Erythropoietin Resistance Index and the Affecting Factors in Children with Peritoneal Dialysis.

BACKGROUND: Erythropoiesis-stimulating agents (ESAs) are used to treat anemia in CKD. Erythropoietin resistance index (ERI) is a useful tool used to evaluate the response to ESAs. In this study, we aimed to evaluate the causes of high ERI in children undergoing peritoneal dialysis (PD). METHOD: Patients who had been on PD for at least 1 year were included in this retrospective study. Demographic characteristics, residual kidney function (RKF), adequacy of dialysis, peritoneal glucose exposure, the number and reason for hospitalization, and medications were recorded. Anemia and laboratory parameters that may affect anemia were noted by taking the average of laboratory values in the last follow-up year (time-averaged). The weekly ESA dose was proportioned to the annual average hemoglobin value and body weight to calculate the ERI in terms of U/kg/week/g/dL. RESULTS: A total of 100 patients were included in the study. The mean ESA dose and ERI value were 119.8 ± 66.22 U/kg/week and 13.01 ± 7.52 U/kg/week/g/dL, respectively. It was determined that the patients <5 years of age have very high ERI value, and these patients need 2 times more ESA than those >10 years of age. Absence of RKF, large number of hospitalization, and ACEI use were also found to affect the ERI value negatively. CONCLUSION: We demonstrate that the most important factor affecting ERI value is young age. We also reveal that absence of RKF, large number of hospitalization, and ACEI use are also important variables affecting the ERI value.

Do children with solitary or hypofunctioning kidney have the same prevalence for masked hypertension?

BACKGROUND: Having a low nephron number is a well-known risk factor for hypertension. There is an inverse relationship between the filtration surface area and systemic hypertension. A significant percentage of masked hypertension can be detected in children with nephron loss by ambulatory blood pressure monitoring (ABPM). METHODS: We prospectively investigated ABPM results of children having reduced kidney mass with normal office blood pressures (BPs) and kidney function. Forty-three children with congenital solitary kidney (group 1), 11 children with acquired solitary kidney (group 2), and 76 children with hypofunctioning kidney (group 3) were compared with age, gender, and BMI-matched healthy control group (group 4). The dietary salt intake of 76 patients was evaluated as salt equivalent (g/day). The primary endpoint was change from baseline in mean 24-h ABPM variables and the proportion of patients with masked hypertension when assessed by ABPM. RESULTS: The masked hypertension ratio of all patients was 12.3% when assessed with ABPM. Night hypertension was significantly higher in all patient groups than in the control group (p = 0.01). Diastolic BP loads of groups 1 and 3 were higher than in controls (p = 0.024). Systolic BP loads were higher only in group 1 than in the control group (p = 0.003). The dietary salt equivalent of patients in group 1 correlated positively with 24-h SBP and mean arterial pressure (MAP) values. Patients with excessive dietary salt intake in group 1 had a significantly higher diastolic BP load than those without excessive salt intake in group 1 (p = 0.002). CONCLUSIONS: Masked hypertension can be seen in children with a solitary kidney or when one of the kidneys is hypofunctioning. Systolic BP loads are higher in children with congenital solitary kidney, and salt intake correlates with systolic BP profiles especially in those. Our results suggest that being born with a congenital solitary kidney increases predisposition to hypertension and salt sensitivity.