The relationship between gestational age, systolic blood pressure and pulse pressure in children

Association between prenatal socioeconomic disadvantage, adverse birth outcomes, and inflammatory response at birth

Prenatal socioeconomic disadvantage is associated with inflammation in mid- to late-life, yet whether a pro-inflammatory phenotype is present at birth and the role of adverse birth outcomes in this pathway remains unclear. We utilized data on prenatal socioeconomic disadvantage at the individual- (i.e., mother's and father's education level, insurance type, marital status, and Women, Infants, and Children benefit receipt) and census-tract level as well as preterm (< 37 weeks gestation) and small-for-gestational-age (SGA) (i.e., < 10th percentile of sex-specific birth weight for gestational age) birth status, and assessed inflammatory markers (i.e., C-reactive protein, serum amyloid p, haptoglobin, and α-2 macroglobulin) in archived neonatal bloodspots from a Michigan population-based cohort of 1000 neonates. Continuous latent variables measuring individual- and combined individual- and neighborhood-level prenatal socioeconomic disadvantage were constructed and latent profile analysis was used to create a categorical inflammatory response variable (high versus low) based on continuous inflammatory marker levels. Structural equation models were used to estimate the total and direct effect of prenatal socioeconomic disadvantage on the inflammatory response at birth as well as indirect effect via preterm or SGA birth (among term neonates only), adjusting for mother's age, race/ethnicity, body mass index, smoking status, comorbidities, and antibiotic use/infection as well as grandmother's education level. There was a statistically significant total effect of both individual- and combined individual- and neighborhood-level prenatal socioeconomic disadvantage on high inflammatory response among all neonates as well as among term neonates only, and a positive but not statistically significant direct effect in both groups. The indirect effects via preterm and SGA birth were both negative, but not statistically significant. Our findings suggest prenatal socioeconomic disadvantage contributes to elevated neonatal inflammatory response, but via pathways outside of these adverse birth outcomes.

Correlates of elevated blood pressure in healthy children: a systematic review

The prevalence of hypertension in children is increasing globally. Addressing this will require a robust understanding of associated risk factors. To this end, we conducted a systematic review to identify correlates of elevated blood pressure (BP) in children. Literature searches were conducted using pre-defined search terms from three academic databases. The abstract and full text of identified studies were screened for eligibility by two independent reviewers. A total of 100 studies were included in this systematic review. An assessment tool was first used to assess study quality; a narrative synthesis was then performed. We found a broad range of physiological, social and behavioural factors associated with elevated BP in children. The most common correlate observed was adiposity, suggesting that childhood obesity may be implicated in the increased prevalence of hypertension observed in children. However, the broad range of other factors identified underscores the multi-factorial aetiology of hypertension. Data from a broad range of studies showed that the correlates of hypertension in children are multi-factorial. Therefore, approaches aimed at preventing hypertension must in turn be multi-factorial to ensure that the burden of hypertension in childhood is addressed.

Predictors and Reference Values of Pulse Wave Velocity in Prepubertal Angolan Children

Carotid-femoral pulse wave velocity (PWV) has been used as the gold standard method to estimate arterial stiffness. However, its use in clinical practice is still limited because reference values for specific groups, such as black children, remain unknown. The authors aimed to investigate predictors and to propose preliminary reference values of PWV in this population. Prepubertal schoolchildren (N=157; mean age, 9.36±1.41 year) from Luanda (Angola) with normal blood pressure values and without obesity were included. Mean PWV was 5.73±0.68 m/s, with no difference between the sexes. Univariate regression analysis showed a significant (P<.05) positive correlation between PWV and height, age, body weight, lean body weight, and blood pressure. In multivariate analysis, however, only height remained an independent predictor of PWV [PWV=0.018×height (cm)+3.230]. Curves of PWV percentiles as a function of height are proposed, thus identifying normal PWV in black children.

Does preterm birth influence cardiovascular risk in early adulthood?

OBJECTIVE

To investigate the effect of preterm birth on risk factors for cardiovascular disease (CVD), independent of birth size.

STUDY DESIGN

Observational study using data of 406 healthy participants aged 18-24 years, from the PROgramming factors for Growth And Metabolism and Prematurity and Small for Gestational Age studies. Associations between gestational age (GA), systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), blood pressure variability, heart rate (HR), pulse wave velocity, and carotid intima media thickness (cIMT) were studied. To study the differential effects of preterm birth and small birth size for gestational age, these parameters were also analyzed in subgroups born either preterm or term: young adults born small for gestational age with short or normal adult stature, and young adults born appropriate for gestational age with normal adult stature.

RESULTS

Subjects born preterm (GA <36 weeks) had higher unadjusted SBP, PP, SBP and DBP variability, and HR, but a lower DBP than subjects born term. GA was inversely associated with SBP, PP, blood pressure variability, and HR, and positively associated with DBP, also after adjustment for confounders. There was no effect of GA on pulse wave velocity and cIMT, a marker of atherosclerosis. Of all the CVD risk factors measured, higher PP affected cIMT the most.

CONCLUSIONS

Young adults born preterm might have a higher risk for CVD than those born term.

[Preterm birth as a risk factor for high blood pressure in children: a systematic review]

Epidemiological studies have suggested that arterial hypertension is a chronic disease that begins in childhood, and that prematurity (birth at less than 37 weeks' gestational age) is potentially associated with the development of hypertension in childhood and adulthood. Our objective was to identify the association between prematurity and high blood pressure in children, using a systematic literature review. Original articles related to the theme and published in English, Portuguese, or Spanish from 1998 to 2009 were selected from the MEDLINE, LILACS, and SciELO databases. We excluded articles without abstracts, review articles, and articles not related to prematurity and hypertension in childhood. Nine articles were located and analyzed: 5 case-control studies, 2 cross-sectional studies, and 2 cohort studies. The majority of the studies failed to show an association between prematurity and arterial hypertension in childhood. However, the influence of prematurity should not be ruled out, given the small number of studies on this theme and the diversity of methodological approaches in the literature.