To analyze the influence of sympathetic activity on blood pressure (BP) and its effects on urinary albumin excretion (UAE), the authors carried out a cross-sectional study in their local health coverage area. The following variables were monitored in a representative sample of the general population made up of 495 individuals: anthropometric parameters; blood glucose, creatinine, and lipid levels; 24-hour urinary albumin, norepinephrine, and epinephrine excretion; and BP of patients with known hypertension and newly discovered BP > or =140/90 mm Hg, evaluated by ambulatory monitoring. In the multivariate analysis, only gender, systolic BP, and UAE were associated with norepinephrine levels; only gender, systolic BP, and body mass index were associated with epinephrine. After excluding those patients with chronic kidney disease, the multivariate analysis showed a strong association between UAE > or =30 mg/d and elevated norepinephrine and epinephrine levels. The authors concluded that in the subject population there is an association between elevated adrenergic activity and higher UAE, independent of factors such as age and BP.