Relationship between endothelium-dependent vasodilation, carotid intima-media thickness and atherosclerotic plaques: is it preserved in the elderly?
Authors: Troshina M S , Ryabikov A N , Palekhina Y Y , Ryabikov M N , Malyutina S K ,   The HAPIEE Group
Published: October 2021

Abstract

Introduction
Vascular ageing refers to the age-related deterioration in vascular structure and function. Endothelial dysfunction (ED), carotid intima-media thickness (CIMT) and atherosclerotic plaques are key-players in this process, but also are indicators of chronological age. As established, they are jointly associated in young and middle age populations but this pattern could be changed over the lifetime.

Purpose
We aimed to assess the association between endothelium-dependent vasodilation, CIMT, atherosclerotic plaques and cardiovascular risk factors in elder and senile population sample.

Methods
The study was carried out in the population sample of men and women aged 58–82 years (n=788/424 women). The intima-media thickness and presence of carotid plaques were assessed by high-resolution ultrasound. The ED was detected with ultrasound reactive hyperemia test (Celermajer) by measurement of flow-mediated dilation (FMD) of brachial artery; ED was identified if FMD lower than 10%. Medical history of cardiovascular diseases and risk factors were assessed by standard methods.

Results
The mean FMD was 2.7% in men (SD 7.32), and 3.2% in women (SD 7.19) and did not differ by sex. The frequency of ED was 88.2% in men and 85.8% in women. The mean CIMT was higher in men than in women (0.95 mm (SD 0.18) vs. 0.88 mm (SD 0.17), p&lt;0.001). Men with ED had significantly higher triglycerides level (125.1 mg/dl (SD 71.2) vs. 102.7 mg/dl (SD 45.7), p=0.033) and ratio “waist circumference/hip circumference” (0.94 (SD 0.05) vs. 0.92 (SD 0.076), p=0.009) than men without ED. Moreover, men with ED had higher body-mass index, but the difference did not reach statistical significance. There was borderline association between smoking and ED found in women (p=0.067) and poor association in men (p=0.106). No linear association was found between CIMT and FMD in men (β=−1.76, SD 2.25; p=0,436) and in women (β=−2.19, SD 2.15; p=0.309); however, the regression coefficients in age-adjusted models were of negative direction as expected. In addition, there was no difference in the mean CIMT and frequency of atherosclerotic plaques in groups with and without ED either in men or in women. There was a tendency of greater CIMT in those men with ED in the youngest of the studied group (58–62 years) vs. the same age men without ED (p=0.242). In women, we encountered significant increase of CIMT among those with ED in age group 63–77 years against women without ED (p=0.047), which faded out in older group.

Conclusions
In our population sample we did not observe the associations of frequency of ED or FMD% neither with CIMT nor presence of atherosclerotic plaques. Only in women below 78 years, the presence of ED was associated with increased CIMT. The subclinical markers of atherosclerosis – synergistically expressed in younger populations – lose their associations in elderly. We should take this into account in development of novel therapies for elderly and senile population.

Funding Acknowledgement
Type of funding sources: Foundation. Main funding source(s): Wellcome Trust No. 081081AIA,Russian Academy of Sciences No. AAAA-A-17-117112850280-2