['To examine the effect of the combination of enalapril with a very low dose of hydrochlorothiazide versus atenolol on urinary albumin excretion in normoalbuminuric patients with mild to moderate essential hypertension. A secondary objective was to compare the effects of the two regimens in patients with different levels of albuminuria.', 'A 12 weeks, randomized, double-blind, double-dummy, multicenter, comparative study with two parallel groups.', 'General practices in Denmark and Finland.', 'The subjects comprised 174 patients with mild to moderate essential hypertension, normal serum creatinine and no proteinuria.', 'Enalapril/hydrochlorothiazide (20/6 mg) daily or atenolol (50 mg) daily.', 'Urinary albumin: creatinine ratio and blood pressure.', 'At baseline, normoalbuminuria was found in 74 and 85 patients in the enalapril/hydrochlorothiazide and atenolol groups, respectively. Blood pressure was reduced similarly by both treatments. The ratio of urinary albumin to creatinine in normoalbuminuric patients was significantly reduced during treatment with enalapril/hydrochlorothiazide at 20/6 mg (from geometic mean x/divided by antilog SD of 0.53 x/divided by 1.77 to 0.47 x/divided by 1.58 mg/mmol, P=0.02) but was unchanged during atenolol treatment (0.55 x/divided by 1.74 and 0.58 x/divided by 1.87 mg/mmol). The difference between the two treatments was statistically significant (P=0.03) and was predominantly achieved through a reduction of albuminuria in the upper-normal range during enalapril/hydrochlorothiazide treatment.'] Does combination of enalapril and low-dose thiazide reduce normoalbuminuria in essential hypertension?