Leukocyte telomere length: Effects of schizophrenia, age, and gender

Telomere length and verbal learning in bipolar disorders

INTRODUCTION

Recent studies indicate accelerated ageing processes, shorter telomere length and poorer cognitive functioning in patients with bipolar disorder. The neurobiology underlying cognitive function in bipolar disorder is yet to be established. We anticipated that accelerated ageing as indicated by shortened telomere length, would be associated with reduced cognitive performance in bipolar disorder, particularly for ageing sensitive functions such as memory and learning.

METHODS

The study consisted of 647 participants (bipolar disorder [n = 246] and healthy controls [n = 401]). All participants underwent a standardized neuropsychological test battery, including working memory, executive functioning, processing speed, verbal learning, and verbal memory. Leucocyte telomere length was measured via blood and determined by quantitative real-time Polymerase Chain Reaction (qPCR) providing a telomere to single copy ratio (T/S ratio). The T/S ratio was used as an estimate of the mean telomere length of each participant. All analyses were adjusted for medication, Daily Defined Dose (DDD), chronological age, sex, and ethnicity.

RESULTS

Patients had shorter telomere lengths than healthy controls (Cohen's d = 0.11, p = 0.01). Within patients', a positive association was observed for verbal learning and telomere length (β = 0.14, p = 0.025), along with a trend for verbal memory and telomere length (β = 0.11, p = 0.07). No other associations were observed for telomere length and cognitive functioning in the patient or the control group (p > 0.1).

CONCLUSION

Our study may suggest poorer brain health in bipolar disorder as indexed by shorter telomere length and reduced learning correlates. However, the role of telomere length on cognitive functioning in bipolar disorder seems limited.

Leukocyte telomere length and bipolar disorder risk: evidence from Mendelian randomization analysis

Objective

We aim to test whether leukocyte telomere length (LTL) is causally associated with the risk of bipolar disorder (BD) using the Mendelian randomization (MR) method.

Methods

Results of a genome-wide association study (GWAS) conducted with 472,174 individuals of European descent were used to screen for single-nucleotide polymorphisms (SNPs) related with LTL traits. Summary-level data for BD (7,647 cases and 27,303 controls) were obtained from UK Biobank. An inverse-variance-weighted (IVW) method was employed as the primary MR analysis. Sensitivity analyses were conducted via MR-Egger, maximum likelihood, MR-pleiotropy residual sum outlier (MR-PRESSO), and MR-robust adjusted profile score (MR-RAPS) methods. Finally, the MR Steiger test was utilized to validate the hypothesized relationship between exposure and outcome.

Results

Two-sample MR analysis revealed inverse relationships between genetically predicted LTL and BD risk (IVW OR [odds ratio] = 0.800, 95% CI [0.647–0.989] P = 0.039). Genetically predicted LTL exhibits a consistent connection with BD across five MR methods. Sensitivity analyses showed that the genetically determined effect of LTL on BD was stable and reliable. Furthermore, the MR Steiger test demonstrated that LTL was causal for BD rather than the opposite (P < 0.001).

Conclusion

Our findings show that genetically determined LTL reduces the risk of BD. More research is required to clarify the mechanisms underlying this apparent causal connection. In addition, these findings may be useful for developing strategies for the prevention and treatment of BD.

Epigenetic clocks in relapse after a first episode of schizophrenia

The main objective of the present study was to investigate the association between several epigenetic clocks, covering different aspects of aging, with schizophrenia relapse evaluated over a 3-year follow-up period in a cohort of ninety-one first-episode schizophrenia patients. Genome-wide DNA methylation was profiled and four epigenetic clocks, including epigenetic clocks of chronological age, mortality and telomere length were calculated. Patients that relapsed during the follow-up showed epigenetic acceleration of the telomere length clock (p = 0.030). Shorter telomere length was associated with cognitive performance (working memory, r = 0.31 p = 0.015; verbal fluency, r = 0.28 p = 0.028), but no direct effect of cognitive function or symptom severity on relapse was detected. The results of the present study suggest that epigenetic age acceleration could be involved in the clinical course of schizophrenia and could be a useful marker of relapse when measured in remission stages.

Leukocyte telomere length in patients with schizophrenia and related disorders: a meta-analysis of case-control studies

CONTEXT

Telomere length may serve as a biomarker of cellular aging. The literature assessing telomere length in schizophrenia contains conflicting results.

OBJECTIVE

To assess differences in leukocyte telomere length (LTL) in peripheral blood in patients with schizophrenia and related disorders and healthy controls and to explore the effect of potential confounding variables.

DATA SOURCES

A search of Ovid MEDLINE, and Proquest databases was conducted to identify appropriate studies published from database inception through December 2020. The review protocol was registered with PROSPERO-ID: CRD42021233280.

STUDY SELECTION

The initial literature search yielded 192 studies. After study selection in 3 phases, we included 29 samples from 22 studies in the meta-analysis database.

DATA EXTRACTION

We used random effects and meta-regression models to derive Cohen d values with pooled 95% confidence intervals (CI) as estimates of effect size (ES) and to test effects of potential moderators.

RESULTS

The overall meta-analysis included 4145 patients with schizophrenia and related disorders and 4184 healthy controls and showed that LTL was significantly shorter in patients, with a small to medium effect size (ES, -0.388; 95% CI, -0.492 to -0.283; p < 0.001). Subgroup meta-analyses did not find a significant effect of age or illness duration on differences in LTL in patients with psychosis relative to controls. Meta-regression analyses showed that none of the putative moderators had a significant effect on effect size estimates.

