Higher metabolic rates can predict early natural mortality, indicating that higher energy turnover may accelerate aging in humans, a new study has suggested.
To investigate whether higher metabolic rate is associated with aging in humans, this study examined whether energy expenditure, measured in a metabolic chamber over 24 hours and during rest predicts natural mortality.
"We found that higher endogenous metabolic rate, that is how much energy the body uses for normal body functions, is a risk factor for earlier mortality," said Reiner Jumpertz, of the National Institute of Diabetes and Digestive and Kidney Diseases in Phoenix, Ariz., and lead author of the study.
"This increased metabolic rate may lead to earlier organ damage (in effect accelerated aging) possibly by accumulation of toxic substances produced with the increase in energy turnover," Jumpertz added.
In this study, researchers evaluated 652 non-diabetic healthy Pima Indian volunteers. Twenty-four hour energy expenditure (24EE) was measured in 508 individuals, resting metabolic rate (RMR) was measured in 384 individuals and 240 underwent both measurements on separate days.
During the study period, 27 study participants died of natural causes. Researchers found that as energy expenditure increased, there was also an increase in risk for natural mortality.
The study will be published in the endocrine society's Journal of Clinical Endocrinology and Metabolism (JCEM).