Preterm birth and subsequent insulin sensitivity: a systematic review

Preterm Birth, Small for Gestational Age, and Large for Gestational Age and the Risk of Atrial Fibrillation Up to Middle Age

Importance

Adverse birth outcomes, including preterm birth, small for gestational age (SGA), and large for gestational age (LGA) are associated with increased risks of hypertension, ischemic heart disease, stroke, and heart failure, but knowledge regarding their associations with atrial fibrillation (AF) is limited and inconsistent.

Objective

To investigate whether preterm birth, SGA, or LGA are associated with increased risks of AF later in life.

Design, Setting, and Participants

This multinational cohort study included Danish, Swedish, and Finnish national health registries. Live singleton births in Denmark from 1978 through 2016, in Sweden from 1973 through 2014, and in Finland from 1987 through 2014, who were followed up until December 31, 2016, in Denmark, December 31, 2021, in Sweden, and December 31, 2014, in Finland were included. Data analyses were performed between January 2021 and August 2022.

Exposures

Preterm birth (less than 37 gestational weeks), SGA (less than 10th percentile birth weight for gestational age), and LGA (more than 90th percentile birth weight for gestational age) identified from medical birth registers.

Main Outcomes and Measures

Diagnosis of AF obtained from nationwide inpatient and outpatient registers. The study team ran multivariable Cox proportional hazard models and flexible parametric survival models to estimate hazard ratios (HRs) and 95% CIs for AF according to preterm birth, SGA, and LGA. Sibling analyses were conducted to control for unmeasured familial factors.

Results

The cohort included 8 012 433 study participants (maximum age, 49 years; median age, 21 years; male, 51.3%). In 174.4 million person-years of follow-up, 11 464 participants had a diagnosis of AF (0.14%; median age, 29.3 years). Preterm birth and LGA were associated with increased AF risk in both the full population cohort and in the sibling analyses; the multivariate HRs from the cohort analyses were 1.30 (95% CI, 1.18-1.42) and 1.55 (95% CI, 1.46-1.63), respectively. Preterm birth was more strongly associated with AF in childhood than in adulthood. Children born SGA had an increased risk of AF in the first 18 years of life but not afterwards.

Conclusions and Relevance

Preterm births and LGA births were associated with increased risks of AF up to middle age independently of familial confounding factors. Individuals born SGA had an increased AF risk only during childhood.

Impact of Suspected Preterm Labor during Pregnancy on Cardiometabolic Profile and Neurodevelopment during Childhood: A Prospective Cohort Study Protocol

Introduction: Suspected preterm labor (SPL), defined as the presence of regular and painful uterine contractions and cervical shortening, represents a prenatal insult with potential long-term consequences. However, despite recent evidence demonstrating suboptimal neurodevelopment at 2 years in this population, it remains underestimated as a significant risk factor for neurodevelopmental disorders or other chronic diseases. The aim of this study is to assess the impact of suspected preterm labor during pregnancy on cardiometabolic profile and neurodevelopment during childhood (6–8 years). Methods and analysis: Prospective cohort study including children whose mothers suffered suspected preterm labour during pregnancy and paired controls. Neurodevelopmental, cardiovascular, and metabolic assessments will be performed at 6–8 years of age. A trained psychologist will carry out the neurodevelopment assessment including intelligence, visual perception, and behavioral assessment. Body composition and physical fitness assessment will be performed by one trained pediatrician and nurse. Finally, cardiovascular evaluation, including echocardiography and blood pressure, will be performed by two pediatric cardiologists. Data regarding perinatal and postnatal characteristics, diet, lifestyle, and weekly screen time of the child will be obtained from medical history and direct interviews with families. Primary outcome measures will include body mass index and adiposity, percentage of fat mass and total and regional lean mass, bone mineral content and density, cardiorespiratory resistance, isometric muscle strength, dynamic lower body strength, systolic and diastolic blood pressure, left ventricle (LV) systolic and diastolic function, general intelligence index, visuospatial working memory span, oculomotor control test, index of emotional, and behavioral problems.

Prescriptions for insulin and insulin analogues in children with and without major congenital anomalies: a data linkage cohort study across six European regions

Are children with major congenital anomalies more likely to develop diabetes requiring insulin therapy, as indicated by prescriptions for insulin, than children without congenital anomalies? The aim of this study is to evaluate prescription rates of insulin/insulin analogues in children aged 0-9 years with and without major congenital anomalies. A EUROlinkCAT data linkage cohort study, involving six population-based congenital anomaly registries in five countries. Data on children with major congenital anomalies (60,662) and children without congenital anomalies (1,722,912), the reference group, were linked to prescription records. Birth cohort and gestational age were examined. The mean follow-up for all children was 6.2 years. In children with congenital anomalies aged 0-3 years, 0.04 per 100 child-years (95% CIs 0.01-0.07) had > 1 prescription for insulin/insulin analogues compared with 0.03 (95% CIs 0.01-0.06) in reference children, increasing ten-fold by age 8-9 years. The risk of > 1 prescription for insulin/insulin analogues aged 0-9 years in children with non-chromosomal anomalies (RR 0.92, 95% CI 0.84-1.00) was similar to that of reference children. However, children with chromosomal anomalies (RR 2.37, 95% CI 1.91-2.96), and specifically children with Down syndrome (RR 3.44, 95% CIs 2.70-4.37), Down syndrome with congenital heart defects (RR 3.86, 95% CIs 2.88-5.16) and Down syndrome without congenital heart defects (RR 2.78, 95% CIs 1.82-4.27), had a significantly increased risk of > 1 prescription for insulin/insulin analogues aged 0-9 years compared to reference children. Female children had a reduced risk of > 1 prescription aged 0-9 years compared with male children (RR 0.76, 95% CI 0.64-0.90 for children with congenital anomalies and RR 0.90, 95% CI 0.87-0.93 for reference children). Children without congenital anomalies born preterm (< 37 weeks) were more likely to have > 1 insulin/insulin analogue prescription compared to term births (RR 1.28, 95% CIs 1.20-1.36).

CONCLUSION

This is the first population-based study using a standardised methodology across multiple countries. Males, children without congenital anomalies born preterm and those with chromosomal anomalies had an increased risk of being prescribed insulin/insulin analogues. These results will help clinicians to identify which congenital anomalies are associated with an increased risk of developing diabetes requiring insulin therapy and allow them to reassure families of children who have non-chromosomal anomalies that their risk is similar to that of the general population.

WHAT IS KNOWN

• Children and young adults with Down syndrome have an increased risk of diabetes requiring insulin therapy. • Children born prematurely have an increased risk of developing diabetes requiring insulin therapy.

WHAT IS NEW

• Children with non-chromosomal anomalies do not have an increased risk of developing diabetes requiring insulin therapy compared to children without congenital anomalies. • Female children, with or without major congenital anomalies, are less likely to develop diabetes requiring insulin therapy before the age of 10 compared to male children.

Early-life determinants of childhood plasma insulin levels: implications for primordial prevention of diabetes

BACKGROUND

We earlier reported prematurity as an independent risk factor for elevated insulin levels. Investigation is still lacking on the influence of prenatal and perinatal factors on childhood insulin levels.

METHODS

In this secondary analysis of a prospective birth cohort, plasma insulin levels were measured at birth and early childhood. Regression models identified early-life factors associated with the primary outcome: log-transformed childhood plasma insulin levels.

RESULTS

One thousand one hundred and nine children had insulin levels at birth and 825 at both time points. Compared to term, preterm infants had higher plasma insulin levels (geometric mean) at birth (612, 95% CI 552-679 vs. 372, 95% CI 345-402 pmol/ml) and in early childhood (547, 95% CI 494-605 vs. 445, 95% CI 417-475 pmol/ml). Factors associated with higher early childhood insulin levels included higher insulin level at birth, black race, female sex, maternal smoking during pregnancy, maternal perceived stress, in utero drug exposure, maternal pregestational diabetes mellitus, and maternal preconception overweight and obesity.

CONCLUSIONS

In this high-risk US birth cohort, we identified multiple prenatal and perinatal risk factors for higher early childhood insulin levels, in addition to prematurity. These findings lend support to primordial preventive strategies for diabetes mellitus.

IMPACT

In this secondary analysis of a large prospective study from a high-risk racially diverse cohort, we identify biological and social factors that contribute to elevated levels of plasma insulin in early childhood. Our study also investigates factors affecting plasma insulin in preterm infants along with comorbidities commonly seen during the neonatal intensive care stay. Our work reaffirms the importance of Developmental Origins of Health and Disease with regards to in utero programming of insulin levels. Our work supports the possibility that primordial preventive strategies for diabetes mellitus in high-risk populations may need to begin as early as the prenatal period.

