Serum soluble Klotho level is associated with abdominal aortic calcification in patients on maintenance hemodialysis

Objective To determine the relationship between serum soluble Klotho (sKL) level and abdominal aortic calcification in maintenance hemodialysis (MHD) patients. Methods One hundred and twenty nine cases of MHD patients were collected prospectively. Serum sKL was detected by ELISA. Abdomen lateral plain were used as a criteria to determine the abdominal aortic calcification. The abdominal aortic calcification score (AAC) was calculated. Logistic regression analysis was used to determine the risk factor of abdominal aortic calcification in MHD patients. The ROC analysis was applied to evaluate the diagnostic value of sKL in abdominal aortic calcification. Results Eighty-seven patients had abdominal aortic calcification. The median AAC was 4.0 (0.00, 11.00). The median sKL concentration was 616.29 (378.19，821.61) ng/L and the sKL concentration was negatively correlated with AAC (r＝-0.255, P＜0.05). Risk of moderate to severe abdominal aortic calcification in patients with lowest quartile of the sKL concentration was significantly higher than those with highest quartile (OR＝4.004, 95%CI 1.350-11.826, P＜0.05), even after the adjustment for demographic data, lifestyle factors and biochemical markers (OR＝4.542, 95%CI 1.368-15.081, P＜0.05). Multivariate Logistic regression analysis showed that lower serum sKL level and smoking were independent risk factors for severe calcification of the abdominal aorta. ROC-AUC of serum sKL for severe abdominal aortic calcification was 0.746 (cut off 265.39 ng/L, accuracy 88.5%, specificity 56.2%). Conclusions The lower serum sKL is independently associated with severe abdominal aorta calcification. Serum sKL may have diagnostic value for severe abdominal aorta calcification in MHD patients.