| Objective:To investigate the association of Single Nucleotide Polymorphism(SNP)distribution and its expressed protein at Klotho G-395 A site in maintenance hemodialysis(MHD)patients with calcium and phosphorous metabolism and osteoporosis.Study subjects:The MHD group had 101 patients,who had long-term maintenance hemodialysis(hemodialysis time > 3months),were selected in the outpatient department of the 908 th Hospital of the people's Liberation Army from December2018 to December 2019.The control group included 80 healthy people.Allele-specific primer PCR was used to detect the SNP of Klotho G-395 A in MHD patients,the serum Klotho protein and fibroblast growth factor(FGF23)were detected by enzyme-linked immunosorbent assay(ELISA),and the biochemical indexes related to calcium and phosphorus were collected.Bone mineral density(BMD)of the femoral neck was measured by dual-energy X-ray absorptiometry.According to WTO standards,MHD patients were divided into three groups,which were normal BMD group,osteopenia group and osteoporosis group.Chi-square test,independent sample t-test,one-way ANOVA and Pearson correlation analysis were used to analyze the difference or correlation among biochemical indexes.Results:(1)The genotype distribution of MHD group and the control group accorded with Hardy-Weinberg equilibrium and had certain representativeness.(2)There were significant differences in genotype and gene frequency between MHD group and the control group(P<0.05),and the G-allele frequency in MHD group was higher than that in control group.(3)There were significant differences in serum calcium,phosphorus and iPTHbetween MHD group and the control group(P<0.05).In MHD group,the levels of Klotho protein and FGF23 were significantly different in different genotypes(P<0.05).(4)The levels of Klotho protein and FGF23 were significantly different in the MHD(P<0.05).(5)In MHD group,83.2% of patients had abnormal bone mass.the level of Klotho protein,dialysis age,age and |T|value were significantly different among different BMD groups(P<0.05).The age of dialysis was significantly different between normal BMD group and osteopenia group,normal BMD group and osteoporosis group(P<0.05).The value of |T| was significantly different between osteopenia group and normal BMD group,osteopenia group and osteoporosis group(P<0.05).There were no significant differences in serum calcium,phosphorus and FGF23 levels among the three groups.(6)The frequency distribution of osteoporosis was significantly different between men and women in MHD group(P < 0.05).There were no significant differences in Klotho protein and FGF23 levels between the two groups.There were no significant differences in the frequency distribution of osteoporosis among different genotypes.(7)Klotho protein was negatively correlated with FGF23 and serum phosphorus(r=-0.312,P=0.002;r=-0.277,P=0.005),positively correlated with serum calcium(r=0.356,P=0.000),but was not correlated with iPTH.FGF23 was positively correlated with serum phosphorus and iPTH(r=0.863,P=0.000;r=0.216,P=0.03),but was not with serum calcium.The value of |T| was positively correlated with Klotho protein(r=0.205,P=0.039),there were no significant correlation between age,dialysis age,FGF23,serum calcium,serum phosphorus and iPTH.(8)Multiple logistic regression analysis,in MHD patients complicated with bone metabolic disorder,age and dialysis age were independent risk factors and Klotho protein was a protective factor.The genotype GG of Klotho G-395 A site was not an independent protective factor for the disease.Conclusion:(1)The rate of the abnormal bone mass in maintenance hemodialysis patientsmay be higher.(2)Klotho protein and FGF23 may be involved in the regulation of calcium and phosphorus metabolism in MHD patients.(3)In MHD patients complicated with bone metabolic disorder,high Klotho protein was a protective factor,age and dialysis age was independent risk factors.The genotype GG of Klotho G-395 A site was not an independent protective factor for the disease. |
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