The relationship between age and physical activity as objectively measured by accelerometers in older adults with and without dementia.

OBJECTIVE

This study sought to investigate differences in physical activity and activity fragmentation between older adults with and without dementia and between older adults with dementia with Lewy bodies (DLB) and older adults with Alzheimer's disease (AD). The study also sought to investigate how these differences vary in magnitude at different ages.

METHODS

Accelerometry data were analyzed from individuals with dementia ( = 94) and individuals without dementia ( = 613) who participated in the National Health and Aging Trends Study (NHATS), as well as from individuals with DLB ( = 12) and AD ( = 10) who participated in a pilot study.

RESULTS

In the NHATS cohort, individuals without dementia had more activity counts (0.325 million [95% CI 0.162 million, 0.487 million]) and a longer active bout length (0.631 minutes [95% CI 0.311, 0.952]) at the mean age of 79 than individuals with dementia at the same age. There was also suggestive evidence that individuals without dementia had a shorter resting bout length (-2.196 minutes [95% CI -4.996, 0.605]) than individuals with dementia. Differences in data collection and processing prevented direct comparisons between the cohorts, and the parallel analyses in the smaller cohort were underpowered to detect statistically significant differences between DLB and AD.

CONCLUSION

This work shows that objectively measured accelerometry data differ between individuals with and without dementia; future studies with larger samples should investigate whether accelerometry data can be used to aid in the early identification of dementia and differentiation of dementia subtypes.