Objective:To investigate the distribution of three cites of single nucleotide polymorphisms(SNPs)and their combination distributions of the KL gene in the Chinese elderly population and analyze their association with hypertension in the aged.Methods:Selected 775 patients with essential hypertension(EH)and 339 heathy people(the age≥60)as research objects.Genomic DNA of leukocytes was extracted from venous blood and the single allele specific primer PCR technique(SASP-PCR)was used to detect allelic genotypes of three sites of SNPs and their distribution of combination genotypes of the KL gene in order to analysis their relations with the EH.Results:The frequency of allele AA genotype of KL G-395A in EH group was higher than that in the control group(P<0.01).According to sex stratification analysis

the frequency of allele AA in the EH male subgroup was obviously higher than that in the control subgroup(P = 0.001).There were no significant difference to be found either in the KL C370S SNP or F352V SNP between EH group and the control group(P>0.5).According to the combination genotype analysis

we found that the allelic genotype frequency of Klotho G-395A+F352V+ C370C

Klotho A-395A+F352V+C370C and Klotho A-395A+F352V+C370S in the EH group was higher than that in the control group(P<0.05)

but according to sex stratification analysis

we only found that the allele genotype frequency of KL G-395A+F352V+ C370C

KL A-395A+F352V+C370C and KL A-395A+F352V+C370S were obviously higher in the EH male subgroup than that in the healthy male subgroup(P<0.05).We also found that the combined allelic genotype frequency of KL A-395A+F352F+S370S and KL G-395G+V352V+C370S were obviously lower in the EH male subgroup than that in the control male subgroup(P<0.04).Conclusion:This study showed that there was an association between SNP of KL G-395A and essential hypertension in the aged.According to the combination genotype analysis

this study found that genotypes of KL G-395A+F352V+C370C

KL A-395A+F352V+C370C and KL A-395A+ F352V+C370S associated with EH in the aged andx difference existed

i.e.the male patients who carried with genotypes of KL G-395A+F352V+C370C

KL A-395A+F352V+ C370C and KL A-395A+ F352V+C370S have a high risk in suffering from EH in the aged.