Milk-Based Bionutrient Trials to Improve Outcomes in Preterm Infants: Challenges and Opportunities

OBJECTIVE

Bionutrients (or immunonutrients) are dietary components present in milk, or supplements that could be added to milk diets, that impact health and disease. With few exceptions, most of these are present in human breastmilk and the majority are also present in amniotic fluid.

STUDY DESIGN

Bionutrients can be proteins and peptides including enzymes, hormones, immunoglobulins, and growth factors and can also be molecules such as human milk oligosaccharides, amino acids, or lipids such as docosahexaenoic acid. Many of these have ancient origins, are found in other species, and existed before mammalian lactation evolved. Bionutrients may act in diverse ways when administered enterally: they may impact gut bacterial communities or epithelial cell metabolism, or they may pass into the lamina propria where they interact with the gut and systemic immune systems. Clinical trials have often used bovine analogs such as lactoferrin or may use artificially synthesized or recombinant compounds including insulin, bile salt stimulated lipase, or oligosaccharides.

RESULTS

Challenges arise because the bioactivity of proteins, such as lactoferrin, may be affected by processing and pasteurization meaning that the impacts of commercial products may differ. The challenge of determining the optimal bioactivity of any single preparation may be even greater in complex compounds such as milk fat globule membrane. It is also possible that bioactivity is affected by the milk matrix, that is, may differ between formula and human milk.

CONCLUSION

Finally, it is important to appreciate that nutrients do not function in isolation, and most will not act like drugs, that is, they may take several days or longer to exert an affect.

KEY POINTS

· Breastmilk contains high concentrations of bionutrients and provides more than macro- and micronutrients.. · Bionutrients can be proteins (e.g. enzymes, hormones, or immunoglobulins) or molecules (e.g. human milk oligosaccharides or amino acids).. · Bionutrients can be added to milk feeds but high quality trials are needed..

Muscle Function, Body Composition, Insulin Sensitivity and Physical Activity in Adolescents Born Preterm: Impact of Gestation and Vitamin D Status

Whilst several studies have explored adolescent metabolic and cognitive function after preterm birth, few have explored muscle function and physical activity. We set out to examine the relationship between gestational age and muscle metabolism in a cohort of adolescents who were born preterm. Participants were recruited from the Newcastle preterm birth growth study cohort. They did not have severe neurological disease and were not on daily medication. Participants underwent an assessment of oxidative muscle function using phosphorus magnetic resonance spectroscopy that included the half-time for recovery of equilibrium of phosphocreatine, τ½PCr. In addition, we measured key variables that might affect muscle function including physical activity levels determined by 3-day accelerometry, body composition using air displacement plethysmography, insulin sensitivity using the homeostatic model assessment/Matsuda index and serum vitamin D concentrations. 60 adolescents (35F) median age 15.6 years (range 12.1−18.8) with a median gestation of 31 weeks (range 24 to 34 weeks) underwent a single assessment. Males were more active and spent less time in sedentary mode. Time spent in light activity was associated with insulin sensitivity (IS) (Matsuda Index; p < 0.05) but there were no strong correlations between activity levels and gestational age. Greater fat mass, waist circumference and body mass index were all associated with lower IS. Gestational age was negatively associated with adjusted measures of oxidative muscle function (τ½PCr). In a stepwise multivariate linear regression model, gestational age at birth was the most significant predictor of oxidative muscle function (p = 0.005). Higher serum vitamin D levels were also associated with faster phosphocreatine recovery time (p = 0.045). Oxidative function in the skeletal muscle of adolescents born preterm is associated with gestational age and vitamin D concentrations. Our study suggests that being born preterm may have a long-term impact on muscle metabolism.

Body composition at 4 to 7 years of age in children born <32 weeks gestational age or 1500 g: A cohort study

BACKGROUND

Small for gestational age preterm infants show differences in body composition when compared to those appropriate for gestational age at term, which have consequences on metabolism.

AIM

To compare growth and body composition of children born small and appropriate for gestational age between 4 and 7 years.

METHOD

A Cohort of small and appropriate for gestational age infants <32 weeks or 1500 g were followed at term and 3 months corrected ages and at 4 to 7 years. Body composition assessment by air displacement plethysmography and anthropometry were performed at all moments. Differences between the two groups were assessed using t-student and Chi-square tests.

RESULTS

Ninety-four infants were included at term (26 small and 68 appropriate for gestational age); 88 at 3 months (24 small and 64 appropriate for gestational age) and 47 between 4 and 7 years (11 small and 36 appropriate for gestational age). At term, small for gestational age infants had lower fat-free mass, fat mass, weight and length compared with those appropriate for gestational age (p < 0.001). At 3 months, fat-free mass (grams) remained lower in small for gestational age group (p < 0.001). Between 4 and 7 years, body composition and anthropometry were similar between the groups.

CONCLUSION

Between 4 and 7 years, children born small and appropriate for gestational age had similar body composition. New long-term longitudinal studies are necessary to understand the influence of fat-free mass and fat mass in the first months of age on body composition throughout life.

Associations between maternal mid-pregnancy apolipoprotein A-1, apolipoprotein B, apolipoprotein B/apolipoprotein A-1 ratio and preterm birth

BACKGROUND AND AIMS

Elevated lipid levels during pregnancy have been shown to be related to the risk of preterm birth. Despite the importance of apolipoprotein (Apo) in lipid metabolism and transportation, evidence regarding apolipoprotein levels during pregnancy and preterm birth is still limited. Therefore, we aim to investigate the associations between maternal ApoA-1, ApoB, ApoB/ApoA-1 ratio and preterm birth.

MATERIALS AND METH

Data were extracted from the information system of Guangdong Women and Children Hospital. Lipoprotein levels were tested using Beckman Coulter AU5800 in mid-pregnancy at a median gestational age of 18 w. Maternal serum ApoB, ApoA-1 and ApoB/ApoA-1 ratio were categorized into tertiles. Logistic regression models were performed to evaluate the odds ratios and 95% confidence intervals for preterm birth.

RESULTS

A total of 5,986 maternal-newborn pairs were included in this study. The rate of preterm birth was 5.7% (n = 344). The multivariate-adjusted ORs (95% CI) of preterm birth were 1.51 (1.06, 2.10) for individuals with high ApoB (>90th), 0.63 (0.38, 0.99) for those with low ApoB (<10th), and 1.64 (1.18, 2.24) for those with high ApoB/ApoA-1 (>90th). Subgroup analyses showed that the association of ApoB and preterm birth was only significant among women with pre-pregnancy BMI 18.5-24 kg/m² (OR = 1.36, 95% CI: 1.12-1.65), age at delivery ≥ 35 years (OR = 1.43, 95% CI: 1.12-1.83).

CONCLUSION

Elevated maternal ApoB level and ApoB/ApoA-1 ratio during mid-pregnancy were related to increased risk of preterm birth. Monitoring maternal serum apolipoprotein levels may help to identify the high-risk population of preterm birth.

Association of Late Preterm Birth and Size for Gestational Age With Cardiometabolic Risk in Childhood

IMPORTANCE

The long-term cardiometabolic consequences of late preterm birth (34-36 weeks' gestation) are not well understood.

OBJECTIVE

To assess whether late preterm birth and size for gestational age are associated with cardiometabolic risk (CMR) in childhood.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective cohort study included 1742 children born in Ontario, Canada, between April 1, 2006, and September 30, 2014, and followed up until September 30, 2019. Data from children enrolled in The Applied Research Group for Kids (TARGet Kids!) primary care practice-based research network were linked to administrative health care data at ICES (formerly known as the Institute for Clinical Evaluative Sciences). Participants were excluded if they had conditions affecting growth (eg, failure to thrive or cystic fibrosis), any acute or chronic conditions (other than asthma and high-functioning autism), severe developmental delay, or families who were unable to communicate in English.

EXPOSURES

Late preterm birth, gestational age as a continuous measure, and size for gestational age.

MAIN OUTCOMES AND MEASURES

The primary outcome was composite CMR score (overall age- and sex-standardized z score of CMR components, including waist circumference, log triglyceride level, glucose level, systolic blood pressure, and high-density lipoprotein cholesterol level). Secondary outcomes were the individual CMR components. Multivariable linear regression analysis was used to separately evaluate the associations of late preterm birth, continuous gestational age, and size for gestational age with CMR at ages 3 to 12 years.

RESULTS

Among 2440 eligible children, 1742 (mean [SD] age, 5.6 [2.2] years; 951 boys [54.6%]) were included in the final cohort. Overall, 87 children (5.0%) were born moderately preterm (<34 weeks' gestation), 145 (8.3%) were born late preterm (34-36 weeks' gestation), 455 (26.1%) were born early term (37-38 weeks' gestation), and 1055 (60.6%) were born full term (≥39 weeks' gestation). Compared with children born full term, those born moderately preterm (adjusted β = 0.50; 95% CI, 0.24-0.75) and late preterm (adjusted β = 0.27; 95% CI, 0.06-0.47) had higher CMR scores. Each additional gestational week was associated with a 0.06 U (adjusted β; 95% CI, -0.08 to -0.03 U) decrease in CMR.

