LAUSR

Objective: In adults, short leukocyte telomere length (LTL) is associated with metabolic disorders such as diabetes and obesity. The causality remains unclear since longitudinal studies do not show influence of metabolic disorders on LTL attrition. These associations could stem from early life interactions between telomere dynamics and metabolic disorders. To test this hypothesis, we measured, in obese children and their controls, LTL and its evolution over time and their associations with metabolic parameters. Design and method: 73 children aged 2–10 years (mean 7.6 ± 2.0) at inclusion were followed between 2 and 4 years (one visit/year). Anthropometric measurements (weight, height, waist and hip circumferences), a body composition analysis and a complete biology were performed annually. LTL was measured by Southern blot and LTL attrition was calculated. Scores for metabolic parameters were created based on the mean value of the parameter throughout the study. Results: Mean LTL attrition was 67 ± 8 bp/year. Baseline LTL correlated negatively with BMI score (p = 0.02), fat percentage score (p = 0.01), glycemia score (p = 0.0007), and insulinemia score (p = 0.02). These associations persisted after adjustment for age and sex. Trends for negative associations were observed between baseline LTL and waist/hip score (p = 0.07), and Hb1Ac score (p = 0.07). No association was found between LTL attrition and any of the metabolic parameters. Conclusions: In young children, metabolic parameters are negatively associated with LTL but not with LTL attrition. These results indicate that either short TL is the cause of metabolic disorders or that these metabolic disorders increased LTL attrition very early in life probably before the age of 5 years.