[Microalbuminuria and arterial hypertension].

Unlabelled: IMPACT OF HYPERTENSION ON THE KIDNEY: Permanent uncontrolled hypertension affects target organs, particularly the kidney. Infraclinical renal dysfunction can be detected by early measurements of microalbuminuria which is an expression of the increased glomerular permeability related to increased arterial pressure, endothelial dysfunction and hormonal factors. Trace albumin can be detected in the urine of normal subjects. Although the amount of albumin in the urine increases with exercise, output should not exceed 20 mg/24 h.

Definitions: Microalbuminuria is defined as urinary excretion of albumin in the 30-300 mg/24 h or 20-200 micrograms/min range. Due to the wide variability, tests should be repeated 2 or 3 times to confirm the persistent nature of the microalbuminuria. In hypertensive patients, microalbuminuria can be reversible if blood pressure levels are normalized. Urinary secretion of albumin above 300 mg/24 h is considered to be a macroalbuminuria expressing a more severe renal condition.

Incidence: The incidence of microalbuminuria in patients with borderline hypertension is 12-15%, in those with mild or moderate hypertension, it is 15-30%, and in those with severe hypertension, the percentages exceed 50%.

Risks: Albuminuria is positively correlated with blood pressure levels measured in inpatients; the correlation is even tighter with ambulatory recordings. Microalbuminuria is a risk factor for cardiovascular disease and for the development of nephroangiosclerosis. It should be searched for in all patients with persistently high blood pressure. Monitoring urine albumin is an effective tool for assessing the efficacy of an antihypertensive treatment and is useful for preventing renal damage.