CONCLUSIONS AND RELEVANCE

In this study, children born late preterm and moderately preterm had higher CMR. These results suggest that screening and early-life interventions for these children may prevent cardiometabolic outcomes.

The association between late preterm birth and cardiometabolic conditions across the life course: A systematic review and meta-analysis

BACKGROUND

The effect of being born late preterm (34-36 weeks gestation) on cardiometabolic outcomes across the life course is unclear.

OBJECTIVES

To systematically review the association between being born late preterm (spontaneous or indicated), compared to the term and cardiometabolic outcomes in children and adults.

DATA SOURCES

EMBASE(Ovid), MEDLINE(Ovid), CINAHL.

STUDY SELECTION AND DATA EXTRACTION

Observational studies up to July 2021 were included. Study characteristics, gestational age, cardiometabolic outcomes, risk ratios (RRs), odds ratios (ORs), hazard ratios (HRs), mean differences and 95% confidence intervals (CIs) were extracted.

SYNTHESIS

We pooled converted RRs using random-effects meta-analyses for diabetes, hypertension, ischemic heart disease (IHD) and body mass index (BMI) with subgroups for children and adults. The risk of bias was assessed using the Newcastle-Ottawa scale and certainty of the evidence was assessed using the grading of recommendations, assessment, development and evaluation (GRADE) approach.

RESULTS

Forty-one studies were included (41,203,468 total participants; median: 5.0% late preterm). Late preterm birth was associated with increased diabetes (RR 1.24, 95% CI 1.17, 1.32; nine studies; n = 6,056,511; incidence 0.9%; I² 51%; low certainty) and hypertension (RR 1.21, 95% CI 1.13, 1.30; 11 studies; n = 3,983,141; incidence 3.4%; I² 64%; low certainty) in children and adults combined. Late preterm birth was associated with decreased BMI z-scores in children (standard mean difference -0.38; 95% CI -0.67, -0.09; five studies; n = 32,602; proportion late preterm 8.3%; I² 96%; very low certainty). There was insufficient evidence that late preterm birth was associated with increased IHD risk in adults (HR 1.20, 95% CI 0.89, 1.62; four studies; n = 2,706,806; incidence 0.3%; I² 87%; very low certainty).

CONCLUSIONS

Late preterm birth was associated with an increased risk of diabetes and hypertension. The certainty of the evidence was low or very low. Inconsistencies in late preterm and term definitions, confounding variables and outcome age limited the comparability of studies.

Low birth weight and small for gestational age are associated with complications of childhood and adolescence obesity: Systematic review and meta-analysis

In recent decades, the incidence of type 2 diabetes (T2D) has increased dramatically in children and adolescents, posing a real public health problem. Beyond unhealthy diets and sedentary lifestyles, growing evidence suggests that some perinatal factors, such as low birth weight (LBW), are associated with higher risk of T2D in adulthood. In this regard, it remains unclear whether the increased risk is already present in childhood and adolescence. We conducted a systematic review and meta-analysis to clarify the association of LBW or being small for gestational age (SGA) with insulin resistance in childhood and adolescence. The systematic review resulted in 28 individual studies, and those with the same outcome were included within two random-effects meta-analyses. Compared with children or adolescents born with adequate size for gestational age, those SGA had 2.33-fold higher risk of T2D (95% confidence interval [CI]: 1.05-5.17). Furthermore, LBW and being SGA were associated with 0.20 higher mean homeostasis model assessment of insulin resistance (HOMA-IR) values (95% CI: 0.02-0.38). Given the high prevalence of preterm babies, from a population perspective, these results may be of great importance as they point to the existence of a potentially vulnerable subgroup of children and adolescents that could benefit from screening tests and early preventive strategies.

Metabolomic Profile of Young Adults Born Preterm

Prematurity is a risk factor for the development of chronic adult diseases. Metabolomics can correlate the biochemical changes to a determined phenotype, obtaining real information about the state of health of a subject at that precise moment. Significative differences in the metabolomic profile of preterm newborns compared to those born at term have been already identified at birth. An observational case–control study was performed at the University Hospital of Siena. The aim was to evaluate and compare the metabolomic profiles of young adults born preterm to those born at term. Urinary samples were collected from 67 young adults (18–23 years old) born preterm (mean gestational age of 30 weeks, n = 49), and at term of pregnancy (mean gestational age of 38 weeks, n = 18). The urinary spectra of young adults born preterm was different from those born at term and resembled what was previously described at birth. The Random Forest algorithm gave the best classification (accuracy 82%) and indicated the following metabolites as responsible for the classification: citrate, CH2 creatinine, fumarate and hippurate. Urine spectra are promising tools for the early identification of neonates at risk of disease in adulthood and may provide insight into the pathogenesis and effects of fetal programming and infants’ outcomes.

Total body water in full-term and preterm newborns: systematic review and meta-analysis

BACKGROUND

Total body water (TBW) is one component of fat-free mass and changes in TBW are influenced by fluid shifts (especially during transition to postnatal life), electrolyte balance and nutritional status. Normal values for term-born neonates and preterm infants at birth have not been defined in large cohorts, limiting investigation into its monitoring and use in clinical practice.

OBJECTIVE

To systematically review the evidence base for percentage of TBW in term-born infants, quantify the effect of prematurity on TBW at birth, and describe normal progression of TBW over time in preterm infants.

METHODS

Systematic review of Medline, Web of Science Core Collection and EBSCO-CINAHL (January 1946 to January 2020). Included articles used dilutional methods to assess TBW.

RESULTS

Searches identified 2349 articles of which 22 included data suitable for analysis. Mean TBW in term-born newborns was 73.8% (95% CI 72.47% to 75.06%, 15 studies, 433 infants). Meta-regression showed that TBW was higher in preterm infants (up to 90% at 26 weeks gestation, dropping to 75% at 36 weeks corrected gestation) and was negatively correlated with gestation at birth, falling 1.44% per week (95% CI 0.63% to 2.24%, 9 studies, 179 infants). Analysis of TBW over time during the ex utero growth of preterm infants was not possible due to paucity of data.

CONCLUSION

This review defines the normal TBW percentage in term-born infants and confirms and quantifies previous findings that preterm infants have a higher TBW percentage.

Postnatal Expression Profile of MicroRNAs Associated with Cardiovascular Diseases in 3- to 11-Year-Old Preterm-Born Children

(1) Background: Preterm-born children have an increased cardiovascular risk with the first clinical manifestation during childhood and/or adolescence. (2) Methods: The occurrence of overweight/obesity, prehypertension/hypertension, valve problems or heart defects, and postnatal microRNA expression profiles were examined in preterm-born children at the age of 3 to 11 years descending from preterm prelabor rupture of membranes (PPROM) and spontaneous preterm birth (PTB) pregnancies. The whole peripheral blood gene expression of 29 selected microRNAs associated with cardiovascular diseases was the subject of our interest. (3) Results: Nearly one-third of preterm-born children (32.43%) had valve problems and/or heart defects. The occurrence of systolic and diastolic prehypertension/hypertension was also inconsiderable in a group of preterm-born children (27.03% and 18.92%). The vast majority of children descending from either PPROM (85.45%) or PTB pregnancies (85.71%) had also significantly altered microRNA expression profiles at 90.0% specificity. (4) Conclusions: Postnatal microRNA expression profiles were significantly influenced by antenatal and early postnatal factors (gestational age at delivery, birth weight of newborns, and condition of newborns at the moment of birth). These findings may contribute to the explanation of increased cardiovascular risk in preterm-born children. These findings strongly support the belief that preterm-born children should be dispensarized for a long time to have access to specialized medical care.

Preterm Birth and Birth Weight and the Risk of Type 1 Diabetes in Chinese Children

AIMS

Findings from previous studies about the association of preterm birth as well as birth weight with the risk of T1DM were still inconsistent. We aimed to further clarify these associations based on Chinese children and explore the role of gender therein.

METHODS

A nationwide multicenter and population-based large cross-sectional study was conducted in China from 2017 to 2019. Children aged between 3 and 18 years old with complete information were included in this analysis. Multiple Poisson regression models were used for evaluating the associations of birth weight as well as preterm birth with T1DM in children.

