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

Background: Several research trials have analyzed the impact of prematurity on the prevalence of hypertension (HT). However, prospective long-term studies are lacking. Objectives: The aim of this study was to evaluate the prevalence of HT at the age of 7 and 11 years in a regional cohort of preterm infants with a birth weight of <= 1000 g. Patients and Methods: This study included 67 children with a birth weight of <= 1000 g who were born in Malopolska between September 2002 and August 2004. The control group consisted of 38 children born at term, matched for age. Each child underwent 24-h ambulatory blood pressure measurement (ABPM) twice, once at the age of 7 and again at 11 years. The presence of HT was estimated according to the mean arterial pressure (MAP) and a number of individual measurements. Results: At aged 7 years, preterm infants had a significantly higher incidence of HT, defined on the basis of MAP (15% vs. 0%; P < 0.02) and on the percent of individual measurements (56% vs. 33%, P < 0.036). After taking into account the group of patients who received anti-HT treatment after the first part of the study, the incidence of HT at the age of 11 years based on MAP was 19% vs. 10%. Based on the individual measurements, it was 36.5% in the preterm infants vs. 24% in the control group. The differences were not statistically significant. At both time points, the preterm group had a higher mean heart rate (HR) than the control group. Conclusions: Children born prematurely are predisposed to HT in later life, in addition to the persistence of an increased HR.