| dc.description.abstract | Background: The Norwegian population is getting older, and the proportion of older adults over the age of 67 is increasing. The older population is heterogeneous, and the aging process includes several aspects to consider. When the aging process accelerates more than normal, it may lead to frailty. Resting energy expenditure (REE) decreases with aging, mostly due to reduced fat-free mass (FFM) and gain in fat mass (FM). However, it is not known whether frail older adults have lower REE compared to their robust counterparts, or if the change in body composition is different in frail compared to robust older adults. Physical activity often decrease with age, but whether the physical activity energy expenditure (PAEE) changes with aging and frailty is unknown. Sleep and sleep quality are reported to change with age, and poor sleep quality is associated with frailty. Aims: To measure REE in older adults, and to examine the association between aging and frailty on REE. The secondary aims were to investigate the associations between frailty on PAEE, body composition, and sleep quality. Methods: Participants were recruited from the Amarone Follow-Up study (Amarone FU), and included older men (n =15) and women (n = 14) living at home. Frailty status was assessed by using the Fried Frailty Phenotype model (FP). REE was measured with the whole room indirect calorimetry (WRIC) facility at the University of Oslo, PAEE and sleep were estimated by the ActiGraph wGT3X-BT sensor, and body composition was measured by Dual-Energy X-ray Absorptiometry (DXA). Multiple linear regression was used to assess the association between frailty on REE and PAEE, adjusting for FFM. Results: Twenty-nine older adults were included in this study, of which 12 were pre-frail. We did not identify any frail subjects among the included subjects. No associations were detected between age and frailty on REE or PAEE after adjusting for FFM. We did observe that pre-frail subjects had less FFM and lean body mass compared to robust subjects, however, in sensitivity analysis with women only, the difference was attenuated. In terms of sleep, pre-frail subjects spent more time in bed, had a lower sleep efficiency, were more awake during the night, and were more restless compared to robust subjects. Conclusions: We did not find associations between aging and frailty and REE, or between frailty and PAEE, after adjusting for FFM. No difference in body composition between pre-frail and robust was observed when comparing women only. We found that pre-frail subjects had poorer sleep quality compared to robust subjects. This study contributes valuable information on REE in older adults, using valid and precise methods. More studies are needed to investigate the factors in frailty and what mediates the syndrome. | eng |