RESULTS

Out of 181,786 children, 82 childhood T1DM cases were identified from questionnaire survey. Children with preterm birth (<37 weeks) had higher risk of type 1 diabetes (OR: 3.17, 95%CI: 1.76-5.71). Children born with high birth weight (≥4,000g) had no statistically significant risk of T1DM (OR:1.71, 95%CI: 0.90-3.22). However, children's gender might modify the effect of high birth weight on T1DM (girls: OR: 3.15, 95%CI: 1.33-7.47; boys: OR: 0.99, 95%CI: 0.38-2.55, p for interaction=0.065). In addition, children with low birth weight were not associated with T1DM (OR: 0.70, 95%CI: 0.24-2.08). The findings from matched data had the similar trend.

CONCLUSIONS

In China mainland, preterm birth increased the risk of childhood T1DM, but high birth weight only affected girls. Therefore, early prevention of T1DM may start with prenatal care to avoid adverse birth outcomes and more attention should be paid to children with preterm birth and girls with high birth weight after birth.

Impact of the Vulnerable Preterm Heart and Circulation on Adult Cardiovascular Disease Risk

Preterm birth accounts for over 15 million global births per year. Perinatal interventions introduced since the early 1980s, such as antenatal glucocorticoids, surfactant, and invasive ventilation strategies, have dramatically improved survival of even the smallest, most vulnerable neonates. As a result, a new generation of preterm-born individuals has now reached early adulthood, and they are at increased risk of cardiovascular diseases. To better understand the sequelae of preterm birth, cardiovascular follow-up studies in adolescents and young adults born preterm have focused on characterizing changes in cardiac, vascular, and pulmonary structure and function. Being born preterm associates with a reduced cardiac reserve and smaller left and right ventricular volumes, as well as decreased vascularity, increased vascular stiffness, and higher pressure of both the pulmonary and systemic vasculature. The purpose of this review is to present major epidemiological evidence linking preterm birth with cardiovascular disease; to discuss findings from clinical studies showing a long-term impact of preterm birth on cardiac remodeling, as well as the systemic and pulmonary vascular systems; to discuss differences across gestational ages; and to consider possible driving mechanisms and therapeutic approaches for reducing cardiovascular burden in individuals born preterm.

Preterm birth and risk of type 1 and type 2 diabetes: a national cohort study

AIMS/HYPOTHESIS

Preterm birth (gestational age <37 weeks) has been associated with insulin resistance early in life. However, no large population-based studies have examined risks of type 1 and type 2 diabetes and potential sex-specific differences from childhood into adulthood. Clinicians will increasingly encounter adults who were born prematurely and will need to understand their long-term risks. We hypothesised that preterm birth is associated with increased risks of type 1 and type 2 diabetes into adulthood.

METHODS

A national cohort study was conducted of all 4,193,069 singletons born in Sweden during 1973-2014, who were followed up for type 1 and type 2 diabetes identified from nationwide diagnoses and pharmacy data to the end of 2015 (maximum age 43 years; median age at the end of follow-up 22.5 years). Cox regression was used to adjust for potential confounders, and co-sibling analyses assessed the influence of shared familial (genetic and/or environmental) factors.

RESULTS

In 92.3 million person-years of follow-up, 27,512 (0.7%) and 5525 (0.1%) people were identified with type 1 and type 2 diabetes, respectively. Gestational age at birth was inversely associated with both type 1 and type 2 diabetes risk. Adjusted HRs for type 1 and type 2 diabetes at age <18 years associated with preterm birth were 1.21 (95% CI, 1.14, 1.28) and 1.26 (95% CI, 1.01, 1.58), respectively, and at age 18-43 years were 1.24 (95% CI, 1.13, 1.37) and 1.49 (95% CI, 1.31, 1.68), respectively, compared with full-term birth. The associations between preterm birth and type 2 (but not type 1) diabetes were stronger among females (e.g. at age 18-43 years, females: adjusted HR, 1.75; 95% CI, 1.47, 2.09; males: 1.28; 95% CI, 1.08, 1.53; p < 0.01 for additive and multiplicative interaction). These associations were only partially explained by shared genetic or environmental factors in families.

CONCLUSIONS/INTERPRETATION

In this large national cohort, preterm birth was associated with increased risk of type 1 and type 2 diabetes from childhood into early to mid-adulthood. Preterm-born children and adults may need early preventive evaluation and long-term monitoring for diabetes.

Effects of preterm birth induced with or without exogenous glucocorticoids on the ovine glucose-insulin axis

Antenatal exogenous glucocorticoids (ANG) are standard management for women at risk of preterm birth but are reputed to impair glucose tolerance in preterm offspring. We compared lambs born preterm (137 days gestation) following labour induced with exogenous glucocorticoids (G-Prem, glucocorticoid-induced preterm group), or with a progesterone synthesis inhibitor (NG-Prem, non-glucocorticoid-induced preterm group), with term-born lambs (Term; 149 days). We assessed glucose tolerance, insulin secretion and sensitivity at 4 and 10 months n = 11-14/group) and pancreatic and hepatic gene and protein expression at 4 weeks post-term (4 weeks; n = 6/group) and 12 months (12 months; n = 12-13/group). NG-Prem had higher plasma glucose concentrations than G-Prem, but not Term, at 4 months (Mean[SEM] mM: NG-Prem = 4.1[0.1]; G-Prem = 3.4[0.1]; Term = 3.7[0.1]; p = 0.003) and 10 months (NG-Prem = 3.9[0.1]; G-Prem = 3.5[0.1]; Term = 3.7[0.1]; p = 0.01). Insulin sensitivity decreased from 4 to 10 months, in NG-Prem but not in Term (Mean[SEM] µmol·ml-1·kg-1·min-1·ng-1, 4 vs. 10 months: NG-Prem = 18.7[2.5] vs. 9.5[1.5], p < 0.01; Term: 12.1[2.8] vs. 10.4[1.5], p = 0.44). At 12 months, β-cell mass in NG-Prem was reduced by 30% vs. G-Prem (p < 0.01) and 75% vs. Term (p < 0.01) and was accompanied by an increased β-cell apoptosis: proliferation ratio at 12 months. At 12 months, pancreatic glucokinase, igf2 and insulin mRNA levels were reduced 21%-71% in NG-Prem vs. G-Prem and 42%-80% vs. Term. Hepatic glut2 mRNA levels in NG-Prem were 250% of those in G-Prem and Term. Thus, induction of preterm birth without exogenous glucocorticoids more adversely affected pancreas and liver than induction with exogenous glucocorticoids. These findings do not support that ANG lead to long-term adverse metabolic effects, but support an effect of preterm birth itself.

Association of Low Birth Weight and Premature Birth With the Risk of Metabolic Syndrome: A Meta-Analysis

The association of preterm or low birth weight (LBW) with the risk of metabolic syndrome is still unclear. This study aimed to assess the association between preterm or LBW and metabolic syndrome risk according to study or participants' characteristics. PubMed, Web of Science, and EMBASE were searched for epidemiologic studies on the association published up to April 30, 2020. Pooled odds ratio (ORs) and weighted mean differences (WMDs) with 95% confidence intervals (CIs) were calculated using the random-effects model. Low birth weight was associated with an increased risk of metabolic syndrome (OR, 1.37; 95% CI, 1.17-1.61). In the subgroup analysis by study design, the pooled ORs for LBW and metabolic syndrome in the cohort and cross-sectional studies were 1.79 and 1.22. In the subgroup analysis by sex, LBW was found to be associated with an increased risk of metabolic syndrome in pooled studies including both men and women or studies including only women. The association between premature birth and risk of metabolic syndrome was significant in cohort studies (OR, 1.72; 95% CI, 1.12-2.65). Also, LBW or preterm was significantly associated with a higher Homeostasis Model Assessment of Insulin Resistance (WMD, 0.28; 95% CI, 0.19-0.36). Low birth weight and preterm might be risk factors for metabolic syndrome.

Adult-Onset Diseases in Low Birth Weight Infants: Association with Adipose Tissue Maldevelopment

Low birth weight (LBW) infants have higher risk of developing insulin resistance and its comorbidities later in life. The concept of “developmental origins of health and disease” suggests that intrauterine and postnatal environments have an important role in increasing these risks. The risk of such adult-onset diseases in LBW infants might be associated with adipose tissue maldevelopment including altered body composition and increased amount of visceral fat, which is the same mechanism as that in children and adults with metabolic syndrome. However, LBW infants often have different characteristics: they are not always overweight or obese over their life course. The inconsistency might be associated with the thrifty phenotype, which is produced in response to impaired growth potential and decreased lean body mass. LBW infants tend to be obese within the limits of impaired growth potential. Through our previous investigations evaluating longitudinal changes in adiponectin levels at an early stage of life, we speculated that probably, the intrauterine life of term infants or the period up to term-equivalent age in preterm infants might be the key age for the development of adipose tissues including fat cells. Because of that, we hypothesized that the smaller number of adipocytes in LBW infants might be associated with overloading of single adipocytes and impaired adipose tissue expandability. The possible mechanisms are discussed from the perspective of adipose tissue maldevelopment in LBW infants.

