Impact of kidney function on stiffness of small conduit arteries in hypertension and obesity.

Abstract

Background: Arterial stiffness is a key cardiovascular risk factor influenced by conditions like hypertension, obesity and kidney function. Although large arteries have been extensively studied, small conduit arteries remain less investigated. This study aims to explore the impact of kidney function on small conduit artery stiffness in two distinct groups: normotensive individuals with severe obesity and normal-weight hypertensive individuals.

Methods: Thirty-three severely obese (OB) individuals, 33 hypertensive (HT) individuals, and 33 normotensive, normal-weight control participants, matched for age and sex, were recruited. Eleven participants (33%) in both the OB and HT groups had estimated glomerular filtration rate (eGFR) less than 60 ml/min/1.73 m 2 . Aortic stiffness (carotid-femoral pulse wave velocity) was recorded. Ultrasound images of common carotid, radial, and interdigital arteries were acquired for the assessment of geometry, distensibility coefficient, circumferential wall stress, and Young's elastic modulus (Einc).

Results: The OB group exhibited higher radial stiffness (both Einc and distensibility coefficient) compared to the HT and control groups, independent of radial diameter adjustments. An inverse correlation between eGFR and radial Einc was noted only in the OB group ( P  = 0.002). Conversely, a direct correlation between eGFR and carotid distensibility coefficient was found only in the HT group ( P  = 0.001). In multivariable analysis, eGFR and BMI were the only predictors of radial Einc in the overall population.

Conclusion: Severe obesity and reduced eGFR synergistically increase radial artery stiffness, a phenomenon not observed in essential hypertension. This study suggests that moderate chronic kidney disease exacerbates vascular alterations in obese individuals, highlighting the need for further research on the role of small conduit arteries in cardiovascular risk.