Decreased serum levels of klotho protein in chronic kidney disease patients: Clinical imortance

Abstract

Objective: to determine the role of serum Klotho (s-Klotho) protein levels changes in patients with different stages of chronic kidney disease (CKD). Methods: The study involved 130 patients with CKD stages 1-5D (mean age 41±6.7 years). Serum levels of parathyroid hormone (PTH), calcium, phosphorus and s-Klotho protein (ELISA method) at baseline and after 1 year of follow-up were examined in all the patients so as the blood pressure (BP), including central (aortic), pulse wave velocity with the help of «Sphygmocor» (Australia), echocardiography, radiography of the abdominal aorta in a lateral projection were also performed. Results: when comparing the s-Klotho levels in patients with different CKD stages, it was found that the level change associated with the reduction of glomerular filtration rate (GFR) ahead of phosphorus and PTH increase in serum, stared at 3A CKD, whereas hyperphosphatemia and PTH increase started at 4-5 CKD stages. According to ROC analysis, decreasing of s-Klotho levels below 387 pg/ml was indicated a calcification risk of abdominal aorta increased with an 80% sensitivity and 75% specificity. In addition, a strong negative relationship of low s-Klotho levels and heart remodeling was found. When comparing the patients with hypertension who were receiving antihypertensive monotherapy, the highest serum levels of Klotho protein were observed in those of them whose target blood pressure level was achieved primarily through Angiotensin II Receptors Blockers (ARB), compared to those who was administered another drug group (p<0.01) or has not reached the target blood pressure level (p=0,008). Conclusion: The change of serum Klotho levels (decrease) in CKD progression is associated with the degree (increase) of cardiovascular calcification and remodeling (the development of left ventricular hypertrophy, and cardiomyopathy) and it can be seen as an early independent marker of the cardiovascular system lesions in CKD. Our preliminary data of the effect of blood pressure correction on s-Klotho levels may indicate the possibility of drug maintaining serum Klotho levels and it requires further research.