The fear factor

The facts

Going to the doctor can be nerve-racking. So much so that for some patients it causes a rise in blood pressure that gives the appearance of hypertension.

The old thinking was that if ones blood pressure was high at the doctors office but otherwise normal,there was no reason for concern. Chalk it up to the jitters.

But a new school of thought has emerged. White-coat hypertension may be more than a false positive: it may help identify people at serious risk for the real thing. In studies,researchers have found that patients whose blood pressure rises to abnormal levels in a clinical setting are far more likely to develop hypertension than those with normal readings at home and at the clinic.

In a 2005 study in The Archives of Internal Medicine,a team of scientists followed about 800 people for eight years,128 of them with white coat hypertension: readings above 140 over 90 in the doctors office,and below 135/85 when measured over a 24-hour period at home. The other subjects had normal pressure (they were normotensive) in both settings.

After eight years,the scientists found that only 20 per cent from the normal group progressed to actual hypertension,compared with 47 per cent from the white-coat group suggesting, the researchers wrote,that white-coat hypertension may carry a poor cardiovascular prognosis.

A 2009 study of 1,400 people over 10 years in the journal Hypertension had similar results. The reason is unclear. But one hypothesis is that people with white-coat hypertension are more susceptible to stress,which can lead to higher blood pressure over time.

The bottom line

White-coat hypertension can be a forerunner of sustained high blood pressure.