Blood Pressure in 6-Year-Old Children Born Extremely Preterm

Early-Onset Fetal Growth Restriction Increases Left Ventricular Sphericity in Adolescents Born Very Preterm

Left ventricular shape alterations predict cardiovascular outcomes and have been observed in children born preterm and after fetal growth restriction (FGR). The aim was to investigate whether left ventricular shape is altered in adolescents born very preterm and if FGR has an additive effect. Adolescents born very preterm due to verified early-onset FGR and two control groups with birthweight appropriate for gestational age (AGA), born at similar gestational age and at term, respectively, underwent cardiac MRI. Principal component analysis was applied to find the modes of variation best explaining shape variability for end-diastole, end-systole, and for the combination of both, the latter indicative of function. Seventy adolescents were included (13-16 years; 49% males). Sphericity was increased for preterm FGR versus term AGA for end-diastole (36[0-60] vs - 42[- 82-8]; p = 0.01) and the combined analysis (27[- 23-94] vs - 51[- 119-11]; p = 0.01), as well as for preterm AGA versus term AGA for end-diastole (30[- 56-115] vs - 42[- 82-8]; p = 0.04), for end-systole (57[- 29-89] vs - 30[- 79-34]; p = 0.03), and the combined analysis (44[- 50-145] vs - 51[- 119-11]; p = 0.02). No group differences were observed for left ventricular mass or ejection fraction (all p ≥ 0.33). Sphericity was increased after very preterm birth and exacerbated by early-onset FGR, indicating an additive effect to that of very preterm birth on left ventricular remodeling. Increased sphericity may be a prognostic biomarker of future cardiovascular disease in this cohort that as of yet shows no signs of cardiac dysfunction using standard clinical measurements.

Pharmacogenomics-based individualized treatment of hypertension in preterm infants: A case report and review of the literature

BACKGROUND

Neonatal hypertension is a rare but potentially serious condition that requires careful monitoring and treatment. Pharmacogenomics can help guide individualized drug therapy and improve outcomes.

CASE SUMMARY

We report a case of a preterm infant with multiple complications, including bronchopulmonary dysplasia (BPD), sepsis, intracranial hemorrhage, and hypertension. The infant was treated with various drugs, including dexamethasone and amlodipine. The infant was diagnosed with neonatal hypertension based on blood pressure measurements exceeding the 95th percentile for his age and sex. The possible causes of hypertension included dexamethasone, hydrochlorothiazide, spironolactone, and BPD. The infant was treated with oral amlodipine to lower his blood pressure. A pharmacogenomic test was performed to evaluate the genetic polymorphisms of ABCB1 and CYP3A5, which are involved in the metabolism and transport of dexamethasone and amlodipine. The infant's blood pressure was well controlled after the dose of amlodipine was reduced according to the pharmacogenomic results. The infant had a stable general condition and was discharged on the 100th d after birth.

CONCLUSION

This case illustrates the importance of regular blood pressure monitoring and etiological investigation in preterm infants with hypertension. Pharmacogenomics can provide useful information for individualized drug therapy and safety in this population.

Persistent high blood pressure and renal dysfunction in preterm infants during childhood

BACKGROUND

Infants born very preterm (≤32 weeks gestational age, GA) and very-low birth weight (≤1500 g; PT-VLBW) demonstrate high systolic blood pressure (SBP), renal dysfunction, and obesity at 6 months-3 years and in early adulthood. Their parallel measurement and progression during childhood is unclear.

METHODS

We reenrolled 62/120 patients originally seen at 1-3 years at 10-13 years and remeasured anthropometric indices, SBP, and serum creatinine (Cr) and cystatin C (cysC) to determine estimated glomerular filtration rate (eGFR). We selected Term-matched Controls at 10-13 years from the 2015-2016 NHANES database at a ratio of 2 Controls:1 Case (124:62).

RESULTS

Reenrolled patients were predominantly Hispanic, birth weight 1073 ± 251 g, and GA at birth 28 ± 2 weeks. At 10-13 years, 45% were classified overweight/obese, 48% had SBP ≥ 90th centile (77% considered hypertensive), and 34% had low eGFR (<90 mL min^-1 [1.73 m²]^-1). Notably, 57% of reenrolled PT-VLBW Cases had low eGFR_cysC at both 1-3 and 10-13 years, P < 0.03. Compared to Controls, Cases had four times the adjusted odds for having an elevated SBP and low eGFR_Cr despite similar proportions with overweight/obesity among Cases and Controls.

CONCLUSIONS

PT-VLBW infants seen at 1-3 years exhibit obesity, elevated SBP, and low eGFR in infancy and 10-13 years. Although the small sample size may limit conclusions, pediatricians should consider serial evaluations of PT-VLBW throughout childhood.

