Prevalence and clinical correlates of microalbuminuria in stage I hypertension. Results from the Hypertension and Ambulatory Recording Venetia Study (HARVEST Study).

The objective of the present study was to examine the association between albumin excretion rate (AER) and office and ambulatory blood pressures (BP), and other recognized cardiovascular risk factors in stage I hypertension. The study was carried out in 870 never-treated 18- to 45-year-old hypertensives (628 men, 242 women). Office and ambulatory BP, 24-h urinary collection for AER assessment, and echocardiographic left ventricular mass (n = 587) were obtained. AER was similar in men and women (12.3 v 12.5 mg/24 h) and was unrelated to age and body mass index. In 85.2% of the subjects, AER was < 16 mg/24 h, in 8.3% it was between 16 and 29 mg/24 h (borderline microalbuminuria), and in 6.1% it was >or= 30 mg/24 h (overt microalbuminuria). Office systolic BP was not different in the three groups, whereas 24-h systolic BP was higher in the subjects with microalbuminuria than in those with normal AER (P < .0001) and was similar in the two microalbuminuric groups. Office and 24-h diastolic BPs were higher in the subjects with overt microalbuminuria than in those with normal AER. Left ventricular mass was correlated to systolic (P < .0001) and diastolic (P = .01) 24-h BP, but was unrelated to AER. Family history for hypertension, smoking, coffee and alcohol intake, and physical activity habits did not influence AER. In a logistic regression analysis, 24-h systolic BP emerged as the only determinant of microalbuminuria (P < .0001). In conclusion, these results indicate that borderline levels of microalbuminuria may also be clinically relevant in stage I hypertension. Overweight and lifestyle factors do not appear to influence AER in these patients. Finally, the lack of correlation between AER and left ventricular mass suggests that renal and cardiac involvement do not occur in a parallel fashion in the initial phase of hypertension.