Association between telomere length and cognitive function among cognitively unimpaired individuals at risk of Alzheimer's disease

Introduction: Leukocyte telomere length (LTL) is an objective biomarker of biological aging, and it is proposed to play a crucial role in Alzheimer's disease (AD) risk. We aimed at evaluating the cross-sectional association between LTL and cognitive performance in middle-aged cognitively unimpaired individuals at increased risk of AD.

Methods: A total of 1520 participants from the ALFA cohort were included. Relative telomere length was measured in leukocytes through qPCR. LTL was residualized against age and sex, and associations with cognitive performance were assessed in short and long groups based on residualized LTL (rLTL). Interactions with sex and genetic risk of AD were tested.

Results: Non-linear associations were found between LTL and episodic memory (EM). Better EM was associated with longer rLTL among women in the short rLTL group.

Discussion: Results suggest a potential role of telomeres in the cognitive aging process with sex-specific patterns.

Keywords: Alzheimer’s disease; Biological aging; Cognitive performance; Sex differences; Telomere length.