Cord blood telomere length, telomerase activity and inflammatory markers in pregnancies in women with diabetes or gestational diabetes

Telomere Length in Patients with Gestational Diabetes Mellitus and Normoglycemic Pregnant Women: a Systematic Review and Meta-analysis

We performed a systematic review and meta-analysis of studies assessing telomere length in blood leukocytes or mononuclear cells in women with gestational diabetes mellitus (GDM) and normoglycemic pregnant women (NPW) and their infants. The review protocol was registered in PROSPERO (CRD42022300950). Searches were conducted in PubMed, Embase, LILACS, CNKI, and Wang Fang, from inception through November 2022. The primary outcomes were maternal and offspring telomere length. The Newcastle-Ottawa Scale was used to assess the quality of included studies. Random-effect meta-analyses were applied to estimate standardized mean differences (SMDs) and their 95% confidence interval (CI). The meta-analysis of four studies showed no significant maternal telomere length difference (SMD = -0.80, 95% CI: -1.66, 0.05) in women with GDM compared to NPW. In the sensibility analysis omitting one study with a small sample of women, the telomere length becomes significantly reduced in women with GDM (SMD = -1.10, 95% CI: -2.18, -0.02). GDM patients had increased glucose (SMD = 0.28, 95% CI: 0.09, 0.46) and glycosylated hemoglobin than NPW (SMD = 0.62, 95% CI: 0.23, 1.01) while total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides did not display differences between women with and without GDM. There was no significant difference in cord blood telomere length in offspring from women with GDM and NPW (SMD = 0.11, 95% CI: -0.52, 0.30). Cord blood insulin levels (SMD = 0.59, 95% CI: 0.33, 0.85) and birthweight (SMD = 0.59, 95% CI: 0.39, 0.79) were higher in offspring from pregnant women with GDM than in those from NPW. There were no significant differences in maternal and offspring telomere length between pregnancies with and without GDM.

Investigating the association of prenatal psychological adversities with mother and child telomere length and neurodevelopment

BACKGROUND

Exposure to prenatal maternal psychological adversities can negatively affect the offspring's developing brain. Shortened telomere length (TL) has been implicated as a mechanism for the transgenerational effects of maternal psychological adversities on offspring. This study aimed to determine associations between prenatal psychological stressors and distress with maternal and early life TL, and associations between maternal, newborn and child TL with neurodevelopmental outcomes at 2 years of age.

METHODS

Follow-up TL was measured in a subgroup of African mothers (n = 138) and their newborns (n = 142) and children (n = 96) at 2-years in the Drakenstein Child Health Study. Prenatal symptoms of depression, distress, intimate partner violence, posttraumatic stress-disorder and childhood trauma were measured at 27 weeks gestation. Neurodevelopment was assessed at 2 years using the Bayley Scales of Infant and Toddler Development III. TLs were measured in whole bloods from mothers and their children at 2-years, and cord bloods in newborns.

RESULTS

Maternal prenatal stressors and distress were not significantly associated with TL in mothers or their children at birth or at 2-years. Furthermore, maternal psychological measures were not associated with early-life attrition of TL. Longer TL in children at 2-years was associated (p = 0.04) with higher motor functioning.

LIMITATIONS

Limited numbers of participants and single time-point psychological measures.

CONCLUSIONS

This study is the first to provide information on the association of early life TL with prenatal psychological adversities and neurodevelopmental outcomes in a population of low-income African mothers and their children.

Significance of cell adhesion molecules profile during pregnancy in gestational diabetes mellitus. A systematic review and meta-analysis

Endothelial dysfunction has been considered as a key etiological factor contributed to the development of vascular disease in diabetes mellitus. Serum level of endothelial cell adhesion molecules (AMs) were reported to be increased in GDM and pregnant women with normal glucose tolerance when compared with nonpregnant women. The literature provides limited evidence of endothelial dysfunction in GDM with heterogeneous and contradictory results respect to their possible involvement in maternal, perinatal and future complications. Our objective is to evaluate current evidence on the role of AMs in maternal and perinatal complications in women with GDM. PubMed, Embase, Web of Science, and Scopus databases were searched. We evaluated the studies' quality using the Newcastle-Ottawa scale. Meta-analyses were conducted, and heterogeneity and publication bias were examined. Nineteen relevant studies were finally included, recruiting 765 GDM and 2368 control pregnant women. AMs levels were generally higher in GDM participants showing statistical significance maternal ICAM-1 levels (SMD=0.58, 95% CI= 0.25 to 0.91; p=0.001). Our meta-analysis did not detect significant differences in subgroups or in meta-regression analyses. Future studies are needed to establish the potential role of these biomarkers in GDM and its complications.

Long-term outcomes and potential mechanisms of offspring exposed to intrauterine hyperglycemia

Diabetes mellitus during pregnancy, which can be classified into pregestational diabetes and gestational diabetes, has become much more prevalent worldwide. Maternal diabetes fosters an intrauterine abnormal environment for fetus, which not only influences pregnancy outcomes, but also leads to fetal anomaly and development of diseases in later life, such as metabolic and cardiovascular diseases, neuropsychiatric outcomes, reproduction malformation, and immune dysfunction. The underlying mechanisms are comprehensive and ambiguous, which mainly focus on microbiota, inflammation, reactive oxygen species, cell viability, and epigenetics. This review concluded with the influence of intrauterine hyperglycemia on fetal structure development and organ function on later life and outlined potential mechanisms that underpin the development of diseases in adulthood. Maternal diabetes leaves an effect that continues generations after generations through gametes, thus more attention should be paid to the prevention and treatment of diabetes to rescue the pathological attacks of maternal diabetes from the offspring.