IMPACT

The association between preterm birth and elevated blood pressure, renal dysfunction, and obesity in young adults begins as early as 1 year and persists at 10-13 years of age. This is the first study reporting serial measurements of blood pressure, renal function, and obesity from infancy to preadolescence in children born very preterm. Fifty-seven percent of preterm 1-3 year olds have persistent low estimated glomerular filtration rate associated with hypertension at 10-13 years. Clinicians should consider serial evaluations of blood pressure, renal function, and obesity throughout infancy and childhood in all preterm births.

Fetal growth restriction followed by very preterm birth is associated with smaller kidneys but preserved kidney function in adolescence

BACKGROUND

Preterm birth and fetal growth restriction (FGR) are associated with structural and functional kidney changes, increasing long-term risk for chronic kidney disease and hypertension. However, recent studies in preterm children are conflicting, indicating structural changes but normal kidney function. This study therefore assessed kidney structure and function in a cohort of adolescents born very preterm with and without verified FGR.

METHODS

Adolescents born very preterm with FGR and two groups with appropriate birthweight (AGA) were included; one matched for gestational week at birth and one born at term. Cortical and medullary kidney volumes and T1 and T2* mapping values were assessed by magnetic resonance imaging. Biochemical markers of kidney function and renin-angiotensin-aldosterone system (RAAS) activation were analyzed.

RESULTS

Sixty-four adolescents were included (13-16 years; 48% girls). Very preterm birth with FGR showed smaller total (66 vs. 75 ml/m²; p = 0.01) and medullary volume (19 vs. 24 ml/m²; p < 0.0001) compared to term AGA. Corticomedullary volume ratio decreased from preterm FGR (2.4) to preterm AGA (2.2) to term AGA (1.9; p = 0.004). There were no differences in T1 or T2* values (all p ≥ 0.34) or in biochemical markers (all p ≥ 0.12) between groups.

CONCLUSIONS

FGR with abnormal fetal blood flow followed by very preterm birth is associated with smaller total kidney and medullary kidney volumes, but not with markers of kidney dysfunction or RAAS activation in adolescence. Decreased total kidney and medullary volumes may still precede a long-term decrease in kidney function, and potentially be used as a prognostic marker. A higher resolution version of the Graphical abstract is available as Supplementary information.

Higher blood pressure in adolescent boys after very preterm birth and fetal growth restriction

BACKGROUND

Although preterm birth predisposes for cardiovascular disease, recent studies in children indicate normal blood pressure and arterial stiffness. This prospective cohort study therefore assessed blood pressure and arterial stiffness in adolescents born very preterm due to verified fetal growth restriction (FGR).

METHODS

Adolescents (14 (13-17) years; 52% girls) born very preterm with FGR (preterm FGR; n = 24) and two control groups born with appropriate birth weight (AGA), one in similar gestation (preterm AGA; n = 27) and one at term (term AGA; n = 28) were included. 24-hour ambulatory blood pressure and aortic pulse wave velocity (PWV) and distensibility by magnetic resonance imaging were acquired.

RESULTS

There were no group differences in prevalence of hypertension or in arterial stiffness (all p ≥ 0.1). In boys, diastolic and mean arterial blood pressures increased from term AGA to preterm AGA to preterm FGR with higher daytime and 24-hour mean arterial blood pressures in the preterm FGR as compared to the term AGA group. In girls, no group differences were observed (all p ≥ 0.1).

CONCLUSIONS

Very preterm birth due to FGR is associated with higher, yet normal blood pressure in adolescent boys, suggesting an existing but limited impact of very preterm birth on cardiovascular risk in adolescence, enhanced by male sex and FGR.

IMPACT

Very preterm birth due to fetal growth restriction was associated with higher, yet normal blood pressure in adolescent boys. In adolescence, very preterm birth due to fetal growth restriction was not associated with increased thoracic aortic stiffness. In adolescence, very preterm birth in itself showed an existing but limited effect on blood pressure and thoracic aortic stiffness. Male sex and fetal growth restriction enhanced the effect of preterm birth on blood pressure in adolescence. Male sex and fetal growth restriction should be considered as additional risk factors to that of preterm birth in cardiovascular risk stratification.

Reshaping the Preterm Heart: Shifting Cardiac Renin-Angiotensin System Towards Cardioprotection in Rats Exposed to Neonatal High-Oxygen Stress

BACKGROUND

Approximately 10% of infants are born preterm. Preterm birth leads to short and long-term changes in cardiac shape and function. By using a rat model of neonatal high-oxygen (80%O₂) exposure, mimicking the premature hyperoxic transition to the extrauterine environment, we revealed a major role of the renin-angiotensin system peptide Angio II (angiotensin II) and its receptor AT1 (angiotensin receptor type 1) on neonatal O₂-induced cardiomyopathy. Here, we tested whether treatment with either orally active compounds of the peptides Angio-(1-7) or alamandine included in cyclodextrin could prevent postnatal cardiac remodeling and the programming of cardiomyopathy induced by neonatal high-O₂ exposure.

