P1418BONE-DERIVED HORMONES, MINERAL METABOLISM, CARDIOVASCULAR DISEASE AND PATIENT OUTCOME IN END-STAGE RENAL PATIENTS

Abstract Background and Aims Chronic kidney disease-mineral and bone disorder (CKD-MBD) is frequent in end-stage renal disease ESRD (ESRD) patients, increasing morbid-mortality. The aim of this study was to analyse the associations between the new CKD-MBD players [alpha-klotho, fibroblast grow factor (FGF) 23, sclerostin] and the usual markers of the disease [parathyroid hormone (PTH), bone alkaline phosphatase (bAP), vitamin D (vitD), phosphorus (Pi), Calcium (Ca) and Magnesium (Mg)], as well echocardiographic findings [left ventricular mass index (LVMI) measured by Devereux formula, valvular calcifications], vascular calcifications and patients outcomes. Method We performed a prospective cohort study of a sample of ESRD patients listed for renal transplant. All patients were submitted to renal transplant and were followed for 12 months. Patient and graft survival were recorded. At inclusion, demographic and clinical data were collected, laboratorial evaluation, bone biopsy and X-ray of the pelvis and hands (Adragão score) were performed. Continuous variables are presented as medians and categorical variables as frequencies. Associations between variables were performed using Wilcoxon rank sum test and Spearman correlation test. STATA software was used and p < 0.05 was considered statistically significant. Results We included 85 patients. Mean age 50.1±12.7 years, 59 men (69.4%), 66 caucasian (77.6%). The median LVMI was 108.5 (92 – 129) g/m2, with 32 patients presenting LVH and 19 valvular calcifications. Median Adragão score was 1 (0 – 2). At the end of 12 months, 4 patients died and 5 had graft failure (non-primary function). Alpha-klotho correlated with bAP (p=0.0006) and marginally with PTH and absence of valvular calcifications (p=0.05). FGF23 correlated with Pi (p<0.001), Ca (p=0.004), PTH (p=0.003), Mg (p=0.002), and inversely with bAP (p=0.003). There was a marginal association with Adragão score (p=0.06). We didn’t found correlations between FGF23 and alpha-klotho or dialysis vintage or echocardiographic characteristics. Sclerostin correlated negatively with bAP (p=0.007) and PTH (p=0.04). The 3rd sclerostin tertile was associated with high scores of vascular calcifications (p=0.02). Lower levels of sclerostin were associated with patient survival at the end of 12 months (p=0.02). Conclusion From these 3 new bone-derived hormones, sclerostin, a bone formation inhibitor, seems to act as a risk factor for vascular calcifications and worse outcomes.