diabetes in fully adjusted models including total muscle area [OR = 1.48, 95% CI (1.09, 2.01), p = 0.01]. Associations between muscle to total abdominal area ratio and diabetes were stronger for normal weight (BMI 18.5 to 24.9; OR = 0.32) than for overweight or obese women (BMI ≥25, OR = 0.71, p = 0.046). The relationship with visceral fat did not differ by BMI (p = 0.71).
The researchers concluded that, “In older women abdominal muscle area is inversely associated with type 2 diabetes independent of visceral adiposity, particularly for normal weight women.”
- The participants in this study were older females free of cardiovascular disease at the time of the CT; therefore results may not generalize to broader populations.
- The CT measures of muscle and fat done in the study were limited to the abdomen.
- There were few subjects with prevalent type 2 diabetes (n = 66); thus the author concluded that interactions in particular, should be interpreted with caution.
Britta A. Larsen, Matthew A. Allison, Gail A. Laughlin, et al. “The Association Between Abdominal Muscle and Type II Diabetes Across Weight Categories in Diverse Post- Menopausal Women”. J Clin Endocrinol Metab, January 2015, 100(1):E105–E109.