Ambulatory blood pressure and its variability in adults born preterm

Oral sodium supplementation on growth and hypertension in preterm infants: an observational cohort study

OBJECTIVE

To evaluate the association between enteral sodium supplementation on growth and hypertension (HTN) in preterm infants.

STUDY DESIGN

A retrospective cohort study of infants born between 22-32 weeks and weighing 450-1500 grams (N = 821). Enteral sodium supplementation amounts, systolic blood pressures (SBP), weight gain, and other infant and maternal risk factors for HTN were electronically extracted.

RESULTS

Infants receiving sodium supplementation were smaller and less mature. Sodium supplementation improved serum sodium levels, weight gain, and head circumference growth without causing hypernatremia. There was no correlation between urine and serum sodium or urine sodium and weight gain. Although infants receiving sodium had higher average SBP and rates of HTN, analysis demonstrated sodium supplementation did not increase odds of hypertension (ORADJ 1.02;0.64-1.64). Postnatal steroids were associated with HTN.

CONCLUSIONS

In preterm infants with poor weight gain, enteral sodium supplementation improved growth without increasing hypertension or hypernatremia.

High Amino Acid Intake in Early Life Is Associated With Systolic but Not Diastolic Arterial Hypertension at 5 Years of Age in Children Born Very Preterm

BACKGROUND

The life course of individuals born very premature is a topic of increasing concern. The association between high early amino acid intake and later high blood pressure (HBP) in preterm neonates is debated.

METHODS AND RESULTS

In a national, prospective, population-based birth cohort, EPIPAGE-2 (Etude Epidémiologique sur Petits Ages Gestationnels), we assessed blood pressure at 5 years. Eligible infants were those born between 24 and 29 weeks of gestation. Infants were distributed in 2 groups of 717 infants matched on propensity score on whether or not they were exposed to high amino acid intake (>3.5 g/kg per day at day 7); 455 control term infants were also enrolled. A value ≥95th percentile of reference values for age and height defined systolic or diastolic HBP. Blood pressure at 5 years of age was assessed for 389 and 385 children in the exposed and nonexposed groups, respectively. Rates (in percent) of systolic and diastolic HBP were 18.0% (95% CI, 14.5%-22.2%), 13.3% (95% CI, 10.3%-17.0%), 8.5% (95% CI, 6.5%-11.1%), and 9.0% (95% CI, 6.6%-12.3%), 10.2% (95% CI, 7.5%-13.6%), and 5.4% (95% CI, 3.8%-7.6%) in exposed, nonexposed, and term-born groups, respectively. Exposure to high early amino acid intake and maximal serum creatinine (by 50 μmol/L) between day 3 and day 7 were 2 independent risk factors for systolic HBP (adjusted odds ratio [aOR], 1.60 [95% CI, 1.05-2.43] and aOR, 1.59 [95% CI, 1.12-2.26], respectively) but not for diastolic HBP (aOR, 0.84 [95% CI, 0.50-1.39] and aOR, 1.09 [95% CI, 0.71-1.67], respectively). After adjustment for 5-year weight Z score, the aOR between high early amino acid intake and systolic HBP was 1.50 [95% CI, 0.98-2.30].

CONCLUSIONS

These results suggest that mechanisms of childhood systolic HBP involve neonatal renal challenge by high amino acid intake or dysfunction.

Accelerated Aging and the Life Course of Individuals Born Preterm

Individuals born preterm have shorter lifespans and elevated rates of chronic illness that contribute to mortality risk when compared to individuals born at term. Emerging evidence suggests that individuals born preterm or of low birthweight also exhibit physiologic and cellular biomarkers of accelerated aging. It is unclear whether, and to what extent, accelerated aging contributes to a higher risk of chronic illness and mortality among individuals born preterm. Here, we review accelerated aging phenotypes in adults born preterm and biological pathways that appear to contribute to accelerated aging. We highlight biomarkers of accelerated aging and various resiliency factors, including both pharmacologic and non-pharmacologic factors, that might buffer the propensity for accelerated aging among individuals born preterm.

Blood pressure, arterial stiffness, and cardiovascular risk profiles in 8-12-year-old children following preeclampsia (FINNCARE-study)

OBJECTIVES

The aim was to study if children following preeclampsia (PE) develop alterations in blood pressure (BP) and arterial stiffness already early in life, and how this is associated with gestational, perinatal and child cardiovascular risk profiles.

METHODS

One hundred eighty-two PE (46 early-onset with diagnosis before 34 gestational weeks, and 136 late-onset) and 85 non-PE children were assessed 8-12 years from delivery. Office and 24-h ambulatory BP, body composition, anthropometrics, lipids, glucose, inflammatory markers, and tonometry-derived pulse wave velocity (PWV) and central BPs were assessed.

RESULTS

Office BP, central BPs, 24-h systolic BP (SBP) and pulse pressure (PP) were higher in PE compared with non-PE. Early-onset PE children had the highest SBP, SBP-loads, and PP. SBP nondipping during night-time was common among PE. The higher child 24-h mean SBP among PE was explained by maternal SBP at first antenatal visit and prematurity (birth weight or gestational weeks), but child 24-h mean PP remained related with PE and child adiposity after adjustments. Central and peripheral PWVs were elevated in late-onset PE subgroup only and attributed to child age and anthropometrics, child and maternal office SBP at follow-up, but relations with maternal antenatal SBPs and prematurity were not found. There were no differences in body anthropometrics, composition, or blood parameters.

CONCLUSIONS

PE children develop an adverse BP profile and arterial stiffness early in life. PE-related BP is related with maternal gestational BP and prematurity, whereas arterial stiffness is determined by child characteristics at follow-up. The alterations in BP are pronounced in early-onset PE.Clinical Trial Registration information: https://clinicaltrials.gov/ct2/show/NCT04676295ClinicalTrials.gov Identifier: NCT04676295.

