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

Abstract 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.