24-hour blood pressure monitoring and renal function evaluation at the predicted term of delivery in prematurely born children.

ABSTRACT

B a c k g r o u n d The cause of the increased risk of hypertension in children born prematurely is still unclear. The aim of this study was to analyze the results of blood pressure monitoring and the levels of variety of kidney function markers at the 40-42 weeks postmenstrual age in children born prematurely and to compare them with the values obtained from full-term newborns. The analysis of the differences in the observed parameters could be used to assess the risk of developing hypertension in preterm infants in the following years of life. M e t h o d o l o g y Prospective cohort study included 37 children born prematurely (<35 weeks of gestation) and 20 full-term newborns. The 24-hour ambulatory blood pressure measurement, serum cystatin C and thrombomodulin levels, urine Neutrophil Gelatinase-Associated Lipocalin (NGAL) concentration, renal ultrasound and bioelectrical impedance were performed. R e s u l t s Analysis of the blood pressure monitoring reveled lower values of diastolic (DBP) and mean blood pressure (MAP) in the preterm group (DBP 47.69 ± 4.79 vs. 53.96 ± 5.3 mmHg; p <0.01; MAP 64 ± 6.7 vs. 68 ± 6 mmHg; p = 0.02), however the preterm children were significantly smaller at the time of evaluation. Moreover, the pulse pressure was significantly higher in the preterm group (44 ± 7.8 vs. 39.4 ± 5.7 mmHg; p = 0.017). In the preterm group serum cystatin C level was lower (1.397 ± 0.22 vs. 1.617 ± 0.22 mg/l; p <0.01) and NGAL urine concentration was higher (57 ± 84 vs 15 ± 21 ng/ml; p = 0.04). There was substantial difference in body composition between groups - the total body water was lower in the preterm group (75.6 ± 13 vs. 82 ± 8%; p = 0.015). C o n c l u s i o n At the predicted date of birth, preterm newborns show significant differences in blood pressure profile, body weight composition, and levels of cystatin C and NGAL compared to full-term babies.