Is childhood stress associated with shorter telomeres?

The Relationship Between Childhood Psychosocial Stressor Level and Telomere Length: A Meta-Analysis

This meta-analysis examined the association between the level of childhood psychosocial stressors and telomere length, an important health biomarker. The meta-analysis, including 27 samples and 16,238 participants, found a significant association of -0.08 between a higher level of childhood stressors and shorter telomere length at a mean age of 42 across studies. Moderator analyses showed a trend in the direction of effect sizes being significantly larger with shorter times between the stressors and telomere measurement. Moderator analyses showed significantly higher effect sizes for studies that used a categorical method for assessing child stressor level and for assays completed with qPCR rather than with the Southern blot method. There was no significant moderation of effect size by whether study assayed leukocytes or buccal cells, whether the study assessed child stressor level by memory-based recall versus archival records, and whether the study controlled for age, sex, or additional variables. The results, focused on childhood events, add to prior findings that perceived stress and negative emotions are associated with telomere length.

Early-Life Experiences and Telomere Length in Adult Rhesus Monkeys: An Exploratory Study

OBJECTIVE

Child-rearing environments have been associated with morbidity in adult rhesus monkeys. We examine whether such links are also seen with leukocyte telomere length.

METHODS

To determine telomere length in leukocytes, blood was collected from 11 adult female monkeys aged 7 to 10 years who had been exposed to different rearing environments between birth and 7 months. Four had been reared with their mothers in typical social groups composed of other female monkeys, their offspring, and 1 to 2 adult male monkeys. The other 7 had been reared in either small groups of peers or individual cages with extensive peer interaction daily. After 7 months, all shared a common environment.

RESULTS

Telomere lengths were longer for those adults who had been reared with their mothers in social groups (median = 16.0 kb, interquartile range = 16.5-15.4) than for those who were reared without their mothers (median = 14.0 kb, interquartile range = 14.3-12.7; 2.2 kb/telomere difference, p < .027).

CONCLUSIONS

This observation adds to emerging knowledge about early adverse child-rearing conditions and their potential for influencing later morbidity. Because newborns were randomly assigned to the mother or other rearing conditions, the findings are not confounded by other conditions that co-occur with adverse child-rearing environments in humans (e.g., prenatal stress, nutrition and health as well as postnatal nutrition and negative life experiences over and above rearing conditions).