Persistent metagenomic signatures of early-life hospitalization and antibiotic treatment in the infant gut microbiota and resistome

Hospitalized preterm infants receive frequent and often prolonged exposures to antibiotics because they are vulnerable to infection. It is not known whether the short-term effects of antibiotics on the preterm infant gut microbiota and resistome persist after discharge from neonatal intensive care units. Here, we use complementary metagenomic, culture-based and machine learning techniques to study the gut microbiota and resistome of antibiotic-exposed preterm infants during and after hospitalization, and we compare these readouts to antibiotic-naive healthy infants sampled synchronously. We find a persistently enriched gastrointestinal antibiotic resistome, prolonged carriage of multidrug-resistant Enterobacteriaceae and distinct antibiotic-driven patterns of microbiota and resistome assembly in extremely preterm infants that received early-life antibiotics. The collateral damage of early-life antibiotic treatment and hospitalization in preterm infants is long lasting. We urge the development of strategies to reduce these consequences in highly vulnerable neonatal populations.

An Online Geographic Data Visualization Tool to Relate Preterm Births to Environmental Factors

Preterm birth (<37 weeks gestation) continues to be a significant cause of disease and death in the United States. Its complex causes are associated with several genetic, biological, environmental, and sociodemographic factors. Organizing and visualizing various data that may be related to preterm birth is an essential step for pattern exploration and hypothesis generation and presents an opportunity to increase public and stakeholder involvement. In this article, we describe a collaborative effort to create an online geographic data visualization tool using open software to explore preterm birth in Fresno County, where rates are the highest in California. The tool incorporates information on births, environmental exposures, sociodemographic characteristics, the built environment, and access to care. We describe data sets used to build the tool, the data-hosting platform, and the process used to engage stakeholders in its creation. We highlight an important example of how collaboration can increase the utility of geographic data visualization to improve public health and address health equity in birth outcomes.

Infant and young child feeding interventions targeting overweight and obesity: A narrative review

findings from systematic reviews into infant feeding and later adiposity are largely negative. World Health Organization (WHO) is auspicing Healthy Life Trajectories Initiative (HeLTI), a suite of trials aiming to prevent overweight/obesity in childhood. To inform planning, this narrative review sought to detail potentially effective components of nutrition-related interventions involving children aged 0 to 2 years. Systematic searches of PubMed and the Cochrane Library (2006-2016) identified 108 systematic reviews. These included 31 randomized trials in the age group of interest. Of these, 11 reported greater than or equal to 1 statistically significant (P < 0.05) benefit on body weight and/or composition. Six multicomponent trials whose interventions incorporated education to promote breastfeeding (four trials), responsive feeding (two trials), and healthy diet (eg, increasing fruit and vegetables and limiting unhealthy snack foods; five trials), delivered through home visits or at baby health clinics, reported relative reductions in body mass index (BMI) at the end of intervention. Early benefits were not maintained in the two trials reporting follow-up 1 to 3 years later. Other potentially effective approaches included lower protein formulas in formula-fed infants and education around reducing sugar-sweetened beverages. There is some evidence that infant feeding interventions can have a transient positive impact on a child's BMI. It is not known whether ongoing intervention can avoid the subsequent expected wash-out.

Perinatal risk factors for type 1 diabetes revisited: a population-based register study

AIMS/HYPOTHESIS

Single-centre studies and meta-analyses have found diverging results as to which early life factors affect the risk of type 1 diabetes during childhood. We wanted to use a large, nationwide, prospective database to further clarify and analyse the associations between perinatal factors and the subsequent risk for childhood-onset type 1 diabetes using a case-control design.

METHODS

The Swedish Childhood Diabetes Register was linked to the Swedish Medical Birth Register and National Patient Register, and 14,949 cases with type 1 diabetes onset at ages 0-14 years were compared with 55,712 matched controls born from the start of the Medical Birth Register in 1973 to 2013. After excluding confounders (i.e. children multiple births, those whose mother had maternal diabetes and those with a non-Nordic mother), we used conditional logistic regression analyses to determine risk factors for childhood-onset type 1 diabetes. We used WHO ICD codes for child and maternal diagnoses.

RESULTS

In multivariate analysis, there were small but statistically significant associations between higher birthweight z score (OR 1.08, 95% CI 1.06, 1.10), delivery by Caesarean section (OR 1.08, 95% CI 1.02, 1.15), premature rupture of membranes (OR 1.08, 95% CI 1.01, 1.16) and maternal urinary tract infection during pregnancy (OR 1.39, 95% CI 1.04, 1.86) and the subsequent risk of childhood-onset type 1 diabetes. Birth before 32 weeks of gestation was associated with a lower risk of childhood-onset type 1 diabetes compared with full-term infants (OR 0.54, 95% CI 0.38, 0.76), whereas birth between 32 and 36 weeks' gestation was associated with a higher risk (OR 1.24, 95% CI 1.14, 1.35). In subgroup analyses (birth years 1992-2013), maternal obesity was independently associated with subsequent type 1 diabetes in the children (OR 1.27, 95% CI 1.15, 1.41) and rendered the association with Caesarean section non-significant. In contrast to previous studies, we found no association of childhood-onset type 1 diabetes with maternal-child blood-group incompatibility, maternal pre-eclampsia, perinatal infections or treatment of the newborn with phototherapy for neonatal jaundice. The proportion of children with neonatal jaundice was significantly higher in the 1973-1982 birth cohort compared with later cohorts.

CONCLUSIONS/INTERPRETATION

Perinatal factors make small but statistically significant contributions to the overall risk of childhood-onset type 1 diabetes. Some of these risk factors, such as maternal obesity, may be amendable with improved antenatal care. Better perinatal practices may have affected some previously noted risk factors over time.

A Long-Acting Neutralizing Monoclonal ACTH Antibody Blocks Corticosterone and Adrenal Gene Responses in Neonatal Rats

The control of steroidogenesis in the neonatal adrenal gland is of great clinical interest. We have previously demonstrated that the postnatal day (PD) 2 rat exhibits a large plasma corticosterone response to hypoxia in the absence of an increase in plasma ACTH measured by RIA, whereas the corticosterone response to exogenous ACTH is intact. By PD8, the corticosterone response to hypoxia is clearly ACTH-dependent. We hypothesized that this apparently ACTH-independent response to hypoxia in the newborn rat is due to an increase in a bioactive, nonimmunoassayable form of ACTH. To evaluate this phenomenon, we pretreated neonatal rats with a novel, specific, neutralizing anti-ACTH antibody (ALD1611) (20 mg/kg or 1 mg/kg IP) on the morning of PD1, PD7, and PD14. Twenty-four hours later, we measured hypoxia- or ACTH-stimulated plasma ACTH and corticosterone. For long-term effects, ALD1611 was given on PD1 and pups were studied on PD8 and PD15. Pretreatment with ALD1611 significantly decreased baseline corticosterone and completely blocked the corticosterone response to hypoxia and exogenous ACTH stimulation at all ages. The effect of 1 mg/kg ALD1611 on PD1 had dissipated by PD15. The decrease in corticosterone in ALD1611-treated pups was associated with decreases in baseline and hypoxia- and ACTH-stimulated adrenal Ldlr, Mrap, and Star mRNA expression at all ages. The adrenal response to hypoxia in the newborn rat is ACTH-dependent, suggesting the release of nonimmunoassayable, biologically active forms of ACTH. ALD1611 is useful as a tool to attenuate stress-induced, ACTH-dependent adrenal steroidogenesis in vivo.

Intrauterine growth restriction affects z-scores of anthropometric parameters during the first 6 years in very low-birth-weight-children born at less than 30 weeks of gestation

OBJECTIVE

Little is known about physical constitution outcomes for very preterm infants. Here, we compare z-scores of anthropometric parameters up to 6 years of age in children born with very low birth weight (VLBW) at less than 30 weeks of gestation, with or without intrauterine growth restriction (IUGR).

DESIGN

Participants were divided into four subgroups: male (M), small for gestational age (SGA) (n = 30); M, appropriate for gestational age (AGA) (n = 59); female (F), SGA (n = 24); and F, AGA (n = 61). z-Scores of body weight (BW), body length (BL), and body mass index (BMI) were assessed at birth, 1 year corrected age, 3 years of age, and 6 years of age.

RESULTS

For boys, BW and BMI were significantly lower among SGA children than among AGA children at all assessments, but there was no difference in BL at 3 or 6 years. For girls, BW and BL were significantly lower among SGA children than among AGA children at all assessments, but no difference was detected in BMI after 1.5 years. No significant variation in the z-score of BW or BMI in either SGA group was observed after 1 year. BL z-score in all groups gradually increased until 6 years of age.

