Factors in the pathogenesis of primary hypertension in children and kidney damage

In recent years, primary hypertension increasing parallel with childhood obesity in puberty, is the most important risk factor for chronic kidney disease in adulthood. Since the blood pressure is continuously changing with the daily activities of the patients, ambulatory blood pressure measurement is the gold standard in the diagnosis of hypertension. Environmental and genetic factors play role in the etiology and pathophysiology of hypertension.The aim of our study was to evaluate ambulatory blood pressure of the patients diagnosed as hypertension during follow-up of healthy children, to investigate the factors causing primary hypertension and the effects of hypertension on kidney.Patients (n=56) who had blood pressure higher than 90 percentile during the healthy children follow up and healthy children (n=27) with the normal blood pressure were included to the study. 24 hours blood pressure measurements with the blood pressure monitor were recorded as the day-night mean blood pressure, the blood pressure loads and the dipper-non-dipper characteristics. Microalbumin, N-Acetyl-ß-D-Glucosaminidase, Na and K in the 24 hour urine and renin, aldosterone, nitric oxide and endothelin, in blood were investigated in all patients and the control group. The chi-square, t test, Mann Whitney U test, Spearman correlation test were used as the statistical analysis.According to the results of ambulatory blood pressure measurements, the mean daytime systolic and diastolic blood pressure, day-night systolic blood pressure loads of the patients were higher than the control group. The two groups did not differ in the ratio of non-dipper blood pressure. 52% of the patients diagnosed as white coat hypertension. Masked hypertension was not observed in the control group. According to the laboratory evaluations the patients have higher levels of blood renin and urinary N-Acetyl-ß-D-Glucosaminidase, lower levels of blood endothelin and urinary Na excretion than the control group. In the patients with white coat hypertension, higher levels of blood renin, urinary N-Acetyl-ß-D-Glucosaminidase, lower level of urinary Na than the control group were observed. In the obese group, daytime systolic blood pressure load, blood renin and nitric oxide levels were found higher than the patients with normal weight.In conclusion, it was thought that ambulatory blood pressure measurement was necessary for the true diagnosis of hypertension in children. In the pathogenesis of childhood primary hypertension and white coat hypertension, which was seen in the half of the children diagnosed as primary hypertension, blood renin and urinary sodium excretion had important roles. It was thought that primary and white coat hypertensions might cause early renal damage.