New methods of differentiation between primary and secondary hypertension in a pediatric population: A single-center experience.

BACKGROUND: Kidney diseases are the main causative factors of secondary hypertension (HTN) in children. Although primary HTN is less common in the pediatric population, its increasing prevalence, especially among teenagers, makes early diagnosis an emerging issue. OBJECTIVES: To analyze the potential differences between primary HTN and HTN secondary to renal diseases, in order to tailor diagnostic procedures to pediatric patients with suspicion of HTN. MATERIAL AND METHODS: A retrospective evaluation was performed of medical records of 168 children (aged from 1 month to 18 years) diagnosed with arterial HTN in the Pediatric Nephrology Department of Wroclaw Medical University (Poland). The comparative analysis concerned demographics, causes of HTN, clinical picture, laboratory tests, and parameters of ambulatory blood pressure monitoring (ABPM). RESULTS: Out of 168 children, 47% were diagnosed with primary HTN and 53% with secondary renal HTN. The patients with primary HTN were significantly older than those with HTN secondary to renal disease. Among the children with primary HTN, 26% were overweight and 42% were obese; among those with renal HTN, the proportions were 16% and 19%, respectively. The patients with primary HTN had significantly higher body mass index (BMI) percentiles and z-scores, and tended toward higher pulse pressure (PP) values. In the group with secondary HTN, ABPM parameters of diastolic blood pressure (DBP) and total cholesterol were significantly elevated. The BMI z-scores correlated positively with PP in the whole group. CONCLUSIONS: As expected, HTN secondary to renal disease prevails in younger children, but primary HTN has become an emerging issue in teenagers. The diagnostics of HTN secondary to kidney disease have revealed risk factors worsening the prognosis, including higher values of cholesterol or of parameters connected with DBP. Primary HTN risk factors include obesity and a tendency towards higher PP values.

Computed Tomography Parameters and Estimated Glomerular Filtration Rate Formulas for Peridonation Living Kidney Donor Assessment.

BACKGROUND: Renal function is usually described by the estimated glomerular filtration rate (eGFR). The standard method used for living kidney donor evaluation in our center is the 24-hour urine creatinine clearance (CrCl) and kidney morphology assessment with computed tomography (CT). The aim of the study was the analysis of the correlation of CrCl with 15 published eGFR formulas and morphologic CT parameters to choose the most accurate kidney function estimation method before and after donation. METHODS: The study included 39 living donors (18 male and 21 female, aged 32-69 years; mean age, 51.4 [SD, 9.7] years). The eGFR was estimated using Cockcroft-Gault, Modification of Diet in Renal Disease 7, Modification of Diet in Renal Disease 4, Chronic Kidney Disease Epidemiology Collaboration, Mayo Clinic, Nankivell, Bjornsson, Davis-Chandler, Edward-Whyte, Walser, Gates, Hull, Jelliffe-1, Jelliffe-2, or Mawer formulas and correlated with CrCl. CT parameters (kidney dimensions, volume, vascularization) were compared with eGFR formulas. RESULTS: The 25% to 34% (mean, 28.5% [SD, 2.3%]) decrease in eGFR after donation and its 1.5% to 5.0% (mean, 3.2% [SD, 1.0%]) increase over a year were observed. Cockcroft-Gault, Bjornsson, Hull, and Mawer equations (all including serum creatinine, age, sex, and body mass) correlated with predonation CrCl (r = 0.54, 0.53, 0.53, and 0.56, respectively; P < .001). From CT parameters, renal cortex volume correlated with CrCl (r = 0.48, P = .002) as well as the 4 abovementioned equations before donation (r = 0.65, 0.61, 0.64, and 0.74, respectively; P < .001) and during the postdonation period (12-month r = 0.59, 0.54, 0.57, and 0.70 respectively; P < .002). CONCLUSIONS: The eGFR calculated with equations combining serum creatinine, age, sex, and body mass as well as renal cortex volume are predictive of pre- and postdonation kidney function.