Correlation analysis between klotho G-395A polymorphism and calcium and phosphorus metabolic disorders in ESRD patients

Abstract

Objective To explore the correlation between klotho G-395A polymorphism and calcium and phosphorus metabolic disorders in end-stage renal disease (ESRD) patients. Methods A total of 137 patients with ESRD who were admitted to the Yangzhou Multi-central Blood Purification Center from April 2015 to December 2016 were selected. 80 people with normal physical examination from the physical examination center were enrolled as control. The klotho G-395A polymorphism was analyzed with TaqMan FQ-PCR method. The levels of klotho protein, fibroblast growth factor (FGF23), and calcium and phosphorus metabolism-related biochemical indicators were also measured and compared. Chi-square test, t-test, one-way ANOVA, Mann-Whitney U test, and Kruskal-Wallis H test were used to analyze the differences. The binary logistic regression method was performed for multivariate analysis. Results ① The genotypes distributions of the ESRD group and the healthy control group were consistent with the Hardy-Weinberg equilibrium (χ2=0.512, χ2 =0.134; P<0.05). ② There were significant differences in gene subtypes and gene frequency distributions between the ESRD group and the control group (χ2=11.467, P=0.003; χ2=10.130, P=0.001), and the A allele frequency was higher in the ESRD group than in the control group. ③ There were significant differences in serum calcium, klotho protein, and FGF23 levels among different genotypes of the ESRD group (P<0.05). There was a statistically significant difference in the level of serum calcium between the GA and the AA types (t=-2.469, P=0.015). There were statistically significant differences in the expression levels of FGF23 and klotho proteins between the GG and the AA types (Z=-4.020, Z=-5.461; P<0.001), as well as between the GA and the AA types (Z=-4.303, Z=- 5.610; P<0.001). ④ Binary logistic regression analysis showed that GA+ AA type was an independent risk factor for calcium and phosphorus metabolism disorders in the ESRD patients. Conclusion The klotho G-395A polymorphism A allele locus might be a susceptibility gene for the ESRD patients, and was related to the calcium and phosphorus metabolism disorders in the ESRD patients. Key words: End-stage renal disease; Klotho polymorphism; Calcium and phosphorus metabolism; Klotho protein