The Association of KLOTHO Gene Polymorphism with Serum Osteoprotegerin Levels in Maintenance Hemodialysis Patients / 대한신장학회지

ABSTRACT

PURPOSE: Klotho mutant mice showed abnormal calcium and vitamin D metabolism, hyperphosphatemia and vascular calcification. We observed the frequencies of klotho gene polymorphism and investigated their relation with some clinical parameters including serum osteoprotegerin (OPG) levels in maintenance hemodialysis (HD) patients. METHODS: Total 88 patients (mean age 58+/-13 years, male:female=47:41) on maintenance HD were enrolled. The genotypings for G-395A in promoter and C1818T in exon 4 of klotho gene were performed with real-time polymerase chain reaction. We measured blood pressure, body mass index (BMI), and serum calcium, phosphorus, parathyroid hormone (PTH), alkaline phosphatase, hs-CRP, lipid profiles and OPG. RESULTS: In G-395A in promoter, the distribution of genotypes was GG 66% (n=58), GA 23% (n=20) and AA 11% (n=10), respectively and the allele frequencies were 0.773 for G allele and 0.227 for A allele. In C1818T in exon 4, the distribution of genotypes was CC 63% (n=55), CT 30% (n=26), and TT 7% (n=7), and the frequencies were 0.773 for C allele and 0.227 for T allele. G-395A shows correlations with BMI and HDL-cholesterol (p<0.005). G-395A and C1818T in klotho gene show no statistical correlation with other clinical parameters of vascular calcification including OPG. CONCLUSION: Klotho G-395A and C1818T polymorphisms are not correlated with OPG in maintenance HD patients. Further research needs for the other klotho polymorphisms on chronic kidney disease and end-stage renal disease.