CONCLUSIONS

This meta-analysis find further support for the hypothesis of accelerated cellular aging in schizophrenia and related disorders and highlights the need for large longitudinal studies with repeated LTL measurements over time and appropriate assessments of associated factors.

Mental Disorders Are Associated With Leukocytes Telomere Shortening Among People Who Inject Drugs

Premature biological aging, assessed by shorter telomere length (TL) and mitochondrial DNA (mtDNA) alterations, has been reported among people with major depressive disorders or psychotic disorders. However, these markers have never been assessed together among people who inject drugs (PWIDs), although mental disorders are highly prevalent in this population, which, in addition, is subject to other aggravating exposures. Diagnosis of mental disorders was performed by a psychiatrist using the Mini International Neuropsychiatric Interview test among active PWIDs in Haiphong, Vietnam. mtDNA copy number (MCN), mtDNA deletion, and TL were assessed by quantitative PCR and compared to those without any mental disorder. We next performed a multivariate analysis to identify risk factors associated with being diagnosed with a major depressive episode (MDE) or a psychotic syndrome (PS). In total, 130 and 136 PWIDs with and without psychiatric conditions were analyzed. Among PWIDs with mental disorders, 110 and 74 were diagnosed with MDE and PS, respectively. TL attrition was significantly associated with hepatitis C virus-infected PWIDs with MDE or PS (adjusted odds ratio [OR]: 0.53 [0.36; 0.80] and 0.59 [0.39; 0.88], respectively). TL attrition was even stronger when PWIDs cumulated at least two episodes of major depressive disorders. On the other hand, no difference was observed in mtDNA alterations between groups. The telomeric age difference with drug users without a diagnosis of psychiatric condition was estimated during 4.2-12.8 years according to the number of MDEs, making this group more prone to age-related diseases.

Multi-omics of human plasma reveals molecular features of dysregulated inflammation and accelerated aging in schizophrenia

Schizophrenia is a devastating psychiatric illness that detrimentally affects a significant portion of the worldwide population. Aging of schizophrenia patients is associated with reduced longevity, but the potential biological factors associated with aging in this population have not yet been investigated in a global manner. To address this gap in knowledge, the present study assesses proteomics and metabolomics profiles in the plasma of subjects afflicted with schizophrenia compared to non-psychiatric control patients over six decades of life. Global, unbiased analyses of circulating blood plasma can provide knowledge of prominently dysregulated molecular pathways and their association with schizophrenia, as well as features of aging and gender in this disease. The resulting data compiled in this study represent a compendium of molecular changes associated with schizophrenia over the human lifetime. Supporting the clinical finding of schizophrenia's association with more rapid aging, both schizophrenia diagnosis and age significantly influenced the plasma proteome in subjects assayed. Schizophrenia was broadly associated with prominent dysregulation of inflammatory and metabolic system components. Proteome changes demonstrated increased abundance of biomarkers for risk of physiologic comorbidities of schizophrenia, especially in younger individuals. These findings advance our understanding of the molecular etiology of schizophrenia and its associated comorbidities throughout the aging process.

Telomere shortening in patients on long-term hemodialysis

Background

Leukocyte telomere length shortening is a characteristic of premature senescence, a process that can be accelerated by oxidative stress. In general, patients with end-stage renal disease undergoing regular hemodialysis (HD) are repeatedly exposed to oxidative stress. Patients undergoing HD tend to have cardiovascular diseases associated with oxidative stress and inflammation. Therefore, we assumed that telomere length is associated with HD vintage and the degree of vascular calcification.

Methods

A total of 144 patients undergoing regular HD before kidney transplantation and 62 patients on hemodialysis, but not undergoing kidney transplantation, were enrolled. We measured common laboratory values, such as calcium, phosphate, and hemoglobin levels, and assessed the degree of vascular calcification in the patients. The leukocyte telomere length was measured using reverse transcription polymerase chain reaction, and Spearman correlation was used for correlation analysis.

Results

The leukocyte telomere length was negatively associated with age (rho = −0.306, P＜0.01); it was shorter in middle-aged patients than in young patients (13.48 ± 4.80 vs. 15.86 ± 4.51, P < 0.01). The telomere length was significantly different among patients aged 52–74 years in groups with different HD vintages. Additionally, the telomere length was positively associated with serum hemoglobin (Hb) levels in all patients (rho = 0.290, P < 0.01). There was a significant difference among patients divided into three groups according to the degree of anemia (17.09 ± 5.64 vs. 14.40 ± 4.07 vs. 13.99 ± 3.95, P < 0.01). Further, a significant difference was observed in the telomere length among patients with different degrees of vascular calcification (16.79 ± 4.91 vs. 13.61 ± 2.82 vs. 14.62 ± 3.63 vs. 10.71 ± 3.74, P < 0.01). The telomere length was shorter in the patients on hemodialysis who did not receive a kidney transplant than in the surgical patients (8.12 ± 1.83 vs. 14.33 ± 4.63, P < 0.01).

Conclusion

This study demonstrated that the telomere length was significantly correlated with HD vintage in patients of a certain age group. The telomere length was shorter in patients on hemodialysis who matched for age and dialysis vintage with kidney transplant patients. It was also associated with vascular calcification and serum Hb levels in all patients undergoing HD.

