"In other words, the greater your muscle mass, the lower your risk of death," said Dr. Arun Karlamangla, an associate professor in the geriatrics division at the Geffen School and the study's co-author. "Thus, rather than worrying about weight or body mass index, we should be trying to maximize and maintain muscle mass."
This study does have some limitations. For instance, one cannot definitively establish a cause-and-effect relationship between muscle mass and survival using a cohort study such as NHANES III. "But we can say that muscle mass seems to be an important predictor of risk of death," Srikanthan said. In addition, bioelectrical impedance is not the most advanced measurement technique, though the NHANES III measurements were conducted in a very rigorous fashion "and practically, this is the best situation possible in a study of this size," she noted.
"Despite these limitations, this study establishes the independent survival prediction ability of muscle mass as measured by bioelectrical impedance in older adults, using data from a large, nationally representative cohort," Srikanthan and Karlamangla write, adding that BMI's association with mortality in older adults has proven inconsistent. "We conclude that measurement of muscle mass relative to body height should be added to the toolbox of clinicians caring for older adults. Future research should determine the type and duration of exercise interventions that improve muscle mass and potentially increase survival in (healthy), older adults."
|Contact: Enrique Rivero|
University of California - Los Angeles Health Sciences