Intra-renal hemodynamics and carotid intima-media thickness in the metabolic syndrome

Abstract

Aims Metabolic syndrome (MetS) is associated with increased cardiovascular risk. We hypothesize that early vascular changes are already present at the time of diagnosis of MetS. The relationship of different measures of early vascular impairment with body fat distribution and the natural progression of MetS was examined in newly diagnosed subjects non-pharmacologically treated. Methods 246 consecutively enrolled subjects were categorized according to the presence of MetS and type 2 diabetes (T2D). Intra-renal Doppler flow was used to ascertain resistive (RI) and pulsatility (PI) indices as markers of vascular resistance. Carotid intima-media thickness (IMT), cutis-rectis (CR) and rectis-aorta (RA) thicknesses were measured by ultrasonography; RA/CR ratio was used as measure of body fat distribution. Pro-inflammatory cytokines, C-reactive protein, oxidative markers insulin and adiponectin blood concentrations were also measured. Results Baseline characteristics demonstrated increasing trends in biochemical, inflammatory, and oxidative parameters from MetS−, MetS+, to MetS+/T2D ( p < 0.001). After adjusting for age, the same increasing trends across the groups were observed in both sexes in IMT ( p < 0.001), RI ( p < 0.001) and PI ( p < 0.001). IMT correlated with RI ( r = 0.25; p < 0.001), PI ( r = 0.26; p < 0.001), and RA/CR ratio ( r = 0.43; p < 0.001). Conclusions Carotid IMT and intra-renal resistances are elevated at an early stage in MetS and are associated with a dysregulated production of fat-derived hormones and cytokines.