Ambulatory Blood Pressure Monitoring in the Diagnosis and Management of Hypertension

Hypertension (HTN) is a major risk factor for cardiovascular morbidity and mortality, especially in patients with diabetes mellitus (1). The classic definition of HTN is based on office blood pressure (BP) measurements, and most data relating HTN to cardiovascular morbidity and mortality are derived from office measurements (2). Yet, the measurements in the office may not reflect the true BP levels. They may be elevated when the true BP is normal (white coat effect), or they may be normal when the true BP is elevated (masked HTN). Office measurements also do not reflect the diurnal variation and nocturnal BP levels. Twenty-four-hour ambulatory BP monitoring (ABPM) is a precise method to quantify BP levels and diagnose HTN. Recent studies showed that 24-h ABPM is more accurate than office BP measurements in predicting cardiovascular morbidity and mortality (3–6). The present review will summarize the advantages of 24-h ABPM over office measurements and will recommend when and how to use 24-h ABPM in the diagnosis of HTN in diabetic patients. ### Ambulatory BP measurements The use of 24-h ABPM was introduced in the late 1970s. In the beginning, the devices were large, heavy, and cumbersome, but today the devices are lightweight and nearly all of them use an oscillometric measurement method to compute BP levels. This method eliminates observer bias and provides information on BP levels and heart rate throughout the day. The large numbers of readings obtained during the patient's daily activities provide a superior assessment of the true BP and can be used for the diagnosis of HTN. Additionally, 24-h ABPM provides information on BP variability, circadian changes, and the effects of environmental and emotional conditions on BP levels. Several studies that compared ABPM with intra-arterial measurements and mercury column sphygmomanometers demonstrated the accuracy of ABPM (7). However, since many new devices have …