METHODS

Sprague-Dawley pups were exposed to room air or 80% O₂ from postnatal day 3 (P3) to P10. Neonatal rats were treated orally from P3 to P10 and assessed at P10 and P28. Left ventricular (LV) shapes were characterized by tridimensional computational atlases of ultrasound images in addition to histomorphometry.

RESULTS

At P10, high O₂-exposed rats presented a smaller, globular and hypertrophied LV shape versus controls. Treatment with cyclodextrin-Angio-(1-7) significantly improved LV function in the O₂-exposed neonatal rats and slightly changed LV shape. Cyclodextrin-alamandine and cyclodextrin-Angio-(1-7) treatments similarly reduced hypertrophy at P10 as well as LV remodeling and dysfunction at P28. Both treatments upregulated cardiac angiotensin-converting enzyme 2 in O₂-exposed rats at P10 and P28.

CONCLUSIONS

Our findings demonstrate LV remodeling changes induced by O₂-stress and the potential benefits of treatments targeting the cardioprotective renin-angiotensin system axis, supporting the neonatal period as an important window for interventions aiming at preventing cardiomyopathy in people born preterm.

Prevalence and Risk Factors for Kidney Disease and Elevated BP in 2-Year-Old Children Born Extremely Premature

BACKGROUND AND OBJECTIVES

Extremely low gestational age neonates born <28 weeks gestation are at risk for chronic disease. We sought to describe the prevalence of kidney outcomes by gestational age and determine risk factors for their development.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The Recombinant Erythropoietin for Protection of Infant Renal Disease (REPAIReD) study examined kidney outcomes of extremely low gestational age neonates enrolled in the Preterm Epo NeuroProtection Trial (PENUT) study. Kidney function, urine albumin, and BP were measured at 2-year (24±2 months) corrected gestational age. We compared outcomes across gestational age categories and evaluated associations between kidney-related outcomes and neonatal and maternal characteristics. The primary outcome was eGFR <90 ml/min per 1.73 m² (CKD); secondary outcomes were spot urine albumin-creatinine ratio ≥30 mg/g (albuminuria) and either systolic BP or diastolic BP >90th percentile for height, age, and sex.

RESULTS

A total of 832 survived to 2 years, and 565 (68%) had at least one outcome measured. Overall, 297 (53%) had one abnormal kidney outcome; 61 (18%) had an eGFR <90 ml/min per 1.73 m², 155 (36%) had albuminuria, 65 (22%) had elevated systolic BP, and 128 (44%) had elevated diastolic BP. Gestational age (odds ratio, 0.94; 95% confidence interval, 0.89 to 0.99), birth weight z-score (odds ratio, 0.92; 95% confidence interval, 0.85 to 0.98), and prenatal steroids (odds ratio, 1.23; 95% confidence interval, 1.08 to 1.39) were associated with an eGFR <90 ml/min per 1.73 m². An elevated systolic BP was associated with indomethacin use (odds ratio, 1.18; 95% confidence interval, 1.04 to 1.33) and Black race (odds ratio, 1.19; 95% confidence interval, 1.01 to 1.39); elevated diastolic BP was associated with male sex (odds ratio, 1.29; 95% confidence interval, 1.12 to 1.49), severe AKI (odds ratio, 1.24; 95% confidence interval, 1.04 to 1.48), and indomethacin use (odds ratio, 1.16; 95% confidence interval, 1.01 to 1.33).

CONCLUSIONS

Approximately 18% of extremely low gestational age neonates have CKD, 36% have albuminuria, 22% have an elevated systolic BP, and 44% have an elevated diastolic BP at 2 years of age. Gestational age, birthweight z-score, and prenatal steroids were associated with CKD. Male sex, Black race, indomethacin use, and severe AKI were associated with elevated BP.

PODCAST

This article contains a podcast at https://www.asn-online.org/media/podcast/CJASN/2022_07_19_CJN15011121.mp3.

Impact of very preterm birth and post-discharge growth on cardiometabolic outcomes at school age: a retrospective cohort study

Background

Adverse metabolic outcomes later in life have been reported among children or young adults who were born as preterm infants. This study was conducted to examine the impact of very preterm/very low birth weight (VP/VLBW) birth and subsequent growth after hospital discharge on cardiometabolic outcomes such as insulin resistance, fasting glucose, and systolic and diastolic blood pressure (BP) among children at 6–8 years of age.