Aging biological markers in a cohort of antipsychotic-naïve first-episode psychosis patients

Schizophrenia is a severe and multifactorial disorder with an unknown causative pathophysiology. Abnormalities in neurodevelopmental and aging processes have been reported. Relative telomere length (RTL) and DNA methylation age (DMA), well-known biomarkers for estimating biological age, are both commonly altered in patients with schizophrenia compared to healthy controls. However, few studies investigated these aging biomarkers in first-episode psychosis (FEP) and in antipsychotic-naïve patients. To cover the existing gap regarding DMA and RTL in FEP and antipsychotic treatment, we aimed to verify whether those aging markers could be associated with psychosis and treatment response. Thus, we evaluated these measures in the blood of FEP antipsychotic-naïve patients and healthy controls (HC), as well as the response to antipsychotics after 10 weeks of treatment with risperidone. RTL was measured in 392 subjects, being 80 FEP and 312 HC using qPCR, while DMA was analyzed in a subset of 60 HC, 60 FEP patients (antipsychotic-naïve) and 59 FEP-10W (after treatment) using the "Multi-tissue Predictor"and the Infinium HumanMethylation450 BeadChip Kit. We observed diminished DMA and longer RTL in FEP patients before treatment compared to healthy controls, indicating a decelerated aging process in those patients. We found no statistical difference between responder and non-responder patients at baseline for both markers. An increased DMA was observed in patients after 10 weeks of treatment, however, after adjusting for blood cell composition, no significant association remained. Our findings indicate a decelerated aging process in the early phases of the disease.

Association between body temperature and leukocyte telomere length in Korean middle-aged and older adults

OBJECTIVES

Data on associations between body temperature (BT) and leukocyte telomere length (LTL), which has been widely used as a biomarker of cellular senescence in recent epidemiological studies, are limited. Therefore, this study aimed to explore the associations between a normal BT range (35.0-37.5°C) and LTL via 6-year longitudinal observations of 2,004 male and female adults aged 50 or older.

METHODS

BT was obtained by measuring the tympanic temperature, and relative LTL was determined by real-time polymerase chain reaction. Robust regression analysis was used to evaluate the association between the baseline and follow-up LTL values and their differences.

RESULTS

A significant inverse association was found between BT and LTL at baseline. The regression coefficient estimate was -0.03 (95% confidence interval, -0.07 to -0.001; p<0.05). This association was stronger in participants with a body mass index >25 kg/m² and males (p<0.01). However, there were no associations between BT and LTL at follow-up or BT and 6-year longitudinal differences in LTL.

CONCLUSIONS

These findings suggest that having a high BT between 35°C and 37.5°C (95°F and 99°F) may be detrimental for obese individuals in terms of biological aging.

Telomeres: New players in immune-mediated inflammatory diseases?

Telomeres are repetitive DNA sequences located at the ends of linear chromosomes that preserve the integrity and stability of the genome. Telomere dysfunctions due to short telomeres or altered telomere structures can ultimately lead to replicative cellular senescence and chromosomal instability, both mechanisms being hallmarks of ageing. Chronic inflammation, oxidative stress and finally telomere length (TL) dynamics have been shown to be involved in various age-related non-communicable diseases (NCDs). Immune-mediated inflammatory diseases (IMIDs), including affections such as inflammatory bowel disease, psoriasis, rheumatoid arthritis, spondyloarthritis and uveitis belong to this group of age-related NCDs. Although in recent years, we have witnessed the emergence of studies in the literature linking these IMIDs to TL dynamics, the causality between these diseases and telomere attrition is still unclear and controversial. In this review, we provide an overview of available studies on telomere dynamics and discuss the utility of TL measurements in immune-mediated inflammatory diseases.

No alteration of leukocyte telomere length in first episode psychosis

Both shorter telomeres and schizophrenia have been associated with a decrease in life expectancy. Furthermore, several studies found a shorter telomere length (TL) in schizophrenia. Understanding whether or not telomere shortening is directly related to pathophysiology of schizophrenia or is a consequence of a cumulative exposure to chronic stress is of major importance. Comparing the TL of subjects at the very beginning of the disease (FEP) and control subjects could help to decide between these two hypotheses. The aim of the present study was to compare TL between FEP subjects (N=91) and controls (N=137). After accounting for multiple potential confounders, no significant association was observed between FEP and TL. Our result is consistent with the hypothesis that psycho-social stress / adversities and stressful situations in people with schizophrenia affect TL rather than that telomere erosion contributes to the development of this disorder.

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.

[Accelerated telomere erosion in schizophrenia: A literature review]