The co-occurrence and cumulative prevalence of hypertension, rheumatoid arthritis, and hypothyroidism in preterm-born women in the Women's Health Initiative

Emerging evidence suggests that preterm-born individuals (<37 weeks gestation) are at increased risk of developing chronic health conditions in adulthood. This study compared the prevalence, co-occurrence, and cumulative prevalence of three female predominant chronic health conditions - hypertension, rheumatoid arthritis [RA], and hypothyroidism - alone and concurrently. Of 82,514 U.S. women aged 50-79 years enrolled in the Women's Health Initiative, 2,303 self-reported being born preterm. Logistic regression was used to analyze the prevalence of each condition at enrollment with birth status (preterm, full term). Multinomial logistic regression models analyzed the association between birth status and each condition alone and concurrently. Outcome variables using the 3 conditions were created to give 8 categories ranging from no disease, each condition alone, two-way combinations, to having all three conditions. The models adjusted for age, race/ethnicity, and sociodemographic, lifestyle, and other health-related risk factors. Women born preterm were significantly more likely to have any one or a combination of the selected conditions. In fully adjusted models for individual conditions, the adjusted odds ratios (aORs) were 1.14 (95% CI, 1.04, 1.26) for hypertension, 1.28 (1.12, 1.47) for RA, and 1.12 (1.01, 1.24) for hypothyroidism. Hypothyroidism and RA were the strongest coexisting conditions [aOR 1.69, 95% CI (1.14, 2.51)], followed by hypertension and RA [aOR 1.48, 95% CI (1.20, 1.82)]. The aOR for all three conditions was 1.69 (1.22, 2.35). Perinatal history is pertinent across the life course. Preventive measures and early identification of risk factors and disease in preterm-born individuals are essential to mitigating adverse health outcomes in adulthood.

Association of Preterm Birth With Prevalent and Incident Hypertension, Early-Onset Hypertension, and Cardiovascular Disease in the Women's Health Initiative

Increasing evidence suggests preterm birth is a risk factor for hypertension and cardiovascular disease (CVD) in adulthood. Whether there is effect modification by hypertension on CVD risk is unknown. To investigate the associations between preterm birth, hypertension, and incident CVD, we identified 2,303 women aged 50 to 79 years who self-reported being born preterm from the Women's Health Initiative. Using multivariable logistic regression, prevalent hypertension at enrollment, age at hypertension diagnosis, and antihypertensive medication use were compared by birth status (preterm, full-term). Risk of incident hypertension, coronary heart disease, and CVD were analyzed using multivariable Cox proportional-hazard models. Both models adjusted for age, race/ethnicity, education, smoking, physical activity, body mass index, and diabetes mellitus. Significant associations were found between preterm birth and prevalent hypertension (37% vs 33.1%; adjusted odds ratio 1.26 [95% confidence interval (CI) 1.15 to 1.28] p = <0.0001), early-onset hypertension (<50 years) (14.7% vs 11.7%; adjusted odds ratio 1.31, 95% CI 1.15 to 1.48, p = <0.0001), and incident hypertension (53.2% vs 51%; ajusted hazard ratio 1.10, 95% CI 1.03 to 1.19, p = 0.008). Preterm-born women reported taking more antihypertensive medications (2.9% vs 2.6%, p = 0.04). Preterm birth had a nonsignificant association with CVD risk, but when stratified by prevalent hypertension, women born preterm without hypertension had elevated CVD risk compared with women born full-term without prevalent hypertension. Women with prevalent hypertension, preterm and full-term, had similar magnitudes of elevations in CVD risk. In conclusion, preterm birth increases the risk of hypertension and coronary heart disease. With 10% of the population born preterm, birth history should be assessed as a CVD risk factor.

A new cardiovascular disease risk factor for young adults: Preterm birth

ABSTRACT

Adults born preterm (birth <37 weeks' gestation) have a two-fold increased risk of early cardiovascular mortality. With 10% of the U.S. population born prematurely and perinatal advancements dramatically improving survival rates, millions of survivors are now reaching adulthood. This phenomenon has introduced a whole new population of individuals with a history of preterm birth. Although the prevailing notion has been that preterm birth is a condition confined only to infancy and early childhood, we now know preterm birth is a risk for lifelong chronic health conditions. Despite almost a decade of epidemiological evidence showing increased cardiovascular risk for those born preterm, this has not yet been translated into clinical practice. As a result, clinicians are caring for adults born prematurely without screening and treatment guidelines for this at-risk population and few inquire about birth history during clinical encounters. This brief report presents growing evidence about disrupted cardiogenesis and consequential structural and functional modifications. By asking the question "Were you born preterm?," nurse practitioners can take the first step of increasing their awareness of this at-risk population and mitigate adverse cardiovascular outcomes by using preterm birth as a risk factor when determining health promotion and treatment decisions.

Precision caffeine therapy for apnea of prematurity and circadian rhythms: New possibilities open up

Caffeine is the globally consumed psychoactive substance and the drug of choice for the treatment of apnea of prematurity (AOP), but its therapeutic effects are highly variable among preterm infants. Many of the molecular underpinnings of the marked individual response have remained elusive yet. Interestingly, the significant association between Clock gene polymorphisms and the response to caffeine therapy offers an opportunity to advance our understanding of potential mechanistic pathways. In this review, we delineate the functions and mechanisms of human circadian rhythms. An up-to-date advance of the formation and ontogeny of human circadian rhythms during the perinatal period are concisely discussed. Specially, we summarize and discuss the characteristics of circadian rhythms in preterm infants. Second, we discuss the role of caffeine consumption on the circadian rhythms in animal models and human, especially in neonates and preterm infants. Finally, we postulate how circadian-based therapeutic initiatives could open new possibilities to promote precision caffeine therapy for the AOP management in preterm infants.