CONCLUSION

IUGR affects BW and BMI in boys and BW and BL in girls during the first 6 years in VLBW children born at less than 30 weeks of gestation. SGA children did not catch up in BW or BMI from 1 to 6 years of age.

Metabolic Syndrome in Very Low Birth Weight Young Adults and Controls: The New Zealand 1986 VLBW Study

OBJECTIVE

To assess the physical well-being and components of the metabolic syndrome in a national cohort of very low birth weight (VLBW) young adults and same age controls.

STUDY DESIGN

The New Zealand VLBW Study cohort prospectively included all infants with birth weight <1500 g born in 1986, with 338 (82%) surviving to discharge home. Height and weight were measured at age 7-8 years. The VLBW cohort (n = 229; 71% alive) and term-born controls (n = 100) aged 27-29 years were clinically assessed in a single center over 2 days, including assessment for components of the metabolic syndrome.

RESULTS

Compared with controls, both male and female VLBW adults were significantly shorter (P < .001), but only females were lighter (P < .001) and had lower mean body mass index (P = .044), fat mass, and body fat percentage. Males, but not females, had significantly higher systolic blood pressure (P = .028), but there were no significant differences in other components of the metabolic syndrome. There was no difference in the prevalence of the metabolic syndrome in VLBW adults compared with controls (males, 22.2% vs 11.1%; P = .15: females, 12.8% vs 13.1%; P = .95). Examining the VLBW cohort with logistic regression, male sex, gestational age <28 weeks, Māori/Pacific Island ethnicity, and body mass index >90th percentile at age 7-8 years were significant predictors for the metabolic syndrome at age 27-29 years, with ORs of 2-4.

CONCLUSIONS

Systolic blood pressure in males was the only component of the metabolic syndrome that was significantly elevated in VLBW adults compared with controls. Extreme prematurity (<28 weeks) and body mass index >90th percentile at age 7-8 years were significant predictors of the metabolic syndrome at age 27-29 years.

TRIAL REGISTRATION

Registered at the Australian Clinical Trials Registry: ACTRN12612000995875.

Preterm Birth Is a Novel, Independent Risk Factor for Altered Cardiac Remodeling and Early Heart Failure: Is it Time for a New Cardiomyopathy?

PURPOSE OF REVIEW

Around 10% of the global population is born preterm (< 37 weeks' gestation). Preterm birth is associated with an increased risk of cardiovascular events, with preterm-born individuals demonstrating a distinct cardiac phenotype. This review aims to summarize the main phenotypic features of the preterm heart and directions for future research to develop novel intervention strategies.

RECENT FINDINGS

Being born between 28 and 31 weeks' gestation results in a 4-fold higher risk of heart failure in childhood and adolescence and 17-fold increased risk when born less than 28 weeks' gestation. In support of this being due to a reduction in myocardial functional reserve, preterm-born young adults have an impaired left ventricular cardiac systolic response to moderate and high intensity physiological stress, despite having a preserved resting left ventricular ejection fraction. Similar impairments under physiological stress were also recently reported regarding the right ventricle in young adults born preterm. Preterm birth relates to a unique cardiac phenotype with an impaired response to stress conditions. These data, combined with the work in animal models, suggest that being born preterm may lead to a novel form of cardiomyopathy. Understanding the driving mechanisms leading to this unique cardiac phenotype is important to reduce risk of future heart failure and cardiovascular events.

Sustained Neonatal Inflammation Is Associated with Poor Growth in Infants Born Very Preterm during the First Year of Life

OBJECTIVE

To determine whether a sustained neonatal systemic inflammatory response was associated with poor postnatal growth among infants born very preterm during the first year of life.

STUDY DESIGN

We studied prospectively 192 infants born preterm (birth weight ≤1.5 kg and gestational age ≤31 weeks). Weight, length, and head circumference were measured at birth, term, 4, and 12 months of corrected age. Serial C-reactive protein and procalcitonin were measured at 1, 3, 7, 14, and 28 days of age and averaged for each infant. A sustained neonatal systemic inflammatory response was defined as an average C-reactive protein level greater than the median for the group. Analysis was undertaken with linear mixed models.

RESULTS

Decreases in mean z scores for weight, length, and head circumference were associated with the presence of a sustained neonatal systemic inflammatory response from birth to 12 months of corrected age (β [95% CI] = -0.282 [-0.306 to -0.258]; -1.899 [-2.028,-1.769]; -0.806 [-0.910, to -0.701], P < .001, respectively) in main effect models. This association remained significant after including interaction terms for bronchopulmonary dysplasia, neonatal sepsis, and necrotizing enterocolitis (β [95% CI] = -0.393 [-0.520 to -0.265]; -2.128 [-2.754, -1.503]; -1.102 [-1.604, -0.600]; P < .001; respectively) in interaction models.

CONCLUSIONS

A sustained neonatal systemic inflammatory response was associated with poor postnatal growth, particularly poor linear growth. Serial C-reactive protein and procalcitonin may be useful markers for identifying infants at risk for postnatal growth failure.

Early body composition changes are associated with neurodevelopmental and metabolic outcomes at 4 years of age in very preterm infants

BACKGROUND

Very preterm (VPT) infants are at-risk for altered growth, slower speed of processing (SOP), and hypertension. This study assesses the relationship between postnatal body composition (BC), neurodevelopment (indexed by SOP), and blood pressure (BP) in VPT infants.

METHODS

Thirty-four VPT infants underwent weekly measurements and BC testing until discharge and post-discharge at 4 mos CGA and 4 yrs. At post-discharge visits, SOP was assessed using visual evoked potentials and the NIH Toolbox; BP was also measured.

RESULTS

In-hospital rate of weight, length and fat-free mass (FFM) gains were associated with faster SOP at 4 yrs. Higher rate of gains in weight and FFM from discharge to 4 mos CGA were associated with faster SOP at 4 mos CGA, while higher fat mass (FM) gains during the same time were positively associated with BP at 4 yrs. BC at 4 yrs nor gains beyond 4 mos CGA were associated with outcomes.

CONCLUSIONS

In VPT infants, early FFM gains are associated with faster SOP, whereas post-discharge FM gains are associated with higher BPs at 4 yrs. This shows birth to 4 mos CGA is a sensitive period for growth and its relation to neurodevelopmental and metabolic outcomes. Close monitoring and early nutritional adjustments to optimize quality of gains may improve outcomes.

Impact of prematurity for pancreatic islet and beta-cell development

As increasing numbers of babies born preterm survive into adulthood, it is becoming clear that, in addition to the well-described risks of neurodevelopmental sequelae, there also are increased risks for non-communicable diseases, including diabetes. Epidemiological studies indicate that risks are increased even for birth at late preterm and early term gestations and for both type 1 and type 2 diabetes. Thus, factors related to preterm birth likely affect development of the fetal and neonatal beta-cell in addition to effects on peripheral insulin sensitivity. These factors could operate prior to preterm birth and be related to the underlying cause of preterm birth, to the event of being born preterm itself, to the postnatal care of the preterm neonate or to a combination of these exposures. Experimental evidence indicates that factors may be operating during all these critical periods to contribute to altered development of beta-cell mass in those born preterm. Greater understanding of how these factors impact upon development of the pancreas may lead to interventions or management approaches that mitigate the increased risk of later diabetes.

What Are We Measuring as Outcome? Looking Beyond Neurodevelopmental Impairment

Outcomes of neonatal intensive care unit (NICU) graduates have been categorized by rates of neurodevelopmental impairment at 2 years old. Although useful as metrics for research, these early childhood assessments may underestimate or overestimate later functional capabilities. Often overlooked are less severe but more prevalent neurobehavioral dysfunctions seen later in childhood, and chronic health concerns that may impact the child's quality of life (QoL). Comprehensive NICU follow-up should include measures of less severe cognitive/learning delays, physical/mental well-being, and the promotion of resilience in children and families. Studies are needed to identify QoL measures that will optimize children's assessments and outcomes.

Epigenetic gestational age acceleration: a prospective cohort study investigating associations with familial, sociodemographic and birth characteristics

Background

Gestational age at delivery is associated with health and social outcomes. Recently, cord blood DNA methylation data has been used to predict gestational age. The discrepancy between gestational age predicted from DNA methylation and determined by ultrasound or last menstrual period is known as gestational age acceleration. This study investigated associations of sex, socioeconomic status, parental behaviours and characteristics and birth outcomes with gestational age acceleration.

