Abstract
Background: The aim of this study is to investigate how physical activity and aging impact on resting energy expenditure (REE) and body composition.
Patients and Methods: Firstly, to investigate the impact of physical activity,30 subjects with the age of fifties were recruited in this study (10: healthy people (55.1±5.7), 11: outpatient (54.5±9.2), 9: inpatient (54.0±5.7)). Secondly, to investigate the impact of aging, 128 subjects were recruited and divided into 6 groups at age as follows;<70 ys. old: 18 outpatients,29 inpatients, 70 〜 80 ys.old: 8 outpatients, 21 inpatients, 80 ys. old ≤ : 4 outpatients,48 inpatients. Indirect calorimetry and bioelectrical impedance analysis (BIA) were conducted for all subjects to measure REE and body composition, respectively. The relationship between REE and skeletal muscle mass indices (SMM) was analyzed and those parameters were compared each group statistically.
Results: In the investigation of the impact of physical activity, there was stronger correlation in healthy people groups between REE and SMM among three. Regarding with the aging, almost all SMM in more than 80 ys. old inpatient group were significantly lower than those of other groups. There was a significant correlation between REE and SMM in outpatients and inpatients less than 70 ys. old groups, whereas no significant correlation among them in more than 80 ys. old inpatient group.
Conclusions: The calculational basal metabolism in more than 80 ys. old inpatient group was quite low due to the lower body weight than expected, which differed from REE considerably. Therefore, indirect calorimetry and BIA are useful to calculate the energy requirement of the patient aged over eighties with decreased SMM.
