SUBCLINICAL TARGET ORGAN DAMAGE IN A SAMPLE OF CHILDREN WITH SOLITARY FUNCTIONING KIDNEY. A PRELIMINARY OBSERVATIONAL STUDY

Abstract

Objective: Solitary Functioning Kidney (SFK) is a condition characterized by a single-functioning kidney. Children bearing this condition are exposed to an increased risk of subclinical organ damage (SOD) due to the compensatory hyperfiltration in the remaining kidney and increased peripheral blood pressure (pBP) values. The aim of the present study was to assess the impact of traditional (pBP) and novel (central systolic blood pressure, cSBP) cardiovascular risk factors on SOD in children and adolescents with solitary functional kidney. Design and method: Carotid ultrasonography was performed to measure carotid Intima-Media Thickness (cIMT), an index of subclinical atherosclerosis. Arterial stiffness was assessed by measuring carotid Distensibility Coefficient (cDC) and carotid-femoral Pulse Wave Velocity (PWV). Cardiac mass and remodeling were analyzed using transthoracic echocardiography. Central and peripheral (both office and ambulatory) BP measurements, as well as biochemical data from blood and urine samples were collected. Results: Forty-eight SFK children and adolescents were included, of whom 45.5% were hypertensive at the Ambulatory Blood Pressure Monitoring. Twenty-four patients had increased cIMT and RWT while 8.4% and 8.9% demonstrated a reduction of cDC and an increase of PWV. Two patients had a left ventricular mass index (LVMi) above the 95th percentile. cSBP correlated with all vascular indices measured (cIMT r = 0.43; cDC r = -0.33; PWV r = 0.42, p < 0.05) and with LVMi (r = 0.41; p = 0.005). Office pSBP correlated with cDC (r = -0.31; p = 0.03), PWV (r = 0.42 and p = 0.004) and LVMi (r = 0.33; p = 0.02). Regarding ABPM measurements, daytime systolic BP correlated with all vascular indices (cIMT r = 0.34, cDC r = -0.31, PWV r = 0.39 p < 0.005) but not with echocardiographic ones. No correlation was found between cardiovascular parameters and the estimated glomerular filtration rate or the urinary albumin to creatinine ratio. Conclusions: Our data show a high prevalence of subclinical atherosclerosis and cardiac remodeling in children and adolescents with SFK. A lesser proportion of patients presented an increased arterial stiffening. cSBP more than pBP (office or ambulatory) associates with SOD. Children with SFK could bear a greater cardiovascular risk pointing out the importance of early preventive efforts.