Telomere length in early childhood : early life risk factors and association with carotid intima-media thickness in later childhood

Background Reduced telomere length is a measure of biological aging that is predictive of cardiac events in adults, and has been mechanistically implicated in the onset and progression of atherosclerosis. We sought to describe the early life factors associated with leukocyte telomere length in early childhood, and to determine whether telomere length measured during early childhood is associated with arterial wall thickening later in childhood. Design A longitudinal birth cohort recruited antenatally in Sydney from 1997 to 1999. Methods Leukocyte telomere length was measured in 331 children at age 3.6 years (SD 1.0); of whom 268 children without diabetes had carotid intima-media thickness assessed by ultrasound at age 8 years. Results Male sex, younger paternal age and higher maternal body mass index were associated with shorter telomere length in early childhood, which in turn was associated with greater carotid intima-media thickness at age 8 years (standardised β = -0.159, P = 0.01). There was a graded association across quartiles of telomere length (Ptrend = 0.001) with the highest odds of elevated intima-media thickness (˃75th percentile) being in children with the shortest telomeres (odds ratio 4.00 (95% confidence interval 1.58 to 10.14) relative to those with the longest telomeres, P = 0.003). This association remained after adjustment for early life risk factors (Ptrend = 0.001). Conclusions Reduced telomere length in early childhood is independently associated with arterial wall thickness in later childhood, suggesting that reduced telomere length during early childhood may be a marker of vascular disease risk.