Methods

This retrospective cohort study included children aged 6–8 years and compared those who were born at < 32 weeks of gestation or weighing < 1,500 g at birth (n = 60) with those born at term (n = 110). Body size, fat mass, BP, glucose, insulin, leptin, adiponectin, and lipid profiles were measured. Weight-for-age z-score changes between discharge and early school-age period were also calculated, and factors associated with BP, fasting glucose, and insulin resistance were analyzed.

Results

Children who were born VP/VLBW had significantly lower fat masses, higher systolic BP and diastolic BP, and significantly higher values of fasting glucose, insulin, and homeostatic model assessment of insulin resistance (HOMA-IR), compared to children born at term. VP/VLBW was correlated with HOMA-IR and BPs after adjusting for various factors, including fat mass index and weight-for-age z-score changes. Weight-for-age z-score changes were associated with HOMA-IR, but not with BPs.

Conclusions

Although children aged 6–8 years who were born VP/VLBW showed significantly lower weight and fat mass, they had significantly higher BPs, fasting glucose, HOMA-IR, and leptin levels. The associations of VP/VLBW with cardiometabolic factors were independent of fat mass and weight gain velocity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12887-021-02851-5.

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.

Association between Neonatal Intakes and Hyperglycemia, and Left Heart and Aortic Dimensions at 6.5 Years of Age in Children Born Extremely Preterm

Survivors of extremely preterm birth (gestational age < 27 weeks) have been reported to exhibit an altered cardiovascular phenotype in childhood. The mechanisms are unknown. We investigated associations between postnatal nutritional intakes and hyperglycemia, and left heart and aortic dimensions in children born extremely preterm. Postnatal nutritional data and echocardiographic dimensions at 6.5 years of age were extracted from a sub-cohort of the Extremely Preterm Infants in Sweden Study (EXPRESS; children born extremely preterm between 2004-2007, n = 171, mean (SD) birth weight = 784 (165) grams). Associations between macronutrient intakes or number of days with hyperglycemia (blood glucose > 8 mmol/L) in the neonatal period (exposure) and left heart and aortic dimensions at follow-up (outcome) were investigated. Neonatal protein intake was not associated with the outcomes, whereas higher lipid intake was significantly associated with larger aortic root diameter (B = 0.040, p = 0.009). Higher neonatal carbohydrate intake was associated with smaller aorta annulus diameter (B = -0.016, p = 0.008). Longer exposure to neonatal hyperglycemia was associated with increased thickness of the left ventricular posterior wall (B = 0.004, p = 0.008) and interventricular septum (B = 0.004, p = 0.010). The findings in this study indicate that postnatal nutrition and hyperglycemia may play a role in some but not all long-lasting developmental adaptations of the cardiovascular system in children born extremely preterm.

Impact of size at birth and postnatal growth on metabolic and neurocognitive outcomes in prematurely born school-age children

Prematurity, size at birth, and postnatal growth are important factors that determine cardiometabolic and neurodevelopmental outcomes later in life. In the present study, we aimed to investigate the associations between the size at birth and growth velocity after birth with cardiometabolic and neurodevelopmental outcomes in preterm infants. Fifty-six preterm infants born at < 32 weeks of gestation or having a birth weight of < 1500 g were enrolled and categorized into small for gestational age (SGA) and appropriate for gestational age (AGA) groups. Anthropometric and cardiometabolic parameters were assessed at school-age, and the Korean Wechsler Intelligence Scale for Children, fourth edition (K-WISC-IV) was used for assessing the intellectual abilities. The growth velocity was calculated by changes in the weight z-score at each time period. Multivariate analysis was conducted to investigate the associations of growth velocity at different periods with cardiometabolic and neurodevelopmental outcomes. Forty-two (75%) were classified as AGA and 25% as SGA. At school-age, despite the SGA children showing significantly lower body weight, lean mass index, and body mass index, there were no differences in the cardiometabolic parameters between SGA and AGA groups. After adjusting for gestational age, birth weight z-score, weight z-score change from birth to discharge and sex, change in weight z-score beyond 12 months were associated with a higher systolic blood pressure, waist circumference, and insulin resistance. Full-scale intelligent quotient (β = 0.314, p = 0.036) and perceptional reasoning index (β = 0.456, p = 0.003) of K-WISC-IV were positively correlated with postnatal weight gain in the neonatal intensive care unit. Although cardiometabolic outcomes were comparable in preterm SGA and AGA infants, the growth velocity at different time periods resulted in different cardiometabolic and neurocognitive outcomes. Thus, ensuring an optimal growth velocity at early neonatal period could promote good neurocognitive outcomes, while adequate growth after 1 year could prevent adverse cardiometabolic outcomes in preterm infants.