Schizophrenia is associated with a weighted average of 14.5 years of potential life lost according to a recent meta-analysis. This is partly explained by high rates of suicide and a high prevalence of non-psychiatric comorbidity (cardiovascular diseases, diabetes, cancers…). However, all these causes could not fully explain the loss of life expectancy in people suffering from schizophrenia. Life expectancy has been strongly correlated with telomere length (TL). Telomeres are noncoding structures consisting of DNA TTAGGG tandem repeats and associated proteins located at the end of the chromosomes. Their role is to help preserve genome stability by protecting chromosomal ends from the loss of genetic material. The progressive loss of telomeric material during cell divisions has led researchers to consider telomeres as molecular clocks that measure the number of divisions left until cellular death. The fact that both shorter telomeres and schizophrenia have been associated with a decrease in life expectancy has fueled the interest in the study of TL in schizophrenia. In this article, after a detailed review of the literature on the relationships between telomere length and schizophrenia, we discuss the different pathophysiological mechanisms which might explain this association. Based on this analysis, in the last part of the article we discuss potential research, therapeutic and prevention prospects. To date, the majority of the studies and meta-analyses found a decrease in TL in subjects with schizophrenia compared to control subjects. Conversely, all the studies exploring the TL in subjects suffering from first episode psychosis (FEP) have shown no significant difference from TL in control subjects. This suggests that excessive shortening of telomeres occurs during the course of the disease, thus it seems more probable that schizophrenia (or processes associated with it) affects TL rather than telomere erosion being a cause of the disorder. Several pathophysiological, non-mutually exclusive mechanisms have been proposed to explain the observed data. A first hypothesis to explain the acceleration of the physiological process of telomere erosion in schizophrenia is the activation of inflammation processes and oxidative stress as a consequence of schizophrenia per se. However, it seems more probable that reduced TL may be a result of cumulative exposure to chronic stress related to schizophrenia. Indeed, in healthy individuals a growing body of evidence has linked chronic stress to accelerated shortening of TL. This might explain why telomere erosion is too small to be detected in FEP patients who are younger and have a shorter duration of illness than subjects with schizophrenia. Based on these both explanations, telomere alterations may be considered as a biomarker of illness progression and might be useful for illness staging. Identifying processes associated with TL reduction might improve our understanding of the increased mortality and morbidity in schizophrenia, improve reliability of diagnosis, and hopefully suggest means for prevention and/or treatment. Treatments that prevent exposure and/or vulnerability to stressful life events that ameliorate schizophrenia may also prevent or decelerate telomere erosion. In this perspective, engaging subjects suffering from schizophrenia in a healthy diet and regular activity could be both promising strategies to protect telomere maintenance and improve health span at old age. In addition, the inflammatory process and oxidative stress involved in the physiopathology in at least a subgroup of subjects with schizophrenia could also be responsible for telomere erosion. Thus, an efficient anti-inflammatory therapeutic approach that targets these specific pathways could be of interest in this subgroup to limit telomere erosion. Mindfulness-based stress reduction (MBSR) therapies have been shown to reduce telomere erosion by increasing telomerase activity, although these psychological therapies should be used carefully in psychosis. Finally, advancing our understanding of the relationship between stress, inflammation and TL is of great interest for psychiatric research and for understanding stress effects in this population.

Biological aging in schizophrenia and psychosis severity: DNA methylation analysis

The physiological changes associated with normal aging are known to occur earlier in individuals with schizophrenia (SCZ). One of the phenomena linked with normal aging is the change in patterns of epigenetic modifications. We recruited 138 individuals with SCZ spectrum disorders and extracted DNA from white blood cells. The combinations of pre-selected DNA methylation sites were utilized to estimate the 'methylation age' (DNAm age) and evaluate evidence of epigenetic age acceleration. We investigated the correlation between the epigenetic age acceleration measures and psychosis severity; furthermore, we estimated blood cell counts based on DNA methylation levels. The extrinsic epigenetic age acceleration showed a significant correlation with the Brief Psychiatric Rating Scale (BPRS) disorganization subscale(r=0.222, p=0.039).Both Horvath age acceleration and Hannum age acceleration showed a significant correlation (r=0.221, p=0.029; r=0.242, p=0.017 respectively) with the Symptom Checklist 90 (SCL-90) psychotic domain. Overall, this study shows some evidence of epigenetic age acceleration associated with psychosis severity using two different algorithms for DNAm age analysis.

Epigenetic Age Acceleration Was Delayed in Schizophrenia

Schizophrenia is a serious neuropsychiatric disorder with abnormal age-related neurodevelopmental (or neurodegenerative) trajectories. Although an accelerated aging hypothesis of schizophrenia has been proposed, the quantitative study of the disruption of the physiological trajectory caused by schizophrenia is inconclusive. In this study, we employed 3 "epigenetic clock" methods to quantify the epigenetic age of a large sample size of whole blood (1069 samples from patients with schizophrenia vs 1264 samples from unaffected controls) and brain tissues (500 samples from patients with schizophrenia vs 711 samples from unaffected controls). We observed significant positive correlations between epigenetic age and chronological age in both blood and brain tissues from unaffected controls and patients with schizophrenia, as estimated by 3 methods. Furthermore, we observed that epigenetic age acceleration was significantly delayed in schizophrenia from the whole blood samples (aged 20-90 years) and brain frontal cortex tissues (aged 20-39 years). Intriguingly, the genes regulated by the epigenetic clock also contained schizophrenia-associated genes, displaying differential expression and methylation in patients with schizophrenia and involving in the regulation of cell activation and development. These findings were further supported by the dysregulated leukocyte composition in patients with schizophrenia. Our study presents quantitative evidence for a neurodevelopmental model of schizophrenia from the perspective of a skewed "epigenetic clock." Moreover, landmark changes in an easily accessible biological sample, blood, reveal the value of these epigenetic clock genes as peripheral biomarkers for schizophrenia.

Gender differences in early onset of chronic physical multimorbidities in schizophrenia spectrum disorder: Do women suffer more?

AIM

The association between various physical illnesses and schizophrenia spectrum disorder (SSD) is well-established. However, the role of gender remains unclear. The present study explored the gender-based differences in the prevalence and early onset of chronic physical multimorbidities (CPM) in patients with SSD and the general population (GEP).

METHODS

We recruited 329 SSD patients and 837 GEP controls in this nested cross-sectional study. The primary outcome was the prevalence of the chronic physical multimorbidities, especially in the youngest age group (<35 years).