The association between gestational diabetes mellitus and DNA damage in umbilical cord leukocytes and placental samples

Objective(s): To evaluate the relation between gestational diabetes mellitus (GDM) and maternal and/or fetal DNA integrity. Method: 59 pregnant women were classified into two groups on the basis of 75 g oral glucose tolerance test (OGTT) and glycemic profile (GP): Control group (OGTT and GP normal, n = 29) and GDM group (abnormal 75 g OGTT, n = 30). The umbilical cord blood and placental samples obtained from the maternal side were collected at the time of delivery. Alkaline comet assay was performed for the determination of DNA damage. The trial was approved with the protocol number 72867572.050.01.04-299082. Result(s): Body mass index (BMI), weight gain during pregnancy, glycemic means and fetal weight were increased in GDM group compared control group (p = .01, .0001, .04, and .01, respectively). In the GDM group, the number of large-for-gestational-age (LGA) infants was significantly higher compared to the nondiabetic group (p = .04). Tail DNA percentages in placental samples were higher in the GDM group compared to controls (p = .01); however, DNA integrity in umbilical cord leukocytes was similar between the groups (p = 0.1). In contrast to umbilical cord DNA damage, placental DNA damage showed positive correlation with maternal glycemia in the whole group and within each group. The positive association of placental DNA damage and GDM remained after adjusting for age, BMI, smoking, glycemia, gestational age at delivery, fetal weight at delivery, and delivery type (p = .01). Conclusion(s): Placental DNA damage is associated with GDM and placental cells seem to be more vulnerable to DNA damage compared to fetal blood cells.

Prenatal exposure to maternal psychological distress and telomere length in childhood

Telomere length (TL) is a biological marker of cellular aging, and shorter TL in adulthood is associated with increased morbidity and mortality risk. It is likely that these differences in TL are established long before adulthood, and there is growing evidence that TL can reflect prenatal experiences. Although maternal prenatal distress predicts newborn TL, it is unknown whether the relation between prenatal exposure to maternal distress and child TL persists through childhood. The purpose of the current longitudinal, prospective study is to examine the relation between prenatal exposure to maternal distress (perceived stress, depressive symptoms, pregnancy-related anxiety) and TL in childhood. Participants included 102 children (54 girls) and their mothers. Mothers' distress was assessed five times during pregnancy, at 12 weeks postpartum, and at the time of child telomere measurement between 6 and 16 years of age. Maternal distress during pregnancy predicted shorter offspring TL in childhood, even after accounting for postnatal exposure to maternal distress and other covariates. These findings indicate that maternal mental health predicts offspring TL biology later in childhood than previously observed. This study bolsters claims that telomere biology is subject to fetal programming and highlights the importance of supporting maternal mental health during pregnancy.

Maternal opioid use is reflected on leukocyte telomere length of male newborns

Opioid use accelerates normal aging in adults that raises a question on whether it may trans-generationally affect aging and aging biomarkers in the offspring of users as well? In the present research, we investigated the relative telomere length in umbilical cord blood of newborns born to opioid consuming mothers compared to normal controls. Telomere length shortening is a known biomarker of aging and aging related diseases. Its measure at birth or early in life is considered as a predictor of individual health in adulthood. Here, we performed a case-control study to investigate whether maternal opioid use affects newborns relative telomere length (RTL). 57 mother-newborn dyads were included in this study, 30 neonates with opioid using mothers (OM), and 27 with not-opioid using mothers (NOM)). RTL was measured in leukocyte cells genomic DNA using real-time PCR. The correlation of maternal opioid use with neonates telomer length was assessed using logistic regression analysis. The results displayed a significant association between odds ratio of long RTL and maternal opioid use when sensitivity analysis was performed by neonate sex; where the data indicates significantly increased odds ratio of long leukocyte RTL in association with maternal opioid use in male neonates only. Further work is necessary to assess this association in larger samples and test the potential underlying mechanisms for this observation.

Telomere length in healthy newborns is not affected by adverse intrauterine environments

Different intrauterine exposures are associated with different metabolic profiles leading to growth and development characteristics in children and also relate to health and disease patterns in adult life. The objective of this work was to evaluate the impact of four different intrauterine environments on the telomere length of newborns. This is a longitudinal observational study using a convenience sample of 222 mothers and their term newborns (>37 weeks of gestational age) from hospitals in Porto Alegre, Rio Grande do Sul (Brazil), from September 2011 to January 2016. Sample was divided into four groups: pregnant women with Gestational Diabetes Mellitus (DM) (n=38), smoking pregnant women (TOBACCO) (n=52), mothers with small-for-gestational age (SGA) children due to idiopathic intrauterine growth restriction (n=33), and a control group (n=99). Maternal and newborn genomic DNA were obtained from epithelial mucosal cells. Telomere length was assessed by qPCR, with the calculation of the telomere and single copy gene (T/S ratio). In this sample, there was no significant difference in telomere length between groups (p>0.05). There was also no association between childbirth weight and telomere length in children (p>0.05). For term newborns different intrauterine environments seems not to influence telomere length at birth.

Association between maternal urinary manganese concentrations and newborn telomere length: Results from a birth cohort study

OBJECTIVE

Telomere length (TL) is a biomarker for biological aging, and the initial setting of TL at birth is a determinant factor of TL in later life. Newborn TL is sensitive to maternal metals concentrations, while study about the association between maternal manganese (Mn) concentrations and newborn TL was not found. Our study aimed to investigate whether newborn TL is related to maternal Mn concentrations.

METHODS

Data were collected from a birth cohort study of 762 mother-newborn pairs conducted from November 2013 to March 2015 in Wuhan, China. We measured the Mn concentrations in spot urine samples collected during three trimesters by inductively coupled plasma mass spectrometry (ICP-MS) and relative cord blood TL by quantitative real-time polymerase chain reaction (qPCR). We applied multiple informant models to investigate the associations between maternal Mn concentrations and cord blood TL.

