Microalbuminuria and hypertension

Abstract

A relationship between blood pressure and albumin excretion in hypertensive patients was first suggested by Parving et al1 in 1974. The range of albumin excretion which they were studying was below that which can be detected by the use of a conventional dipstick test such as Albustix but above the normal ranges which had been determined by Petersen et al2 and Mileset al3 in 1969 and 1979 respectively. This range of albumin excretion was termed microalbuminuria. Much work has been carried out on the role of microalbuminuria in predicting diabetic nephropathy, but comparatively little is known about its relationship with blood pressure. In order to determine if certain commonly encountered factors (smoking, alcohol and catfeine intake) had any effect on albumin excretion a questionnaire was conducted on the hypertension clinic population. Urine samples for detection of albumin were also collected from a proportion of those questioned. This study failed to show any relationship between microalbuminuria and smoking, alcohol intake or caffeine intake. A relationship was found between blood pressure and microalbuminuria. This relationship was then investigated further in two studies. The first study took “spot” samples of urine from a large number of patients and looked at the correlation between blood pressure and microalbuminuria. The relationship appeared to be strongest in the group of treated patients, especially those of caucasian treated males. The second study locked at a group of untreated patients who were subsequently started on mono antihypertensive therapy. Their medication doses were increased until their blood pressure was within acceptable limits. This study failed to find any relationship between blood pressure and microalbuminuria either before or after treatment in either of the two treatment groups.