How Do Occupational Sedentary Behavior and Occupational Cognitive Complexity Relate to Cognitive Function? A...

Lower occupational cognitive complexity (OCC) and physical inactivity have been associated with advanced brain aging and cognitive decline in older adulthood. We examined whether the association of occupational sedentary time with cognitive function remains after adjustment for OCC and education.

In this cross-sectional study, we included participants from the Framingham Heart Study who did not have dementia, were not retired or unemployed, and completed the neuropsychology and occupation assessments, and wore an accelerometer for at least 3 days (n = 1821, 47% men, mean age 48.5). Three cognitive function assessments were used: logical memory delayed recall (LMD), Weschler Adult Intelligence Scale (WAIS) similarities subtest (SIM), and Trail Making Test B minus A (Trails B-A). Lastly, OCC was measured using data from the U.S. Department of Labor's Occupational Information Network (O*NET). Analysis of covariance (ANCOVA) models were used to evaluate the association of occupational sedentary time (independent variable) with cognitive function (dependent variable), including models adjusting for age, sex, leisure time physical activity (LTPA), education, and OCC.

Higher self-reported occupational sedentary time ("often/always" compared to "never/seldom") was associated with higher cognitive function after adjusting for age, sex, and LTPA (beta = 0.72 [SE = 0.21], 0.76 [0.18], and 0.04 [0.01], for LMD, SIM, Trails B-A, respectively, all with p < 0.001). OCC was also associated with higher cognitive function. When additionally adjusting for education and OCC, the association of occupational sedentary time with cognitive performance was attenuated and no longer statistically significant for LMD and SIM (beta= 0.18 [SE = 0.22], 0.11 [0.19], p > 0.05).

Our findings indicate that the association of higher occupational sedentary time with higher cognitive function was partially explained by a combination of higher OCC and education level. Occupations with higher OCC, may contribute to cognitive resilience despite these occupations being more sedentary.