RESULTS

The geometric mean of creatinine-corrected urinary Mn concentrations were 1.58 μg/g creatinine, 2.53 μg/g creatinine, and 2.62 μg/g creatinine in the first, second, and third trimester, respectively. After adjusting for potential confounders, a doubling of maternal urinary Mn concentration during the second trimester was related to a 2.10% (95% CI: 0.25%, 3.99%) increase in cord blood TL. Mothers with the highest tertile of urinary Mn concentrations during the second trimester had a 9.67% (95% CI: 2.13%, 17.78%) longer cord blood TL than those with the lowest tertile. This association was more evident in male infants. No relationship was found between maternal urinary Mn concentrations and cord blood TL during the first and third trimesters in our study.

CONCLUSIONS

Our findings suggested that maternal Mn concentration during the second trimester was positively associated with newborn TL. These results might provide an epidemiology evidence on the protective role of maternal Mn for newborn TL and offer clues for the early prevention of telomere shortening related diseases.

Telomere length determinants in childhood

Telomere length (TL) is a dynamic marker that reflects genetic predispositions together with the environmental conditions of an individual. It is closely related to longevity and a number of pathological conditions. Even though the extent of telomere research in children is limited compared to that of adults, there have been a substantial number of studies providing first insights into child telomere biology and determinants. Recent discoveries revealed evidence that TL is, to a great extent, determined already in childhood and that environmental conditions in adulthood have less impact than first believed. Studies have demonstrated that large inter-individual differences in TL are present among newborns and are determined by diverse factors that influence intrauterine development. The first years of child growth are associated with high cellular turnover, which results in fast shortening of telomeres. The rate of telomere loss becomes stable in early adulthood. In this review article we summarise the existing knowledge on telomere dynamics during the first years of childhood, highlighting the conditions that affect newborn TL. We also warn about the knowledge gaps that should be filled to fully understand the regulation of telomeres, in order to implement them as biomarkers for use in diagnostics or treatment.

Diabetes, metabolic disease, and telomere length

Telomeres are regions of repetitive nucleotide sequences at the ends of chromosomes. Telomere length is a marker of DNA damage, which is often considered a biomarker for biological ageing, and has also been linked with cardiovascular disease, diabetes, and cancer. Emerging studies have highlighted the role of genetic and environmental factors, and explored the effect of modulating telomere length. We provide an overview of studies to date on diabetes and telomere length, and compare different methods and assays for evaluating telomere length and telomerase activity. We highlight the limitations of current studies and areas that warrant further research to unravel the link between diabetes and telomere length. The value of adding telomere length to clinical risk factors to improve risk prediction of diabetes and related complications also merits further investigation.

The metabolic syndrome in pregnancy and its association with child telomere length

AIMS/HYPOTHESIS

The aim of this study was to determine whether presence of the metabolic syndrome in pregnancy associates with child telomere length or child anthropometry (weight, BMI) and BP, measured at 10 years of age.

METHODS

The Screening for Pregnancy Endpoints study (SCOPE) was a multicentre, international prospective cohort of nulliparous pregnant women recruited from Australia, New Zealand, Ireland and the UK (N = 5628). The current analysis is a 10 year follow-up of SCOPE pregnant women and their children, from the Australian cohort. Clinical data collected at 14-16 weeks' gestation during the SCOPE study were used to diagnose the metabolic syndrome using IDF criteria. Telomere length, a biomarker of ageing, was assessed by quantitative PCR from children's saliva collected at 10 years of age.

RESULTS

In women who completed follow-up (n = 255), 20% had the metabolic syndrome in pregnancy. After adjusting for a range of confounders, children of mothers who had the metabolic syndrome in pregnancy had 14% shorter telomeres than children of mothers without the metabolic syndrome in pregnancy (mean difference -0.36 [95% CI -0.74, 0.01]). Height- and weight-for-age, and BMI z scores were similar in children of mothers who did and did not have the metabolic syndrome during pregnancy.

CONCLUSIONS/INTERPRETATION

Children of mothers who had the metabolic syndrome in pregnancy have shorter telomeres, a biomarker of accelerated ageing. These findings warrant further studies in larger cohorts of children, as well as investigations into whether telomere length measured in cord blood associates with telomere length in childhood.

Maternal diabetes and the risk of feeding and eating disorders in offspring: a national population-based cohort study

INTRODUCTION

Previous studies have suggested that maternal diabetes may have programming effect on fetal brain development. However, little is known about the association between maternal diabetes and neurodevelopmental disorders in offspring that mainly manifest in infancy or early childhood. We aimed to examine the association between maternal diabetes before or during pregnancy and feeding and eating disorders (FED) in offspring.

RESEARCH DESIGN AND METHODS

This population-based cohort study included 1 193 891 singletons born in Denmark during 1996-2015. These children were followed from birth until the onset of FED, the sixth birthday, death, emigration, or 31 December 2016, whichever came first. Relative risk of FED was estimated by HRs using Cox proportional hazards model.

RESULTS

A total of 40 867 (3.4%) children were born to mothers with diabetes (20 887 with pregestational diabetes and 19 980 with gestational diabetes). The incidence rates of FED were 6.8, 4.6 and 2.9 per 10 000 person-years among children of mothers with pregestational diabetes, gestational diabetes and no diabetes, respectively. Offspring of mothers with diabetes had a 64% increased risk of FED (HR 1.64; 95% CI 1.36 to 1.99; p<0.001). The HR for maternal pregestational diabetes and gestational diabetes was 2.01 (95% CI 1.59 to 2.56; p<0.001) and 1.28 (95% CI 0.95 to 1.72; p=0.097), respectively. The increased risk was more pronounced among offspring of mothers with diabetic complications (HR 2.97; 95% CI 1.54 to 5.72; p=0.001).

