Ambulatory Blood Pressure Monitoring: An Invaluable Tool Comes of Age for Patients with Chronic Kidney Disease

ditionally, hypertension diagnosis is based on clinic BP measurements during three separate visits, while other available strategies, such as home measurements and ambulatory BP monitoring (ABPM), the ‘gold standard’ of diagnosis, are reserved for uncertain cases, including suspicion of ‘white-coat’ and ‘masked’ hypertension [2] . A very important recent study [9] compared the costeffectiveness of the three aforementioned strategies for diagnosis of essential hypertension. The authors performed a Markov-model analysis on a hypothetical primary-care population older than 40 years with a screening BP reading 1 140/90 mm Hg. They concluded that ABPM was clearly the most cost-effective strategy, producing cost-savings for all genderand age-stratified groups studied and gains in quality-adjusted life years (QALYs) for older subjects. Clearly, the greater cost-effectiveness of ABPM was due to higher diagnostic accuracy in detecting hypertension [10] , leading to effective treatment and associated reductions in cardiovascular events in more hypertensive individuals, and less unnecessary treatment of people without hypertension. Several methodological strengths support the validity of this study’s conclusions [9] . The model was run separately for ten genderand age-stratified groups; the study time horizon was particularly long and a reasonable annual discount rate was applied; periodic rechecking of BP was incorporated to allow for the possibility that peoHypertension is the most common chronic disease in the Western world, with a documented prevalence of 25– 30% of adults in developed societies [1] , and a major risk factor for cardiovascular events; thus, it is no wonder why it is considered the most important attributable cause of death worldwide [2] . Chronic kidney disease (CKD), on the other hand, is another major public health issue; it is also a potent risk factor for cardiovascular morbidity and mortality, and it has a prevalence of around 10% of adults, with incident end-stage renal disease (ESRD) increasing much faster than expected from CKD growth [3] . Elevated blood pressure (BP) is an established cause, but can also be a consequence of kidney injury [4] , and hypertension prevalence rates are 1 90% in individuals with advanced CKD [5] . Thus, all previous major guidelines in the field have put increased emphasis on the quick diagnosis and aggressive control of BP in CKD patients [2, 4, 6, 7] . Despite substantial efforts from health authorities and effective treatment options being available for decades, BP control rates in the general population remain low in many countries [8] and they are even worse in CKD patients [5] . Of note, reduced hypertension awareness leading to inadequate treatment is proposed as a major factor contributing to poor control, both in the general population and individuals with CKD [5, 8] , highlighting the need for proper diagnosis of elevated BP levels. TraPublished online: February 15, 2012 Nephrology American Journal of