Renal resistive index and low-grade inflammation in patients with essential hypertension

• Published in: Journal of human hypertension Vol. 26; no. 12; pp. 723 - 730
• Main Authors: Berni, A, Ciani, E, Bernetti, M, Cecioni, I, Berardino, S, Poggesi, L, Abbate, R, Boddi, M
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-12-2012; Nature Publishing Group
• Subjects: 631/250/256; 692/699/1585/2760/267; 692/699/75/243; Adult; Aged; Aged, 80 and over; Arterial hypertension. Arterial hypotension; Biological and medical sciences; Blood and lymphatic vessels; C-reactive protein; C-Reactive Protein - metabolism; Cardiology. Vascular system; Clinical manifestations. Epidemiology. Investigative techniques. Etiology; Comorbidity; Complications and side effects; Cross-Sectional Studies; Diabetes mellitus; Diagnosis; Doppler effect; Epidemiology; Essential Hypertension; Female; Health Administration; Humans; Hypertension; Hypertension - blood; Hypertension - epidemiology; Hypertension - physiopathology; Inflammation; Inflammation - blood; Inflammation - epidemiology; Inflammation - physiopathology; Inflammatory diseases; Kidney - diagnostic imaging; Kidney - physiopathology; Kidney Tubules - diagnostic imaging; Kidney Tubules - physiopathology; Logistic Models; Male; Medical sciences; Medicine; Medicine & Public Health; Middle Aged; original-article; Physiological aspects; Public Health; Renal failure; Renal function; Risk factors; Serum levels; Severity of Illness Index; Ultrasonography, Doppler; United Arab Emirates; renal resistive index; tubulo-interstitial damage; low-grade inflammation; Human; Hypertension; Cardiovascular disease; Inflammation
• ISSN: 0950-9240; 1476-5527
• DOI: 10.1038/jhh.2011.93

In essential hypertension, increased renal resistive index (RRI) is associated to a reduction of renal function and microalbuminuria, and to renal tubulo-interstitial damage. A tubulo-interstitial inflammatory infiltration was found in experimental models of hypertension, and serum high-sensitive C-reactive protein (hsCRP) levels correlated with urinary markers of tubulo-interstitial damage in humans. We studied the relationship between RRI and serum hsCRP in hypertensives with preserved renal function, without microalbuminuria. We investigated hypertensive patients without diabetes, renal failure, microalbuminuria or major inflammatory disease. Serum levels of hsCRP were assayed. RRI was calculated by intrarenal Doppler ultrasound and considered pathologic when ⩾0.70 or >95% of upper confidence limit expected for age decade. The renal volume–to–resistive index ratio (RV/RRI) was also calculated. We evaluated 85 patients (57±14 years, 61 males). Patients with pathologic RRI (
n
=21) were older and had significantly higher hsCRP levels (4.70±2.30 vs 2.93±2.09 mg l
−1
,
P
<0.01) compared with patients with normal RRI, as well as patients with decreased RV/RRI (
n
=43). HsCRP was directly related with RRI (r=0.41,
P
<0.001) and inversely with RV/RRI (r=−0.35,
P
<0.001). HsCRP proved to be a significant predictor of both pathologic RRI and decreased RV/RRI, even after adjustment. In essential hypertension low-grade inflammation is associated with tubulo-interstitial damage evaluated by Doppler ultrasonography.