Depressive Symptoms and Salivary Telomere Length in a Probability Sample of Middle-Aged and Older Adults

Posttraumatic Stress Disorder, Depression, and Accelerated Aging: Leukocyte Telomere Length in the Nurses' Health Study II

Background

Exposure to trauma, posttraumatic stress disorder (PTSD), and depression have been independently associated with leukocyte telomere length (LTL), a cellular marker of aging associated with mortality and age-related diseases. However, the joint contributions of trauma and its psychological sequelae on LTL have not been examined.

Methods

We conducted an analysis of LTL in a subset of women from the Nurses' Health Study II (N = 1868). Lifetime exposure to traumatic events, PTSD, and depression was assessed with validated measures. DNA was extracted from peripheral blood leukocytes and telomere repeat copy number to single gene copy number was determined by quantitative real-time polymerase chain reaction telomere assay. Linear regression models assessed the association of trauma, PTSD, and depression with LTL after adjustment for health behaviors and medical conditions.

Results

Trauma, PTSD, and depression were not independently associated with LTL in mutually adjusted models. However, individuals with severe psychological distress-characterized by comorbid PTSD and depression-had shorter LTL equivalent to being 7.62 years older (95% CI, 0.02 to 17.97) than participants who had never experienced a traumatic event and were not depressed. Further examination found only an association among individuals with the highest number of PTSD symptoms and comorbid depression equivalent to 9.71 additional years of aging (95% CI, 1.36 to 20.49). No effect was found among individuals meeting the minimum threshold for probable PTSD with comorbid depression.

Conclusions

Severe psychological distress, as indicated by the presence of comorbid PTSD and depression, may be associated with shorter LTL.

Telomere Shortening and Psychiatric Disorders: A Systematic Review

Telomeres are aging biomarkers, as they shorten while cells undergo mitosis. The aim of this study was to evaluate whether psychiatric disorders marked by psychological distress lead to alterations to telomere length (TL), corroborating the hypothesis that mental disorders might have a deeper impact on our physiology and aging than it was previously thought. A systematic search of the literature using MeSH descriptors of psychological distress ("Traumatic Stress Disorder" or "Anxiety Disorder" or "depression") and telomere length ("cellular senescence", "oxidative stress" and "telomere") was conducted on PubMed, Cochrane Library and ScienceDirect databases. A total of 56 studies (113,699 patients) measured the TL from individuals diagnosed with anxiety, depression and posttraumatic disorders and compared them with those from healthy subjects. Overall, TL negatively associates with distress-related mental disorders. The possible underlying molecular mechanisms that underly psychiatric diseases to telomere shortening include oxidative stress, inflammation and mitochondrial dysfunction linking. It is still unclear whether psychological distress is either a cause or a consequence of telomere shortening.

Telomere Length and ADHD Symptoms in Young Adults

Objective: Previous research examining telomeres in individuals with neuropsychiatric disorders shows that greater illness, symptoms, or cognitive impairment are linked with shorter telomeres. However, the relationships of telomere length and neuropsychological processes or psychiatric symptoms are not understood in individuals with Attention Deficit/Hyperactivity Disorder (ADHD). Method: 390 young adults with and without ADHD completed a multi-informant diagnostic assessment and neuropsychological testing battery. Participant DNA was isolated from saliva samples, and telomere length was determined using qPCR. Results: Linear regression models demonstrated the only significant association to survive correction for multiple testing was for childhood hyperactivity-impulsivity symptoms and longer telomere length. Conclusion: Contrary to expectations, longer telomere length in young adults was associated only with childhood ADHD symptoms, particularly hyperactivity-impulsivity, in this sample. These findings are an important demonstration that the neuropsychological deficits and symptoms experienced by individuals diagnosed with ADHD during adulthood may not be negatively associated with telomere length.

Is early life adversity a trigger towards inflammageing?

