Microalbuminuria, Blood Pressure Load, and Systemic Vascular Permeability in Primary Hypertension

• Published in: American journal of hypertension Vol. 19; no. 11; pp. 1183 - 1189
• Main Authors: Viazzi, Francesca, Leoncini, Giovanna, Ratto, Elena, Vaccaro, Valentina, Tomolillo, Cinzia, Falqui, Valeria, Parodi, Angelica, Conti, Novella, Deferrari, Giacomo, Pontremoli, Roberto
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01-11-2006; Oxford University Press; Elsevier Science
• Subjects: Adult; Aged; Albuminuria - physiopathology; Arterial hypertension. Arterial hypotension; Biological and medical sciences; Blood and lymphatic vessels; blood pressure; Blood Pressure - physiology; Blood Pressure Monitoring, Ambulatory; Capillary Permeability; Cardiology. Vascular system; Clinical manifestations. Epidemiology. Investigative techniques. Etiology; Female; Fundamental and applied biological sciences. Psychology; Hemodynamics. Rheology; Humans; Hypertension - physiopathology; Male; Medical sciences; Microalbuminuria; Middle Aged; primary hypertension; Renal Circulation - physiology; Renin-Angiotensin System - physiology; transcapillary escape rate; vascular permeability; Vertebrates: cardiovascular system; transcapillary escape rate; blood pressure; vascular permeability; primary hypertension; Microalbuminuria; Hypertension; Urinary system disease; Albumin; Cardiovascular disease; Arterial pressure; Blood pressure; Permeability; Proteinuria
• ISSN: 0895-7061; 1879-1905; 1941-7225
• DOI: 10.1016/j.amjhyper.2006.04.012

Microalbuminuria, a powerful predictor of cardiovascular events, is thought to reflect widespread subclinical vascular abnormalities. To explore the pathogenesis of increased urinary albumin excretion in primary hypertension we evaluated systemic capillary permeability and ambulatory blood pressure (BP) measurement in two groups of matched untreated patients with (
n = 11) and without (
n = 29) microalbuminuria.
Albuminuria was measured as the mean of albumin-to-creatinine ratio (ACR) in three nonconsecutive first morning urine samples. Systemic capillary permeability was evaluated by transcapillary escape rate of albumin (TERalb) (ie, the 1-h decline rate of intravenous
125I-albumin). Twenty-four-hour ambulatory BP, renal hemodynamics, and hormones of the renin-angiotensin-aldosterone system (RAAS) were also assessed.
Patients with microalbuminuria showed greater body mass index (BMI) (
P < .04), higher 24-h systolic and diastolic BP levels (
P = .02), and higher capillary permeability to albumin (
P < .02) as compared to normoalbuminurics. Renal hemodynamics and RAAS hormones were similar in the two groups. Univariate analysis showed that urinary ACR was related to ambulatory pressure components (
P < .02), TERalb (
r = 0.31,
P < .05), smoking habits (
r = 0.36,
P = .02), and left ventricular mass index (LVMI) (
r = 0.57,
P < .001) among the whole study group. Logistic regression analysis showed that each 1% increment in TERalb or 10 mm Hg increase in systolic BP entailed an almost three times higher risk of having microalbuminuria.
Microalbuminuria is associated with greater systemic BP load and increased vascular permeability in patients with primary hypertension.