Morbid obesity is associated with hypertrophic outward remodeling and increased stiffness of small conduit arteries: An ultra-high frequency ultrasound study

Abstract

Background and aims: Although many studies have been published on the effect of obesity on large and small arteries, there are no data in the literature regarding the effect of obesity on medium-sized arteries, and in particular of small conduit arteries. The aim of the present study was to investigate whether patients with severe obesity presented structural or functional alterations in different arterial segments.

Methods and results: 34 patients with severe obesity (BMI≥35 kg/m²) and 34 age-and sex-matched normal weight patients were recruited as controls. Aortic stiffness (carotid-femoral pulse wave velocity) and wave reflection (augmentation index) were recorded. Ultrasound images of common carotid, radial and interdigital arteries were acquired for the assessment of wall-to-lumen ratio, wall cross-sectional area (WCSA), compliance, distensibility coefficient (DC) and Young's elastic modulus (Einc). Insulin sensitivity was calculated by oral glucose sensitivity index (OGIS). No differences between groups in carotid artery remodeling were found, while WCSA of the radial and interdigital arteries were higher in obese group than in controls. As regard the parameters of vascular elasticity, the DC of radial and interdigital arteries were lower (p = 0.025 and p = 0.001, respectively), as well as the Einc of radial arteries was higher (p = 0.021), in subject with obesity compared to controls. All these correlations were consistent after adjustment for the main covariates. Finally, in a multiple regression analysis OGIS was and independent determinant of interdigital artery DC (R² = 0.29, p = 0.001).

Conclusions: For the first time, we describe an outward remodeling and increased stiffness in small conduit arteries in severe obesity.

Keywords: Arterial stiffness; Obesity; Small arteries conduit; Vascular remodeling.