Changes of FGF23 and hearing in chronic renal failure and their correlation analysis.

BACKGROUND: To explore the association between fibroblast growth factor 23 (FGF23) and hearing in chronic renal failure (CRF). METHODS: Pure tone audiometry was used to detect the hearing of patients with CRF; the level of serum FGF23, creatinine, blood urea nitrogen (BUN), parathyroid hormone (PTH), and mean binaural hearing threshold were compared to the control group (people without kidney disease). The rat model of renal failure was established by 5/6 nephrectomy, and the auditory brainstem response (ABR) of rats after modeling was detected by the Tucker Davis Technologies (TDT) system; the expression level of FGF23 in the peripheral blood, renal and cochlear tissue was also detected. RESULTS: The incidence of hearing loss (HL) and serum FGF23 were higher in CRF patients than the control group; the sFGF23 was positively correlated with the mean binaural hearing threshold. Animal studies showed that the ABR threshold, creatinine, FGF23, BUN, and PTH increased after modeling; although, an increase in FGF23 was observed earlier than other indicators. The HL of rats with renal failure was significantly correlated with BUN, phosphate, PTH, sFGF23, kFGF23/ß-actin, eFGF23/ß-actin, weight, and modeling cycle. CONCLUSIONS: Both CRF patients and rat models showed high-frequency HL. FGF23 was highly expressed in the serum of HL renal failure patients and rats, as well as in the renal tissue and cochlea of renal failure rats. Therefore, FGF23 may be involved in the occurrence and development of HL caused by CRF.

Predictive value of serum d-serine level for hearing impairment in uremic patients.

OBJECTIVE: To investigate the predictive value of serum d-serine level for hearing impairment (HI) in uremic patients. METHODS: In this study, 30 uremic patients with HI and 30 with normal hearing were selected. The basic conditions, biochemical indicators, and serum serine levels of the two groups were compared to analyze the influencing factors of HI. RESULTS: The age and d-serine levels were higher in the HI group, while the l-serine level was lower than uremia in the normal hearing group. Logistic regression analysis showed that d-serine level ≥10 µM and older age increased the risk of HI. The area of the receiver operating characteristic (ROC) curve drawn by the prediction probability of HI was 0.838, indicating that age, d-serine, and l-serine had predictive diagnostic values for HI (p < .001). Among these, the ROC curve area of d-serine in predicting HI in uremic patients was 0.822 (p < .001). CONCLUSIONS: Increased d-serine and age are two risk factors for HI, while l-serine is a protective factor. d-Serine level has a predictive value for HI in uremic patients. Uremic patients are recommended hearing assessment, estimation of d-serine levels, and early intervention.

Correlation study of FGF23/D-serine in maintenance hemodialysis patients with combined hearing impairment.

BACKGROUND: Recent studies have reported an association between chronic renal failure and hearing impairment. Yet, the exact mechanism of action is still not fully understood. In this study, we investigated the expression of fibroblast growth factor 23 (FGF23) and D-serine in maintenance hemodialysis (MHD) patients with end-stage renal disease (ESRD) complicated with hearing impairment and further investigated the correlation between FGF23/D-serine and hearing impairment. METHODS: A total of 90 subjects, including 30 MHD patients complicated with hearing impairment, 30 MHD patients with normal hearing, and 30 controls, were included in this case-control study. Relevant data were obtained by questionnaire survey, audiometric test, enzyme-linked immunosorbent assay (ELISA) to determine FGF23 level, and high-performance liquid chromatography to determine D-serine level. RESULTS: MHD patients showed abnormally high expression of FGF23 and D-serine, where FGF23 and D-serine levels were significantly higher in the group with hearing impairment than in the group with normal hearing and normal controls (all P<0.01). Also, elevated FGF23 and D-serine were identified as risk factors for hearing impairment in ESRD, with ORs of 16.54 (95%CI, 2.75-99.55) and 15.22 (95%CI, 2.59-89.51), respectively. Further Person correlation analysis showed a moderate positive correlation between FGF23 and D-serine (r = 0.683, P<0.001). CONCLUSION: This study provides potential biomarkers for the early detection of hearing impairment complicated by chronic renal failure, and the reduction of FGF23/D-serine may provide a potential target for the treatment of hearing impairment complicated by chronic renal failure.