The Long-Term Effect of Preterm Birth on Renal Function: A Meta-Analysis

The preterm-born adult population is ever increasing following improved survival rates of premature births. We conducted a meta-analysis to investigate long-term effects of preterm birth on renal function in preterm-born survivors. We searched PubMed and EMBASE to identify studies that compared renal function in preterm-born survivors and full-term-born controls, published until 2 February 2019. A random effects model with standardized mean difference (SMD) was used for meta-analyses. Heterogeneity of the studies was evaluated using Higgin’s I² statistics. Risk of bias was assessed using the Newcastle–Ottawa quality assessment scale. Of a total of 24,388 articles screened, 27 articles were finally included. Compared to full-term-born controls, glomerular filtration rate and effective renal plasma flow were significantly decreased in preterm survivors (SMD −0.54, 95% confidence interval (CI), −0.85 to −0.22, p = 0.0008; SMD −0.39, 95% CI, −0.74 to −0.04, p = 0.03, respectively). Length and volume of the kidneys were significantly decreased in the preterm group compared to the full-term controls (SMD −0.73, 95% CI, −1.04 to −0.41, p < 0.001; SMD −0.82, 95% CI, −1.05 to −0.60, p < 0.001, respectively). However, serum levels of blood urea nitrogen, creatinine, and cystatin C showed no significant difference. The urine microalbumin to creatinine ratio was significantly increased in the preterm group. Both systolic and diastolic blood pressures were also significantly elevated in the preterm group, although the plasma renin level did not differ. This meta-analysis demonstrates that preterm-born survivors may be subject to decreased glomerular filtration, increased albuminuria, decreased kidney size and volume, and hypertension even though their laboratory results may not yet deteriorate.

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.

Right Heart Structure, Geometry and Function Assessed by Echocardiography in 6-Year-Old Children Born Extremely Preterm-A Population-Based Cohort Study

Preterm birth has been associated with altered cardiac phenotype in adults. Our aim was to test the hypothesis that children surviving extremely preterm birth have important structural or functional changes of the right heart or pulmonary circulation. We also examined relations between birth size, gestational age, neonatal diagnoses of bronchopulmonary dysplasia (BPD) and patent ductus arteriosus (PDA) with cardiac outcomes. We assessed a population-based cohort of children born in Sweden before 27 weeks of gestation with echocardiography at 6.5 years of age (n = 176). Each preterm child was matched to a healthy control child born at term. Children born preterm had significantly smaller right atria, right ventricles with smaller widths, higher relative wall thickness and higher estimated pulmonary vascular resistance (PVR) than controls. In preterm children, PVR and right ventricular myocardial performance index (RVmpi’) were significantly higher in those with a PDA as neonates than in those without PDA, but no such associations were found with BPD. In conclusion, children born extremely preterm exhibit higher estimated PVR, altered right heart structure and function compared with children born at term.

Physical Activity in 6.5-Year-Old Children Born Extremely Preterm

Physical activity (PA) can prevent cardiovascular diseases. Because of increased risks of impairments affecting motor activity, PA in children born preterm may differ from that in children born at term. In this prospective cohort study, we compared objectively measured PA in 71 children born extremely preterm (<27 weeks gestational age), to their 87 peers born at term, at 6.5 years of age. PA measured with accelerometer on the non-dominant wrist for 7 consecutive days was compared between index and control children and analyzed for associations to prenatal growth, major neonatal brain injury, bronchopulmonary dysplasia and neonatal septicemia, using ANOVA. Boys born extremely preterm spent on average 22 min less time per day in moderate to vigorous physical activity (MVPA) than control boys (95% CI: -8, -37). There was no difference in girls. Amongst children born extremely preterm, major neonatal brain injury was associated with 56 min less time in MVPA per day (95%CI: -88, -26). Subgroups of children born extremely preterm exhibit lower levels of physical activity which may be a contributory factor in the development of cardiovascular diseases as adults.

Neonatal oxygen saturations and blood pressure at school-age in children born extremely preterm: a cohort study

OBJECTIVE

To explore the relationship between neonatal oxygen saturation and BP at age 6-7 years in a cohort of infants born extremely preterm.

STUDY DESIGN

Infants <28 weeks gestation were assigned to a higher or lower oxygen saturation target. Oximeter data were monitored throughout the neonatal period. A subset of survivors was seen at age 6. BP was measured and compared by group assignment, achieved saturations, and time spent in hypoxemia (saturations <80%).

RESULTS

There was no difference in systolic or diastolic BP between assigned groups. Median achieved weekly oxygen saturation was not associated with BP. Longer duration of hypoxemia during the first week of age was associated with higher systolic BP.

CONCLUSIONS

Neither target nor actual median oxygen saturations in this study was associated with BP at school age. Increased duration of hypoxemia in the first postnatal week was associated with higher systolic BP at 6-7 years of age.

Lung function and pulmonary vascular resistance are not associated in 6-year-old children born extremely preterm

AIM

Children born preterm are at increased risk of reduced lung function. The aim was to test whether lung function was associated with pulmonary vascular resistance.