There are many 'faces' of early life adversity (ELA), such as childhood trauma, institutionalisation, abuse or exposure to environmental toxins. These have been implicated in the onset and severity of a wide range of chronic non-communicable diseases later in life. The later-life disease risk has a well-established immunological component. This raises the question as to whether accelerated immune-ageing mechanistically links early-life adversity to the lifelong health trajectory resulting in either 'poor' or 'healthy' ageing. Here we examine observational and mechanistic studies of ELA and inflammageing, highlighting common and distinct features in these two life stages. Many biological processes appear in common including reduction in telomere length, increased immunosenescence, metabolic distortions and chronic (viral) infections. We propose that ELA shapes the developing immune, endocrine and nervous system in a non-reversible way, creating a distinct phenotype with accelerated immunosenescence and systemic inflammation. We conclude that ELA might act as an accelerator for inflammageing and age-related diseases. Furthermore, we now have the tools and cohorts to be able to dissect the interaction between ELA and later life phenotype. This should, in the near future, allow us to identify the ecological and mechanistic processes that are involved in 'healthy' or accelerated immune-ageing.

Association of sleep quality with telomere length, a marker of cellular aging: A retrospective cohort study of older adults in the United States

BACKGROUND

Sleep quality is a risk factor for age-related diseases, and although the underlying mechanisms remain unclear, the effects of poor sleep quality on telomere length (TL) may play a role.

OBJECTIVE

The objective of the study was to evaluate the independent association between sleep quality and salivary TL in a large sample of older adults.

DESIGN

We adopted a retrospective cohort design, and participants comprised 5,268 adults drawn from the Health and Retirement Study. We used the 2006 (baseline) and 2008 (follow-up) waves. Baseline sleep quality was assessed using 4 Likert scale questions (trouble falling asleep, waking up during the night, waking up too early and not being able to fall sleep again, and feeling well rested in the morning). The TL was assessed using the T/S ratio, a continuous variable. The associations between sleep quality and T/S were assessed using multivariable ordinary least squares regressions. All analyses were adjusted for demographics, lifestyle characteristics, psychosocial, and other factors.

RESULTS

Overall, 16% reported never feeling well rested in the morning; 25.7% of respondents always had trouble waking during the night; and 12.8% always had trouble waking up too early in the morning. Respondents who never felt rested in the morning had significantly shorter TL than those who always felt rested in the morning (adjusted beta = -0.08, standard error = 0.03, P < .01). The composite sleep measure was not significantly associated with shorter TL.

CONCLUSIONS

In this cohort of older adults, not feeling well rested in the morning was significantly and inversely associated with TL; however, the composite measure of sleep quality was not significantly associated with TL. These findings suggest a potential connection between one of the measures of impaired sleep and reduction in TL, a marker of cellular aging that has been linked to multiple chronic conditions.

Does Salivary Telomere Length Explain Race/Ethnic Differences in Aging?

Telomere length (TL) is a biomarker that can be used to characterize variability in aging and may explain race/ethnic differences in aging. Yet, it remains unclear if TL is related to aging-associated health risks in multi-ethnic populations or if it explains race/ethnic differences in health. We examine whether salivary TL (STL) explains any of the race/ethnic variability in 15 indicators of high-risk biological, physical and cognitive health among 4,074 white, black, and Latinx older adults ages 54+ in the 2008 Health and Retirement Study. TL was assayed from saliva using quantitative PCR (T/S ratio). Decomposition analyses from logistic regression models show variation in STL does not account for any of the observed race/ethnic differences health. In age-adjusted, race-stratified models, STL was associated with HDL, total cholesterol, and lung function among whites, but was not associated with any markers of health among black or Latinx groups. In this diverse national sample of older adults, STL does not account for race/ethnic differences in late life health, is associated with relatively few indicators of health among whites, and is not associated with indicators of health among black or Latinx groups. STL may not be a useful biomarker for understanding racial/ethnic differences in population aging among older adults.

