Manuela Mogavero

Association of renal resistive index with aortic pulse wave velocity in hypertensive patients.

Background Recent data suggest that renal haemodynamic parameters obtained by duplex Doppler sonography, especially the intrarenal resistive index (RI), may be associated with systemic vascular changes. However, conflicting data exist about the independent relationship between aortic stiffness and RI. The aim of this study was to evaluate the relationship between RI and arterial stiffness, assessed by aortic pulse wave velocity (aPWV), in hypertensive patients. Design Cross-sectional study. Methods We enrolled 264 hypertensive subjects aged between 30 and 70 years. They were divided into two groups, either with normal renal function (n = 140) or with chronic kidney disease (CKD) (n = 124). Each patient underwent assessment of ultrasonographic renal RI and measurement of aPWV through oscillometric device. Results Patients with renal RI>0.7 showed higher values of aPWV, both in the overall population (p < 0.001) and in the subgroups with (p < 0.01) and without CKD (p < 0.01). Moreover, statistically significant correlations were observed between aPWV and RI in the whole population (r = 0.38, p < 0.001) and in the subgroups with (r = 0.35, p < 0.001) and without CKD (r = 0.31, p < 0.001). These correlations held even after adjustment for several confounding factors in multivariate analyses. Conclusions Our results seem to corroborate the concept that the RI may be considered as a marker of systemic vascular changes and therefore a predictor of cardiovascular risk.

Renal haemodynamics and severity of carotid atherosclerosis in hypertensive patients with and without impaired renal function

BACKGROUND AND AIM Renal resistance index (RRI), assessed by Duplex-Doppler sonography, has been classically considered as a mere expression of intrarenal vascular resistance. Recent studies, however, have showed that RRI is also influenced by upstream factors, especially arterial compliance, confirming its possible role as a marker of systemic vascular alterations. Several studies have shown that carotid intima-media thickness (cIMT) and carotid plaques (cP), assessed by ultrasonography, are documented markers of subclinical organ damage as well as expression of progressive atherosclerotic disease, and that they get worse with the progressive deterioration of renal function. The study was aimed to evaluate the relationship between RRI and severity of carotid atherosclerosis in hypertensive subjects with and without impaired renal function. METHODS AND RESULTS The study population, including 263 hypertensive patients (30-70 years), was split into 3 groups based on cIMT and presence of cP (cIMT ≤ 0.9 mm and no cP; cIMT > 0.9 mm and no cP; cP). All patients were also divided into 2 subgroups (normal renal function; CKD stage I-IV). A stepwise increase in RRI corresponding to the groups of progressive severity of carotid atherosclerosis was observed (respectively 0.61 ± 0.07, 0.65 ± 0.06, 0.68 ± 0.06; p < 0.001). A strong positive correlation was observed between RRI and cIMT in the whole population (r = 0.43; p < 0.001) and in the subgroups with (r = 0.42; p < 0.001) and without (r = 0.39; p < 0.001) CKD. These associations remained statistically significant even after adjustment for various confounding factors. CONCLUSION Showing a close association between RRI and severity of carotid atherosclerosis, our results strengthen the concept that RRI is a marker of systemic vascular changes.

Association Between Uric Acid and Renal Hemodynamics: Pathophysiological Implications for Renal Damage in Hypertensive Patients

The role of vascular renal changes in mediating the association between serum uric acid (SUA) and renal damage is unclear. The purposes of this study were to investigate the relationship between SUA and renal resistive index (RRI), assessed by duplex Doppler ultrasonography, and to assess whether hemodynamic renal changes may explain the association between SUA and renal damage in hypertensive patients. A total of 530 hypertensive patients with and without chronic kidney disease were enrolled and divided into SUA tertiles based on sex‐specific cutoff values. RRI and albuminuria were greater and glomerular filtration rate (GFR) was lower in the uppermost SUA tertile patients when compared with those in the lowest tertiles (all P<.001). Moreover, SUA strongly correlated with RRI (P<.001) in all patients. However, RRI did not seem to explain the relationship between SUA and renal damage, and GFR significantly related with SUA in the overall population (P<.001) even after adjustment for RRI.

Absence of an independent association between serum uric acid and left ventricular mass in Caucasian hypertensive women and men

BACKGROUND AND AIM Experimentally uric acid may induce cardiomyocyte growth and interstitial fibrosis of the heart. However, clinical studies exploring the relationship between serum uric acid (SUA) and left ventricular (LV) mass yielded conflicting results. The aim of our study was to evaluate the relationships between SUA and LV mass in a large group of Caucasian essential hypertensive subjects. METHODS AND RESULTS We enrolled 534 hypertensive patients free of cardiovascular complications and without severe renal insufficiency. In all subjects routine blood chemistry, including SUA determination, echocardiographic examination and 24 h ambulatory blood pressure (BP) monitoring were obtained. In the overall population we observed no significant correlation of SUA with LV mass indexed for height(2.7) (LVMH(2.7)) (r = 0.074). When the same relationship was analysed separately in men and women, we found a statistically significant correlation in female gender (r = 0.27; p < 0.001), but not in males (r = -0.042; p = NS). When we grouped the study population in sex-specific tertiles of SUA, an increase in LVMH(2.7) was observed in the highest tertiles in women (44.5 ± 15.6 vs 47.5 ± 16 vs 55.9 ± 22.2 g/m(2.7); p < 0.001), but not in men. The association between SUA and LVMH(2.7) in women lost statistical significance in multiple regression analyses, after adjustment for age, 24 h systolic BP, body mass index, serum creatinine and other potential confounders. CONCLUSIONS Our findings do not support an independent association between SUA and LV mass in Caucasian men and women with arterial hypertension.

Relationship Between Carotid Atherosclerosis and Pulse Pressure with Renal Hemodynamics in Hypertensive Patients.

BACKGROUND Structural atherosclerotic damage, arterial stiffness, pulse pressure (PP), and renal hemodynamics may interact and influence each other. Renal resistance index (RRI) appears as a good indicator of systemic vascular changes. The aim of our study was to assess the independent relationships of carotid intima-media thickness (cIMT), aortic pulse wave velocity (aPWV), and peripheral PP with RRI in hypertensives with various degrees of renal function. METHODS We enrolled 463 hypertensive patients (30-70 years) with normal renal function (group 0; n = 280) and with chronic kidney disease (groups I-V; n = 183). All subjects underwent ultrasonographic examination of intrarenal and carotid vasculature, as well as a 24-h ambulatory blood pressure monitoring. RESULTS A statistically significant difference in RRI, cIMT, aPWV, and clinic PP was observed in the different 6 groups (all P < 0.001), even after adjustment for age. RRI correlated with cIMT (r = 0.460, P < 0.001), aPWV (r = 0.386, P < 0.001), clinic PP (r = 0.279, P < 0.001), and 24-h PP (r = 0.229, P < 0.001) in the entire study population. These correlations were similar in subjects with and without renal dysfunction. In the overall study population, the association between RRI, cIMT, and clinic PP remained statistically significant even after adjustment for various confounding factors, whereas the relationship between RRI and aPWV was lost in multivariate analysis. CONCLUSIONS cIMT and clinic PP rather than directly aPWV are associated with intrarenal hemodynamics. Our results confirm that in hypertensives RRI not only detects derangement of intrarenal circulation but may also be considered as a sensor of systemic vascular changes, independently of level of renal function.