Results

Using data from the Avon Longitudinal Study of Parents and Children (n = 863), we found that pre-pregnancy maternal overweight and obesity were associated with greater gestational age acceleration (mean difference = 1.6 days, 95% CI 0.7 to 2.6, and 2.9 days, 95% CI 1.3 to 4.4, respectively, compared with a body mass index < 25 kg/m², p < .001). There was evidence of an association between male sex and greater gestational age acceleration. Greater gestational age acceleration was associated with higher birthweight, birth length and head circumference of the child (mean differences per week higher gestational age acceleration: birthweight 0.1 kg, 95% CI 0.1 to 0.2, p < .001; birth length 0.4 cm, 95% CI 0.2 to 0.7, p < .001; head circumference 0.2 cm, 95% CI 0.1 to − 0.4, p < .001). There was evidence of an association between gestational age acceleration and mode of delivery (assisted versus unassisted delivery, odds ratio = 0.9 per week higher gestational age acceleration, 95% CI 0.7, 1.3 (p = .05); caesarean section versus unassisted delivery, odds ratio = 0.6, 95% CI 0.4 to 0.9 per week higher gestational age acceleration (p = .05)). There was no evidence of association for other parental and perinatal characteristics.

Conclusions

The associations of higher maternal body mass index and larger birth size with greater gestational age acceleration may imply that maternal overweight and obesity is associated with more rapid development of the fetus in utero. The implications of gestational age acceleration for postnatal health warrant further investigation.

Electronic supplementary material

The online version of this article (10.1186/s13148-018-0520-1) contains supplementary material, which is available to authorized users.

Effect of a melanocortin type 2 receptor (MC2R) antagonist on the corticosterone response to hypoxia and ACTH stimulation in the neonatal rat

The adrenal stress response in the neonatal rat shifts from ACTH-independent to ACTH-dependent between postnatal days 2 (PD2) and 8 (PD8). This may be due to an increase in an endogenous, bioactive, nonimmunoreactive ligand to the melanocortin type 2 receptor (MC2R). GPS1574 is a newly described MC2R antagonist that we have shown to be effective in vitro. Further experimentation with GPS1574 would allow better insight into this seemingly ACTH-independent steroidogenic response in neonates. We evaluated the acute corticosterone response to hypoxia or ACTH injection following pretreatment with GPS1574 (32 mg/kg) or vehicle for GPS1574 in PD2, PD8, and PD15 rat pups. Pretreatment with GPS1574 decreased baseline corticosterone in PD2 pups but increased baseline corticosterone in PD8 and PD15 pups. GPS1574 did not attenuate the corticosterone response to hypoxia in PD2 pups and augmented the corticosterone response in PD8 and PD15 pups. GPS1574 augmented the corticosterone response to ACTH in PD2 and PD15 pups but had no significant impact on the response in PD8 pups. Baseline adrenal Mrap and Star mRNA increased from PD2 to PD15, whereas Mrap2 mRNA expression was low and did not change with age. The data suggest that GPS1574 is not a pure MC2R antagonist, but rather acts as a biasing agonist/antagonist. Its ability to attenuate or augment the adrenal response may depend on the ambient plasma ACTH concentration and/or developmental changes in early transduction steroidogenic pathway genes.

Neonatal hyperglycemia induces CXCL10/CXCR3 signaling and microglial activation and impairs long-term synaptogenesis in the hippocampus and alters behavior in rats

BACKGROUND

Hyperglycemia is common in extremely low gestational age newborns (ELGAN) and is associated with increased mortality and morbidity, including abnormal neurodevelopment. Hippocampus-mediated cognitive deficits are common in this population, but the specific effects of hyperglycemia on the developing hippocampus are not known.

METHODS

The objective of this study was to determine the acute and long-term effects of hyperglycemia on the developing hippocampus in neonatal rats using a streptozotocin (STZ)-induced model of hyperglycemia. STZ was injected on postnatal day (P) 2, and littermates in the control group were injected with an equivalent volume of citrate buffer. The acute effects of hyperglycemia on markers of oxidative stress, inflammatory cytokines, microglial activation, and reactive astrocytosis in the hippocampus were determined in the brain tissue collected on P6. The long-term effects on hippocampus-mediated behavior and hippocampal dendrite structure were determined on P90.

RESULTS

On P6, the transcript and protein expression of markers of oxidative stress and inflammatory cytokines, including the CXCL10/CXCR3 pathway, were upregulated in the hyperglycemia group. Histological evaluation revealed microglial activation and astrocytosis. The long-term assessment on P90 demonstrated abnormal performance in Barnes maze neurobehavioral testing and altered dendrite structure in the hippocampus of formerly hyperglycemic rats.

CONCLUSIONS

Neonatal hyperglycemia induces CXCL10/CXCR3 signaling, microglial activation, and astrocytosis in the rat hippocampus and alters long-term synaptogenesis and behavior. These results may explain the hippocampus-specific cognitive deficits common in ELGAN who experience neonatal hyperglycemia.

Food and nutrient intakes in young adults born preterm

BackgroundAdults born preterm have higher levels of cardiometabolic risk factors than their term-born peers. Studies have suggested that at least those born smallest eat less healthily. We examined the association between early (<34 weeks) and late (34-36 weeks) preterm birth and diet and food preferences in adult age.MethodsParticipants of two cohort studies located in Finland completed a validated food frequency questionnaire (FFQ) at the age of 24 years to assess their usual diet and the adherence to healthy eating guidelines by using a recommended diet index (RDI). Overall, 182 were born early preterm, 352 late preterm, and 631 were term-born controls.ResultsYoung women born early preterm scored 0.77 points (95% confidence interval (CI) 0.03, 1.51) lower in RDI when adjusted for sex, age, parental education, and early-life confounders, indicating a lower quality of diet. There were no differences between young women born late preterm and controls or among men. When food groups were assessed separately, men born early preterm had lower consumption of fruits and berries than controls.ConclusionsYoung women born early preterm have poorer adherence to the healthy eating guidelines than their peers born at term. Differences in diet may contribute to an increased cardiometabolic risk among adults born early preterm.

Pediatric Cardiovascular Morbidity of the Early Term Newborn

OBJECTIVE

To determine whether early term delivery (at 37^0/7-38^6/7 weeks of gestation) is associated with long-term pediatric cardiovascular morbidity of the offspring.

STUDY DESIGN

A population-based cohort analysis was performed including all term deliveries occurring between 1991 and 2014 at a single tertiary medical center. Gestational age at delivery was subdivided into early term (37^0/7-38^6/7), full term (39^0/7-40^6/7), late term (41^0/7-41^6/7) and post term (≥42^0/7) delivery. Hospitalizations of children up to the age of 18 years involving cardiovascular morbidity were evaluated, including structural valvular disease, hypertension, arrhythmias, rheumatic fever, ischemic heart disease, pulmonary heart disease, perimyoendocarditis, congestive heart failure, and others. Kaplan-Meier survival curves were used to compare cumulative hospitalization incidence between groups. A multivariable Weibull parametric model was used to control for confounders.

RESULTS

During the study period, 223 242 term singleton deliveries met the inclusion criteria. Of them, 24% (n = 53 501) occurred at early term. Hospitalizations involving cardiovascular morbidity were significantly more common in children delivered at early term (0.7%) as compared with those born at full (0.6%), late (0.6%), or post term (0.5%; P = .01). The survival curve demonstrated a significantly higher cumulative incidence of cardiovascular-related hospitalizations in the early term group (log-rank P <.001). In the Weibull model, early term delivery was found to be an independent risk factor for cardiovascular-related hospitalization as compared with full term delivery (adjusted HR, 1.16; 95% CI, 1.01-1.32; P = .02).

CONCLUSION

Early term delivery is independently associated with pediatric cardiovascular morbidity of the offspring as compared with offspring born at full term.

Associations between birthweight, gestational age at birth and subsequent type 1 diabetes in children under 12: a retrospective cohort study in England, 1998-2012

AIMS/HYPOTHESIS

With genetics thought to explain only 40-50% of the total risk of type 1 diabetes, environmental risk factors in early life have been proposed. Previous findings from studies of type 1 diabetes incidence by birthweight and gestational age at birth have been inconsistent. This study aimed to investigate the relationships between birthweight, gestational age at birth and subsequent type 1 diabetes in England.

METHODS

Data were obtained from a population-based database comprising linked mother-infant pairs using English national Hospital Episode Statistics from 1998 to 2012. In total, 3,834,405 children, categorised by birthweight and gestational age at birth, were followed up through record linkage to compare their incidence of type 1 diabetes through calculation of multivariable-adjusted HRs.

RESULTS

Out of 3,834,405 children, 2969 had a subsequent hospital diagnosis of type 1 diabetes in childhood. Children born preterm (<37 weeks) or early term (37-38 weeks) experienced significantly higher incidence of type 1 diabetes than full term children (39-40 weeks) (HR 1.19 [95% CI 1.03, 1.38] and 1.27 [95% CI 1.16, 1.39], respectively). Children born at higher than average birthweight (3500-3999 g or 4000-5499 g) after controlling for gestational age experienced higher incidence of type 1 diabetes than children born at medium birthweight (3000-3499 g) (HR 1.13 [95% CI 1.03, 1.23] and 1.16 [95% CI 1.02, 1.31], respectively), while children at low birthweight (<2500 g) experienced lower incidence (0.81 [95% CI 0.67, 0.98]), signifying a statistically significant trend (p trend 0.001).

