LAUSR

To explore:i)differences in predictive variables between TrabecularBoneScore(TBS)-derived and LumbarT-score derived bone types.ii)the relationship difference of TBS and LumbarT-score with various ranges of PTH levels in order to identify the levels of PTH that overcome PTH resistance iii) to conform normal upper limit of PTHi levels in hemodialysis patients recommended by K-DIGO guidelines. In twenty-five hemodialysis patients,following variables were recorded:biochemical variables,DXA derived variables(including TBS),FRAX-tool derived HRs.The relationship of variables with TBS-derived and LumbarTscore-derived bone types was tested by univariate analysis. The association of TBS,LumbarTscore and fracture HRs with PTHi was tested by univariate analysis and regression curve fitting(maximizing R²). Using univariate analysis,the predictive variables of lumbarT-score derived and TBS-derived bone types are different.By curve fitting regression TBS vs PTHi had a sinusoidal pattern with higher values,correlating to PTHi values in the 4th quartile(462 pg/ml (341 -696)corresponding to the normal levels recommended by K-DIGO guidelines.In the same range of values,LumbarT-score vs PTHi for BMD-derived bone type has a progressively increasing trend for osteopenia and osteoporosis,with a statistically significant difference(P0.008). The predictive variables of TBs-derived and LumbarT-score derived bone types are different.Bone microarchitecture(MA),measured by TBS,correlates oppositely than LumbarT-score with higher PTHi values in the normal range of PTHi levels recommended by the K-DIGO-CKD-MBD2009-2017 guidelines.Within this range,PTHi values overcome PTH-resistance and improve the bone mineral metabolism. Results must not be extended to higher or lower levels of PTHi compared to those considered in the study for which there is a clear evidence of increase in the relative risk of mortality.