CONCLUSIONS

Maternal diabetes was associated with an increased risk of FED in offspring in infancy and early childhood. Our findings can inform clinical decisions for better management of maternal diabetes, in particular before pregnancy, which can reduce early neurodevelopmental problems in the offspring.

Telomere length: how the length makes a difference

Telomerase is perceived as an immortality enzyme that might provide longevity to cells and whole organisms. Importantly, it is generally inactive in most somatic cells of healthy, adult men. Consequently, its substrates, i.e. telomeres, get shorter in most human cells with time. Noteworthy, cell life limitation due to telomere attrition during cell divisions, may not be as bad as it looks since longer cell life means longer exposition to harmful factors. Consequently, telomere length (attrition rate) becomes a factor that is responsible for inducing the signaling that leads to the elimination of cells that lived long enough to acquire severe damage. It seems that telomere length that depends on many different factors (including telomerase activity but also genetic factors, a hormonal profile that reflects sex, etc.) might become a useful marker of aging and exposition to stress. Thus in the current paper, we review the factors that affect telomere length in human cells focusing on sex that all together with different environmental and hormonal regulations as well as parental aspect affect telomere attrition rate. We also raise some limitations in the assessment of telomere length that hinders a trustworthy meta-analysis that might lead to acknowledgment of the real value of this parameter.

Early-life Programming of Type 2 Diabetes Mellitus: Understanding the Association between Epigenetics/Genetics and Environmental Factors

Type 2 Diabetes Mellitus is an increasing public health problem that poses a severe social and economic burden affecting both developed and developing countries. Defects in insulin signaling itself are among the earliest indications that an individual is predisposed to the development of insulin resistance and subsequently Type 2 Diabetes Mellitus. To date, however, the underlying molecular mechanisms which result in resistance to the actions of insulin are poorly understood. Furthermore, it has been shown that maternal obesity is associated with an increased risk of obesity and insulin resistance in the offspring. However, the genetic and/or epigenetic modifications within insulin-sensitive tissues such as the liver and skeletal muscle, which contribute to the insulin-resistant phenotype, still remain unknown. More importantly, a lack of in-depth understanding of how the early life environment can have long-lasting effects on health and increased risk of Type 2 Diabetes Mellitus in adulthood poses a major limitation to such efforts. The focus of the current review is thus to discuss recent experimental and human evidence of an epigenetic component associated with components of nutritional programming of Type 2 Diabetes Mellitus, including altered feeding behavior, adipose tissue, and pancreatic beta-cell dysfunction, and transgenerational risk transmission.

Adverse Birth Outcomes and Birth Telomere Length: A Systematic Review and Meta-Analysis

OBJECTIVES

To synthesize previous findings on the difference in birth telomere length between newborns with and without intrauterine growth restriction (IUGR) or with and without preterm birth.

STUDY DESIGN

We systematically searched 3 databases (PubMed, Embase, and Web of Science) for publications that examined the relationships of IUGR or preterm birth with birth telomere length. We conducted meta-analysis to pool the estimated difference in birth telomere length either between IUGR and non-IUGR or between preterm birth and full-term birth. Subgroup analyses were conducted by tissues (newborn blood vs placenta) and techniques used for telomere length measurement (quantitative polymerase chain reaction [qPCR] vs telomere restriction fragment).

RESULTS

We included 11 articles on comparing birth telomere length between IUGR (combined n = 227) and non-IUGR (n = 1897) and 7 articles on comparing birth telomere length between preterm birth (n = 182) and full-term birth (n = 1320). We found IUGR was associated with shorter birth telomere length only when birth telomere length was measured in placenta (pooled standardized mean difference [SMD] = -0.85; 95% CI -1.13 to -0.57; IUGR/non-IUGR n = 87/173), but not in newborn blood (pooled SMD = 0.00, 95% CI -0.18 to 0.19; IUGR/non-IUGR n = 148/1733). Birth telomere length was significantly longer in preterm birth than in full-term birth when birth telomere length was measured by qPCR (pooled SMD = 0.40, 95% CI 0.18-0.63; preterm birth/full-term birth n = 137/682) but not by telomere restriction fragment (pooled SMD = 0.05, 95% CI -0.29 to 0.38; preterm birth/full-term birth n = 44/444).

CONCLUSIONS

IUGR is associated with shorter placental telomere length and preterm birth is associated with longer birth telomere length measured by qPCR.

Metformin and insulin treatment prevent placental telomere attrition in boys exposed to maternal diabetes

Shortened leukocyte and placental telomeres associated with gestational diabetes mellitus (GDM) suggest this exposure triggers telomere attrition contributing to adverse outcomes. We applied high resolution Single Telomere Length Analysis (STELA) to placenta from GDM pregnancies with different treatment pathways to determine their effectiveness at preventing telomere attrition. Differences in telomere length between control (N = 69), GDM lifestyle intervention (n = 14) and GDM treated with metformin and/or insulin (n = 17) was tested by Analysis of Covariance (ANCOVA) followed by group comparisons using Fisher's least significant difference. For male placenta only, there were differences in mean telomere length (F(2,54) = 4.98, P = 0.01) and percentage of telomeres under 5 kb (F(2,54) = 4.65, P = 0.01). Telomeres were shorter in the GDM lifestyle intervention group compared to both controls (P = 0.02) and medically treated pregnancies (P = 0.003). There were more telomeres under 5 kb in the GDM lifestyle intervention group compared to the other two groups (P = 0.03 and P = 0.004). Although further work is necessary, we suggest that early adoption of targeted medical treatment of GDM pregnancies where the fetus is known to be male may be an effective strategy for ameliorating adverse outcomes for children.

