The Klotho gene G-395A polymorphism and metabolic syndrome in very elderly people

BACKGROUND: To investigate the possible association of the Klotho G-395A polymorphism and metabolic syndrome (MetS) among a population of Chinese nonagenarians and centenarians. METHODS: Subjects were from the Project of Longevity and Aging in Dujiangyan (PLAD). The genotyping of G-395A (rs1207568) in the promoter region of the Klotho gene was performed using the TaqMan allelic discrimination assay. MetS was diagnosed according to the International Diabetes Federation criteria. RESULTS: We included 695 subjects aged 93.5 ± 3.2 years. G and A allele frequencies were 0.852 and 0.148, respectively. In the whole population, the frequency of MetS was 10.8 % and 5.9 % in the GG and GA + AA genotype group, respectively (p = 0.004). The -395A allele carriers had significantly lower risk of MetS in the whole population (odd ratio [OR] 0.50, 95 % confidential interval [CI] 0.25 to 0.98) and in women (OR 0.51, 95 % CI 0.24 to 0.97), but not in men (OR 0.42, 95 % CI 0.05 to 3.85). In the whole population and women, the relationship between the Klotho G-395A SNP and MetS might due to its influence on high blood pressure (OR 0.48, 95 % CI 0.34 to 0.67; OR 0.47, 95 % CI 0.31 to 0.71, respectively) and hypertriglyceridemia (OR 0.66, 95 % CI 0.39 to 0.95; OR 0.54, 95 % CI 0.31 to 0.98, respectively). In men, this relationship might due to its influence on high blood pressure (OR 0.47, 95 % CI 0.25 to 0.90) and low HDL-C (OR 0.69, 95 % CI 0.27 to 0.93). CONCLUSIONS: The -395A allele carriers of the Klotho gene were correlated with lower risk of MetS among Chinese nonagenarians and centenarians, especially in women. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12877-016-0221-6) contains supplementary material, which is available to authorized users.