Microalbuminuria, renal function and development of sustained hypertension: a longitudinal study in the early stage of hypertension.
OBJECTIVE
Microalbuminuria (MA) is a marker of adverse outcome in hypertension. The aim of this study was to investigate the association of MA with cardiovascular risk factors and glomerular hyperfiltration in the early stage of hypertension and to assess its predictive value for the development of sustained hypertension requiring antihypertensive treatment.


METHODS
We studied 1041 young stage 1 hypertensive subjects. Study variables were 24-h ambulatory blood pressure and heart rate, anthropometric measures, metabolic variables, creatinine clearance and lifestyle factors analyzed as a function of ascending urinary albumin measured from 24-h collections. Subjects were followed until they developed sustained hypertension and were eligible for antihypertensive medication according to current guidelines.


METHODS
Seventeen outpatient clinics in Italy.


RESULTS
Eighty-five percent of the subjects were normoalbuminuric, 9% had borderline MA, and 6% had overt MA. No between-group differences were found for age, body mass index, heart rate, lifestyle factors and biochemistry in both genders. Creatinine clearance was greater in the subjects with overt MA and borderline MA than in the normoalbuminuric subjects (P = 0.003 and 0.011, respectively). In a two-way ANCOVA, microalbuminuric subjects both with hyperfiltration (P < 0.001) and with normal filtration (P = 0.04) had higher 24-h systolic blood pressure than subjects with normoalbuminuria and normal filtration. In a Cox analysis, neither MA nor hyperfiltration were significant predictors of development of sustained hypertension.


CONCLUSIONS
MA is not associated with an adverse metabolic risk profile in the early stage of hypertension. MA is associated with greater hemodynamic load and with glomerular hyperfiltration in this clinical setting, but does not help in predicting those subjects destined to develop sustained hypertension requiring antihypertensive therapy.
Palatini
Paolo
P
Clinica Medica 4, University of Padova, Padova, Italy. palatini@unipd.it
Mormino
Paolo
P
Mos
Lucio
L
Mazzer
Adriano
A
Dorigatti
Francesca
F
Zanata
Giuseppe
G
Longo
Daniele
D
Garbelotto
Raffaella
R
De Toni
Renzo
R
Graniero
Gianrocco
G
Pessina
Achille C
AC
D000328:Adult; D000419:Albuminuria / Q000453:epidemiology* / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006977:Hypertension, Renal / Q000453:epidemiology* / Q000503:physiopathology*; D007677:Kidney Function Tests; D008137:Longitudinal Studies; D008297:Male; D012307:Risk Factors; D012720:Severity of Illness Index