BCL2 and miR-181a transcriptional alterations in umbilical-cord blood cells can be putative biomarkers for obesity

Several findings suggest that in utero stressor stimuli can alter fetal development by promoting transcriptional changes, and predisposing the neonate to diseases later in life. This study aimed to investigate whether a hyperglycemic environment in pregnant women with gestational diabetes mellitus (GDM) is able to cause fetal genetic alterations and predispose neonates to obesity. Transcriptional alteration of SIRT1, TP53 and BCL2 genes, miR-181a (a SIRT1 or BCL2 regulator) and telomere length were evaluated in placental and umbilical-cord blood cells. Healthy (HP; n = 20) and GDM (n = 20) pregnant women and their respective neonates were included in the study. Additionally, obese (n = 20) and eutrophic (n = 20) adults also participated as reference populations. Gene expression data showed down-regulation of BCL2 in umbilical-cord and peripheral blood cells from GDM neonates and obese adults, respectively. The miR-181a was down-regulated only in umbilical-cord blood cells of GDM neonates. Telomere length presented no significant difference. In conclusion, our study demonstrated that the GDM hyperglycemic intrauterine environment promotes transcriptional alterations in BCL2 and miR-181a in neonate umbilical-cord blood cells. Furthermore, both GDM neonates and obese subjects share the same transcriptional alteration in BCL2. Considering the relationship between obesity development and the functions regulated by these two genes, BCL2 and miR-181a could be adopted as potential biomarkers for childhood obesity. However, further study designs are recommended to confirm this hypothesis.

Exposure to different intrauterine environments: implications for telomere attrition in early life

Objective: Studies focusing on telomere attrition in newborns and what factors could be involved in this issue are sparse; most reports have been in adult populations. Thereby, the aim of this study was to present an overview of what is currently known about the relationship between environmental exposure of the fetus during pregnancy and telomere length outcomes in early life. Methods: The MEDLINE (via PubMed) and Bireme databases were searched for studies published until 1 June 2016. Studies that reported telomere length measurement from birth to age 1 year were included. Results: Fifteen articles were selected that evaluated possible relationships between maternal smoking, hyperglycemia, hypertension, sleep apnea, psychological stress, folate concentration in early pregnancy, and radiation, in addition to small-for-gestational-age status and preterm birth. We found that sleep apnea, psychological stress, and folate concentration in early pregnancy were associated with telomere shortening in the newborn. No association was found with radiation, small-for-gestational-age status, or preterm birth. Results for maternal smoking, hyperglycemia, and hypertension were conflicting, and further studies should be considered. Conclusion: The actual clinical implications of these findings have yet to be investigated.

Telomere length is reduced in 9- to 16-year-old girls exposed to gestational diabetes in utero

AIMS/HYPOTHESIS

Shortened telomere length is a marker of cell damage and is associated with oxidative stress, chronic inflammation and metabolic disease. We hypothesised that the offspring of women with gestational diabetes mellitus (GDM) with increased risk of cardiovascular and metabolic diseases might exhibit shorter telomere length.

METHODS

We investigated telomere length in 439 GDM and 469 control group offspring, aged between 9 and 16 years, recruited from the Danish National Birth Cohort. Relative telomere length was measured in peripheral blood DNA (n = 908) using a quantitative PCR approach. Multivariate regression analysis was used to investigate the association between mothers' GDM status and telomere length in the offspring.

RESULTS

Female offspring had longer telomeres than males. Offspring of mothers with GDM had significantly shorter telomere length than control offspring, but this difference was observed only in girls. There was a negative association between telomere length and GDM exposure among the female offspring (14% shorter telomeres, p = 0.003) following adjustment for the age of the offspring. Telomere length in female offspring was negatively associated with fasting insulin levels and HOMA-IR (p = 0.03). Maternal age, smoking, gestational age, birthweight and the offspring's anthropometric characteristics were not associated with telomere length (p ≥ 0.1).

CONCLUSIONS/INTERPRETATION

The 9- to 16-year-old girls of mothers with GDM had shorter telomeres than those from the control population. Further studies are needed to understand the extent to which shortened telomere length predicts and/or contributes to the increased risk of disease later in life among the offspring of women with GDM.

The fetal programming of telomere biology hypothesis: an update

Research on mechanisms underlying fetal programming of health and disease risk has focused primarily on processes that are specific to cell types, organs or phenotypes of interest. However, the observation that developmental conditions concomitantly influence a diverse set of phenotypes, the majority of which are implicated in age-related disorders, raises the possibility that such developmental conditions may additionally exert effects via a common underlying mechanism that involves cellular/molecular ageing-related processes. In this context, we submit that telomere biology represents a process of particular interest in humans because, firstly, this system represents among the most salient antecedent cellular phenotypes for common age-related disorders; secondly, its initial (newborn) setting appears to be particularly important for its long-term effects; and thirdly, its initial setting appears to be plastic and under developmental regulation. We propose that the effects of suboptimal intrauterine conditions on the initial setting of telomere length and telomerase expression/activity capacity may be mediated by the programming actions of stress-related maternal-placental-fetal oxidative, immune, endocrine and metabolic pathways in a manner that may ultimately accelerate cellular dysfunction, ageing and disease susceptibility over the lifespan. This perspectives paper provides an overview of each of the elements underlying this hypothesis, with an emphasis on recent developments, findings and future directions.This article is part of the theme issue 'Understanding diversity in telomere dynamics'.

Leukocyte Telomere Length in the Neonatal Offspring of Mothers with Gestational and Pre-Gestational Diabetes

Aims

Telomeres undergo shortening with cell division, accelerated by increased oxidative stress. We aimed to demonstrate shortened telomeres in the offspring of mothers who have diabetes as a consequence of exposure to increased oxidative stress during intrauterine development.

