title: Microalbuminuria, blood pressure load, and systemic vascular permeability in primary hypertension.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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 (125)I-albumin). Twenty-four-hour ambulatory BP, renal hemodynamics, and hormones of the renin-angiotensin-aldosterone system (RAAS) were also assessed.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  Microalbuminuria is associated with greater systemic BP load and increased vascular permeability in patients with primary hypertension.
authors.affiliation: Department of Internal Medicine and Cardionephrology, Azienda Universitaria Ospedale San Martino, University of Genoa, Genoa, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Viazzi
authors.forename: Giovanna
authors.initials: G
authors.lastname: Leoncini
authors.forename: Elena
authors.initials: E
authors.lastname: Ratto
authors.forename: Valentina
authors.initials: V
authors.lastname: Vaccaro
authors.forename: Cinzia
authors.initials: C
authors.lastname: Tomolillo
authors.forename: Valeria
authors.initials: V
authors.lastname: Falqui
authors.forename: Angelica
authors.initials: A
authors.lastname: Parodi
authors.forename: Novella
authors.initials: N
authors.lastname: Conti
authors.forename: Giacomo
authors.initials: G
authors.lastname: Deferrari
authors.forename: Roberto
authors.initials: R
authors.lastname: Pontremoli
mesh_terms: D000328:Adult; D000368:Aged; D000419:Albuminuria / Q000503:physiopathology*; D001794:Blood Pressure / Q000502:physiology; D018660:Blood Pressure Monitoring, Ambulatory; D002199:Capillary Permeability; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012079:Renal Circulation / Q000502:physiology; D012084:Renin-Angiotensin System / Q000502:physiology