Domains of Sedentary Behavior and Cognitive Function: The Health, Aging, and Body Composition Study, 1999/2000 to 2006/2007.

BACKGROUND

This study examines the relationship between various domains of sedentary behavior and subsequent cognitive function to evaluate whether different sedentary activities have specific associations with future cognitive performance.

METHODS

Data were from 1 261 older adults participating in the Health, Aging, and Body Composition (Health ABC) Study between 1999/2000 and 2006/2007. Total sitting time (hours/day), reading time (hours/week), and TV time (≤27/≥28 h/wk) were self-reported at baseline and 3 years later. At follow-up, cognitive function was evaluated using the Teng Mini-Mental State Examination (3MS) and the Digit Symbol Substitution Test (DSST). Multivariable linear regression modeling examined the independent associations of baseline sedentary behaviors and 3-year change in those behaviors with cognitive function scores at follow-up, adjusting for important covariables.

RESULTS

Baseline total sitting time was positively associated with 3MS (β = 0.14 ± 0.07; p < .05) and DSST (β = 0.20 ± 0.10; p < .05) scores at follow-up, as was reading time (β = 0.09 ± 0.03; p < .05 for 3MS score and β = 0.14 ± 0.04; p < 0.01 for DSST score). Participants who increased their TV watching time over 3 years had a significantly lower 3MS score (β = -1.45 ± 0.71; p < .05) at follow-up, compared with those who maintained a low level of TV time (referent). These findings were independent of age, sex, race, education level, health status, depressive symptoms, and physical activity.

CONCLUSION

Some types of sedentary behavior may have benefits for cognitive function in older age, thus highlighting the importance of measuring different domains of sitting time.