Abstract
<p>Objectives: The present study aimed to determine if objectively measured physical activity moderated the association between speech-in-noise hearing ability and cognitive performance in middle-aged and older adults. Exploratory analyses also examined whether physical activity was associated with social isolation, and whether this association varied according to hearing ability.Design: A cross-sectional analysis was conducted using data from the UK Biobank cohort. The final descriptive sample included 18,787 participants aged 46 – 85 years, including 10,372 females and 8,415 males. Hearing ability was determined by calculating the better-ear speech reception threshold (SRT) derived from the Digit Triplet Test. Physical activity levels were objectively captured over a continuous seven-day window using wrist-worn accelerometers. Cognitive performance was evaluated using a global cognitive composite score derived via Principal Component Analysis, and social isolation was classified as a binary variable. Multiple linear and binary logistic regression models evaluated primary moderation and exploratory associations, adjusting for age, sex, and educational attainment.Results: The primary cognitive model included 18,753 participants, and the exploratory social isolation model included 15,703 participants. Higher better-ear SRT was associated with lower cognitive composite scores (B = −0.060, p &lt; .001). Objective physical activity was not associated with cognitive composite scores (B = −0.001, p = .302), and the interaction between objective physical activity and better-ear SRT was not statistically significant (p = .612). In the exploratory models, higher levels of objective physical activity were significantly associated with lower odds of social isolation (B = −0.024, p &lt; .001). However, better-ear SRT did not moderate this relationship (p = .659).Conclusion: In this UK Biobank sample, poorer speech-in-noise performance was associated with lower cognitive performance, but objectively measured physical activity did not moderate this association. Greater levels of objective physical activity were associated with lower social isolation, and this association was not influenced by hearing ability. These findings suggest that physical activity may be relevant to social isolation outcomes in later life, but the present cross-sectional behavioural data do not support physical activity as a moderator of the association between speech-in-noise hearing ability and cognitive performance.</p>