Association between fibroblast growth factor 23 and trabecular bone score in early stages of ckd

Abstract Background and Aims Newer markers of kidney damage and mineral and bone changes in chronic kidney disease (CKD) are needed. The fracture risk increases with worsening of CKD with highest incidence in later stages. Thus methods for early bone status assessment and laboratory marker of kidney function is needed. Aim of the study was to evaluate bone mineral density (BMD) and trabecular bone score (TBS) – a novel surrogate of trabecular bone microstructure, in relationship with newer laboratory markers of CKD, such as fibroblast growth factor 23 (FGF23) and klotho. Method A cross-sectional study during July 2018-July2019 was conducted. Plasma levels of soluble klotho and FGF23 were determined by ELISA (enzyme-linked immuno -assay). All patients undergone bone mineral density (BMD) and trabecular bone scores (TBS) measurement. Patients were divided into 2 groups as follows: A - patients in stages G1 - G3; B - patients in stages G4 – 5 accoridng to KDIGO. Results A total of 74 CKD patients (42 males and 32 females; mean age 68.8 years) were included in the study. Greater FGF23 levels in group B(N = 15) in comparison to group A (N = 59)(p = .001) were observed. FGF23 was associated with glomerular filtration (GF)(R = -0.43; p = 0.003), with greater levels of FGF23 at GF less than 0.8 ml/s. Significant difference in TBS within first 3 CKD stages (mean TBS in G1 = 1.374 vs. G2 = 1.304 vs. G3a = 1.24; p = 0.03) and negative correlation of FGF23 and TBS (R = -0.33; p = 0.05) and a positive correlation between klotho and TBS (R = 0.419; p = 0.04) was observed. Conclusion This study confirmed that FGF23 is associated with TBS. However, TBS reflects kidney function decline only in first 3 stages of CKD. Thus, FGF23 together with TBS are promising markers of early trabecular bone impairment in CKD.