Latent profiles of physical actigraphy patterns among older adults: Differential relationships with cognition and vascular burden by sex

• Published in: Alzheimer's & dementia Vol. 18; no. S11
• Main Authors: Paolillo, Emily W, Lee, Shannon Y., Djukic, Nina, VandeBunte, Anna M., Saloner, Rowan, Kramer, Joel H., Casaletto, Kaitlin B
• Format: Journal Article
• Language: English
• Published: 01-12-2022
• ISSN: 1552-5260; 1552-5279
• DOI: 10.1002/alz.063322

Background
Physical activity (PA) is well‐known to benefit cognition and vascular health, yet it is less clear how specific PA patterns relate to cognitive and vascular outcomes and whether these relationships differ by person‐specific factors. Thus, we characterized empirically‐derived latent profiles of PA among older adults and examined their associations with cognition, vascular burden, and person‐specific factors (e.g., sex).
Method
124 older adults from the UCSF Memory and Aging Center (Meanage = 72.2; SDage = 8.4; 54% women; 83% non‐Hispanic White) wore a FitbitTM during waking hours for 30 days. Minute‐level Fitbit data were used to calculate daily averages for three distinct PA metrics: step count, sedentary time (0 steps/minute), high‐intensity time (≥120 steps/minute). Composite memory and executive functioning z‐scores were calculated for a subset of participants (n = 86) who completed neurocognitive testing. Vascular burden was estimated via a count of vascular conditions. Homogenous subgroups with similar PA patterns were identified via latent profile analysis (LPA). ANCOVAs and Poisson regression examined independent and interactive effects of PA group and sex on cognition and vascular burden, respectively, covarying for age and education.
Result
LPA identified 3 latent PA classes: Class1 (high overall activity but low intensity; n = 59), Class2 (low overall activity and low intensity; n = 49), and Class3 (high overall activity and high intensity; n = 16). PA class membership was associated with executive functioning and vascular burden, driven by better outcomes in Class3 than Class2 (executive: mean difference = 0.59, p = 0.013; vascular: b = ‐0.84; p = 0.028). PA class was not related to memory (p = 0.32). There was an interaction between class and sex on executive functioning (F2,78 = 3.20; p = 0.046) and vascular burden (b = 2.37; p = 0.032). In males, Class3 demonstrated the best executive functioning (vs. Class1 p = 0.038; vs. Class2 p = 0.057) and the least vascular burden (vs. Class1 p = 0.025; vs. Class2 p = 0.022). In contrast, there was no clear relationship between PA class and cognition or vascular burden among women (ps>0.05).
Conclusion
Differential PA patterns relevant to cognitive and vascular health can be identified using actigraphy in older adults. Sex‐differences emerged suggesting men may require higher intensity PA to improve cognitive and vascular health, whereas specific PA patterns did not significantly predict outcomes in women.