Does Telomere Length Indicate Biological, Physical, and Cognitive Health Among Older Adults? Evidence from the Health and Retirement Study

Telomere length (TL) has been suggested as a biomarker that can indicate individual variability in the rate of aging. Yet, it remains unclear whether TL is related to recognized indicators of health in an aging, older nationally representative sample. We examine whether TL is associated with 15 biological, physical, and cognitive markers of health among older adults ages 54+. TL was assayed from saliva using quantitative polymerase chain reaction (T/S ratio) in the 2008 Health and Retirement Study (n = 4,074). We estimated probability of high-risk levels across indictors of health by TL and age-singly and jointly. TL was associated with seven indicators of poor functioning: high-density lipoprotein and total cholesterol, cystatin C, pulse pressure, body mass index, lung function, and walking speed. However, after adjusting for age, associations were substantially attenuated; only associations with cholesterol and lung function remained significant. Additionally, findings show TL did not add to the predictive power of chronological age in predicting poor functioning. While TL may not be a useful clinical marker of functional aging in an older adult population, it may still play an important role in longitudinal studies in young and middle aged populations that attempt to understand aging.

Weight Loss Maintenance and Cellular Aging in the Supporting Health Through Nutrition and Exercise Study

OBJECTIVE

The aim of the study was to determine, within a weight loss clinical trial for obesity, the impact of intervention arm, weight change, and weight loss maintenance on telomere length (TL).

METHODS

Adults (N = 194) with a body mass index between 30 and 45 were randomized to a 5.5-month weight loss program with (n = 100) or without (n = 94) mindfulness training and identical diet-exercise guidelines. We assessed TL at baseline and 3-, 6-, and 12-month postbaseline in immune cell populations (primarily in peripheral blood mononuclear cells [PBMCs], but also in granulocytes and T and B lymphocytes). We defined weight loss maintenance as having lost at least 5% or 10% of body weight (tested in separate models) from preintervention to postintervention, and having maintained this loss at 12 months. We predicted that greater weight loss and weight loss maintenance would be associated with TL lengthening.

RESULTS

Neither weight loss intervention significantly predicted TL change nor did amount of weight change, at any time point. Across all participants, weight loss maintenance of at least 10% was associated with longer PBMC TL (b = 239.08, 95% CI = 0.92 to 477.25, p = .049), CD8+ TL (b = 417.26, 95% CI = 58.95 to 775.57, p = .023), and longer granulocyte TL (b = 191.56, 95% CI = -4.23 to 387.35, p = .055) at 12 months after accounting for baseline TL. Weight loss maintenance of 5% or more was associated with longer PBMC TL (b = 163.32, 95% CI = 4.00 to 320.62, p = .045) at 12 months after accounting for baseline TL. These tests should be interpreted in light of corrections for multiple tests.

CONCLUSIONS

Among individuals with obesity, losing and maintaining a weight loss of 10% or more may lead to TL lengthening, which may portend improved immune and metabolic function. TL lengthening in this study is of unknown duration beyond 12 months and requires further study.

TRIAL REGISTRATION

Clinicaltrials.govidentifierNCT00960414; Open Science Framework (OSF) preregistration: https://osf.io/t3r2g/.

Stress, Telomeres, and Psychopathology: Toward a Deeper Understanding of a Triad of Early Aging

Telomeres play an important part in aging and show relationships to lifetime adversity, particularly childhood adversity. Meta-analyses demonstrate reliable associations between psychopathology (primarily depression) and shorter telomere length, but the nature of this relationship has not been fully understood. Here, we review and evaluate the evidence for impaired telomere biology as a consequence of psychopathology or as a contributing factor, and the important mediating roles of chronic psychological stress and impaired allostasis. There is evidence for a triadic relationship among stress, telomere shortening, and psychiatric disorders that is positively reinforcing and unfolds across the life course and, possibly, across generations. We review the role of genetics and biobehavioral responses that may contribute to shorter telomere length, as well as the neurobiological impact of impaired levels of telomerase. These complex interrelationships are important to elucidate because they have implications for mental and physical comorbidity and, potentially, for the prevention and treatment of depression.