Methods

We examined the level of glycaemia (glucose, HbA1c, fructosamine), oxidative stress (lipid peroxidation) and the levels of antioxidant enzymes (Superoxide dismutase (SOD) and Selenium dependent glutathione peroxidase) and correlate these findings with mean telomere length (TL) in maternal and foetal blood in groups of pregnant women with pre-gestational diabetes (PGD), gestational diabetes (GD) and a euglycaemic control group.

Results

Foetal and maternal glucose, maternal HbA1c, and foetal insulin and C-peptide were higher in the PGD group with the GD group being intermediate. Markers of oxidative stress did not vary between groups with the exception of foetal SOD activity that was highest in the GD group. There were no detectable differences in maternal or foetal TL between study groups. An exploratory analysis looking at correlations between glycaemic and oxidative stress parameters and TL revealed a negative correlation between maternal and foetal glucose and TL across the whole study population. This relationship held for the short-term marker of glycaemic control, fructosamine.

Conclusions

We were unable to show significant telomere shortening in the offspring of mothers with PGD or GD. Exploratory analysis revealed a relationship between foetal TL and short-term glycaemia particularly in PGD. It is possible that increased telomerase activity can compensate for long-term increased oxidative stress but not for short-term dysglycaemia.

Hyperglycemia Differentially Affects Maternal and Fetal DNA Integrity and DNA Damage Response

Objective: Investigate the DNA damage and its cellular response in blood samples from both mother and the umbilical cord of pregnancies complicated by hyperglycemia. Methods: A total of 144 subjects were divided into 4 groups: normoglycemia (ND; 46 cases), mild gestational hyperglycemia (MGH; 30 cases), gestational diabetes mellitus (GDM; 45 cases) and type-2 diabetes mellitus (DM2; 23 cases). Peripheral blood mononuclear cell (PBMC) isolation and/or leukocytes from whole maternal and umbilical cord blood were obtained from all groups at delivery. Nuclear and mitochondrial DNA damage were measured by gene-specific quantitative PCR, and the expression of mRNA and proteins involved in the base excision repair (BER) pathway were assessed by real-time qPCR and Western blot, respectively. Apoptosis was measured in vitro experiments by caspase 3/7 activity and ATP levels. Results: GDM and DM2 groups were characterized by an increase in oxidative stress biomarkers, an increase in nuclear and mitochondrial DNA damage, and decreased expression of mRNA (APE1, POLβ and FEN1) and proteins (hOGG1, APE1) involved in BER. The levels of hyperglycemia were associated with the in vitro apoptosis pathway. Blood levels of DNA damage in umbilical cord were similar among the groups. Newborns of diabetic mothers had increased expression of BER mRNA (APE1, POLβ and FEN1) and proteins (hOGG1, APE1, POLβ and FEN1). A diabetes-like environment was unable to induce apoptosis in the umbilical cord blood cells. Conclusions: Our data show relevant asymmetry between maternal and fetal blood cell susceptibility to DNA damage and apoptosis induction. Maternal cells seem to be more predisposed to changes in an adverse glucose environment. This may be due to differential ability in upregulating multiple genes involved in the activation of DNA repair response, especially the BER mechanism. However if this study shows a more effective adaptive response by the fetal organism, it also calls for further studies to determine the limit of this response that definitely changes the fate of a fetus under these conditions of cellular stress.

Post-transcriptional down regulation of ICAM-1 in feto-placental endothelium in GDM

Maternal gestational diabetes (GDM) is associated with hyperglycaemia and hyperinsulinemia in the fetal circulation which consequently may induce endothelial dysfunction in the feto-placental vasculature. In fact, feto-placental vasculature reveals various morphological changes in response to GDM. The cell adhesion molecules (CAMs) ICAM-1, VCAM-1 and E-selectin promote attachment and trans-endothelial migration of leukocytes, and are up regulated in inflammation and endothelial dysfunction. Thus, we hypothesized that the GDM environment upregulates ICAM-1, VCAM-1 and E-selectin in the feto-placental endothelium. We isolated primary feto-placental endothelial cells (fpEC) after normal (n=18) and GDM pregnancy (n=11) and analyzed mRNA (RT-qPCR) and protein expression (Immunoblot) of ICAM-1, VCAM-1 and E-selectin. While other CAMs were unchanged on mRNA and protein levels, ICAM-1 protein was decreased by GDM. Further analysis revealed also a decrease in the release of soluble ICAM-1 (sICAM-1), whose levels correlated negatively with maternal BMI. We conclude that this reduction of ICAM-1 protein species is the result of post-translational regulation, since ICAM-1 mRNA expression was unchanged. In fact, miRNAs targeting ICAM-1 were upregulated in GDM fpEC. Immunohistochemistry showed weaker ICAM-1 staining in the placental endothelium after GDM pregnancies, and demonstrated ICAM-1 binding partners CD11a and CD18 expressed on leukocytes in fetal circulation and on placental tissue macrophages. This study identified reduction of ICAM-1 protein in fpEC in GDM pregnancy, which was regulated post-transcriptionally. Low ICAM-1 protein production may represent a protective, placenta-specific mechanism to avoid leukocyte transmigration into the placenta in response to GDM.

Reduced telomere length is not associated with early signs of vascular aging in young men born after intrauterine growth restriction: a paradox?

OBJECTIVE

The mechanisms that increase cardiovascular risk in individuals born small for gestational age (SGA) are not well understood. Telomere shortening has been suggested to be a predictor of disease onset. Our aim was to determine whether impaired intrauterine growth is associated with early signs of vascular aging and whether telomere length could be a biomarker of this pathway.