Arterial stiffness and nocturnal hypertension in preterm children and adolescents

BACKGROUND AND OBJECTIVES

Preterm birth has been associated with increased risk for developing hypertension and other chronic diseases during childhood and adulthood. The aim of the current prospective case-control study was to investigate the associations of preterm birth with ambulatory blood pressure (BP) levels and arterial stiffness during childhood and adolescence.

METHODS

The study population included 52 children and adolescents born preterm and 26 healthy children born full term with similar age. The participants underwent ambulatory BP monitoring (ABPM) and assessment of carotid-femoral pulse wave velocity (PWV).

RESULTS

Preterm children presented higher night SBP z score values compared to controls, but did not differ in other ABPM parameters, office peripheral and central SBPs. Nocturnal hypertension was found in 78% (7/9) of ex-preterm children with ambulatory BP hypertension. Preterm birth was an independent predictor of PWV z score adjusted for heart rate. Estimated marginal means for PWV z score adjusted for age, sex, presence of kidney disease at birth, office BPs, night BPs, central SBP, and BMI z scores were significantly higher in preterm individuals compared to controls (0.703, 95% confidence interval [CI] 0.431-0.975 versus -0.19, 95% CI -0.574-0.536, respectively, P  = 0.027). Preterm children who were overweight presented the highest values of night SBP and PWV z score.

CONCLUSION

Preterm birth is associated with higher nocturnal BP and increased arterial stiffness in childhood and adolescence. Increased awareness for detection of hypertension and prevention of obesity in childhood could prevent future adverse cardiovascular outcomes in preterm individuals.

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.

Outcomes into adulthood of infants born extremely preterm

As survival of infants born extremely preterm increases, more are now reaching adulthood. It is well documented that survivors born extremely preterm experience more developmental delay and disability in multiple domains compared with term-born controls in early childhood and school age. However, with increasing age, health problems involving physical and mental health become more evident. Despite these challenges, it is reassuring that self-reported quality of life remains good. Future directions of research include development of age-appropriate interventions to optimise health and development of individuals born extremely preterm beyond school age.

Nutritional Management and Recommendation for Preterm Infants: A Narrative Review

Background: Preterm birth is defined as birth before 37 completed weeks of pregnancy. It is the most important predictor of adverse health and development infant outcomes that extend into the early childhood and beyond. It is also the leading cause of childhood mortality under 5 years of age worldwide and responsible for approximately one million neonatal deaths. It is also a significant contributor to childhood morbidities, with many survivors are facing an increased risk of lifelong disability and poor quality of life. Purpose: In this article, we aimed to describe features of preterm infants, what makes them different from term infants, and what to consider in nutritional management of preterm infants through a traditional narrative literature review. Discussion: Preterm infants are predisposed to more health complications than term infants with higher morbidity and mortality. This morbidity and mortality can be reduced through timely interventions for the mother and the preterm infant. Maternal interventions, such as health education and administration of micronutrient supplementation, are given before or during pregnancy and at delivery, whereas appropriate care for the preterm infants should be initiated immediately after birth, which include early breastfeeding and optimalization of weight gain. Conclusion: Essential care of the preterm infants and early aggressive nutrition should be provided to support rapid growth that is associated with improved neurodevelopmental outcomes. The goal is not only about survival but making sure that these preterm infants grow and develop without any residual morbidity.

Increased aortic stiffness and elevated blood pressure in response to exercise in adult survivors of prematurity

Objectives

Adults born prematurely have an increased risk of early heart failure. The impact of prematurity on left and right ventricular function has been well documented, but little is known about the impact on the systemic vasculature. The goals of this study were to measure aortic stiffness and the blood pressure response to physiological stressors; in particular, normoxic and hypoxic exercise.

Methods

Preterm participants (n = 10) were recruited from the Newborn Lung Project Cohort and matched with term‐born, age‐matched subjects (n = 12). Aortic pulse wave velocity was derived from the brachial arterial waveform and the heart rate and blood pressure responses to incremental exercise in normoxia (21% O₂) or hypoxia (12% O₂) were evaluated.

Results

Aortic pulse wave velocity was higher in the preterm groups. Additionally, heart rate, systolic blood pressure, and pulse pressure were higher throughout the normoxic exercise bout, consistent with higher conduit artery stiffness. Hypoxic exercise caused a decline in diastolic pressure in this group, but not in term‐born controls.

Conclusions

In this first report of the blood pressure response to exercise in adults born prematurely, we found exercise‐induced hypertension relative to a term‐born control group that is associated with increased large artery stiffness. These experiments performed in hypoxia reveal abnormalities in vascular function in adult survivors of prematurity that may further deteriorate as this population ages.

Preterm Birth With Neonatal Interventions Accelerates Collagen Deposition in the Left Ventricle of Lambs Without Affecting Cardiomyocyte Development

Background

Adults born preterm (< 37 weeks’ gestation) exhibit altered cardiac growth and are susceptible to cardiac dysfunction. Sheep studies have shown that moderate preterm birth results in maladaptive structural remodelling of the cardiac ventricles. The aim of this study was to examine ventricular structure in lambs born at a greater severity of preterm birth and ventilated postnatally.

Methods

Former-preterm lambs delivered at 128 days’ gestation, and mechanically ventilated for a week after birth, were compared with unventilated lambs born at term (150 days’ gestation), at 2 months (term: n = 10, former-preterm: n = 8), and 5 months (term: n = 9, former-preterm: n = 8) term-equivalent age. The right ventricle and left ventricle plus septum were analysed using immunohistochemistry, histology, and stereology.

