Genetic background of high blood pressure is associated with reduced mortality in premature neonates

Lung Function of Preterm Children Parsed by a Polygenic Risk Score for Adult COPD

BACKGROUND: Chronic obstructive pulmonary disease (COPD) in adults is a result of environmental risk factors and genetic factors. Polygenic COPD risk scores are highly predictive for lung function in adults. We hypothesized that a polygenic COPD risk score is also predictive for lung function in children who are born preterm. METHODS: Infants with a birth weight of less than 1500 g (n=17,394) were enrolled in the German Neonatal Network. Among these children, we included those with chip genotyping and 5-year follow-up assessment (n=1957) in this analysis. A polygenic COPD risk score derived in adults with COPD was calculated on the basis of 1,637,882 single-nucleotide polymorphisms associated with forced expiratory volume within 1 second (FEV1) and 1,179,331 single-nucleotide polymorphisms associated with FEV1/FVC (forced vital capacity). This score was related to FEV1, FVC, and FEV1/FVC z scores by linear regression analysis. RESULTS: At a mean age at follow-up of 5.8±0.4 years, the polygenic COPD risk score was strongly associated with FEV1 (−0.05 z score/decile, P=6.5 × 10−9) and FEV1/FVC (−0.07 z score/decile, P=4.4 × 10−11) but not FVC. Children in the 10th decile of the polygenic COPD risk score — that is, those at the highest risk — had a mean FEV1 z score of −1.74 (±1.1), indicating lower lung function by these measures and higher rates of obstructive bronchitis. CONCLUSIONS: The upper deciles of a polygenic COPD risk score derived in adults identified a subgroup of children who were born preterm and who are at high risk for obstructive pulmonary disease of prematurity. This finding supports the notion that COPD-associated genes strongly impact lung function in premature children. (Funded by the German Federal Ministry of Education and Research.)

Associations of molecular genetic predictors of arterial hypertension in adults with the development and course of arterial hypotension in premature newborns

Purpose. This study aims at assessing the association of the development and clinical course of arterial hypotension in premature newborns, depending on the polymorphism of the genes of predisposition to hypertension.

Material and methods. The study design is prospective, controlled, single-center, and non-randomized. Genomic DNA samples were studied in premature newborns (n = 199), as well as a population sample of adults (n = 100). Newborns with arterial hypotension (n = 23) formed the study group, patients without it (n = 100) formed the comparison group. Loci with already known association with the development of arterial hypertension and coronary heart disease were selected for analysis: AGT (rs4762), AGTR1 (rs5186), ACE (Ins\Del), ADRB1 (rs1801253), ADD1 (rs4961), CYP11B2 (rs1799998), eNOS (rs1799983), eNOS (rs1549758), eNOS (rs2070744). The distribution of allele frequencies between the studied groups of individuals was compared.

Results. Premature babies are significantly more likely to be carriers of the allele with the AGT gene. In newborns with arterial hypotension, we additionally revealed a more frequent occurrence of dominant alleles of the eNOS gene, and children with the SS genotype of the eNOS gene required longer vasopressor therapy. Conclusion. The carriage of risky alleles of genes predisposing to arterial hypertension, not only does not increase the risk of arterial hypotension in premature newborns, but also may, in the case of carriage of mutant alleles of the eNOS rs1549758 gene, contribute to less prolonged vasopressor therapy. 

Diastolic Blood Pressure Alleles Improve Congenital Heart Defect Repair Outcomes

BACKGROUND

Congenital heart defects (CHDs) affect 40 000 US births per year, half of which require surgical intervention. Individual differences in surgical outcomes including mortality and complications are not well understood but may be due to genetic variability. We hypothesized that polygenic risk scores (PRSs) for blood pressure in adults are associated with treatments and postsurgical outcomes in children with CHD, as CHD survivors are at higher risk of negative cardiometabolic disease.

METHODS

We used imputed genotype data from pediatric participants requiring surgery for CHD (median age at surgery, 201 days; n_max=2498). Base data for the systolic and diastolic blood pressure PRSs (n_max=760 226) came from published genome-wide association study. The blood pressure PRSs were tested for association with postsurgical outcomes. All effects presented are per SD increase in PRS and adjusted for age, sex, body mass index, surgical complexity score, and first 10 principal components of ancestry.