METHODS

One hundred and fourteen healthy young men born SGA or after normal pregnancy [appropriate for gestational age (AGA)] were enrolled. Patient data were gathered from questionnaires and clinical exams, including blood pressure (BP) measurement routine laboratory analyses, and carotid intima-media thickness (cIMT). Leukocyte telomere length (LTL) was assessed by quantitative PCR. Birth data were obtained from medical records.

RESULTS

The SGA group had significantly higher pulse pressure and cIMT, and a trend to increased SBP and heart rate in comparison to the AGA group. Interestingly, SGA men exhibited a 42% longer LTL than the AGA group. LTL was inversely associated with age, BMI, BP and birth parameters. In multiple regression analysis, BMI was the key determinant of SBP and cIMT.

CONCLUSION

Young men born SGA show early signs of vascular aging. Unexpectedly, in our cohort, the SGA group had longer telomeres than the normal controls. Although longer telomeres are predictive of better health in the future, our findings could indicate a faster telomere attrition rate and probable early onset of cardiovascular risk in SGA participants. Follow-up of this cohort will clarify hypothesis and validate telomere dynamics as indicators of future health risks.

Telomere length in the two extremes of abnormal fetal growth and the programming effect of maternal arterial hypertension

We tested the hypothesis that leukocyte telomere length (LTL) is associated with birth weight in both extremes of abnormal fetal growth: small (SGA) and large for gestational age newborns (LGA). Clinical and laboratory variables of the mothers and the neonates were explored; 45 newborns with appropriate weight for gestational age (AGA), 12 SGA and 12 LGA were included. Whether the differences might be explained by variation in OBFC1 (rs9419958) and CTC1 (rs3027234) genes associated with LTL was determined. A significant association between birth weight and LTL was observed; LTL was significantly shorter in LGA newborns (1.01 ± 0.12) compared with SGA (1.73 ± 0.19) p < 0.005, mean ± SE. Maternal (Spearman R = −0.6, p = 0.03) and neonatal LTL (R = −0.25, p = 0.03) were significantly and inversely correlated with maternal history of arterial hypertension in previous gestations. Neonatal LTL was not significantly associated with either rs9419950 or rs3027234, suggesting that the association between neonatal LTL and birth weight is not influenced by genetic variation in genes that modify the interindividual LTL. In conclusion, telomere biology seems to be modulated by abnormal fetal growth; modifications in telomere length might be programmed by an adverse environment in utero.

DNA damage and its cellular response in mother and fetus exposed to hyperglycemic environment

The increased production of reactive oxygen species (ROS) plays a key role in pathogenesis of diabetic complications. ROS are generated by exogenous and endogenous factors such as during hyperglycemia. When ROS production exceeds the detoxification and scavenging capacity of the cell, oxidative stress ensues. Oxidative stress induces DNA damage and when DNA damage exceeds the cellular capacity to repair it, the accumulation of errors can overwhelm the cell resulting in cell death or fixation of genome mutations that can be transmitted to future cell generations. These mutations can lead to and/or play a role in cancer development. This review aims at (i) understanding the types and consequences of DNA damage during hyperglycemic pregnancy; (ii) identifying the biological role of DNA repair during pregnancy, and (iii) proposing clinical interventions to maintain genome integrity. While hyperglycemia can damage the maternal genetic material, the impact of hyperglycemia on fetal cells is still unclear. DNA repair mechanisms may be important to prevent the deleterious effects of hyperglycemia both in mother and in fetus DNA and, as such, prevent the development of diseases in adulthood. Hence, in clinical practice, maternal glycemic control may represent an important point of intervention to prevent the deleterious effects of maternal hyperglycemia to DNA.

Placental telomere length decreases with gestational age and is influenced by parity: a study of third trimester live-born twins

BACKGROUND

In contrast to the postnatal period, little is known about telomere length (TL) during prenatal life. The decrease in placental TL remains unknown, although intra uterine growth retardation and preeclampsia are associated with shorter placental TL. The aim of this study is to assess the decrease of placental TL during the third trimester of gestation and to explore the role of potential "growth influencing factors".

METHODS

The study sample consisted of 329 live-born twins from the East Flanders Prospective Twin Survey. TL was determined using a multiplex quantitative PCR method. Gestational age, sex, birth order, placental characteristics, parity, maternal and paternal age, diabetes, hypertension, smoking, alcohol use, and socio economic status (SES) were considered "growth influencing factors". Bivariable multilevel regression analysis with "growth influencing factors" was performed.

RESULTS

Placental TL ranged from 4.3 kbp to 84.4 kbp with a median of 10.8 kbp. Ln(TL) decreased in a linear fashion with an estimated TL decreasing from 13.98 kbp at 28 weeks to 10.56 kbp at 42 weeks. The regression coefficient of gestational age became smaller if considered together with SES (b = -0.017; p = 0.08) or diabetes (b = -0.018; p = 0.07) and bigger if considered together with parity (b = -0.022; p = 0.02), indicating that part of the association between gestational age and telomere length is explained by these three confounding factors.

CONCLUSION

Placental TL decreases during the third trimester of gestation of live-born twins with approximately 25% indicating that telomere shortening may play a role in aging of the placenta.

Reduced fetal telomere length in gestational diabetes

Gestational diabetes mellitus (GDM) is an important complication of pregnancy that poses significant threats to women and their offspring. Telomere length shortens as cellular damage increases and is associated with metabolic diseases. Telomere length in fetal leucocytes was determined in 82 infants of women with GDM (N = 82) and 65 normal pregnant women (N = 65). Women with preeclampsia (N = 45) and gestational hypertension (N = 23) were also studied. In the GDM group, telomere length was significantly shorter than normal pregnancy (P = 0.028), but there were no significant differences in fetal telomere length between preeclampsia and normal pregnancy (P = 0.841) and between gestational hypertension and normal pregnancy (P = 0.561). Regression analysis revealed that fetal telomere length was significantly associated with intrauterine exposure to GDM (P = 0.027 after adjustment for maternal age, gestational age at delivery, birth weight and fetal gender). Shortened telomere length may increase the risk of metabolic diseases in adulthood of GDM offspring.

