Lower cardiorespiratory fitness (CRF) and higher coronary artery calcium (CAC) in midlife were independently associated with greater risk of later-life dementia, according to results from the Cooper Center Longitudinal Study published Aug. 10 in JACC: Advances. The findings underscore the potential role of both physical fitness and long-term cardiovascular health in dementia risk reduction.

Yariv Gerber, PhD, et al., linked nearly 11,000 Cooper Center Longitudinal Study participants who underwent treadmill fitness testing and CAC scanning between 1998 and 2018 with Medicare claims from 1999 to 2019. The investigators examined mid-to-late midlife CRF and CAC in relation to later-life dementia. Participants had a mean age of 57 years, 70% were men and nearly all were White; all were free of cardiovascular disease and dementia at baseline.

CRF was assessed by treadmill testing and categorized as low, moderate or high by age and sex; CAC was categorized as <100 or ≥100 Agatston units. Incident all-cause dementia was identified through Medicare surveillance.

During a median follow-up of 5.8 years, 868 dementia cases occurred. After adjustment for other risk factors, high CRF vs. low CRF was associated with lower dementia risk (hazard ratio [HR], 0.69), while CAC ≥100 vs. <100 Agatston units was associated with higher risk (HR, 1.24). Continuous analyses showed a linear inverse association for CRF and a graded positive association for CAC. No interaction between CRF and CAC was observed.

"Future longitudinal cohort studies should focus on evaluating trajectories and dynamic changes in CRF and CAC over time, rather than single-point exposures," write the authors, adding that such work would help clinicians "better understand how progressive changes in cardiovascular and functional health influence cognitive decline."