ESPN 51th Annual Meeting

ESPN 2018


 
Cardiovascular manifestations in X-linked hypophosphatemia
OLAYA HERNáNDEZ-FRíAS 1 HELENA GIL-PEñA 2 JOSé Mª PéREZ-ROLDáN 2 SUSANA GONZáLEZ-SáNCHEZ 2 ROCíO FUENTE-PEREZ 1 ÁNGELA FERNáNDEZ-IGLESIAS 1 ENRIQUE RODRíGUEZ-RUBIO 1 FERNANDO SANTOS 1 RenalTube Group 2

1- UNIVERSITY OF OVIEDO
2- HOSPITAL UNIVERSITARIO CENTRAL DE ASTURIAS
 
Introduction:

 Objectives: X-linked hypophosphatemia (XLH) is a rare disease that occurs with elevated serum fibroblast growth factor 23 (FGF23). This study aimed to find out if cardiovascular findings such as hypertension, atherosclerosis and left ventricular hypertrophy (LVH), which have been related to high serum FGF23 in patients with chronic kidney disease, are present in children with XLH.

Material and methods:

 

Multicenter prospective clinical study involving 21 patients (1-17 years of age) included in Renaltube database with genetically confirmed diagnosis of XLH. After informed consent, the following data were analyzed: (i) serum biochemistry, (ii) serum FGF23 by immuno-assay, (iii) ambulatory blood pressure monitoring (ABPM), (iv) carotid intima-media thickness (c-IMT) by ultrasound, (v) echocardiogram (ECG). All cases were under phosphate and 1-OH or 1,25-(OH)2 vitamin D derivative treatment. Echocardiographic measurements were compared with reference values (Pettersen et al. 2008) and expressed as SD z-scores. A left ventricular mass index (LVMI) >51 g/m2.7 was considered indicative of left ventricular hypertrophy (Flynn et al. 2017).

 

Results:

Serum concentrations (X±SEM) of phosphate and intact PTH were 2.68±0.11 mg/dl and 65.81±6.93 pg/ml, respectively. Serum FGF23 concentration was 276.56±67.06 pg/ml (normal <60 pg/ml).  Abnormally high c-IMT was found in one patient, who was obese and hypertensive as revealed by ABPM. In 2 other patients, ABPM also showed arterial hypertension. Mean z-scores for ECG interventricular septal end diastole (IVSd) and left ventricular posterior wall end diastole (LVPWd) were +0.65±0.13 and +0.79±0.15, respectively. Mean left ventricular mass index (LVMI) was 27.4±2.95 g/m2.7. There was no correlation between these ECG parameters and serum FGF23 concentrations. 

 

Conclusions:

Paediatric patients with XLH receiving conventional treatment do not have clinical manifestations suggestive of cardiovascular disease. However, some echocardiographic measurements of ventricular mass stand above the mean and may indicate a risk of developing left ventricular hypertrophy in adult life.