The value of serum FGF-23 as a cardiovascular marker in HD patients

Fibroblast growth factor 23 (FGF-23) is a recently discovered regulator of phosphate and mineral metabolism and has been associated with both progression of CKD and mortality in dialysis patients. To evaluate the association between serum FGF-23 levels and echocardiographic measurements in long-term HD (HD) patients without cardiac symptoms, we studied 90 consecutive patients treated in a single HD center (51 males, 39 females; mean age 41.5 ± 14.2 years, mean HD duration 71.2 ± 14.2 months). Comprehensive echocardiography was performed after HD and blood samples were obtained before HD. The serum FGF-23 level in dialysis patients was 95.7 ± 88.4 pg/mL. In univariate analysis, serum calcium levels (r = 0.33, P <0.05), serum creatinine (r = 0.34, P <0.05), serum albumin (r = 0.35, P <0.05) and left ventricular mass index (LVMI) (r = 0.33, P <0.001) were correlated weakly with the FGF-23 levels. Neither s. phosphorus nor calcium x phosphorus product correlated with FGF-23. In univariate regression analysis, only LVMI [β = 0.42, P <0.05, confidence interval (CI) 0.3-4.3], serum calcium (β= 0.87, P <0.001, CI 0.8-7.3), serum albumin (β= 0.87, P < 0.001, CI 0.8-7.3) and serum creatinine (β= 0.67, P <0.05, CI 0.5-6.5) significantly correlated with FGF-23. FGF-23 was identified as a factor that is weakly associated with LVMI. Thus, FGF-23 alone may not be a parameter that can be used for evaluation of the cardiac status in HD patients.