RESULTS

A higher diastolic blood pressure PRS was associated with decreased in-hospital mortality risk (odds ratio, 0.57 [0.39-0.82]; P=0.0022). Additional analyses suggest an interaction between diastolic blood pressure PRS and vasopressor dose. Those with a diastolic blood pressure PRS 1 SD above the mean, receiving a vasopressor dose in the top tertile, were estimated to have 52% (32%-66%) lower risk of in-hospital mortality compared with those with a vasopressor dose in the bottom tertile.

CONCLUSIONS

These results suggest a genetically determined postsurgical survival advantage for CHD patients with blood pressure increasing alleles. Further study may reveal novel mechanisms contributing to postoperative morbidity and mortality, and this approach may assist in early identification of children at risk for adverse postoperative outcomes.

Risk Factors of Mechanical Ventilation in Premature Infants During Hospitalization

Background

The purpose of this study was to identify the risk factors for premature neonates requiring mechanical ventilation.

Methods

Premature neonates admitted to Chengdu Women’s and Children’s Central Hospital between July 2014 and December 2020 were retrospectively included in this study. Clinical and demographic factors were collated. Univariate and multivariate logistic regression analyses were conducted to identify the risk factors for premature infants requiring mechanical ventilation.

Results

A total of 1262 premature neonates participated in the study. Among them, 423 (33.53%) neonates required mechanical ventilation, whereas 839 (66.48%) neonates did not require mechanical ventilation. Multivariate logistic regression analysis determined that a lower Apgar score at 5 min (OR = 0.595, 95% CI: 0.472–0.74; P < 0.001), lower gestational age (very preterm) (OR = 11.745, 95% CI: 4.362, 31.619, P < 0.001), lower systolic blood pressure (OR = 0.864, 95% CI: 0.812–0.917, P = 0.001), lower diastolic blood pressure (OR = 0.894, 95% CI: 0.831–0.96, P = 0.002), higher respiratory rate (OR = 1.292, 95% CI: 1.238–1.355, P < 0.001), increased C-reactive protein levels (OR=1.044, 95% CI: 1.003–1.086, P = 0.036), and presence of patent ductus arteriosus (OR = 2.174, 95% CI: 1.185–3.972, P = 0.012) were independently associated with an increased possibility of adopting mechanical ventilation in premature infants. ROC analysis demonstrated that the predicted power for premature neonates requiring mechanical ventilation was 0.855 (95% CI: 0.808–0.902, P < 0.001).

Conclusion

In conclusion, we determined that a lower Apgar score at 5 min, lower gestational age, lower systolic blood pressure, lower diastolic blood pressure, higher respiratory rate, increased C-reactive protein levels and presence of patent ductus arteriosus were independently associated with an increased possibility of adopting mechanical ventilation in premature infants.

Blood group AB increases risk for surgical necrotizing enterocolitis and focal intestinal perforation in preterm infants with very low birth weight

Necrotizing enterocolitis (NEC) and focal intestinal perforation (FIP) are two of the most common emergencies of the gastrointestinal tract in preterm infants with very low birth weight (VLBW, birth weight < 1500 g). Identification of risk factors among these children is crucial for earlier diagnosis and prompt intervention. In this study, we investigated a relationship between ABO blood groups and the risk for surgical NEC/FIP. We genotyped the ABO locus (rs8176746 and rs8176719) in VLBW infants enrolled in a prospective, population-based cohort study of the German Neonatal Network (GNN). Of the 10,257 VLBW infants, 441 (4.3%) had surgical NEC/FIP. In univariate analyses, the blood group AB was more prevalent in VLBW infants with surgical NEC/FIP compared to non-AB blood groups (OR 1.51, 95% CI 1.07–2.13, p = 0.017; absolute risk difference 2.01%, 95% CI 0.06–3.96%). The association between blood group AB and surgical NEC/FIP was observed in a multivariable logistic regression model (OR of 1.58, 95% CI 1.10–2.26, p = 0.013) as well. In summary, our study suggests that the risk of surgical NEC and FIP is higher in patients with blood group AB and lower in those having non-AB blood groups.