METHODS

Participants were recruited from a population-based cohort born in 2004-2007. Lung function was assessed with spirometry after administration of a beta2-agonist. Forced vital capacity (FVC) and forced expiratory volume in one second (FEV₁ ) were determined. Estimations of pulmonary vascular resistance, arterial dimensions, right ventricular wall thickness, sphericity, and systolic (TAPSE) and diastolic functions were performed with echocardiography. Adjusted regression analyses were used to study associations.

RESULTS

Sixty-six children (33 boys) born at 22-26 weeks of gestational age (birthweights 460-1134 g) were assessed at a mean age of 6.7 years. Despite large variations in lung function with FVC z-scores ranging from -4.6 to +2.8, there were no associations between lung function and pulmonary arterial pressure, right ventricular structure or function. Children with higher FVC z-scores (r = .52, β = .55 mm, P = .015) and higher FEV₁ z-scores (r = .58, β = .73 mm, P = .001) exhibited larger pulmonary arteries.

CONCLUSION

In children born extremely preterm, lung function was not associated with pulmonary vascular resistance. Routine echocardiographic evaluation of extremely preterm children may not be indicated at age 6.5 years.

Duration of neonatal oxygen supplementation, erythropoiesis and blood pressure in young adults born preterm

BACKGROUND

Although erythropoiesis is impaired and anaemia frequent in neonates born preterm, haematopoiesis in adults born preterm has not been previously studied.

OBJECTIVE

We, thus, aimed to evaluate haemoglobin and erythropoietin levels in young adults born preterm, to identify neonatal events associated with erythropoiesis in adulthood and to examine the relationships of haemoglobin levels with respiratory function and blood pressure.

METHODS

We assessed a cohort of 101 young adults (ages 18-29) born preterm (≤29 weeks of gestation), in comparison to 105 full-term controls. We measured haemoglobin, erythropoietin levels and blood pressure. We also assessed respiratory function using spirometry.

RESULTS

Compared with controls, tobacco use and sex-adjusted haemoglobin levels were 5.3 (95% CI 2.9 to 7.7) g/L higher in preterm-born individuals, but erythropoietin levels were similar. Duration of oxygen supplementation in the neonatal period was independently associated with higher haemoglobin levels in the preterm group. In young adults born preterm with bronchopulmonary dysplasia, airflow limitation was associated with higher haemoglobin levels. Both systolic (SBP) and diastolic (DBP) blood pressure were increased in individuals born preterm (p=0.042 and p=0.0008, respectively). Higher haemoglobin levels were associated with higher SBP and DBP, independently of term or preterm status. Mediation analysis suggests that haemoglobin increase contributes to 37% and 32% of the effect of preterm birth on SBP and DBP, respectively.

CONCLUSIONS

Haemoglobin levels are higher in young adults born preterm, while erythropoietin levels are similar, especially in case of bronchopulmonary dysplasia and airflow limitation, and haemoglobin increase is associated with elevated blood pressure in this population.

The Effect of Preterm Birth on Renal Development and Renal Health Outcome

Preterm birth is associated with adverse renal health outcomes including hypertension, chronic kidney disease, and an increased rate of progression to end-stage renal failure. This review explores the antenatal, perinatal, and postnatal factors that affect the functional nephron mass of an individual and contribute to long-term kidney outcome. Health-care professionals have opportunities to increase their awareness of the risks to kidney health in this population. Optimizing maternal health around the time of conception and during pregnancy, providing kidney-focused supportive care in the NICU during postnatal nephrogenesis, and avoiding accelerating nephron loss throughout life may all contribute to improved long-term outcomes. There is a need for ongoing research into the long-term kidney outcomes of preterm survivors in mid-to-late adulthood as well as a need for further research into interventions that may improve ex utero nephrogenesis.

Prevalence and factors associated with hypertension in primary school children, in the centre region of Cameroon

BACKGROUND

There has been a progressive increase in hypertension among children and adolescents over the years. Hypertension in childhood is influenced by various risk factors including; childhood obesity, lifestyle and hereditary factors. This study is aimed at assessing the prevalence of hypertension and elevated blood pressure (BP); as well as the associated factors to hypertension among primary school children in a rural setting in the, Centre Region of Cameroon.

METHODS

A cross sectional study was carried out from November 2017 to May 2018 in 13 primary schools in Mbankomo subdivision. A two staged cluster sampling technique was used to select participants: the first stage we conveniently selected 13 out of 71 (18%) primary schools in the study area by probability proportionate to size since the subdivision does not have an equal number of primary schools in the rural and semi-urban areas. In the second stage, we also used probability proportional to size to randomly select participants from the 13 clusters because the classes did not have equal number of students. We randomly selected 13% pupils enrolled in each class of the 13 schools. BP and anthropometric measurements were taken, together with socio-demographic characteristics, lifestyle and past history.