Results

Cardiomyocyte number, cross-sectional area, proliferation, and apoptosis were not affected by preterm birth or age. Left ventricle plus septum interstitial collagen levels increased with age (P = 0.0015) and were exacerbated by preterm birth (P = 0.0006; 2 months term: 0.57% ± 0.07%, former-preterm: 1.44% ± 0.18%; 5 months term: 1.37% ± 0.25%, former-preterm: 2.15% ± 0.31%). Right ventricle interstitial collagen levels increased with age (P = 0.012) but were not affected by preterm birth.

Conclusion

This study is the first to explore the effect of preterm birth combined with modern neonatal interventions on the ventricular myocardium in lambs. There was no adverse impact on cardiomyocyte growth in early postnatal life. Of concern, however, there was increased collagen deposition in the preterm hearts, which has the potential to induce cardiac dysfunction, especially if it becomes exaggerated with ageing.

Current obesity was associated with hypertension in children born very low birth weight

Objectives

Previous studies from the developed countries showed that children born very low birth weight have a higher risk of hypertension compared with that of the normal birth weight controls. However, studies regarding the prevalence of hypertension in such children from the developing countries are scarce. This study aimed to identify the perinatal and postnatal factors associated with hypertension in children born very low birth weight.

Results

Forty-six children aged ≥ 6 years from the VLBW cohort of Ramathibodi Hospital, Bangkok, Thailand underwent the ambulatory blood pressure monitoring. The prevalence of hypertension was 15.2% (7/46). The hypertension group had a significant higher BMI z-score at 3 years of age (0.90 ± 1.44 vs − 0.45 ± 1.47, p = 0.045) and a greater proportion of current obesity (42% vs 2.5%, p < 0.01) compared to those in the normotensive group. Multivariate analysis revealed that current obesity was associated with hypertension (OR 34.77, 95%CI 1.814–666.5). Among 36 children with normal office blood pressure, four children (11.1%) had high blood pressure uncovered by ABPM, called “masked hypertension”. Office systolic blood pressure at the 85th percentile was the greatest predictor for masked hypertension with a sensitivity of 75% and a specificity of 81.2%.

Adrenal Steroid Metabolism and Blood Pressure in 5- to 7-Year-Old Children Born Preterm as Compared to Peers Born at Term

Background: Previous studies indicated preterm birth to be a risk factor for hypertension in adolescence and adulthood. However, studies in children investigating the underlying mechanisms are scarce. Objective: We hypothesized children born preterm to have higher excretion of cortisol and/or androgen metabolites per day concomitantly with higher blood pressure as compared to peers born at term. We thus aimed to compare urinary steroid profiles and blood pressure between 5- to 7-year-old children born preterm and peers born at term. Furthermore, aldosterone precursor excretion per day was compared between both groups. Methods: Blood pressure was measured in 236 children (preterms n = 116; gestational age 29.8 ± 2.6 (30; 24-33) weeks [mean ± standard deviation (median; range)]) using an automatic oscillometric device. Urinary steroid profiles were determined in 24-h urine samples (preterms n = 109; terms n = 113) using gas chromatographic-mass spectrometric analysis. To assess excretion of cortisol and androgen metabolites per day, major cortisol and androgen metabolites were summed, respectively. To assess aldosterone excretion per day tetrahydrocorticosterone, 5α-tetrahydrocorticosterone, and tetrahydro-11-deydrocorticosterone were summed. Results: Multiple regression analyses showed prematurity to be associated with systolic but not with diastolic blood pressure. When adjusted for potential confounders (prematurity, gender, age at day of examination, being born small for gestational age, breastfeeding, accelerated weight gain during infancy, family history of cardiovascular disease, parental hypertension, and body mass index) prematurity was shown to be associated with an increase in systolic blood pressure by 2.87 mmHg (95% confidence interval 0.48-5.27; p = 0.02). Cortisol, androgen metabolite, and aldosterone precursor excretion per day were not higher in individuals born preterm. In contrast to our hypothesis, multiple regression analysis showed prematurity to independently decrease cortisol and aldosterone precursor excretion per day (p < 0.001 and 0.04, respectively). Conclusion: This study provides further evidence for systolic blood pressure to be higher after preterm birth as early as at the age of 5 to 7 years. However, this seems not to be explained by elevated excretion of cortisol and/or androgen metabolites.

Secondary Hypertension in Children and Adolescents: Novel Insights

Hypertension is a significant risk factor for cardiovascular morbidity and mortality, not only in adults, but in youths also, as it is associated with long-term negative health effects. The predominant type of hypertension in children is the secondary hypertension, with the chronic kidney disease being the most common cause, however, nowadays, there is a rising incidence of primary hypertension due to the rising incidence of obesity in children. Although office blood pressure has guided patient management for many years, ambulatory blood pressure monitoring provides useful information, facilitates the diagnosis and management of hypertension in children and adolescents, by monitoring treatment and evaluation for secondary causes or specific phenotypes of hypertension. In the field of secondary hypertension, there are numerous studies, which have reported a strong association between different determinants of 24-hour blood pressure profile and the underlying cause. In addition, in children with secondary hypertension, ambulatory blood pressure monitoring parameters offer the unique advantage to identify pediatric low- and high-risk children for target organ damage. Novel insights in the pathogenesis of hypertension, including the role of perinatal factors or new cardiovascular biomarkers, such as fibroblast growth factor 23, need to be further evaluated in the near future.

