Profiles of 24‐hour Activity Cycle in Older Adults with Mild Cognitive Impairment: Does it Matter for Cognition?

Abstract

AbstractBackgroundMild cognitive impairment (MCI) is associated with increased risk for dementia and is characterized by poorer cognitive performance. Physical activity, sedentary behaviour, and sleep constitute the 24‐hour activity cycle (24‐HAC). Each of these share an inter‐dependent relationship with each other and are associated with cognitive health in older adults. It is unclear whether differences in the 24‐HAC profiles in older adults with MCI are associated with cognitive performance. Therefore, we examined whether older adults with MCI showed differences in cognitive performance based on profiles of 24‐HAC.MethodA cross‐sectional analysis of 247 community‐dwelling older adults (aged 55+ years) with MCI (Montreal Cognitive Assessment <26). MotionWatch8© assessed 24‐HAC (5‐7 days) of physical activity, sedentary behaviour, and sleep duration and quality. We measured cognitive performance with composite z‐scores of executive function (verbal fluency test, digit span forward and backward), processing speed (trail making tests A and B), and memory (word recognition, word recall, and delayed recall). Latent profile analysis identified common profiles of the 24‐HAC. ANCOVAs compared cognitive performance between profiles, adjusted for age, biological sex, body mass index, and educational attainment.ResultWe identified four distinct profiles with acceptable fit (Table 2). Profile 1 (n = 84) showed balanced levels in the 24‐HAC and longer sleep duration. Profile 2 (n = 44) had below‐average physical activity, sleep duration and quality, and above‐average sedentary behaviour. Profile 3 (n = 37) showed the lowest physical activity levels, the highest sedentary behaviour, above‐average sleep duration and quality. Profile 4 (n = 71) had the highest physical activity, the lowest sedentary behaviour, and below‐average sleep duration and quality. ANCOVAs revealed a main effect of profile (p = 0.046) on processing speed (Table 3). Post‐hoc analysis (Estimated mean difference = 0.39, p = 0.036) showed that participants in Profile 1 demonstrated better performance (0.08 [95%CI ‐0.23; 0.39]) compared with participants in Profile 3 (‐0.31 [95%CI ‐0.68; 0.06]) (Table 3). No other statistically significant differences were noted.ConclusionOlder adults with MCI appear to have four distinct 24‐HAC profiles. Balanced levels of 24‐HAC are associated with better processing speed compared with a less physically active, more sedentary, and lower sleep quality profile.