380 What influences blood pressure variability in children with essential hypertension?

Abstract

<h3></h3> Blood pressure variability (BPV) is a complex physiological phenomenon and it is known that increased BPV exacerbates the progression of hypertension and correlates with adverse cardiovascular outcomes. However, there is paucity of data regarding factors influencing BPV in pediatric population. This study aimed to analyze blood pressure (BP) pattern and assess blood pressure variability and its possible determinants in untreated children with essential hypertension. The study group included 132 children, average age 15 y (7- 18 y), 84 boys and 48 girls with essential hypertension and no use of antihypertensive therapy. Anthropometric parameters, serum glucose level (sG), serum uric acid (sUA), serum creatinine (sCr), total cholesterol (TCh), HDL cholesterol (HDL), LDL cholesterol (LDL) and triglycerides (TG) were measured in all participants. Office blood pressure (BP) and ambulatory blood pressure (AMBP) was measured according to recent European Society of Hypertension (ESH) guidelines. BPV was defined as value of the standard deviation of blood pressure for day and night time periods. In addition to the classical statistical analysis, an unsupervised machine learning approach using the expected maximization algorithm was implemented to find groups of patients with similar characteristics. The average age was 14.98 ± 2.1 years. Comparing sex-specific BP parameters, boys had higher daytime and nighttime systolic BP, although the difference was not statistically significant (p = 0.067 and p = 0.583). Girls had significantly higher daytime and nighttime diastolic BP values (p=0.017; p=0.027). There was no difference in BPV according to gender while boys have higher values of sCr, sG, and sUA despite similar body mass index (BMI) [27.18±5.27 kg/m2 (males) vs 27.94±5.27 kg/m2 (females), p= 0.427]. A statistically significant positive correlation was found between the Z-score for BMI and daytime systolic BPV, nighttime systolic BP and total cholesterol, nighttime diastolic BPV and sUA (r= 0.19, r= 0.28 and r = 0.26, respectively). Within the male population two clusters were found. The subjects in cluster 2 had higher daytime and nighttime systolic and diastolic BP values, higher total cholesterol and triglycerides and significantly higher night time systolic and diastolic BPV. Understanding potential determinants of BPV in hypertensive children could help identify patients with increased cardiovascular risk earlier. Our results suggest that clustering of metabolic factors influence BPV in untreated children with essential hypertension which could also be gender specific for male subjects.