Middle East Journal of Family Medicine

Adnan Moh`d Ammoura MD
Family practitioner, Jordanian Board
Flight Surgeon, Dip.Av.Med, Royal college of physicians, London

Nashat Halasah MD
Internal Medicine, Jordanian Board
Royal Jordanian Air Force Medical Services
Amman - Jordan

Correspondence:
Dr. Adnan Moh`d Ammoura
P.O. Box 410352
Amman - 11141 - JORDAN
Tel: 962-79-6404848
Fax: 962-6-5231599
Email: AdnanAmm@hotmail.com

ABSTRACT

Studies suggest that about 10% of patients may experience white-coat syndrome. The cause of the syndrome is unclear but may be a conditioning phenomenon.

This study was conducted on 240 patients recorded in the family practice clinic, in the Royal Jordanian Air Force medical facility. Patients were selected according to the discordance in blood pressure readings (by doctor, nurse and home measurements), during a period of three years (January 2000- January 2003), and numbered 220 males and 20 females, aged 30-60 years, with mean age of the patients (42.3). It was conceived to evaluate the management of White coat syndrome patients.

In our study, we referred all patients to King Hussein Medical Center for cardiac consultation to confirm the white-coat syndrome, by using a 24-hour ambulatory blood pressure monitor.

Out of 240 patients, 60 patients were labeled hypertensive (25%) of cases, the rest of the patients were kept on follow up as white coat syndrome; (16.7%) of the cases were found to have bad blood pressure monitors at home.
The best way to diagnose hypertension when in doubt with white coat syndrome , is accomplished by using a 24-hour ambulatory blood pressure monitor.

Keywords: Hypertension, White coat syndrome, Ambulatory monitoring.

White coat syndrome (hypertension) refers to individuals showing a rise in blood pressure to a hypertensive level when measured by physicians, but remains normal when measured by the nurses or at home⁽¹⁾. The cause and clinical implications of the white coat syndrome are unclear and the subject of an ongoing debate⁽²⁾. Anxiety of early visits to the physician's office is "learned" and subconsciously repeated during subsequent visits. Studies suggest that for patients with white coat hypertension, the heart disease risk is between that of patients with true hypertension and patients with normal blood pressure⁽³⁾. That is, cardiovascular risk is increased, but is not as high as someone with sustained hypertension.

The white coat effect is important in diagnosing and assessing control of hypertension in primary care⁽⁴⁾. This is best accomplished by using ambulatory blood pressure monitoring⁽⁵⁾, which will periodically measure and record the blood pressure outside the physician's office. If the blood pressure is normal in this ambulatory assessment, it would be consistent with white coat syndrome. Also, we must ask the patients to check their home blood pressure monitor. If it is accurate, it could be used to document out-of-office blood pressure levels. If white-coat hypertension is confirmed, we generally rely on the home assessments to guide therapy.

There is no evidence that treating patients with white coat syndrome increases risk, but this possibility has not been studied at length. Initiation and maintenance of treatment for white coat syndrome represents an enormous opportunity and cost for health professionals and for patients, in addition to the unnecessary anxiety and side effects^(6,7), Also some of the patients have symptoms of excessively reduced blood pressure, like light-headedness when rising from a chair, or unusual fatigue or tiredness, which necessitates stopping medication.

But according to other studies, all patients must be monitored because white coat syndrome has also shown to advance frequently into sustained hypertension in the future life of the patient⁽⁸⁾.

In the Royal Jordanian Air Force medical facility, a retrospective study of the family practitioner clinic records was done; 240 patients were recorded as having discordance in blood pressure readings between (physicians, nurses, and home readings) during a period of three years (January 2000- January 2003), 220 males and 20 females, aged 30-60 years, mean age of the patients (42.3).

As a standard definition of white coat syndrome is lacking, we classed subjects as normotensive if their blood pressure was <140/90mm Hg measured by a technician and <160/95 mm Hg measured by a physician^(2,9,10). These cut off values were taken according to WHO criteria for normotension, borderline hypertension, and sustained hypertension⁽¹¹⁾. A case definition was set up for any patient in whom we found discordance in blood pressure readings. We asked them to bring their blood pressure monitors for check-up, then a one week, twice daily, follow up of blood pressure readings was undertaken (by physicians, nurses, home monitors). After analyzing data, all patients were referred to King Hussein Medical Center for cardiac consultation and ambulatory blood pressure monitoring.

All patients were detected, diagnosed, and managed in the family practice clinic, in the Royal Jordanian Air Force Medical Center. Out of 48,000 patients seen in the family practice clinic in the period of one year, 240 patients (0.5%) were found to have white coat syndrome.

Table 1 Shows that the highest number of patients was in age group (41-50) years, accounting for 45.8% of the cases; however the lowest number was among age group (51-60) years, because the majority of our patients are on duty air force personnel.

Male patients were 91.7% of cases while females 8.3%, due to the constitutional nature of the air force personnel, as shown in Table 2.

Table 3 shows that the majority of cases were discovered during a routine annual medical checkup - 50%, while 20.8% of cases were found to have high blood pressure readings incidentally during a physical examination for other medical problems. On the other hand only 70 patients were complaining of symptoms of hypertension.

Table 4 demonstrates that after investigations, and using the 24 hour ambulatory blood pressure monitor, 75% of the cases were labeled as white coat syndrome patients, only 60 patients were labeled hypertensive. False low blood pressure readings due to bad blood pressure monitors at home, was the cause in 40 cases.

Hypertension is perhaps the most common reason for initiation of lifelong drug treatment and ongoing management by doctors, because hypertension results in secondary organ damage and reduced life span, it should be evaluated fully and when appropriate treated⁽¹²⁾.

In order to establish the diagnosis of hypertension, it is necessary to document in the course of several examinations that the arterial blood pressure remains elevated⁽¹²⁾. In our study we allowed one week of repeated measurement of blood pressure to establish the diagnosis of hypertension versus white coat syndrome.

Many definitions of the white coat syndrome exist^(1,2,13), but we worked out our patients according to the definition used by many other studies^(3,9,10), based on WHO criteria⁽¹¹⁾.

The prevalence of white coat syndrome in our study was 0.5% which is low in comparison with other studies where it was about 10%⁽³⁾. This may be due to the group quality in our study (young, healthy, air force personnel), while M. Matangi et al, found that the prevalence of white coat syndrome is 4.7% in patients referred for specific blood pressure problems⁽¹³⁾.

In our study we detected 40 devices used by patients for home blood pressure measurement, with false readings, while many devices have failed to meet minimum standers for accuracy and reproducibility in other studies⁽¹⁴⁾. In other studies, home measurement at the moment is less reliable but is easier and cheaper⁽¹⁵⁾.

We found that ambulatory blood pressure monitoring was the best way to establish the diagnosis, as also found in other studies^(3,4,5,15).

In our study, after cardiological consultation, no cardiac involvement was detected, but in another study⁽³⁾ their was an association between white coat syndrome and an increase in left ventricular mass and an increased prevalence of left ventricular hypertrophy.

Physicians in primary care clinics must be aware of the white coat syndrome in the diagnosis and follow-up of hypertension.

The best way to diagnose hypertension when in doubt of white coat syndrome, is accomplished by using a 24-hour ambulatory blood pressure monitor.