Associations of childhood and adulthood body size, and child‐to‐adult body size change with adult telomere length.

Aim: To comprehensively examine the associations of childhood and adulthood body size, and child‐to‐adult body size change with adult leucocyte telomere length (LTL). Methods: We included 453 602 participants from the UK Biobank. Childhood body size at the age of 10 years was collected through a questionnaire. Adulthood body size was assessed using body mass index (BMI), waist circumference (WC), waist‐to‐hip ratio (WHR), fat mass index (FMI), and fat‐free mass index (FFMI). Results: Individuals with plumper body size in childhood exhibited shorter LTL in adulthood (−0.0086 [−0.0017, −0.0004]). Adulthood BMI (−0.0286 [−0.0315, −0.0258]), WC (−0.0271 [−0.0303, −0.0238]), WHR (−0.0269 [−0.0308, −0.0230]) and FMI (−0.0396 [−0.0438, −0.0351]) were negatively associated with LTL, whereas FFMI (0.0095 [0.0039, 0.0152]) was positively associated with LTL. Compared to individuals consistently having an average/normal weight in both childhood and adulthood, those who maintained or developed overweight/obesity from childhood to adulthood had a shorter adult LTL, regardless of childhood body size. Notably, the LTL shortening effect was not observed in individuals with plumper body size in childhood but normal weight in adulthood. Conclusions: Childhood and adulthood obesity are both associated with LTL shortening in adulthood. Transitioning to or maintaining overweight/obese status from childhood to adulthood is associated with shorter adult LTL, whereas this effect can be reversed if plumper children become normal weight. [ABSTRACT FROM AUTHOR]