Blood Pressure Profile in the 7th and 11th Year of Life in Children Born Prematurely

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 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.