CONCLUSIONS/INTERPRETATION

High birthweight for gestational age and low gestational age at birth are both independently associated with subsequent type 1 diabetes. These findings help contextualise the debate about the potential role of gestational and early life environmental risk factors in the pathogenesis of type 1 diabetes, including the potential roles of insulin sensitivity and gut microbiota.

The impact of intrauterine and extrauterine weight gain in premature infants on later body composition

BackgroundThe impact of intrauterine and extrauterine growth on later insulin resistance and fat mass (FM) in very low birth weight (VLBW) infants is not well established. The aim of our study was to evaluate the effects of intrauterine and early/late extrauterine growth on later insulin resistance and body composition in VLBW infants from 6 months' corrected age (CA) to 36 months.MethodsProspective measurements of body composition by dual-energy X-ray absorptiometry and insulin resistance by homeostasis model assessment insulin resistance (HOMA-IR) along with other fasting plasma biochemistries were made in 95 VLBW infants at 6, 12, 18, and 24 months' CA and 36 months' postnatal age. Mixed-effect models were used to evaluate the effects of age, sex, maturation status, and Δweight SD score on percentage FM (PFM), FM index (FMI), fat-free mass index (FFMI), and HOMA-IR.ResultsPFM and FMI were negatively associated with a decrease in weight-SD scores from birth to 36 weeks' postmenstrual age (PMA; P=0.001) and from 36 weeks' PMA to 6 months' CA (P=0.003). PFM and FMI were higher in AGA than in small for gestational age (SGA) infants. HOMA-IR was not associated with the Δweight-SD scores in either period.ConclusionsCatch-down growth in terms of weight is associated with persistently lower adiposity but not insulin resistance up to 36 months of age.

Insulin sensitivity, leptin, adiponectin, resistin, and testosterone in adult male and female rats after maternal-neonatal separation and environmental stress

Care of premature infants often requires parental and caregiver separation, particularly during hypoxic and hypothermic episodes. We have established a neonatal rat model of human prematurity involving maternal-neonatal separation and hypoxia with spontaneous hypothermia prevented by external heat. Adults previously exposed to these neonatal stressors show a sex difference in the insulin and glucose response to arginine stimulation suggesting a state of insulin resistance. The current study used this cohort of adult rats to evaluate insulin resistance [homeostatic model assessment of insulin resistance (HOMA-IR)], plasma adipokines (reflecting insulin resistance states), and testosterone. The major findings were that daily maternal-neonatal separation led to an increase in body weight and HOMA-IR in adult male and female rats and increased plasma leptin in adult male rats only; neither prior neonatal hypoxia (without or with body temperature control) nor neonatal hypothermia altered subsequent adult HOMA-IR or plasma adiponectin. Adult male-female differences in plasma leptin were lost with prior exposure to neonatal hypoxia or hypothermia; male-female differences in resistin were lost in the adults that were exposed to hypoxia and spontaneous hypothermia as neonates. Exposure of neonates to daily hypoxia without spontaneous hypothermia led to a decrease in plasma testosterone in adult male rats. We conclude that neonatal stressors result in subsequent adult sex-dependent increases in insulin resistance and adipokines and that our rat model of prematurity with hypoxia without hypothermia alters adult testosterone dynamics.

Preterm infants have significantly longer telomeres than their term born counterparts

There are well-established morbidities associated with preterm birth including respiratory, neurocognitive and developmental disorders. However several others have recently emerged that characterise an 'aged' phenotype in the preterm infant by term-equivalent age. These include hypertension, insulin resistance and altered body fat distribution. Evidence shows that these morbidities persist into adult life, posing a significant public health concern. In this study, we measured relative telomere length in leukocytes as an indicator of biological ageing in 25 preterm infants at term equivalent age. Comparing our measurements with those from 22 preterm infants sampled at birth and from 31 term-born infants, we tested the hypothesis that by term equivalent age, preterm infants have significantly shorter telomeres (thus suggesting that they are prematurely aged). Our results demonstrate that relative telomere length is highly variable in newborn infants and is significantly negatively correlated with gestational age and birth weight in preterm infants. Further, longitudinal assessment in preterm infants who had telomere length measurements available at both birth and term age (n = 5) suggests that telomere attrition rate is negatively correlated with increasing gestational age. Contrary to our initial hypothesis however, relative telomere length was significantly shortest in the term born control group compared to both preterm groups and longest in the preterm at birth group. In addition, telomere lengths were not significantly different between preterm infants sampled at birth and those sampled at term equivalent age. These results indicate that other, as yet undetermined, factors may influence telomere length in the preterm born infant and raise the intriguing hypothesis that as preterm gestation declines, telomere attrition rate increases.

Pulmonary arterial resistance and compliance in preterm infants

BACKGROUND

Preterm birth is known to be associated with an increased risk of pulmonary arterial hypertension, although how preterm birth influences pulmonary hemodynamics has not been fully understood. Pulmonary arterial resistance (Rp) and compliance (Cp) are important factors to assess the pulmonary circulation. The purpose of this study is to clarify the relationship between Rp and Cp in preterm infants.

METHODS

We performed cardiac catheterization in 96 infants (50 males) with ventricular septal defect, and compared pulmonary hemodynamic parameters including Rp and Cp between preterm and full-term infants.

RESULTS

Thirteen infants were preterm. There were no significant differences in sex, age, preoperative pulmonary arterial pressure, preoperative pulmonary-to-systemic flow ratio, and preoperative Rp between the 2 groups. However, preoperative Cp and resistor-capacitor (RC) time in preterm infants were significantly lower than those in full-term infants (2.1 vs 2.8mL/mmHg/m² and 0.31 vs 0.36s, respectively; p<0.05 and p<0.01, respectively). Postoperative systolic and mean pulmonary arterial pressures were higher in preterm infants than those in full-term infants (29 vs 25mmHg and 18 vs 14mmHg, respectively; both p<0.01). It was also observed that postoperative Cp was lower in preterm infants, although postoperative Rp remained unchanged.

CONCLUSIONS

We demonstrated that preterm infants with pulmonary arterial hypertension had lower Cp than full-term infants, causing a modest increase in pulmonary arterial pressure. It is important to consider the unique pulmonary vasculature characterized by lower Cp, when managing preterm infants with congenital heart disease.

Long-Term Impact of Preterm Birth: Neurodevelopmental and Physical Health Outcomes

Preterm birth severely disrupts the normal developmental maturation of organ systems, resulting in lasting adverse effects. High blood pressure, cardiac dysfunction, obstructive lung disease, elevated blood glucose, and mental health problems occur earlier and at higher rates in the preterm-born than in the term populations. Disadvantageous health conditions may have a significant impact on the well-being of preterm-born individuals from childhood through adulthood. This review summarizes the impact of preterm birth on neurodevelopment and on cardiovascular, renal, metabolic, and pulmonary health.

Betamethasone-exposed preterm birth does not impair insulin action in adult sheep

Preterm birth is associated with increased risk of type 2 diabetes (T2D) in adulthood; however, the underlying mechanisms are poorly understood. We therefore investigated the effect of preterm birth at ~0.9 of term after antenatal maternal betamethasone on insulin sensitivity, secretion and key determinants in adulthood, in a clinically relevant animal model. Glucose tolerance and insulin secretion (intravenous glucose tolerance test) and whole-body insulin sensitivity (hyperinsulinaemic euglycaemic clamp) were measured and tissue collected in young adult sheep (14 months old) after epostane-induced preterm (9M, 7F) or term delivery (11M, 6F). Glucose tolerance and disposition, insulin secretion, β-cell mass and insulin sensitivity did not differ between term and preterm sheep. Hepatic PRKAG2 expression was greater in preterm than in term males (P = 0.028), but did not differ between preterm and term females. In skeletal muscle, SLC2A4 (P = 0.019), PRKAA2 (P = 0.021) and PRKAG2 (P = 0.049) expression was greater in preterm than in term overall and in males, while INSR (P = 0.047) and AKT2 (P = 0.043) expression was greater in preterm than in term males only. Hepatic PRKAG2 expression correlated positively with whole-body insulin sensitivity in males only. Thus, preterm birth at 0.9 of term after betamethasone does not impair insulin sensitivity or secretion in adult sheep, and has sex-specific effects on gene expression of the insulin signalling pathway. Hence, the increased risk of T2D in preterm humans may be due to factors that initiate preterm delivery or in early neonatal exposures, rather than preterm birth per se.