FREE WATER TRANSPORT AND ITS ASSOCIATION WITH CARDIOVASCULAR STATUS IN CHILDREN ON PERITONEAL DIALYSIS

<jats:sec><jats:title>Background</jats:title><jats:p>Volume overload is one of the most important factors associated with left ventricular hypertrophy (LVH) and cardiovascular disease in chronic peritoneal dialysis (PD) patients. MiniPET is a reliable tool to evaluate free water transport (FWT). In a clinical setting, the significance of FWT has not been evaluated in terms of outcome in children on PD. The objective was to define a FWT value of clinical significance in children on PD, fixing its relationship to left ventricular mass index (LVMI) as a well-known outcome parameter.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>MiniPET was performed with 3.86% glucose, 1-h long, to measure FWT in PD patients &gt; 6 years old. An echocardiogram (ECG) was performed within 2 months of the MiniPET. Left ventricular hypertrophy was defined as LVMI ≥ 38.6 g/height<jats:sup>2.7</jats:sup>(95th percentile). Receiver operating characteristic curve (ROC) analysis was used to determine the cut-off value of FWT searching the highest sensitivity and specificity to differentiate patients with normal/abnormal LVMI. A p &lt; 0.05 was considered significant.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Forty-six studies were performed on 32 patients, 16 males; mean age 11.59 ± 3.07 years. Mean normalized FWT (nFWT) was 144.4 ± 84.8 mL/m<jats:sup>2</jats:sup>, corresponding to 46.7% of total ultrafiltration. Mean LVMI was 42 ± 11.3 g/m<jats:sup>2.7</jats:sup>with a negative correlation to nFWT ( p &lt; 0.01). Eighteen out of 32 patients had LVH. The ROC analysis (nFWT vs LVMI) showed an area under the curve of 0.71 (95% confidence interval [CI], 0.53 – 0.89; p = 0.04), allowing a cut-off nFWT value of 110 mL/m<jats:sup>2</jats:sup>to be defined, dividing the population into 2 groups of patients according to the LVMI cut-off value of 38,6 g/m<jats:sup>2.7</jats:sup>.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>The nFWT showed an inverse correlation to LVMI. A nFWT value &lt; 110 mL/m<jats:sup>2</jats:sup>was significantly associated with LVH. The negative relationship observed between nFWT and LVMI, and the cut-off level for nFWT according to the 95th percentile of LVMI, suggest that the regular evaluation of nFWT could become a useful tool in assessing the capacity of PD treatment to keep patients’ volume status under control, avoiding cardiovascular impairment.</jats:p></jats:sec>