Serum Renalase Levels in Children with Essential Hypertension

Abstract

Objective: Left ventricular hypertrophy is the most commonly studied index for hypertension related target organ damage due to the wide usage of echocardiography. Renalase is a monoamine oxidase, mainly produced by the kidneys, regulating blood pressure by reducing catecholamines and acting on cardiovascular functions. In this study, the relationship between serum renalase level and hypertensive cardiac changes in children with essential hypertension was compared with the healthy control group. Materials and Methods: A total of 60 hypertensive children (female/male 20/40) aged between 4-18 years (mean 15.1 ± 1.9 years) were included in the study. Twenty healthy children with normal body mass index (4-18, mean14.2 ± 1.3 years) and similar gender (female/male 10/10) formed the control group. In 30 of hypertensive children (female/male: 9/21), echocardiography showed left ventricular hypertrophy. Echocardiographic findings of 30 remaining hypertensive patients (female/male: 11/19) were normal. A venous blood sample was collected from the hypertensive groups for biochemical examinations and renalase level. Urine samples and 24-hour urine samples were collected. 24-hour ambulatory blood pressure monitoring (ABPM) was used to measure blood pressure of hypertensive groups. The cardiac evaluation of hypertensive groups was performed using M-mode echocardiography. Results: The body mass index was significantly higher in hypertensive groups than the group with normal blood pressure (p <0.05). In comparison of hypertensive groups, no significant difference was found in terms of body mass index. All day systolic, diastolic; night systolic, diastolic, and daytime systolic blood pressure loads were significantly higher in hypertensive left-ventricular hypertrophic group than hypertensive non-hypertrophic group (p <0.05). Left ventricular mass index in M-mode echocardiography, revealed 39.7 g/m2 in the left ventricular hypertrophic group and 27.9 g/m2 in the hypertensive non-hypertrophic group (p <0.05). When the relationship between blood pressure loads and left ventricular mass index was compared between the groups, a significant correlation was found between daytime systolic blood pressure load and increased left ventricular mass index (p <0.05). Renalase level was significantly lower in hypertensive groups compared to normotensive group (p <0.05). There is a relationship between renalase deficiency and increased left ventricular mass index. Conclusion: There is a correlation between renalase deficiency and increased left ventricular mass index. We believe that utilization of low renalase levels as an early marker may be a useful and valuable parameter for determining the patients at risk for left ventricular hypertrophy and long-term complications of hypertension