[See Editorial Comments by Luigi Ferrucci, Jennifer A. Schrack, Nicolas D. Knuth, and Eleanor M. Simonsick on pp 1768–1769]
Resting Metabolic Rate in Old-Old Women with and without Frailty: Variability and Estimation of Energy Requirements
Article first published online: 17 SEP 2012
© 2012, Copyright the Authors Journal compilation © 2012, The American Geriatrics Society
Journal of the American Geriatrics Society
Volume 60, Issue 9, pages 1695–1700, September 2012
How to Cite
J Am Geriatr Soc 60:1695–1700, 2012.
- Issue published online: 17 SEP 2012
- Article first published online: 17 SEP 2012
- Robert Wood Johnson Harold Amos Medical Faculty Development Program
- National Institute on Aging Grant. Grant Number: R01 AG11703
- National Institutes of Health
- National Center for Research Resources (NIH-NCRR) Grant. Grant Number: M01-RR000052
- Johns Hopkins School of Medicine
- NCRR Grant. Grant Number: UL1 RR 025005
- NIH Roadmap for Medical Research
- resting metabolic rate;
- older adults
To measure resting metabolic rate (RMR) in old-old adults living in the community and examine the association between measured RMR and frailty status and compare it with expected RMR generated by a predictive equation.
Physiological substudy conducted as a home visit within an observational cohort study.
Baltimore City and County, Maryland.
Seventy-seven women aged 83 to 93 enrolled in the Women's Health and Aging Study II.
Resting metabolic rate with indirect calorimetry, frailty status, fat-free mass, ambient and body temperature, expected RMR according to the Mifflin-St. Jeor equation.
Average RMR was 1,119 ± 205 kcal/d (range 595–1,560 kcal/d). Agreement between observed and expected RMR was biased and poor (between-subject coefficient of variation 38.0%, 95% confidence interval = 35.1–40.8). Variability of RMR was greater in frail individuals (heteroscedasticity F-test P = .02). Low and high RMR were associated with being frail (odds ratio 5.4, P = .04) and slower self-selected walking speed (P < .001) after adjustment for covariates.
Equations to predict RMR that are not validated in old-old adults appear to correlate poorly with measured RMR. RMR is highly variable in old-old women, with deviations from the mean predicting clinical frailty. These exploratory findings suggest a pathway to clinical frailty through high or low RMR.