Developmental ORIgins of Healthy and Unhealthy AgeiNg: the role of maternal obesity--introduction to DORIAN

Europe has the highest proportion of elderly people in the world. Cardiovascular disease, type 2 diabetes, sarcopenia and cognitive decline frequently coexist in the same aged individual, sharing common early risk factors and being mutually reinforcing. Among conditions which may contribute to establish early risk factors, this review focuses on maternal obesity, since the epidemic of obesity involves an ever growing number of women of reproductive age and children, calling for appropriate studies to understand the consequences of maternal obesity on the offspring's health and for developing effective measures and policies to improve people's health before their conception and birth. Though the current knowledge suggests that the long-term impact of maternal obesity on the offspring's health may be substantial, the outcomes of maternal obesity over the lifespan have not been quantified, and the molecular changes induced by maternal obesity remain poorly characterized. We hypothesize that maternal insulin resistance and reduced placental glucocorticoid catabolism, leading to oxidative stress, may damage the DNA, either in its structure (telomere shortening) or in its function (via epigenetic changes), resulting in altered gene expression/repair, disease during life, and pathological ageing. This review illustrates the background to the EU-FP7-HEALTH-DORIAN project.

Prenatal stress, telomere biology, and fetal programming of health and disease risk

A substantial body of epidemiological, clinical, cellular, and molecular evidence converges to suggest that conditions during the intrauterine period of life play a critical role in developmental programming to influence subsequent health and susceptibility for common, complex disorders. Elucidation of the biological mechanisms underlying these effects is an area of considerable interest and investigation, and it is important to determine whether these mechanisms are distinct for different health outcomes or whether there are some common underlying pathways that may account for the effects of disparate prenatal and early postnatal conditions on various health and disease risk phenotypes. We propose that telomere biology may represent a common underlying mechanism connecting fetal programming and subsequent health outcomes. It appears that the initial establishment of telomere length and regulation of telomere homeostasis may be plastic and receptive to the influence of intrauterine and other early life conditions. Moreover, telomere homeostasis in various cell types may serve as a fundamental integrator and regulator of processes underlying cell genomic integrity and function, aging, and senescence over the life span. We advance the hypothesis that context- and time-inappropriate exposures to various forms of physiological stress (maternal-placental-fetal endocrine aberrations and immune, inflammatory, and oxidative stresses) during the intrauterine period of development may alter or program the telomere biology system in a manner that accelerates cellular dysfunction, aging, and disease susceptibility over the life span.

Leukocyte telomere length in HIV-infected pregnant women treated with antiretroviral drugs during pregnancy and their uninfected infants

OBJECTIVES

HIV disease can lead to accelerated telomere attrition, although certain drugs used as part of antiretroviral therapy (ART) can inhibit telomerase reverse transcriptase activity. This could in turn lead to shorter telomeres. We hypothesized that HIV and ART exposure would be associated with shorter leukocyte telomere length (TL) in exposed mother/infant pairs compared with controls.

METHODS

In these retrospective and prospective observational cohort studies, TL was evaluated in peripheral blood leukocytes obtained from HIV-infected pregnant women treated with ART and their uninfected infants, and compared with HIV untreated (retrospective cohort) or HIV mothers and their infants (prospective cohort).

RESULTS

In HIV-infected ART-exposed mothers, leukocyte TL was not significantly shorter than that in HIV untreated mothers or HIV controls, nor was their infants' TL significantly different. Cord blood of ART-exposed infants exhibited TL shorter than that from infants born to HIV-negative mothers. Placenta also showed evidence of shorter TL after adjustment for relevant covariates. Factors associated with shorter maternal and infant TL included smoking and the use of drugs of addiction in pregnancy.

CONCLUSIONS

These results suggest that maternal HIV infection or exposure to ART has minimal effect on infant leukocyte TL, a reassuring finding. In contrast, tissues that express higher telomerase activity such as umbilical cord blood and placenta appear comparatively more affected by ART. Smoking and the use of drugs of addiction have a negative impact on maternal and infant leukocyte TL, possibly through oxidative telomere damage.

Low-grade inflammation in young adults exposed to intrauterine hyperglycemia

AIM

To investigate associations between fetal exposure to intrauterine hyperglycemia and plasma concentrations of interleukin-6 (IL-6) and high sensitivity C-reactive protein (hs-CRP) in adult offspring.

METHOD

We studied 597 offspring, aged 18-27 years, from four different groups concerning exposure to intrauterine hyperglycemia and genetic predisposition to type 2 diabetes (offspring of women with: gestational diabetes mellitus (GDM), risk factors for GDM but normal glucose tolerance, type 1 diabetes and women from the background population, respectively). The participants were characterized by fasting plasma levels of IL-6 and hs-CRP, a 75 g oral glucose tolerance test and anthropometric measurements.

RESULTS

No association between intrauterine exposure to hyperglycemia and levels of IL-6 and hs-CRP in the offspring was found. In contrast maternal overweight (body mass index ≥ 25 kg/m(2)) was positively associated with levels of both IL-6 and hs-CRP (p for both=0.003). Offspring who had already developed overweight or conditions of abnormal glucose tolerance were characterized by higher levels of IL-6 and hs-CRP compared with the remaining offspring (all p<0.007).

CONCLUSION

Maternal overweight but not exposure to intrauterine hyperglycemia was associated with low-grade inflammation in adult offspring.