Microalbuminuria and hypertension

Impact of hypertension on the kidney: Permanent uncontrolled hypertension a ffects target organs, particularly the kidney. Infraclinical renal dysfunct ion can be detected by early measurements of microalbuminuria which is an e xpression of the increased glomerular permeability related to increased art erial pressure, endothelial dysfunction and hormonal factors. Trace albumin can be detected in the urine of normal subjects. although the amount of al bumin in the urine increases with exercise, output should not exceed 20 mg/ 24h. Definitions: Microalbuminuria is defined as urinary excretion of albumin in the 30-300 mg/24h or 20-200 mu g/ min range. Due to the wide variability, tests should be repeated 2 or 3 times to confirm the persistent nature of t he microalbuminuria. In hypertensive patients, microalbuminuria can be reve rsible if blood pressure levels are normalized. Urinary secretion of albumi n above 300 mg/24h is considered to be a macroalbuminuria expressing a more severe renal condition. Incidence: The incidence of microalbuminuria in patients with borderline hy pertension 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 meas ured in inpatients; the correlation is even tighter with ambulatory recordi ngs. Microalbuminuria is a risk factor for cardiovascular disease and for t he development of nephroangiosclerosis. it should be searched for in all pa tients with persistently high blood pressure. Monitoring urine albumin is a n effective tool for assessing the efficacy of an antihypertensive treatmen t and is useful for preventing renal damage.