RESULTS

Women with SSD had more than double the odds for having CPM than men (OR = 2.47; 95% CI 1.35-4.50), while the gender-related burden of chronic diseases in controls was nearly the same (OR = 0.89; 95% CI 0.65-1.22). Furthermore, the prevalence of chronic disease in younger women patients was significantly higher than in controls (P = .002), while younger men did not seem to experience this increased comorbidity burden.

CONCLUSIONS

This study suggests that women with SSD are at increased physical comorbidity risk compared to men, particularly early in the course of psychiatric illness. Tailored and individualized treatment plans must consider this, aiming to deliver holistic care and effective treatment outcomes.

Association between leucocyte telomere length and cardiovascular disease in a large general population in the United States

Leucocyte telomere length (LTL) has been reported to be linked to ageing, cancer and cardiovascular disease (CVD). This study aimed to explore the association between LTL and CVD risk in a nationally representative sample of U.S. adults. Complex associations, including nonlinearity and interaction, were also examined. A total of 7,378 subjects from the National Health and Nutrition Examination Survey (NHANES) 1999-2002 were collected. Telomere length was detected from DNA samples and expressed as the mean T/S ratio (telomere repeats per single-copy gene). We performed multiple logistic regression models and interactive analysis to explore the associations between LTL and CVD risk by adjusting for potential confounders. We also performed a sensitivity analysis to investigate the robustness of our results. Among all participants, LTL was associated with the risk of CVD (OR = 0.79, 95% CI: 0.63~0.98, P = 0.033) in a linear manner rather than in a nonlinear manner (P = 0.874). Interaction effects of LTL with both education (P = 0.017) and hypertension (P = 0.007) were observed. Furthermore, using subgroup analyses, protective effects of LTL on CVD risk were found in females and in individuals who were college graduates or above, had serum cotinine >10 ng/ml, did not have hypertension, or had normal white blood cell levels. LTL is linearly inversely associated with CVD risk in the general population of the United States.

Heart-Breaking Telomeres

Telomeres, the protective ends of linear chromosomes, shorten throughout an individual's lifetime. Accumulation of critically short telomeres is proposed to be a primary molecular cause of aging and age-associated diseases. Mutations in telomere maintenance genes are associated with pathologies referred to as or telomeropathies. The rate of telomere shortening throughout life is determined by endogenous (genetic) and external (nongenetic) factors. Therapeutic strategies based on telomerase activation are being developed to treat and prevent telomere-associated diseases, namely aging-related diseases and telomeropathies. Here, we review the molecular mechanisms underlying telomere driven diseases with particular emphasis on cardiovascular diseases.

Childhood Adversity and Schizophrenia: The Protective Role of Resilience in Mental and Physical Health and Metabolic Markers

OBJECTIVE

To determine the impact of childhood adversity and current (adulthood) resilience on mental and physical health and markers of metabolic function among adults with schizophrenia and nonpsychiatric comparison participants (NCs).

METHODS

We conducted a cross-sectional study of 114 participants with schizophrenia (DSM-IV-TR criteria) and 101 NCs aged 26-65 years during 2012-2017. Sociodemographic, clinical, and laboratory measures were examined. Childhood Trauma Questionnaire was used to retrospectively assess emotional abuse/neglect, physical abuse/neglect, and sexual abuse experienced during childhood. Connor-Davidson Resilience Scale was employed to measure resilience.

RESULTS

Persons with schizophrenia reported more severe childhood trauma, lower resilience, and worse mental and physical health and had worse metabolic biomarker levels than NCs. Trauma severity correlated with worse depression in the NCs (r = 0.34), but not in the schizophrenia group (r = 0.02). In both groups, trauma severity was associated with worse physical well-being, higher fasting insulin levels, and greater insulin resistance (P ≤ .02). Notably, resilience appeared to counteract effects of trauma and diagnosis on mental and physical health. The schizophrenia subgroup with high resilience and severe trauma reported mental and physical well-being and had glycosylated hemoglobin levels and insulin resistance scores that were comparable to those of NCs with low resilience and severe trauma.

CONCLUSIONS

To our knowledge, this is the first study to quantitatively assess effects of both childhood trauma and resilience in schizophrenia on health, notably metabolic function. Interventions to bolster resilience in the general population and in people with schizophrenia may improve outcomes for those with a history of childhood adversity.

Serum Level of Total Lipids and Telomere Length in the Male Population: A Cross-Sectional Study

Telomeres contain TTAGGG (T; Thymine, A; Adenine and G; Guanine) repetitive sequences and are placed at the end of human chromosomes. Telomere dysfunction is implicated in some age-related and chronic diseases, but its association with total serum lipids and obesity is unknown. Our objective was to determine influenced of total serum lipids on leukocyte telomere lengths (TLs). Participants were selected by cluster sampling from 22 districts of Tehran. The questionnaires were completed by 500 subjects and after the initial assessment in terms of lifestyle, nutrition, home, and job, 300 healthy people, aged 25-40 years were finally selected. TLs and serum level of total lipids were measured by quantitative real-time PCR and the Phillips method, respectively. The average telomere length (T/S) and total lipids were 1.05 ± 0.3 mg/dl and 643.3 ± 70.8 mg/dl, respectively. We found that a one unit difference in the following parameters were associated with kilo base pair differences in TL: Age -0.0002 (95% CI [-0.0022, -0.0018]), BMI -0.0019 (95% CI [-0.0003, -0.0034]), TC 0.0001 (95% CI [-0.0006, -0.0007]), TG -0.0010 (95% CI [-0.0015, -0.0004]), PL 0.0001 (95% CI [-0.0005, -0.0007]), and TSL -0.0003 (95% CI [-0.0008, 0.0001]). Spearman correlation analysis revealed an inverse relationship between TC (R = -0.53; 95% CI [-0.61, -0.44]), TG (R = -0.50; 95% CI [-0.58, -0.41]), PL (R = -0.46; 95% CI [-0.54-0.36]), and TSL (R = -0.63; 95% CI [-0.69, -0.56]) with T/S. Our research suggests that the inverse relationship was found between TL and weight, BMI, age, and TSL which were associated with obesity. High serum lipids concentration may be associated with systemic inflammation and atherosclerosis and may lead to oxidative stress, resulting in telomere shortening.