Asthma prevalence, lung and cardiovascular function in adolescents born preterm

Our main objective was to study respiratory evolution and pulmonary and cardiac function in adolescents born preterm in the post-surfactant era. Observational cross-sectional study, comparing very preterm (< 32 weeks) and moderately-late preterm adolescents (≥ 32 weeks) (74 each group). We recorded respiratory symptoms, spirometry and functional echocardiogram. Very preterm adolescents required more respiratory admissions (45.9% vs. 28.4%) (p = 0.03, OR 2.1, CI95% 1.1–4.2) and had more current asthma (21.6% vs. 9.5%, p = 0.04, OR 2.3, CI95% 1.1–5.2). Preterm subjects with intrauterine growth restriction (IUGR) presented lower FEV₁ (88.7 ± 13.9 vs. 95.9 ± 13.3, p = 0.027) and lower FVC (88.2 ± 13.6 vs. 95.5 ± 13.3, p = 0.025). When assessing right ventricle, very preterm showed a greater E/E’ ratio (p = 0.02) and longer myocardial performance index (MPI) (p = 0.001). Adolescents with IUGR showed less shortening fraction (p = 0.016), worse E/E′ ratio (p = 0.029) and longer MPI (p = 0.06). Regarding left ventricle, very preterm showed less E′ wave velocity (p = 0.03), greater E/E′ ratio (p = 0.005) and longer MPI (p < 0.001). Gestational age < 32 weeks is independently associated with current asthma in adolescence. Children 13–14 years old born very preterm required more respiratory admissions and had poorer diastolic and global function of both ventricles. IUGR is a risk factor for poorer lung function in preterm adolescents, regardless gestational age.

Factors Predisposing to Hypertension in Subjects Formerly Born Preterm: Renal Impairment, Arterial Stiffness, Endothelial Dysfunction or Something Else?

Subjects formerly born preterm subsequently develop arterial - particularly isolated systolic- hypertension more frequently than their peers born at term.

Numerous factors may influence this predisposition, including an incomplete nephrogenesis, implying the presence of kidneys with a reduced number of nephrons and consequent reduction in haematic filtration, increased sodium absorption and activation of renin-angiotensin-aldosterone system, increased arterial rigidity produced by an elastin deficiency previously observed in anatomic specimens of human immature aorta, and reduced endothelial nitric oxide excretion, due to high blood levels of ADMA, a strong direct inhibitor of nitric oxide that exerts a vasoconstrictor effect.

Other possible factors (i.e. excretion of neuroendocrine compounds) may also be implicated. The aim of this paper was to review all possible mechanisms involved in the observed increase in blood pressure in individuals who had been born preterm and/or with intrauterine growth restriction. The outlook for new and promising laboratory techniques capable of identifying alterations in the metabolic pathways regulating blood pressure levels, such as metabolomics, is also provided.

High Blood Pressure in Young Adult Survivors Born Extremely Preterm or Extremely Low Birthweight in the Post Surfactant Era

More infants born extremely preterm (<28 weeks’ gestation) or extremely low birthweight (<1000 g) are surviving into adulthood in recent years. Preterm adolescents have higher blood pressure (BP) than normal birthweight controls, but how their BP changes with increasing age is not known. We compared BP at 25 years and trajectories of BP (change per year) from 18 to 25 years between survivors born <28 weeks/<1000 g and normal birthweight (>2499 g) controls born in the early 1990s, when survival rates began to rise. Participants were derived from 297 consecutive survivors born <28 weeks/<1000 g in 1991 to 1992 in Victoria, Australia, and 260 contemporaneous controls. At age 25 years, ambulatory BP was measured in 151 and 119 participants, respectively. Participants born <28 weeks/<1000 g had higher 24-hour systolic (mean difference 4.5 [95% CI, 1.2–7.7 mm Hg]), diastolic (3.4 [1.5–5.2 mm Hg]), and mean BPs (3.6 [1.4–5.8 mm Hg]) compared with the controls. Similar patterns were observed for both awake and asleep periods. Asleep ambulatory BP between 18 and 25 years increased more in participants born <28 weeks/<1000 g than in controls (systolic 0.56, diastolic 0.41, and mean 0.41 mm Hg increase per year; all P <0.05). Young adults born <28 weeks/<1000 g in the post surfactant era have higher BP and an increased trajectory of ambulatory BP compared with controls. With more survivors born <28 weeks/<1000 g now reaching adulthood, these findings are important for early detection and timely management of hypertension in this high-risk population.

Postexercise Heart Rate Recovery in Adults Born Preterm

OBJECTIVE

To evaluate postexercise heart rate recovery (HRR) in adults born preterm.

STUDY DESIGN

We studied the association between preterm birth and postexercise HRR in 545 adults (267 women) at 23.3 years of age (range 19.9-26.3 years). One hundred three participants were born early preterm (<34 completed weeks), 178 late preterm (34-36), and 264 were full term (control group). HRR was calculated as change in heart rate (HR) 30 seconds and 60 seconds after cessation of submaximal step test and maximum HR slope during the first minute after.

RESULTS

Mean peak HR was 159.5 bpm in the early preterm (P = .16 with controls), 157.8 bpm in the late preterm (P = .56), and 157.0 bpm in the control group. Mean HRR 30 seconds after exercise was 3.2 bpm (95% CI 1.1-5.2) lower in the early preterm group and 2.1 bpm (0.3-3.8) lower in the late preterm group than the full term controls. Mean 60s HRR was 2.5 (-0.1 to 5.1) lower in the early preterm group and 2.8 bpm (0.6-4.9) lower in the late preterm group. Mean maximum slope after exercise was 0.10 beats/s (0.02-0.17) lower in the early preterm group and 0.06 beats/s (0.00-0.12) lower in the late preterm group.

