Interactive Associations of Age, Apolipoprotein E ε4 Gene, Physical Activity, and Physical Functioning on Processing...

Area of Science:

• Neuroscience
• Gerontology
• Genetics

Background:

• Cognitive processing speed declines with age, influenced by genetic factors like apolipoprotein E ε4 (APOE4) and lifestyle.
• Understanding the interplay of age, genetics, physical activity, and physical functioning is crucial for cognitive health in aging populations.

Purpose of the Study:

• To investigate the interactive associations of age, APOE4 genetic status, physical activity energy expenditure (PAEE), and physical functioning on processing speed over a 10-year period.

Main Methods:

• Longitudinal study of 2518 Japanese adults (2002-2012) from the NILS-LSA.
• Assessed processing speed (Digit Symbol Substitution Test), APOE4 status, PAEE (accelerometry), and physical functioning (handgrip strength, walking speed).
• Utilized mixed-effects models, controlling for covariates like health status and lifestyle factors.

Main Results:

• Significant 3-way interactions found between PAEE × age × APOE4 carrier and slowness × age × APOE4 carrier on processing speed.
• Higher PAEE correlated with better processing speed; slowness correlated with poorer processing speed, especially in older APOE4 carriers.
• Weakness showed interactions with age and APOE4, but no 3-way interaction.

Conclusions:

• Complex interplay exists between physical activity, physical functioning, age, and genetic risk in influencing processing speed.
• Higher PAEE and better physical functioning offer protective effects on cognitive processing speed, particularly for older APOE4 carriers.
• Active lifestyle and maintained mobility are key for individuals with genetic predisposition to cognitive decline.