Epigenetic clock analysis of blood samples from Japanese schizophrenia patients

The accelerated aging hypothesis of schizophrenia (SCZ) has been proposed. DNA methylation profiles were developed for determining “epigenetic age.” Here, we assessed intrinsic and extrinsic epigenetic age acceleration (IEAA and EEAA, respectively) in SCZ. We examined two independent cohorts of Japanese ancestry. The first cohort consisted of 80 patients with SCZ under long-term or repeated hospitalization and 40 controls, with the economical DNA pooling technique. The second cohort consisted of 24 medication-free patients with SCZ and 23 controls. Blood of SCZ subjects exhibited decreased EEAA in the first cohort (p = 0.0162), but not in the second cohort. IEAA did not differ in either cohort. We performed replication analyses using publicly available datasets from European ancestry (three blood and one brain datasets). One blood dataset showed increased EEAA in SCZ (p = 0.0228). Overall, our results provide evidence for decreased EEAA in SCZ associated with hospitalization in the Japanese population.

Telomere length and its association with hippocampal gray matter volume in antipsychotic-naïve/free schizophrenia patients

Accelerated ageing processes are postulated to underlie schizophrenia pathogenesis. This postulate is supported by observations of reduced telomere length in schizophrenia patients. Hippocampus, one of the most important brain regions implicated in schizophrenia, is shown to atrophy at a faster rate in aging. In this study, telomere length (TL) was measured in 30 antipsychotic-naive/free schizophrenia patients and 60 healthy controls using quantitative PCR assay. Hippocampus volume was measured using voxel-based morphometry. Schizophrenia was associated with differential TL between sexes [Status × Sex; F(1,85) = 5.9, p = 0.017, η² = 0.065]. Male schizophrenia patients had significantly lower relative TL than female patients [F(1,85) = 7.38, p = 0.008], while such sex difference was not observed in healthy controls [F(1,85) = 0.16, p = 0.69]. Schizophrenia patients showed a significant sex-by-telomere interaction with both right & left hippocampus, with male patients showing positive association of telomere length with volume, while female patients showed negative association. Telomere shortening and the positive association of telomere length with hippocampus volume was observed only in male patients with schizophrenia. Since correlational observations in this cross-sectional study does not necessarily support definitive causal relationship, further longitudinal studies examining hippocampus volume and telomere in schizophrenia patients are needed.

Neurocognitive Impairment and Associated Genetic Aspects in HIV Infection

HIV enters the central nervous system (CNS) early after infection. HIV-associated neurocognitive disorders (HAND) remain a serious complication of HIV infection despite available antiretroviral therapy (ART). Neurocognitive deficits observed in HAND are heterogeneous, suggesting a variability in individuals' susceptibility or resiliency to the detrimental CNS effects of HIV infection. This chapter reviews primary host genomic changes (immune-related genes, genes implicated in cognitive changes in primary neurodegenerative diseases), epigenetic mechanisms, and genetic interactions with ART implicated in HIV progression or HAND/neurocognitive complications of HIV. Limitations of the current findings include diversity of the HAND phenotype and limited replication of findings across cohorts. Strategies to improve the precision of future (epi)genetic studies of neurocognitive consequences of HIV infection are offered.

Shorter telomere length in schizophrenia: Evidence from a real-world population and meta-analysis of most recent literature

Schizophrenia is a severe, chronic mental disorder. Schizophrenia is visualized as an accelerated cellular aging syndrome characterized by early onset of cardiovascular disease causing premature mortality. In human aging involves alterations in telomere length (TL). To investigate the presence of TL shortening in schizophrenia and psychiatric syndromes associated, this condition was studied in leukocytes (LTL) of a sample of patients suffering from schizophrenia and other psychotic disorders, and compared with a group of non-psychiatric controls. We explored the relationship between LTL and age, gender, and smoking habit with the aim to control whether these potential confounding factors may influence the rate of telomeres shortening. We also performed a new comprehensive meta-analysis including studies on LTL in schizophrenia patients compared to healthy subjects published in the last two years and the results of the present study. Our results suggest that a diagnosis of schizophrenia, more than gender, age, cigarette smoking or alcohol drinking, is the most important condition responsible of the LTL shortening. A strong LTL shortening was observed in patients affected by schizophrenia, Schizoaffective disorder, and Psychosis not otherwise specified when they were younger than 50 years, while in the group of older subjects no major differences were observed. Additional evidence supporting the causal link of schizophrenia with accelerated telomeres shortening came from the analysis of the updated meta-analysis. The availability of a personalized profile of mechanistic pathways, risk factors, and clinical features may pose the basis for a rehabilitative treatment addressing individual needs of the psychiatric patients.

