Clinical trial NCT03858413: a-Klotho in Relation to Calcification in the Coronary Arteries and Aortic Valve in Patients With Chronic Kidney Disease
Official title: Correlation of a-Klotho Levels With the Severity of Calcification in the Coronary Arteries and Aortic Valve in Patients With Chronic Kidney Disease
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Vascular Calcification
Chronic Kidney Diseases
Lead sponsor: Royal Brompton & Harefield NHS Foundation Trust
Sponsor class: OTHER
Collaborators: name: AHEPA University Hospital
First posted: 2019-02-28
Enrollment: 60
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: CASE_ONLY
Time perspective: CROSS_SECTIONAL
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Two different populations have been selected. First group with patients with chronic kidney disease under hemodialysis. Second group with patients with chronic kidney disease stage III stable for the last at least 3 months

Brief summary: To define the correlation of the levels of a-Klotho with the severity of vascular calcification in the coronary arteries and aortic valve.

Detailed description: Vascular calcification is a well-defined risk factor for cardiovascular disease and a-Klotho has been suggested to be an implicating factor in the process of vascular calcification, particularly in patients with chronic kidney disease (CKD).

With this study the investigators will examine the possible correlation of the levels of secreted a-Klotho with the severity of vascular calcification in the coronary arteries and aortic valve in patients with CKD at different stages of CKD. More precisely, a-Klotho was measured in 30 patients with end-stage renal disease under intermittent regular hemodialysis and 30 outpatients with stable CKD stage III (estimated glomerular filtration rate between 30 and 59 mL/min/1.73\^2).

Participants in both groups were eligible only if stable for at least the last 3 months pre-enrollment. Calcification will be calculated using the well-established Agatston score after submitting all patients to multi-slice computed tomography.

Continuous variables will be described as median (25th-75th percentile) and categorical variables as N (%). Variables will be compared between groups using the non-parametric Mann-Whitney U test for continuous and Fisher's exact test for categorical variables. Bivariate correlations of a-Klotho levels with clinical variables and calcification scores using the Spearman correlation coefficient will be examined. Identification of a-Klotho determinants, log-transformation of a-Klotho levels was done because of log-normal distribution and stepwise linear regression was used, with probability to remove the variable\>0.1. Identification of determinants of coronary and aortic calcification was done via log-transformation of the corresponding calcium scores, (a value of 0 was assumed; log-transformed-1 for absent calcium) and, stepwise linear regression was used as above. Because of the small sample size, all regression estimates, and confidence intervals were calculated with re-sampling so that robust variable selection and stable estimates can be ensured.

Eligibility criteria: Inclusion Criteria:

* Patients with stable chronic kidney disease stage V under intermittent hemodialysis and, patients with stable chronic kidney disease stage III

Exclusion Criteria:

* Active cancer
* Inflammatory or granulomatous disease
* Primary hyperparathyroidism
* Patients unable to provide informed consent

Primary outcomes:
measure: Agatston score in coronary arteries.
timeFrame: During enrollment.
measure: Agatston score in aortic valve.
timeFrame: During enrollment.
measure: Circulating a-Klotho.
timeFrame: During enrollment.
Secondary outcomes:
Other outcomes:
Locations:
Study officials:
affiliation: Head of Interventional Cardiology Department
name: Stavros Hadjimiltiades, Professor
role: STUDY_DIRECTOR
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