Comparison between continuous ambulatory arterial blood pressure monitoring and standard blood pressure measurements among patients of younger and older age group.

The purpose of the study was to evaluate whether there is a difference between blood pressure measured in a physician's office and the average 24 hr continuous blood pressure monitored by hypertensive patients at home. If there is a difference between these two situations then is it possibly the result of a blood pressure response by the patient to the physician which is known as "white coat effect" or "white coat hypertension". We studied 80 hypertensive outpatients which were divided into two groups of 40 patients each--a younger patient group, with a mean age of 22.8 +/- 1.8 years, and an older patient group with a mean age of 50.3 +/- 5.7 years. They were selected because they had been diagnosed as essentially hypertension grade 1, according to 2007 ESH/ESC Guidelines, or the USA Joint National Committee Guidelines (JNC 7) (i.e., arterial blood pressure > 140/90 mm Hg and < 160/100 mmHg) and 35 were not having any antihypertensive treatment. All participants in the study went through a two-week "wash-out" period without medication. At the beginning of the study blood pressure was measured using the Riva-Rocci-Korotkoff method (mercury sphygmomanometer) after 5 minutes of rest and with the patient in the sitting position. The average of the two last measurements by sphygmomanometer was used in the analysis. The subsequent measurement was made by continuous ambulatory blood pressure monitoring (SpaceLabs 90207 device). Continuous ambulatory blood pressure monitoring revealed that 17 patients of the younger age group (42.5%) who were diagnosed hypertonic, according to mercury sphygmomanometeric measurement, were in fact normotonic. In the older age group only 7 (17.5%) of participants were normotonic during 24 hr blood pressure monitoring. The proportion of miss-diagnosed normotonic younger patients was directly related to elevated clinic blood pressure, which could be referred to as office hypertension or isolated clinic hypertension (white coat hypertension). This was statistically significant (chi2 = 5.95; p = 0.015). Hypertension diagnosed in younger patients based only on occasional doctor's office mesurements, using a mercury sphygmomanometer, could be miss-interpreted and treated as the start of arterial hypertension. This could sometimes have unwanted results due to the side effects of precipitate antihypertensive medication as well as the unnecessary cost of testing, cost of treatment, prevalence of white-coat hypertension at baseline, and the varying incidence of new hypertension after the initial screening. The results indicate a potential savings of 3-14% in the cost of care for hypertension, and a 10-23% reduction in treatment days when ambulatory blood pressure monitoring is incorporated into the diagnostic process. Therefore CABPM should be used as a legitimate method in the diagnosing of "white coat hypertension", particularly in young patients. The identification of white coat hypertensive"' patients should be followed by a search for metabolic risk or organ damage using the latest guidelines, and medication should start after an organ damage or cardiovascular risk assesement.