CONCLUSIONS

Our results suggest reduced HRR after exercise in adults born preterm, including those born late preterm. This suggests altered reactivation of the parasympathetic nervous system, which may contribute to cardiovascular risk among adults born preterm.

Preterm Birth as a Risk Factor for Metabolic Syndrome and Cardiovascular Disease in Adult Life: A Systematic Review and Meta-Analysis

OBJECTIVE

To determine if preterm birth is associated with components of the metabolic syndrome in adult life.

STUDY DESIGN

A structured literature search was performed using PubMed. All comparative studies reported metabolic and cardiovascular outcomes in adults (≥18 years of age) born preterm (<37 weeks of gestation) compared with adults born at term (37-42 weeks of gestation) and published through March 2018 were included. The major outcomes assessed were body mass index, waist circumference, waist-to-hip ratio, fat mass, systolic blood pressure (SBP), diastolic blood pressure (DBP), 24-hour SBP, 24-hour DBP, endothelium-dependent brachial artery flow-mediated dilation, carotid intima-media thickness, pulse wave velocity, fasting glucose and insulin, Homeostasis Model Assessment-Estimated Insulin Resistance Index, and lipid profiles. Quality appraisal was performed using a modified version of the Newcastle-Ottawa scale. A meta-analysis was performed for comparable studies which reported sufficient data.

RESULTS

Forty-three studies were included, including a combined total of 18 295 preterm and 294 063 term-born adults. Prematurity was associated with significantly higher fat mass (P = .03), SBP (P < .0001), DBP (P < .0001), 24-hour SBP (P < .001), and 24-hour DBP (P < .001). Furthermore, preterm-born adults presented higher values of fasting glucose (P = .01), insulin (P = .002), Homeostasis Model Assessment-Estimated Insulin Resistance Index (P = .05), and total cholesterol levels (P = .05) in comparison with adults born at term, in random effect models. No statistically significant difference was found between preterm and term-born adults for the other outcomes studied.

CONCLUSIONS

Preterm birth is strongly associated with a number of components of the metabolic syndrome and cardiovascular disease in adult life.

Cardiac Autonomic Function in Adults Born Preterm

OBJECTIVE

To evaluate cardiac autonomic function in adults born preterm.

STUDY DESIGN

We studied the association between prematurity and cardiac autonomic function using heart rate variability measurements in 600 adults (mean age of 23.3 years) from a geographically based cohort in Northern Finland. There were 117 young adults born early preterm (<34 weeks), 207 born late preterm (34-36 weeks), and 276 born at term (≥37 weeks, controls). Autonomic function was analyzed by calculating time and frequency domain heart rate variability measurements using linear regression.

RESULTS

Compared with controls, the mean difference in root mean square of successive differences (indicating cardiac vagal activity) was -12.0% (95% CI -22.2%, -0.5%, adjusted for sex, age, source cohort, and season P = .04) for the early preterm group and -7.8% (-16.8%, 2.0%, P = .12) for the late preterm group. Mean differences with controls in low frequency power (indicating cardiac vagal activity, including some sympathetic- and baroreflex-mediated effects) were -13.6% (-26.7%, 1.8%, P = .08) for the early preterm group and -16.4% (-27.0%, -4.3%, P = .01) for the late preterm group. Mean differences in high frequency power (quantifying cardiac vagal modulation in respiratory frequency) were -19.2% (-36.6%, 2.9%, P = .09) for the early preterm group and -13.8% (-29.4%, 5.3%, P = .15) for the late preterm group. Differences were attenuated when controlled for body mass index and physical activity.

CONCLUSIONS

Our results suggest altered autonomic regulatory control in adults born preterm, including those born late preterm. Altered autonomic regulatory control may contribute to increased cardiovascular risk in adults born preterm.

Kidney Size, Renal Function, Ang (Angiotensin) Peptides, and Blood Pressure in Young Adults Born Preterm

Preterm birth incurs a higher risk for adult cardiovascular diseases, including hypertension. Because preterm birth may impact nephrogenesis, study objectives were to assess renal size and function of adults born preterm versus full term and to examine their relationship with blood pressure (BP; 24-hour ambulatory BP monitoring) and circulating renin-Ang (angiotensin) system peptides. The study included 92 young adults born (1987-1997) preterm (≤29 weeks of gestation) and term (n=92) matched for age, sex, and race. Young adults born preterm had smaller kidneys (80±17 versus 90±18 cm³/m²; P<0.001), higher urine albumin-to-creatinine ratio (0.70; interquartile range, 0.47-1.14 versus 0.58, interquartile range 0.42 to 0.78 mg/mmol, P=0.007), higher 24-hour systolic (121±9 versus 116±8 mm Hg; P=0.001) and diastolic (69±5 versus 66±6 mm Hg; P=0.004) BP, but similar estimated glomerular filtration rate. BP was inversely correlated with kidney size in preterm participants. Plasma Ang I was higher in preterm versus term participants (36.3; interquartile range, 13.2-62.3 versus 19.4; interquartile range, 9.9-28.1 pg/mL; P<0.001). There was no group difference in renin, Ang II, Ang (1-7), and alamandine. In the preterm, but not in the term group, higher BP was significantly associated with higher renin and alamandine and lower birth weight and gestational age with smaller adult kidney size. Young adults born preterm have smaller kidneys, higher urine albumin-to-creatinine ratio, higher BP, and higher circulating Ang I levels compared with term controls. Preterm young adults with smaller kidneys have higher BP. Clinical Trial Registration- URL: http://www.clinicaltrials.gov . Unique identifier: NCT03261609.

Does History of Prematurity Prompt Blood Pressure Evaluations at Primary Care Visits?

