Ambulatory blood pressure measurement in the renal patient.

Ambulatory blood pressure monitoring has been steadily growing in popularity as equipment becomes more accurate, affordable, and patient-friendly. In addition, software packages are more powerful and physician-customizable, and more physicians are accepting of ambulatory blood pressure monitoring's advantages. Summarizing the studies that deal mainly with hemodialysis patients, there are clear advantages to using more than isolated pre- and posthemodialysis blood pressure readings. If enough predialysis blood pressure readings are taken and averaged, this is a reasonable guide to end-organ damage (ie, left ventricular hypertrophy). Home and ambulatory blood pressure-derived values are complementary, and only this approach can discern any further contribution from diurnal blood pressure elevation. The cross-sectional association between blood pressure and end-organ damage is very weak in end-stage renal disease patients if the blood pressure values are "casual," but the relationship is much stronger when ambulatory blood pressure monitoring-derived measurements are used. One prospective study clearly linked the sustained loss of diurnal blood pressure fall with sleep with progressive left ventricular dilatation. Loss of circadian variation in blood pressure is associated with an increased mortality rate for dialysis patients and for diabetic patients, regardless of diabetes type. The combination of nondipping in renal impairment leads to a high mortality rate. Much more work is needed to dissect out the causes for abnormal diurnal blood pressure rhythm and attempt to modulate this parameter. Obstructive sleep apnea may be a promising target for intervention.