P. Abizanda, L. Romero, P.M. Sánchez-Jurado, T.F. Ruano, S. Salmerón Ríos, M. Fernández Sánchez

J Gerontol A Biol Sci Med Sci. 2016;71(6):787-96

Resting metabolic rate (RMR) and total daily energy expenditure (TDEE) decrease with aging, but it is not known whether frailty modulates this association. The authors hypothesized that RMR and TDEE values are similar between younger and older nonfrail adults, whereas they are lower in older prefrail and frail compared with younger adults.

A cross-sectional analysis of the FRADEA study, Albacete (Spain), including 402 participants older than 70 years (range 70–91), was conducted.

Estimated RMR (eRMR), oxygen consumption (VO2), expired volume (Ve), TDEE; and fat-free mass was determined.

Mean TDEE was 1,889 (SD 470) kcal and eRMR was 1,071 (SD 323) kcal. Both TDEE (B = −24 kcal/day; 95% CI: −35.4 to −14.2; p < .001) and eRMR (B= −15.8 kcal/day; 95% CI: −23.1 to −8.5; p < .001) diminished linearly with age, with lower values in frail and prefrail participants. There was a strong trend between frailty and lower eRMR (F = 2.9; p = .058), with a modifying effect between age and frailty (F = 3.6; p = .002). eRMR in prefrail and frail participants were respectively on average 160 and 114 kcal/day less than in the nonfrail participants and, taken together, 154 kcal/day less (F = 5.4; p = .020). Frail and prefrail participants also presented lower Ve and VO2 values that were partially compensated by an RF increase.