RESULTS

The overall prevalence of hypertension among the 822 pupils sampled was 1.6% (with 1.5% in stage I and 0.1% in stage II) and that of elevated BP was 8.1%, with a systolic predominance of 1.6%. SBP and DBP had a significant positive correlation with age (r=0.17; P=0.000 and r=0.07; P=0.000 respectively) and BMI (r=0.18; P=0.000 and r=0.11; P=0.000 respectively). The associated risk factors for hypertension were: the pupil's age >10 years (95% CI: 1.2581-33.1841; P=0.0254), family history of overweight (95% CI: 1.6906-32.9401; P=0.008), and excess weight (95% CI: 2.5094-40.7063; P=0.0011), and being born at term (P=0.0004) as a protecting factor.

CONCLUSIONS

This study revealed a high prevalence of hypertension among primary school children in rural areas, with a number of preventable risk factors. Considering the risk factors found, children should be educated on proper nutrition, and the need for physical exercises at home and in school to avoid overweight and obesity.

Maternal-Infant Supplementation with Small-Quantity Lipid-Based Nutrient Supplements Does Not Affect Child Blood Pressure at 4-6 Y in Ghana: Follow-up of a Randomized Trial

BACKGROUND

In the International Lipid-Based Nutrient Supplements (iLiNS)-DYAD-Ghana trial, prenatal small-quantity lipid-based nutrient supplements (LNSs) had a positive effect on birth weight. Birth weight may be inversely related to blood pressure (BP) later in life.

OBJECTIVES

We examined the effect of the intervention on BP at 4-6 y of age, and maternal and child factors related to BP.

METHODS

The iLiNS-DYAD-Ghana study was a partially double-blind, randomized controlled trial which assigned women (n = 1320) ≤20 weeks of gestation to daily supplementation with: 1) iron and folic acid during pregnancy and 200 mg Ca for 6 mo postpartum , 2) multiple micronutrients during pregnancy and postpartum, or 3) LNSs during pregnancy and postpartum plus LNSs for infants from 6 to 18 mo of age. At 4-6 y of age (n = 858, 70% of live births), we compared BP, a secondary outcome, between non-LNS and LNS groups and examined whether BP was related to several factors including maternal BP, child weight-for-age z score (WAZ), and physical activity.

RESULTS

Non-LNS and LNS groups did not differ in systolic (99.2 ± 0.4 compared with 98.5 ± 0.6 mm Hg; P = 0.317) or diastolic (60.1 ± 0.3 compared with 60.0 ± 0.4 mm Hg; P = 0.805) BP, or prevalence of high BP (systolic or diastolic BP ≥90th percentile of the US National Heart, Lung, and Blood Institute reference: 31% compared with 28%; P = 0.251). BP at 4-6 y of age was positively related to birth weight; this relation was largely mediated through concurrent WAZ in a path model. Concurrent WAZ and maternal BP were the factors most strongly related to child BP.

CONCLUSIONS

Despite greater birth weight in the LNS group, there was no intervention group difference in BP at 4-6 y. In this preschool population at high risk of adult hypertension based on BP at 4-6 y, high maternal BP and child WAZ were key factors related to BP. This trial was registered at clinicaltrials.gov as NCT00970866.

Postnatal nutritional intakes and hyperglycemia as determinants of blood pressure at 6.5 years of age in children born extremely preterm

BACKGROUND

Adverse developmental programming by early-life exposures might account for higher blood pressure (BP) in children born extremely preterm. We assessed associations between nutrition, growth and hyperglycemia early in infancy, and BP at 6.5 years of age in children born extremely preterm.

METHODS

Data regarding perinatal exposures including nutrition, growth and glycemia status were collected from the Extremely Preterm Infants in Sweden Study (EXPRESS), a population-based cohort including infants born <27 gestational weeks during 2004-2007. BP measurements were performed at 6.5 years of age in a sub-cohort of 171 children (35% of the surviving children).

RESULTS

Higher mean daily protein intake (+1 g/kg/day) during postnatal weeks 1-8 was associated with 0.40 (±0.18) SD higher diastolic BP. Higher mean daily carbohydrate intake (+1 g/kg/day) during the same period was associated with 0.18 (±0.05) and 0.14 (±0.04) SD higher systolic and diastolic BP, respectively. No associations were found between infant growth (weight, length) and later BP. Hyperglycemia and its duration during postnatal weeks 1-4 were associated primarily with higher diastolic BP z-scores.

CONCLUSIONS

These findings emphasize the importance of modifiable early-life exposures, such as nutrition and hyperglycemia, in determining long-term outcomes in children born extremely preterm.