Early Senescence and Leukocyte Telomere Shortening in SCHIZOPHRENIA: A Role for Cytomegalovirus Infection?

Schizophrenia is a severe, chronic mental disorder characterized by delusions and hallucinations. Several evidences support the link of schizophrenia with accelerated telomeres shortening and accelerated aging. Thus, schizophrenia patients show higher mortality compared to age-matched healthy donors. The etiology of schizophrenia is multifactorial, involving genetic and environmental factors. Telomere erosion has been shown to be accelerated by different factors including environmental factors such as cigarette smoking and chronic alcohol consumption or by psychosocial stress such as childhood maltreatment. In humans, telomere studies have mainly relied on measurements of leukocyte telomere length and it is generally accepted that individuals with short leukocyte telomere length are considered biologically older than those with longer ones. A dysregulation of both innate and adaptive immune systems has been described in schizophrenia patients and other mental diseases supporting the contribution of the immune system to disease symptoms. Thus, it has been suggested that abnormal immune activation with high pro-inflammatory cytokine production in response to still undefined environmental agents such as herpesviruses infections can be involved in the pathogenesis and pathophysiology of schizophrenia. It has been proposed that chronic inflammation and oxidative stress are involved in the course of schizophrenia illness, early onset of cardiovascular disease, accelerated aging, and premature mortality in schizophrenia. Prenatal or neonatal exposures to neurotropic pathogens such as Cytomegalovirus or Toxoplasma gondii have been proposed as environmental risk factors for schizophrenia in individuals with a risk genetic background. Thus, pro-inflammatory cytokines and microglia activation, together with genetic vulnerability, are considered etiological factors for schizophrenia, and support that inflammation status is involved in the course of illness in schizophrenia.

Telomere length and early trauma in schizophrenia

BACKGROUND

Childhood trauma is emerging as a risk factor for schizophrenia, but its mechanism with respect to etiology is unknown. One possible pathway is through leucocyte telomere length (LTL) shortening, a measure of cellular aging associated with trauma. This study examined early trauma and LTL shortening in schizophrenia and considered sex effects.

METHODS

The early trauma inventory (ETI) was administered to 48 adults with DSM-5 schizophrenia and 18 comparison participants. LTL was measured using qPCR.

OUTCOMES

Cases had significantly more global trauma (F=4.10, p<0.01) and traumatic events (F=11.23, p<0.001), but case and control groups had similar LTL (1.91±0.74 and 1.83±0.62: p=0.68). The association of early trauma and LTL differed by sex in cases and controls (Fisher's R: Z<0.05). Significant negative associations were shown in male cases and, conversely, in female controls. For example, physical punishment was associated LTL shortening in males' cases (r=-0.429, p<01). Only female controls showed significant telomere shortening in association with early trauma.

INTERPRETATION

This data confirms the substantial excess of early trauma among schizophrenia cases. There were significant sex-differences in the relationship of the trauma to LTL, with only male cases showing the expected shortening. There were converse sex effects in the control group. Mean LTL was notably similar in cases and controls, despite the trauma-related shortening in male cases, cigarette smoking, older age and chronic illness of the cases. Factors may lengthen LTL in some schizophrenia cases. The converse sex differences in the cases are consistent with findings defective sexual differentiation in schizophrenia, consistent with other findings in the field.

DNA methylation age is not accelerated in brain or blood of subjects with schizophrenia

Individuals with schizophrenia (SZ) exhibit multiple premature age-related phenotypes and die ~20years prematurely. The accelerated aging hypothesis of SZ has been advanced to explain these observations, it posits that SZ-associated factors accelerate the progressive biological changes associated with normal aging. Testing the hypothesis has been limited by the absence of robust, meaningful, and multi-tissue measures of biological age. Recently, a method was described in which DNA methylation (DNAm) levels at 353 genomic sites are used to produce "DNAm age", an estimate of biological age with advantages over existing measures. We used this method and 3 publicly-available DNAm datasets, 1 from brain and 2 from blood, to test the hypothesis. The brain dataset was composed of data from the dorsolateral prefrontal cortex of 232 non-psychiatric control (NPC) and 195 SZ subjects. Blood dataset #1 was composed of data from whole blood of 304 NPC and 332 SZ subjects, and blood dataset #2 was composed of data from whole blood of 405 NPC and 260 SZ subjects. DNAm age and chronological age correlated strongly (r=0.92-0.95, p<0.0001) in both NPC and SZ subjects in all 3 datasets. DNAm age acceleration did not differ between NPC and SZ subjects in the brain dataset (t=0.52, p=0.60), blood dataset #1 (t=1.51, p=0.13), or blood dataset #2 (t=0.93, p=0.35). Consistent with our previous findings from a smaller study of postmortem brains, our findings suggest there is no acceleration of brain or blood aging in SZ and, thus, do not support the accelerated aging hypothesis of SZ.

A widening longevity gap between people with schizophrenia and general population: A literature review and call for action

Individuals with schizophrenia have higher mortality rates than the population at large. General mortality rates have declined in developed countries since the early 1970s, extending average lifespan by nearly a decade. This review of eight longitudinal studies of mortality in schizophrenia found that the mean standardized mortality ratio (SMR, a measure of mortality rate in schizophrenia compared to the general population) increased 37%, from 2.2 in the pre-1970s studies to 3.0 in the post-1970s reports. Major changes in societal stigma, healthcare, and economic policy are urgently warranted to ensure that this vulnerable segment of the population participates in the longevity revolution.

