The relationship of kidney function with arterial wall condition in individuals without chronic kidney disease and cardiovascular diseases

Background: Chronic kidney disease (CKD) is a known risk factor for cardiovascular disease (CVD). However, there is a small information about increased risk of CVD already with a slight decrease in kidney function. Substrate for CVD development is subclinical changes in the arterial wall, which can be accelerated by known risk factorsHypothesis: We have assumed that even an initial impairment of kidney function were capable of adversely affecting on the arterial wall.Objective: To examine the association of kidney function with the condition of the arterial wall in persons without CKD and CVD in different age groups.Materials and methods: The study group included 253 subjects free of known CVD and CKD. The average age of the subjects was 51.5 ± 13.3 g. There were 172 women and 81 men. The group of conditionally “older” (women 55 years, men 45 years) was 117 people, conditionally “younger” (women ≤ 55 years, men ≤ 45 years) - 136. 55 subjects had arterial hypertension 1-2 st. All subjects had a glomerular filtration rate (GFR) ≥60 ml / min / 1.73 m2, albuminuria 30 mg /24h. When assessing the condition of the arterial wall, the pulse wave velocity (PWV) 10 m / s had 93 people, the complex intima-media thickness (CIMT) 0.9 mm had 42 people, the presence of atherosclerotic plaques (AP) had 106 people, and a decrease in endothelium-dependent vasodilation (EDVD) 10% in 86 people. An elevated urea level 8.3 mmol / l in the blood was detected in 10 people. Determination of creatinine, urea in the blood serum was carried out by routine methods. Measurement of PWV with the help of applanation tonometry. Measurement of CIMT and determination of AP was carried out by means of duplex scanning of carotid arteries. Measurement of EDVD - using a test with reactive hyperemia.Results: Statistical analysis of the results of this study was carried out using the SAS application statistical software package (StatisticalAnalysisSystem, SAS InstituteInc., USA). In the course of multivariate linear regression analysis, a statistically significant independent association of the urea level with CIMT (β = 0.023, p = 0.023) was detected in the “older” group taking into account the correction for sex, systolic blood pressure level, smoking, body mass index, fasting glucose level and albuminuria. Independent relationships of levels of GFR, creatinine and albuminuria with parameters of the vascular wall were not revealed.Conclusions: The level of urea had a direct independent relationship with CIMT in the older age group, which is more likely due to the ability of urea to enhance oxidative stress. Interrelations of the level of GFR, albuminuria, creatinine with the condition of the arterial wall were not obtained in the study group