[Microalbuminuria in essential hypertension and normal kidney function]

In patients with essential hypertension increased albumin excretion in the urine compared to healthy controls is well known. In 38 patients (age: Mean +/- SD = 37 +/- 16 yr, f: m = 19:19) with benign essential hypertension and normal renal function (creatinine clearance: Mean +/- SD = 99 +/- 16 ml/min) we found a mean urinary albumin excretion of 79 +/- 61 mg/24 h in comparison to 14 +/- 13 mg/24 h (p less than 0.01) in 10 healthy controls (age: Mean +/- SD = 35 +/- 14 yr, f: m = 5:5). In 13 patients with hypertension urinary albumin excretion was increased (greater than 25 mg/24 h) in a subclinical range (microalbuminuria), the other 25 hypertensive patients had normoalbuminuria. Comparing the hypertensive patients with and without microalbuminuria, those with elevated albumin excretion were older (age: Mean +/- SD = 42 +/- 12 yr vs. 32 +/- 19 yr), had a longer average duration of hypertension (8 +/- 5 yr vs. 5 +/- 4 yr) and a higher prevalence both of hypertensive retinopathy (77% vs. 28%) and of abnormalities in the electrocardiogram (23% vs. 4%) than those with normal albumin excretion. The difference in the prevalence of hypertensive retinopathy (grade I and II) was statistically significant (p less than 0.05). Furthermore the patients with microalbuminuria required a more intensive antihypertensive therapy than those with normoalbuminuria, 46% requiring triple drug therapy as opposed to 24% in the latter group. Thus the demonstration of microalbuminuria in patients with benign essential hypertension is associated with a higher prevalence of funduscopic and electrocardiographic abnormalities, and therefore can be considered as an indicator of early vascular damage in essential hypertension.