BPA comment on white coat study
UK charity the Blood Pressure Association has commented on a new study which suggests that the 'white-coat' effect - when blood pressure rises during a check by a doctor - is even worse in those who already have moderate or high blood pressure. 
A team of researchers in Australia compared ambulatory blood pressure measurements with those taken by doctors and nurses and found that there could be a difference of as much as 29 units if a doctor checked it, compared with a rise of 17 units if a nurse took the measurement.
They also found that the closer the patient's blood pressure was to normal levels (120/80mmHG), the less of a difference between measurements taken by ambulatory monitoring and those taken by a nurse or doctor.
Professor Graham MacGregor, Chairman of the Blood Pressure Association, said: "This is interesting research which clearly illustrates how external factors such as environment and who is checking blood pressure can have a significant impact on blood pressure readings.
"Many people feel slightly anxious when going to see a doctor, which is why we have always encouraged blood pressure measuring at home as well as in the clinic, and promotes the use of home blood pressure monitors and ambulatory testing where indicated.
"This research may well be considered as part of the review of the NICE [National Institute of Health and Clinical Excellence] guidelines for the treatment of hypertension which is currently being conducted, and will be released next year."
 Reference: BMJ 2010;340:c1104 'Definition of ambulatory blood pressure targets for diagnosis and treatment of hypertension in relation to clinic blood pressure: prospective cohort study'