Relationship between water compartments, body composition assessed by bioelectrical impedance analysis and blood pressure in school children.

BACKGROUND: Electrical bioimpedance analysis (BIA) is becoming more widely used in clinical practice as a method of body composition analysis. In healthy children blood pressure (BP) changes with age, body mass and height. Until now the relation between water compartments and BP in healthy children has not been evaluated. The aim of this study was to evaluate the relationship between body composition as well as water compartments (measured by electrical bioimpedance) and BP. METHODS: The study was performed in 72 children (32 girls and 40 boys) aged: 6-7 and 12-13 years. BIA measurements were taken using Nutriguard Data Input device with Bianostic electrodes and following parameters were calculated: total body water (TBW), lean body mass (LBM), fat mass (FM), intra- and extracellular water (ICW, ECW) and phase angle alpha. BP was measured twice using the oscillometric method. RESULTS: Elevated BP > 95th percentile for gender, age and height were observed in 9 children. A significant correlation between systolic (S)BP and TBW (R = 0.4023, p < 0.001), LBM (R = 0.3600, p = 0.002), FM (R = 0.4725, p < 0.001), ECW (R = 0.4598, p < 0.001) and body mass index (BMI) (R = 0.4089, p < 0.001) was found. Furthermore, diastolic (D)BP significantly correlated with TBW (R = 0.3056, p = 0.011), LBM (R = 0.2783, p = 0.021), FM (R = 0.3956, p < 0.001), ECW (R = 0.3869, p = 0.001) and BMI (R = 0.3550, p = 0.002). In the studied group malnutrition (weight < 3rd percentile) was found in 8 children and 2 had obesity (BMI > 95th percentile). Growth disorders were found in 6 children (5 of them being undernourished). CONCLUSIONS: In the studied children SBP and DBP correlated with water compartments, lean body and fat masses derived from BIA. The problem of unrecognized hypertension and malnutrition in children and adolescents is still underestimated in the Polish population.

Oxidative Stress Biomarkers and Left Ventricular Hypertrophy in Children with Chronic Kidney Disease.

Cardiovascular diseases remain the most frequent cause of morbidity and mortality in patients with chronic kidney disease (CKD). The aim of the study was to assess the association between oxidative stress biomarkers and cardiovascular risk factors and left ventricular hypertrophy in children with CKD. Material and Methods. The studied group consisted of 65 patients aged 1.4-18.6 (mean 11.2) years with stages 1 to 5 CKD. Serum oxidized low-density lipoprotein (oxLDL), protein carbonyl group, creatinine, cystatin C, albumin, lipids, high-sensitivity C-reactive protein, intercellular adhesion molecule-1, insulin, plasma renin activity, and aldosterone levels were measured. Patients were divided into groups depending on CKD stage. Anthropometric measurements, ambulatory blood pressure (BP) measurements, and echocardiography with left ventricular mass (LVM) calculation were performed. Results. Serum oxLDL strongly correlated with creatinine (R = 0.246; p = 0.048), cystatin C (R = 0.346; p = 0.006), total cholesterol (R = 0.500; p < 0.001), triglycerides (R = 0.524; p < 0.001), low-density lipoprotein concentrations (R = 0.456; p < 0.001), and 24 hour BP values of systolic (R = 0.492; p = 0.002), diastolic (R = 0.515; p < 0.001), and mean arterial pressure (R = 0.537; p < 0.001). A significant correlation between oxLDL levels and LVM z-scores (R = 0.299; p = 0.016) was found. Conclusions. Hypertension and dyslipidemia correlated with lipid oxidation in children with CKD. oxLDLs seem to be valuable markers of oxidative stress in CKD patients, correlating with left ventricular hypertrophy.

[Office and 24-hour ambulatory blood pressure measurements in hypertension assessment in children with chronic kidney disease].

Introduction: Hypertension (HT) is one of the major risk factors of chronic kidney disease (CKD) progression and cardiovascular complications. The aim of the study was to analyze blood pressure (BP) values and assess the usefulness of clinical measurements in BP monitoring in children with chronic kidney disease. Material and methods: The study was conducted in 62 children (40 boys and 22 girls) aged 4,2-18,6 years (median age 12.4 (9.1; 16.0) with CKD stages 1 + 2 (n = 9), 3 (n = 17), 4 (n = 15) and 5. Creatinine concentration was measured and glomerular filtration rate was calculated using the Schwartz formula. Each of the patients underwent clinical BP measurements and 24-hour ambulatory blood pressure monitoring (ABPM). Results: Based on clinical meaurements elevated BP values were found in 25 patients (40.3%): in stages 1 + 2 in 33.3%, in stage 3 in 41.2%, in stage 4 in 46.6% and in stage 5 in 38.1% patients. Hypertension was diagnosed with ABPM in 30 patients (48.4% of the studied population): in stages 1 + 2 - 3 patients (33.3%), in stage 3 - 8 patients (47, 1%), in stage 4 - 7 patients (46.7%) and stage 5 - 12 patients (57.1%). Only 12 patients (19.4%) had hypertension diagnosed in both clinical and ABPM measurements. White coat effect was found in 13 children (21.0%) and masked HT in 18 children (29.0%). In 24-hour BP monitoring the highest values of systolic, diastolic and mean BP values were found in children with masked HT. In children with masked HT higher values of 24-hour systolic (120 vs. 105.5 mmHg, p<0.001) and diastolic (75 vs. 65 mmHg, p<0.001) BP compared with clinical values were detected. Children with masked HT had significantly higher nighttime diastolic BP compared with children with HT (1.43 vs. 0.74 z-score, p<0.001). Conclusions: The large percentage of children with masked hypertension is an indication for frequent ABPM measurements in children with chronic kidney diseses. Office measurements are not sufficient to detect HT in children with CKD. The best diagnostic method to confirm and monitor hypertension in patients with CKD is 24-hour ambulatory blood pressure monitoring.