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.

Systemic Biomarkers of Accelerated Aging in Schizophrenia: A Critical Review and Future Directions

BACKGROUND

Schizophrenia is associated with increased physical morbidity and early mortality, suggesting that the aging process may be accelerated in schizophrenia. However, the biological underpinnings of these alterations in aging in schizophrenia are unclear.

METHOD

We conducted a detailed search of peer-reviewed empirical studies to evaluate evidence for accelerated biological aging in schizophrenia based on systemic, age-related biomarkers. We included studies that investigated differences between persons with schizophrenia and healthy comparison subjects in levels of biomarkers known to be associated with aging and examined the relationship of these biomarkers to age in the 2 groups.

RESULTS

Forty-two articles that met our selection criteria were reviewed. Nearly 75% reported abnormal biomarker levels among individuals with schizophrenia, including indices of inflammation, cytotoxicity, oxidative stress, metabolic health, gene expression, and receptor/synaptic function, with medium to large effect sizes reported in many studies. Twenty-nine percent of the studies observed differential age-related decline in schizophrenia. Markers of receptor/synaptic function and gene expression were most frequently differentially related to age in schizophrenia. Schizophrenia patients with greater disease severity and longer illness duration exhibited higher levels of inflammatory and oxidative stress biomarkers and shorter telomere length.

CONCLUSIONS

Most studies show biomarker abnormalities in schizophrenia, and there is some suggestion for accelerated aging. Although definitive interpretation is limited by cross-sectional design of the published reports, findings in the area of gene expression and synaptic function are promising and pave the way for future longitudinal studies needed to fully test this hypothesis.

Common mental disorders and association with telomere length

Telomeres are repeated 5′-TTAGGG-3′ sequences at the end of chromosomes, which maintain genomic stability. Their length is related to a number of diseases that affect humans. Apart from cancer, cardiovascular diseases, diabetes and other, telomere length has been associated with chronic diseases. Chronic mental illness includes various types of mental disorders with the most common being depression, schizophrenia and stress-anxiety. The aim of this review is to summarize the current state of knowledge on the role of telomeres in these disorders and to compare telomere length variations in patients receiving medication and patients not taking treatment. Most studies report reduced telomere length in patients suffering from mental disorders, compared to the general population. Since the factors that can affect telomere length are various, more experiments and investigations are required to understand the general impact of different factors on telomere length.

Leukocyte telomere length variation in different stages of schizophrenia

Recent research has demonstrated that telomere maintenance might be a key integrating point for the cumulative effect of genetic and environmental factors in patients with first-episode psychosis (FEP) and schizophrenia (SCZ). Eighty-one participants with antipsychotic-naïve FEP, 173 with SCZ and 438 HC were enrolled in this study. Psychiatric diagnosis was assessed using the Semi-Structured Clinical Interview for DSM-IV Axis-I (SCID-I). The Positive and Negative Syndrome Scale (PANSS), Young Mania Rating Scale (YMRS) and Calgary Depression Scale for Schizophrenia (CDSS) were used to measure symptoms severity. Telomere length (TL) was determined using a multiplex qPCR assay. After adjustment for age, years of education, and smoking status, we found that patients with SCZ had longer TL (relative ratio (RR) = 1.08) than the HC group (RR = 1.00, Wald χ² = 12.48, p = 0.002). Further, non-remitted SCZ patients presented longer TL (RR = 1.00) compared to remitted SCZ (RR = 0.88, Wald χ² = 7.20, p = 0.007). TL in patients also correlated to psychopathology assessment in terms of total (p = 0.003) and positive PANSS scores (p = 0.001). No correlation with negative PANSS, YMRS, and CDSS or effects of medication was found on TL. Although the exact pathways underlying longer TL in SCZ patients remain unclear, these findings raise more questions than answers and suggest that TL may be of immense value on SCZ progression. Further studies are required to investigate the association of TL in FEP and SCZ.

Shorter telomere length in people with schizophrenia: A preliminary study from Australia

Schizophrenia is a complex mental illness affecting the normal functioning of the brain, interfering with the ability to think, feel and act. It can be conceptualised as a syndrome of accelerated ageing, with early onset of cardiovascular disease and high rates of premature mortality. Telomere attrition increases with oxidative stress and is considered a biomarker of ageing. Previous studies have assessed abnormalities in telomere length in schizophrenia, but the results are inconsistent. The present study used a case-control design to assess whether people with schizophrenia have shortened telomeres, indicative of accelerated ageing. Subjects were all male, aged 25-35years, living in the same urban region of Adelaide, South Australia. Telomere length was measured using a quantitative real-time polymerase chain reaction (PCR) method. We found significantly shorter telomeres in people with schizophrenia relative to healthy controls. This is the first study to show telomere attrition among people with schizophrenia in Australia. Shorter telomere length may indicate the common pathways that schizophrenia shares with other neuropsychiatric and neurodevelopmental disorders associated with increased cellular senescence. Further well-controlled larger studies in people with schizophrenia are required to fully understand (i) the role of variables that have the potential to modulate telomere length such as use of antipsychotic drugs, medical conditions, parental age, smoking, alcohol abuse and use of illicit drugs; (ii) effective treatments to slow telomere erosion and (iii) mechanisms responsible for accelerating and reducing telomere damage.