Association between serum alpha Klotho levels and the likelihood of abdominal aortic calcification

As an anti-aging protein, alpha Klotho (α-Klotho) plays an important role in cardiovascular disease. However, the correlation between α-Klotho and abdominal aortic calcification (AAC) is unclear. The present study explored the relationship between α-Klotho and AAC in US adults. We used data from the National Health and Nutrition Examination Survey (NHANES) 2013–2014 for this cross-sectional study with participants aged 40 years or older, and with complete data on serum α-Klotho levels and AAC scores. And weighted multivariate linear regression and multivariate logistic regression to explore the association between α-Klotho and AAC. A total of 2411 subjects were included in this study. The AAC score for all participants was 1.19 ± 0.07 and the prevalence of severe AAC was 5.85%. In the fully adjusted Model 3, we observed that the AAC score of the highest α-Klotho quartile was 0.71 units lower than the lowest quartile (β = -0.71, 95%CI: -1.25 ~-0.17, p = 0.01) and a 53% lower risk of Severe AAC in the highest α-Klotho quartile than in the lowest quartile (Quartile 4: OR: 0.47, 95% CI: 0.19–0.74, p = 0.01). Interaction terms were also used to test the heterogeneities among each subgroup, and a significant difference was revealed among male, indicating that this association was dependent on gender. In US adults, α-Klotho levels were associated with lower AAC scores and a reduced risk of severe AAC. Future work is needed to confirm these findings and to define any clinical relevance.