Correlations between Objective and Subjective Instruments on the Measurement of Energy Expenditure in Older Adults

Abstract

PURPOSE: Many objective and subjective instruments have been developed to estimate energy expenditure (EE). However, the validity and correlations on these measurements are lacking especially in the older adult population. American Association of Retired Persons (AARP) questionnaire and Community Healthy Activities Model Program for Seniors (CHAMPS) questionnaire are common self-reported questionnaires. The purpose of the study was to examine which self-reported physical activity instruments correlated with objective data from ActiGraph accelerometers and fitness tests. We also compared outcomes from the above instruments with total EE (TEE) measured by the gold standard of doubly labeled water (DLW). METHODS: Data sets were obtained from the Interactive Diet and Activity Tracking in AARP (IDATA) study through the National Cancer Institute. A total of 681 participants aged between 50-74 years were included in the analysis. The outcomes of our interest from each instrument were as follows: total number of steps and EE from ActiGraph, VO2 max from fitness test, activity EE (AEE) from CHAMPS and AARP, and TEE from DLW. Pearson’s correlations were conducted to examine the relationships between objective and subjective measures. RESULTS: The results showed that AEE from AARP was moderately significantly associated with VO2 max (r = .348) and EE from ActiGraph (r = .365). A weak but significantly positive relationship was also observed between AEE from AARP and steps from ActiGraph (r = .136). However, AEE from CHAMPS was only related to steps from ActiGraph (r = .172). No significant correlations were found between AEE from CHAMPS and the other objective measures. Each instrument was also compared to DLW. The strongest positive relationships with TEE from DLW were seen in EE from ActiGraph (r = .484) and VO2 max (r = .474). However, there was no significant association between AEE from CHAMPS and TEE from DLW, p > .05. CONCLUSIONS: AEE from AARP appears to be the subjective instrument most positively associated with the objective instruments in older adults. Of all subjective and objective instruments, objective measures may estimate TEE more accurately than the subjective instruments. AEE from CHAMPS performed the worst estimate on TEE and was least likely to be related to the objective instruments.