Inverse relationship between ambulatory arterial stiffness index and glomerular filtration rate in arterial hypertension.
BACKGROUND
Arterial stiffness and mild-to-moderate renal dysfunction are predictors of cardiovascular (CV) morbidity and mortality. Recently, the ambulatory arterial stiffness index (AASI) has been proposed as a surrogate index of arterial stiffness. It has been associated with an enhanced risk of stroke. The aim of our study was to assess the relationship between AASI and glomerular filtration rate (GFR) in a group of hypertensive patients with no CV complications.


METHODS
A total of 143 untreated hypertensive subjects (mean age: 44 +/- 12 years; men 57%), with serum creatinine <1.5 mg/dl, were enrolled. AASI was calculated as one minus the regression slope of diastolic on systolic blood pressure (BP) obtained by individual 24-h BP recordings. GFR was computed from the scintigraphic determination of the technetium-99m diethylenetriaminepentaacetic acid uptake within the kidneys, by the Gates' method.


RESULTS
Hypertensive patients with AASI above the median value (n = 71) had lower GFR than those with AASI below the median (n = 72) (98.3 +/- 31 vs. 122.4 +/- 32 ml/min/1.73 m(2); P < 0.001). This difference held even after adjustment for age and gender. The linear regression analysis disclosed a significant inverse correlation between GFR and AASI (r = -0.30; P < 0.001), that was replicated (beta = -0.19; P = 0.02) in a multiple regression model including, as independent variables (besides AASI), age, gender, high-density lipoprotein cholesterol, body mass index, 24-h pulse pressure (PP) and nocturnal reduction in BP.


CONCLUSIONS
AASI is inversely related to GFR in arterial hypertension. This may help to explain the increased CV risk associated with mild-to-moderate renal dysfunction.
Mulè
Giuseppe
G
Dipartimento di Medicina Interna, Malattie Cardiovascolari e Nefrourologiche, Cattedra di Medicina Interna e Cattedra di Nefrologia, Università di Palermo, Italy. giusemme@unipa.it
Cottone
Santina
S
Cusimano
Paola
P
Incalcaterra
Francesca
F
Giandalia
Maria
M
Costanzo
Miriam
M
Nardi
Emilio
E
Palermo
Alessandro
A
Geraci
Calogero
C
Costa
Renato
R
Cerasola
Giovanni
G
D000328:Adult; D001158:Arteries / Q000503:physiopathology*; D001794:Blood Pressure; D018660:Blood Pressure Monitoring, Ambulatory; D002318:Cardiovascular Diseases / Q000209:etiology* / Q000503:physiopathology; D003971:Diastole; D004548:Elasticity; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000503:physiopathology*; D007674:Kidney Diseases / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D011866:Radioisotope Renography