Abstract
INTRODUCTION: Biological age (BA) measures were developed to capture changes in aging that chronological age does not. We aimed to investigate the association between BA and cognitive performance and whether the Klotho protein mediated this association. METHODS: We used data from participants aged 60 years or older from Mexico, India, the United States, and England. We used linear regression to investigate the association between BA and cognitive performance. Mediation analysis using data from the United States used the counterfactual framework. RESULTS: In 8547 participants, 53.6% were women, mean (SD) chronological age was 69.6 (7.6) years and mean (SD) biological age 70.2 (9.6) years. Higher biological age was associated with poorer cognitive performance across all evaluated countries. Klotho did not mediate these associations. DISCUSSION: Implementing the BA metric at the population level could help identify individuals at higher risk of poorer cognitive performance, facilitating targeted interventions. HIGHLIGHTS: Increasing biological age is associated with poorer global cognitive performance in older adults.Accelerated aging is associated with poorer cognitive performance in all countries studied.Klotho did not mediate the association between biological age and cognition.Implementing biological age metrics may help identify high-risk individuals.