Posttraumatic Stress Disorder, Adverse Childhood Events, and Buccal Cell Telomere Length in Elderly Swiss Former Indentured Child Laborers

Abstract

Posttraumatic stress disorder (PTSD) is associated with increased risk for age-related diseases and early mortality. Accelerated biological aging could contribute to this elevated risk. The aim of the present study was to assess buccal cell telomere length (BTL) – a proposed marker of biological age – in men and women with and without PTSD. The role of childhood trauma was assessed as a potential additional risk factor for shorter telomere length. The sample included 62 former indentured Swiss child laborers (age: M = 76.19, SD = 6.18) and 58 healthy controls (age: M = 71.85, SD = 5.97). Structured clinical interviews were conducted to screen for PTSD and other psychiatric disorders. The Childhood Trauma Questionnaire (CTQ) was used to assess childhood trauma exposure. Quantitative polymerase chain reaction was used to measure BTL. Covariates include age, sex, years of education, self-evaluated financial situation, depression, and mental and physical functioning. Forty-eight (77.42%) of the former indentured child laborers screened positive for childhood trauma, and 21 (33.87%) had partial or full-blown PTSD. Results did not support our hypotheses that PTSD and childhood trauma would be associated with shorter BTL. In fact, results revealed a trend toward longer BTL in participants with partial or full PTSD [F(2,109) = 3.27, p = 0.04, η2 = 0.06], and longer BTL was marginally associated with higher CTQ scores (age adjusted: β = 0.17 [95% CI: −0.01 to 0.35], t = 1.90, p = 0.06). Furthermore, within-group analyses indicated no significant association between BTL and CTQ scores. To the best of our knowledge, this is the first study exploring the association between childhood trauma and BTL in older individuals with and without PTSD. Contrary to predictions, there were no significant differences in BTL between participants with and without PTSD in our adjusted analyses, and childhood adversity was not associated with BTL. Possible explanations and future research possibilities are discussed.

Adverse childhood experiences, epigenetics and telomere length variation in childhood and beyond: a systematic review of the literature

“…The remaining studies adopted retrospective ACE reporting measures with adult participants. The most common psychiatric conditions considered in the studies were major depressive disorder [11,[21][22][23][24][25] and borderline personality disorder [23,24,[26][27][28][29], followed by post-traumatic stress disorder [8,23,30,31]. Two studies considered eating disorders [26,32].…”

“…Six demonstrated a shortened telomere length correlating with ACEs [8][9][10][11][12] and one showed a link between shortened telomeres and ACE exposure which was not sustained over time [22]. One paper showed no link between telomere length and exposure [30]. Tyrka and colleagues reported shorter telomere length in adults exposed to ACEs, even after controlling for confounders [10].…”

Adverse Childhood Experiences Run Deep: Toxic Early Life Stress, Telomeres, and Mitochondrial DNA Copy Number, the Biological Markers of Cumulative Stress

“…For example, parental separation in early childhood alone was not be enough to predict telomere erosion in a sample of n ¼ 1486 individuals (n ¼ 215 with childhood separation). [71][72][73] Variability in TL measurement methods across studies, ranging from different DNA extraction procedures [79] to varied TL quantifications, [80] may also account for the inconsistencies observed. [39,78] As such, TL exhibits a similar pattern to health risk after ACE exposure and may help explain the dose-response relationship between number of exposures and health burden.…”

“…[70,71] In a sample of elderly Swiss former indentured child laborers, there was no relationship between childhood adversity and buccal TL. [72] Similarly, an analysis of the Netherlands Study of Depression and Anxiety cohort initially reported that childhood trauma was not associated with shorter TL. [73] However, a more recent analysis of this cohort found a significant relationship between childhood trauma and the 6 year telomere attrition rate despite there still being no association between childhood trauma and TL.…”

“…For example, psychological or biological resiliency may buffer the effects of ACEs in later life. [71][72][73] Variability in TL measurement methods across studies, ranging from different DNA extraction procedures [79] to varied TL quantifications, [80] may also account for the inconsistencies observed. [39] Failure to consider immune cell sub-populations when measuring TL in PBMCs may be another limitation given that sub-populations differ with respect to TL and stress exposure may precipitate changes in the preponderance of certain sub-populations.…”