Skeletal muscle adiposity and cognitive decline in a biracial cohort: Insights from coronary artery risk development in young adults (CARDIA) study.

Greater abdominal intermuscular adipose tissue (IMAT) at Year 25 predicted steeper 5-year decline in the Digit Symbol Substitution Test (DSST) in the overall sample.

• The association was statistically significant (β = -0.52, p = 0.035).
• IMAT was not significantly associated with change in Stroop test or Rey Auditory Verbal Learning Test (RAVLT).
• IMAT was measured by computed tomography at Year 25 of the CARDIA study.
• The analysis used multivariable linear regression adjusting for traditional dementia risk factors.

The association between greater IMAT and DSST decline was significant only among White participants, not among Black participants.

• Among White participants, greater IMAT predicted DSST decline (β = -0.73, p = 0.044).
• No significant association was observed for Black participants in race-stratified analyses.
• The total sample included 1080 men (41.9% Black) and 1432 women (49.0% Black).
• These findings suggest ethnicity may modify the relationship between myosteatosis and cognitive decline.

Five-year cognitive change was statistically significant across all three cognitive tests assessed.

• DSST showed a 2.8% change with a mean of 21.8.
• RAVLT showed a 2.8% change with a mean of 17.5.
• Stroop test showed a 6.5% change with a mean of 49.5.
• Cognition was assessed at baseline (Year 25) and at 5-year longitudinal follow-up (Year 30).

The study examined a biracial cohort of middle-aged adults from the CARDIA study to investigate skeletal muscle adiposity and cognitive decline.

• Total sample included 2512 participants: 1080 men and 1432 women.
• The cohort was 41.9% Black among men and 49.0% Black among women.
• Abdominal myosteatosis was quantified as intermuscular adipose tissue (IMAT, cubic centimeters) via computed tomography at Year 25.
• Three cognitive domains were assessed: psychomotor speed (DSST), verbal memory (RAVLT), and executive function/processing speed (Stroop test).

Myosteatosis, previously identified as a risk factor for cardiometabolic diseases, was proposed as a novel risk factor for cognitive decline beyond traditional dementia risk factors.

• Abdominal myosteatosis predicted cognitive processing speed decline independent of traditional dementia risk factors.
• The study highlights abdominal CT scans as a potential tool to identify middle-aged adults at risk for dementia.
• The authors note a critical need for more longitudinal studies to confirm these findings.
• Targeted prevention strategies were highlighted, particularly for middle-aged White adults.