Prematurity is a risk factor for elevated blood pressure (BP). We performed a mixed-methods study of care patterns and awareness of early BP screening recommendations for infants born prematurely (IBP) by interviewing/surveying providers on practice- and provider-level BP screening. IBP’s records were reviewed for BP screening documentation, demographics, and gestational age (GA). Visits <33 months were reviewed for anthropometrics, BP, and comorbidities. Chi-square analysis evaluated BP screening by GA and comorbidities. Twenty-six of 49 practices completed interviews; 81% had infant BP equipment available; 4% had BP measurement protocol for IBP. Twenty-eight of 86 providers were aware of screening guidelines; none reported routine assessment. Twenty-eight of 118 IBP had ≥1 BP documented; 43% had BP ≥90th percentile. Screening did not differ by GA group. Kidney-related diagnosis was associated with more frequent BP screening (P = .0454). BP is not routinely measured though often elevated before age 3 in IBP.

Adult outcomes of being born late preterm or early term - What do we know?

The literature on adult outcomes of people born late preterm (LPT, 34-36 completed weeks) or early term (ET, 37-38 weeks) was reviewed. In PubMed, 9547 articles were identified; 53 were eligible. Of these, 12 were based on clinical cohorts, 32 on medical birth register linkages, and nine on historical birth cohorts; 48 out of 53 on Nordic countries; 50 out of 53 reported on LPT and eight out of 53 reported on ET. LPT plus ET have increased early (<45 years) adult all-cause mortality. Despite increased cardiometabolic risk factors and slightly lower cardiorespiratory fitness in LPT, no studies showed increased risk for coronary heart disease, some showed increased risk for stroke, and all showed increased risk for type 2 diabetes. Most show increased risk for asthma and decreased allergic rhinitis. LPT have slightly lower cognitive abilities and higher rates of several mental disorders; ET have intermediate values. LPT and ET adults have slightly lower education, occupational status, and income. We recommend that authors report findings of LPT/ET separately from those born more preterm.

Lung function in adults born preterm

Very preterm birth, before the gestational age (GA) of 32 weeks, increases the risk of obstructed airflow in adulthood. We examined whether all preterm births (GA<37 weeks) are associated with poorer adult lung function and whether any associations are explained by maternal, early life/neonatal, or current life factors. Participants of the ESTER Preterm Birth Study, born between 1985 and 1989 (during the pre-surfactant era), at the age of 23 years participated in a clinical study in which they performed spirometry and provided detailed medical history. Of the participants, 139 were born early preterm (GA<34 weeks), 239 late preterm (GA: 34-<37 weeks), and 341 full-term (GA≥37 weeks). Preterm birth was associated with poorer lung function. Mean differences between individuals born early preterm versus full-term were -0.23 standard deviation (SD) (95% confidence interval (CI): -0.40, -0.05)) for forced vital capacity z-score (zFVC), -0.44 SD (95% CI -0.64, -0.25) for forced expiratory volume z-score (zFEV1), and -0.29 SD (95% CI -0.47, -0.10) for zFEV1/FVC. For late preterm, mean differences with full-term controls were -0.02 SD (95% CI -0.17, 0.13), -0.12 SD (95% CI -0.29, 0.04) and -0.13 SD (95% CI -0.29, 0.02) for zFVC, zFEV1, and zFEV1/FVC, respectively. Examination of finer GA subgroups suggested an inverse non-linear association between lung function and GA, with the greatest impact on zFEV1 for those born extremely preterm. The subgroup means were GA<28 weeks: -0.98 SD; 28-<32 weeks: -0.29 SD; 32-<34 weeks: -0.44 SD; 34-<36 weeks: -0.10 SD; 36-<37weeks: -0.11 SD; term-born controls (≥37weeks): 0.02 SD. Corresponding means for zFEV1/FVC were -1.79, -0.44, -0.47, -0.48, -0.29, and -0.02. Adjustment for maternal pregnancy conditions and socioeconomic and lifestyle factors had no major impact on the relationship. Preterm birth is associated with airflow limitation in adult life. The association appears to be attributable predominantly to those born most immature, with only a modest decrease among those born preterm at later gestational ages.

Endothelial Colony-Forming Cells in Young Adults Born Preterm: A Novel Link Between Neonatal Complications and Adult Risks for Cardiovascular Disease

BACKGROUND

Preterm birth is linked to cardiovascular risks and diseases. Endothelial progenitor cells play a critical role in vascular development and repair. Cord blood endothelial progenitor cells of preterm-born infants, especially endothelial colony-forming cells (ECFC), show enhanced susceptibility to prematurity-related pro-oxidant stress. Whether ECFC dysfunction is present in adulthood following preterm birth is unknown.

METHODS AND RESULTS

This cross-sectional observational study includes 55 preterm-born (≤29 gestational weeks) young adults (18-29 years old, 38% male) and 55 sex- and age-matched full-term controls. ECFC were isolated from peripheral blood; cell proliferative and vascular cord formation capacities were assessed in vitro. Daytime systolic blood pressure was higher, whereas glucose tolerance and body mass index were lower in preterm-born subjects. ECFC colonies grew in culture for 62% of full-term- and 58% of preterm-born participants. Preterm-born participants have formed ECFC colonies later in culture and have reduced proliferation compared with controls. Only in preterm-born individuals, we observed that the later the ECFC colony grows in culture, the worse was overall ECFC function. In addition, in preterms, elevated systolic blood pressure significantly correlated with reduced ECFC proliferation (r_S=-0.463; P=0.030) and numbers of branches formed on matrigel (r_S=-0.443; P=0.039). In preterm-born subjects, bronchopulmonary dysplasia was associated with impaired ECFC function, whereas exposure to antenatal steroids related to better ECFC function.

