#5440 bone turnover markers and bone mineral density 1 year after kidney transplantation

Abstract Background and Aims Alterations of bone metabolism are a hallmark of chronic kidney disease (CKD) patients and do not completely ameliorate after kidney transplantation. In the setting of a secondary analysis of a RCT, we evaluated changes of bone turnover biomarkers (BTM) and their associations with changes of bone mineral density (BMD) as assessed by DXA. Method Sixty-six Kidney Transplant (KTx) recipients were enrolled between 2014-2017. In these patients, at baseline (T0) and 12 months (T12) we measured BTM (Figure 1). The prevalence of vitamin K deficiency was assessed based on undercarboxylated-BGP (uc-BGP) cut-off: > = 4.5 ng/ml, whilst dephosphorylated-ucMGP (dp-ucMGP) we considered a cut-off >500 pmol/L levels. DXA data were assessed at lumbar spine, femoral neck, total hip, one-third and ultradistal radius both baseline and after one year, evaluating the changes in areal BMD (aBMD). Results were expressed as mean ±SD or median and inter-quartile range, as appropriate. Correlations were investigated by Spearman's analysis. Results The mean age of enrolled patients was 51± 13 years, 34% were female. BMI was on average 27.8 ± 5.5 kg/m2. 24 patients (39.3%) were pre-emptive and 37 (60.7%) on dialysis and 19% of patients had a history of fracture. In Figure 1 the trend of BTM 1 year after KTx. We highlighted a significant reduction of PTH, CTX, P1NP, and VKDPs. This latter while improving but was not completely restored. Table 1 shows the correlations between the percentage variation of BTM and percentage variation of BMD at several sites evaluated. Conclusion In the first-year post-transplant, along with the improvement of renal function, PTH values were reduced as well those of CTX and P1NP. Moreover, we observed an inverse correlation between BTM and BMD, the reduction of bone turnover expressed by the trend of BTM translates into an improvement of BMD.