High Blood Pressure at Early School Age Among Extreme Preterms

BACKGROUND AND OBJECTIVES

Former preterm infants are at increased risk of hypertension with increasing age. Our objective was to identify rates of high blood pressure (BP) (≥90th percentile) and hypertension (BP ≥95th percentile) and associated risk factors among extreme preterm (EPT) infants at 6 to 7 years of age.

METHODS

Assessment included BP and anthropometrics. Comparisons were made by BP ≥90th versus <90th percentile. Regressions were run to identify relative risk (RR) of factors associated with BP ≥90th percentile.

RESULTS

Among 379 EPT infants, 20.6% had systolic high BP, 10.8% systolic hypertension, 21.4% diastolic high BP, and 11.4% diastolic hypertension. Children with systolic high BP had higher rates of BMI, triceps skinfolds >85th percentile, and waist circumference >90th percentile. In regression analyses, weight gain velocity from 18 months to school age (RR = 1.36), and maternal gestational diabetes (MGD) (RR = 2.04) predicted systolic and either systolic and/or diastolic high BP (RR = 1.27 and RR = 1.67). Among children with BMI <85th percentile, 17% had systolic and 19% had diastolic high BP. Regression analysis for normal weight children indicated public insurance (RR = 2.46) and MGD (RR = 2.16) predicted systolic high BP, and MGD (RR = 2.08) predicted either systolic or diastolic high BP.

CONCLUSIONS

Both overweight and normal weight EPT children are at risk for high BP and hypertension. Public insurance, MGD, and weight gain velocity are risk factors. Findings of high BP among EPT children at early school age are worrisome and indicate a need for close follow-up.

Impaired autonomic function in adolescents born preterm

Preterm birth temporarily disrupts autonomic nervous system (ANS) development, and the long-term impacts of disrupted fetal development are unclear in children. Abnormal cardiac ANS function is associated with worse health outcomes, and has been identified as a risk factor for cardiovascular disease. We used heart rate variability (HRV) in the time domain (standard deviation of RR intervals, SDRR; and root means squared of successive differences, RMSSD) and frequency domain (high frequency, HF; and low frequency, LF) at rest, as well as heart rate recovery (HRR) following maximal exercise, to assess autonomic function in adolescent children born preterm. Adolescents born preterm (less than 36 weeks gestation at birth) in 2003 and 2004 and healthy age-matched full-term controls participated. Wilcoxon Rank Sum tests were used to compare variables between control and preterm groups. Twenty-one adolescents born preterm and 20 term-born controls enrolled in the study. Preterm-born subjects had lower time-domain HRV, including SDRR (69.1 ± 33.8 vs. 110.1 ± 33.0 msec, respectively, P = 0.008) and RMSSD (58.8 ± 38.2 vs. 101.5 ± 36.2 msec, respectively, P = 0.012), with higher LF variability in preterm subjects. HRR after maximal exercise was slower in preterm-born subjects at 1 min (30 ± 12 vs. 39 ± 9 bpm, respectively, P = 0.013) and 2 min (52 ± 10 vs. 60 ± 10 bpm, respectively, P = 0.016). This study is the first report of autonomic dysfunction in adolescents born premature. Given prior association of impaired HRV with adult cardiovascular disease, additional investigations into the mechanisms of autonomic dysfunction in this population are warranted.

The Preterm Heart in Childhood: Left Ventricular Structure, Geometry, and Function Assessed by Echocardiography in 6-Year-Old Survivors of Periviable Births

BACKGROUND

Preterm birth has been associated with increased risk of cardiovascular morbidity in adult life. We evaluated whether preterm birth is associated with deviating cardiac structure and function before school start.

METHODS AND RESULTS

In total, 176 children aged 6 years and born extremely preterm (EXPT; gestational age of 22-26 weeks) and 134 children born at term (control [CTRL]) were studied. We used echocardiography to assess left heart dimensions, geometry, and functions. Recording and off-line analyses of echocardiographic images were performed by operators blinded to group belonging. Body size, blood pressure, and heart rate were also measured. Rates of family history of cardiovascular disease and sex distribution were similar in the EXPT and CTRL groups. Heart rate and systolic blood pressure did not differ, whereas diastolic blood pressure was slightly higher in EXPT than CTRL participants. After adjusting for body surface area, left ventricular length, width, and aortic valve annulus diameter were 3% to 5% smaller in EXPT than CTRL participants. Left ventricular longitudinal shortening and systolic tissue velocity were 7% to 11% lower, and transversal shortening fraction was 6% higher in EXPT than CTRL participants. The EXPT group also exhibited lower atrial emptying velocities than the CTRL group. Sex, fetal growth restriction, or a patent ductus arteriosus in the neonatal period did not contribute to cardiac dimensions or performance.

CONCLUSIONS

Six-year-old children born extremely preterm exhibit a unique cardiac phenotype characterized by smaller left ventricles with altered systolic and diastolic functions than same-aged children born at term.