CONCLUSIONS

This study is the first to examine ECFC in preterm-born adults and to demonstrate ECFC dysfunction compared with full-term controls. In the preterm-born group, ECFC dysfunction was associated with bronchopulmonary dysplasia, the major prematurity-related neonatal morbidity, and with increased systolic blood pressure into adulthood.

The effect of sex and prematurity on the cardiovascular baroreflex response in sheep

NEW FINDINGS

What is the central question of this study? Late preterm infants are often assumed to escape long-term morbidities known to impact earlier preterm offspring. Is this true for the cardiovascular system? What is the main finding and its importance? We show that late preterm birth is a risk factor for cardiovascular dysfunction in early adulthood and is influenced by sex. Early signs of cardiovascular dysfunction might predispose to heart disease in adulthood. Very preterm infants have an increased risk of cardiovascular disease; however, the effects of a late preterm birth on future cardiovascular function are not known. We hypothesized that after a late preterm birth, the well-described impairments in heart rate variability and baroreflex sensitivity would persist into adulthood. To test this hypothesis, sheep born preterm (0.9 gestation; nine male and seven female) or term (11 male and six female) underwent surgery at 14 months of age for insertion of femoral arterial and venous catheters and a femoral flow probe. After recovery, heart rate variability was assessed, followed by a baroreflex challenge (using the vasoactive agents phenylephrine and sodium nitroprusside) in conscious adult lambs. Our data demonstrate decreased low-frequency normalised units (LFnu) and low-frequency/high-frequency ratio in female but not male ex-preterm sheep at rest. When challenged, mature male ex-preterm sheep have an increased blood pressure response but dampened heart rate baroreflex response. We show that even a late preterm birth leads to cardiovascular dysfunction in adulthood. These early signs of cardiovascular dysfunction might underpin the later hypertension and increased risk of heart disease observed in adults born preterm. These findings are particularly important because late preterm infants are often assumed to escape the long-term morbidities known to impact on very preterm and extremely preterm offspring.

Blood pressure regulation determined by ambulatory blood pressure profiles in children and adolescents with type 1 diabetes mellitus: Impact on diabetic complications

BACKGROUND

The combination of high blood pressure and hyperglycemia contributes to the development of diabetic complications. Ambulatory monitoring of blood pressure (ABPM) is seen as standard to assess blood pressure (BP) regulation.

OBJECTIVE

We evaluated 24-hour BP regulation in 3529 children with type 1 diabetes, representing 5.6% of the patients <20 years of age documented in the DPV registry, and studied the influence of BP parameters including pulse pressure (PP) and blood pressure variability (BPV) on microalbuminuria (MA) and diabetic retinopathy (DR).

RESULTS

BP was increased in this selected cohort of children with diabetes compared to healthy German controls (standard deviation score (SDS) day: systolic BP (SBP) +0.06, mean arterial pressure (MAP) +0.08, PP +0.3; night: SBP +0.6, diastolic BP +0.6, MAP +0.8), while daytime diastolic BP (SDS -0.2) and dipping of SBP and MAP were reduced (SBP -1.1 SDS, MAP 12.4% vs 19.4%), PP showed reverse dipping (-0.7 SDS). Children with microvascular complications had by +0.1 to +0.75 SDS higher BP parameters, except of nocturnal PP in MA and diurnal and nocturnal PP in DR. Reverse dipping of PP was more pronounced in the children with MA (-5.1% vs -0.8%) and DR (-2.6% vs -1.0%). BP alteration was stronger in girls and increased with age.

CONCLUSION

There is an early and close link between 24-hour blood pressure regulation and the development of diabetic complications not only for systolic, diastolic, and mean arterial BP but also for the derived BP parameter PP and BPV in our selected patients.

Adults born preterm: a review of general health and system-specific outcomes

In this review of 126 publications, we report that an overwhelming majority of adults born at preterm gestations remain healthy and well. However, a small, but a significant fraction of them remain at higher risk for neurological, personality and behavioural abnormalities, cardio-pulmonary functional limitations, systemic hypertension and metabolic syndrome compared to their term-born counterparts. The magnitude of increased risk differed across organ systems and varied across reports. The risks were proportional to the degree of prematurity at birth and seemed to occur more frequently among preterm infants born in the final two decades of the 20th century and later. These findings have considerable public health and clinical practice relevance.

CONCLUSION

Preterm birth needs to be considered a chronic condition, with a slight increase in the risk for long-term morbidities among adults born preterm. Therefore, obtaining a history of gestational age and weight at birth should be a routine part of care for patients of all age groups.

Should we assess cardiovascular risk in young adults born preterm?

PURPOSE OF REVIEW

Eleven percent of infants are born preterm worldwide. Preterm infants continue their development and growth in a substantially different environment than in uterus. The prenatal and postnatal period have long-lasting effects on a child's health. Previous studies have shown that adults born preterm with very low birth weight show enhancement of cardiometabolic risk factors such as elevated blood pressure and impaired glucose regulation compared with their peers born at term.

RECENT FINDINGS

Recent studies have more often included individuals born less preterm, as over 70% of premature infants are born late preterm (in 34-36 gestational weeks). Adults born preterm have elevated levels of cardiometabolic-risk factors concerning several aspects such as body size and composition, energy metabolism, blood pressure, vascular structure, glucose and lipid metabolism, lifestyle, and some emerging cardiometabolic-risk factors.

SUMMARY

Most of the cardiometabolic-risk factors related to preterm birth are modifiable. Favorable early-life circumstances of premature infants, such as optimal nutrition and growth, might reduce the risk of later cardiometabolic disorders. In addition, adults born preterm might particularly benefit from screening of risk factors and promotion of a healthy lifestyle.