Ambulatory blood pressure and the kidney

During the last few years there has been a renewed interest in blood-pressure-induced kidney damage, due to a progressive increase in the incidence and prevalence of hyipertension and vascular diseases as a cause of end-stage renal disease (ESRD). The need to prevent ESRD demands continued efforts to achieve the early identification of persons with hypertension who are at risk and to provide them with effective antihypertensive therapy. Ambulatory blood pressure monitoring (ABPM) has been used successfully to assess blood pressure values and identify risk markers for cardiovascular diseases. A logical approach would be to use it also to identify those for ESRD. For hypertensive and type 1 diabetics ABPM data usually have a stronger correlation to the presence and magnitude of microalbuminuria than do routine office blood pressure measurements. The best Pearson correlation coefficients for relationship between ambulatory blood pressure values and urinary excretion of albumin were obtained with nocturnal blood pressure regardless of whether systolic, diastolic or mean blood pressure were considered. Moreover, high percentages of non-dippers have been found among subjects with renal failure, subjects undergoing dialysis (haemofiltration, peritoneal dialysis, continuous ambulatory peritoneal dialysis (CAPD), subjects with renovascular hypertension and with cystic kidney disease, subjects who have had a kidney transplant and subjects with cyclosporine-induced hypertension. Finally, ABPM seems to be prognostic for development of proteinuria in some refractory hypertensives. Whether higher nocturnal blood pressure values and the non-dipping pattern constitute a cause or are consequences of renal disease should be addressed in prospective studies. Assessment of nocturnal blood pressure seems to be an important tool in the management of patients with hypertensive-related renal disease and of patients who are susceptible to developing it.