Telomere length and 4-year changes in cognitive function in an older Mediterranean population at high risk of cardiovascular disease

Abstract Background Cognitive decline, a common process of brain ageing, has been associated with telomere length (TL). Delving into the identification of reliable biomarkers of brain ageing is essential to prevent accelerated cognitive impairment. Methods We selected 317 non-smoking ‘Prevención con Dieta Mediterránea-Plus’ (PREDIMED-Plus) participants (mean age, 65.8 ± 5.0 years) with metabolic syndrome from two trial centres who were following a lifestyle intervention. We measured TL and cognitive function at baseline and after 3 and 4 years of follow-up, respectively. Associations between baseline or 3-year changes in TL and baseline or 4-year changes in cognitive function were analysed using multivariable regression models. Results Baseline TL was not associated with baseline cognitive performance. Nevertheless, longer baseline TL was associated with improved 4-year changes in the Executive Function domain (β: 0.29; 95%CI: 0.12 to 0.44; P < 0.001) and the Global Cognitive Function domain (β: 0.19; 95%CI: 0.05 to 0.34; P = 0.010). Besides, a positive association was found between longer baseline TL and improved 4-year changes in the animal version of the Verbal Fluency Test (β: 0.33; 95%CI: 0.12 to 0.52; P = 0.002). By contrast, 3-year changes in TL were not associated with changes in cognitive function after 4 years. Conclusions Longer baseline TL could protect from cognitive decline and be used as a useful biomarker of brain ageing function in an older Mediterranean population at risk of cardiovascular disease and cognitive impairment.