Telomere-mitochondrial dynamics differ depending on childhood maltreatment history, catabolic postpartum state, and developmental period

Telomere attrition, a hallmark of aging, is linked to high-energy demand states like early development and biological or psychological stress. Metabolic regulation of telomere length (TL) may occur in these states as part of an energetic trade-off, prioritizing immediate needs over long-term requirements such as telomere maintenance, though this has not been observed in healthy humans. We examined associations between TL and mitochondrial bioenergetics, density, and DNA markers in immune cells of women at 1-week (n = 175) and 1-year postpartum (n = 106), depending on their history of childhood maltreatment (CM), and in their newborns (n = 132). At 1-week postpartum, a catabolic state of high energy demand, women with lower mitochondrial energy production efficiency exhibited shorter TL. One year later, these dynamics appeared only in women with a history of CM. In newborns, TL was shorter when mitochondrial density-normalized routine and ATP production-related respiration was higher. Mitochondrial DNA copy number was associated with TL in both mothers and newborns, regardless of the energetic state. Our findings suggest that telomere-mitochondrial dynamics can adapt to the body's energetic needs.