The impact of 24-h activity patterns on executive function in older adults with chronic diseases: analysis of the isotonic substitution effect.

Sedentary behavior (SB) was positively correlated with both inhibitory control and working memory in older adults with chronic diseases.

• SB positively correlated with inhibitory control (β = 0.892, 95% CI = 0.044 to 1.741)
• SB positively correlated with working memory (β = 1.610, 95% CI = 0.801 to 2.420)
• Note: positive correlation with z-scores here likely indicates worse performance given the Stroop task scoring context
• Assessed using component linear regression in a sample of 75 older adults with chronic diseases (mean age 72.64 ± 6.82 years)

MVPA was negatively correlated with inhibitory control scores in older adults with chronic diseases.

• β = -0.596, 95% CI = -1.156 to -0.036
• Negative correlation indicates better inhibitory control performance associated with higher MVPA
• Inhibitory control was assessed using the Stroop task
• Finding derived from component linear regression analysis

LPA was negatively correlated with working memory scores in older adults with chronic diseases.

• β = -0.969, 95% CI = -1.812 to -0.127
• Working memory was assessed using the N-back task
• No significant association was found between any activity component and cognitive flexibility (p > 0.05)
• Cognitive flexibility was assessed using the More-odd-shifting task

Isotemporal substitution of SB with MVPA for 30 minutes produced the largest improvement in inhibitory control.

• Replacing SB with MVPA for 30 min reduced inhibitory control z-scores by 0.285
• Replacing SB with SP (sleep) for 30 min reduced inhibitory control z-scores by 0.068
• Both substitutions represent improvements in inhibitory control performance
• Dose-response curves indicated that progressively increasing the proportion of time in SP and MVPA improved inhibitory control

Isotemporal substitution of SB with LPA for 30 minutes improved working memory in older adults with chronic diseases.

• Replacing SB with LPA every 30 min resulted in a working memory z-score decrease of 0.152
• Dose-response curves indicated that increasing LPA enhanced working memory
• Working memory was objectively assessed using the N-back task
• This substitution effect was explored using 'one-for-one' dose-response substitution modeling

The study sample consisted of 75 older adults with chronic diseases drawn from an initial recruitment of 105 older adults.

• 105 older adults were initially recruited; 75 with chronic diseases were ultimately included following questionnaire screening
• Mean age of participants was 72.64 ± 6.82 years
• Accelerometers were used to objectively measure daily SP, SB, LPA, and MVPA
• Executive function was objectively assessed using the Stroop task, N-back task, and More-odd-shifting task