I. Overview
White coat hypertension (WCH) is a condition in which a patient’s blood pressure is elevated when measured in a doctor’s office, but normal when measured at home or by 24-hour ambulatory blood pressure monitoring (where the patient carries the device with him or herself and no medical personnel are present). This may be due to the patient’s nervousness after seeing a doctor in a white coat, and the presence of excessive catecholamines in the blood, which increases the heart rate and also causes peripheral vasoconstriction and increased resistance, resulting in the so-called “white coat effect”, which leads to an increase in blood pressure.
With the progress of hypertension diagnosis and prevention research, WCH has received more and more attention. Epidemiological surveys have found that WCH accounts for 9% to 16% of hypertensive patients, and the mechanism of WCH is not yet clear, but in the past it was thought that WCH was only mental stress, and my blood pressure was still normal. It may be related to the stress and alertness reactions generated by the patient. Current research has found that this WCH may be an intermediate state between normotension and persistent hypertension, with a higher incidence in young, female, non-smoking people. Therefore, this kind of “white coat hypertension” should be strengthened with follow-up observation.
Etiology
1, WCH may be related to the “pressurization stimulation” of patients by medical personnel measuring blood pressure
The tone of voice and emotion of the medical staff talking with the patient in a particular place can affect the measured blood pressure value.
2. Patients have an enhanced response to stress
Studies have found that patients with WCH have an activated renin-angiotensin system, increased plasma renin and aldosterone levels, and increased norepinephrine levels.
3. Patients with WCH have genetic characteristics of stress-related stress response
may be part of the prehypertensive state.
III. Clinical presentation
WCH is an untreated patient who presents with consistently elevated blood pressure measured in the office, while ambulatory blood pressure monitoring is normal. It is thought to be more appropriately referred to as “pure office hypertension”.
IV. Testing
Ambulatory blood pressure monitoring is currently the gold standard for confirming the diagnosis of WCH. Self-measured blood pressure at home can be used as a screening tool.
In patients with WCH, 24-h ambulatory blood pressure is significantly lower than in patients with persistent hypertension, and compared to normal subjects, 24-h and daytime mean blood pressure is elevated, even by a significant margin. Therefore, cardiovascular risk stratification is necessary for appropriate treatment planning.
1, risk factors:including gender, age, smoking or not, obesity or not, collection of family history of early onset cardiovascular disease and measurement of glucose, lipids, homocysteine.
2. Target organ damage: electrocardiogram, cardiac ultrasound, carotid ultrasound, pulse wave velocity, ankle/arm index, glomerular filtration rate, serum creatinine measurement, urine albumin/creatinine ratio, etc.
In addition, psychological assessment should be performed for patients with anxiety status.
V. Diagnosis
In the unmedicated state, elevated blood pressure at the doctor’s office measurement and normal blood pressure at the 24-hour ambulatory blood pressure monitoring is diagnosed.
The reference diagnostic criteria in China are: office systolic blood pressure > 140 mmHg and/or diastolic blood pressure > 90 mmHg in patients with WCH, and daytime ambulatory blood pressure systolic < 135 mmHg diastolic < 85 mmHg.
The 2013 European guidelines for hypertension propose diagnostic criteria of in-office blood pressure >140/90 mmHg and out-of-office or home self-measured blood pressure <135/85 mmHg during the day and 24-hour ambulatory blood pressure <130/80 mmHg throughout the day.
VI. Treatment
The 1999 WHO and ISH guidelines for the treatment of hypertension state that the need for treatment of simple office-based hypertension should be determined by the overall risk profile and the presence of target organ damage. 2013 European guidelines suggest lifestyle modification with close follow-up for 3-6 months if no other risk factors are present, and close follow-up for 3-6 months if combined with high risk factors for cardiovascular disease, concomitant antihypertensive drug therapy based on lifestyle modification is required.
In recent years, stress management has been emphasized for patients with WCH, including biofeedback, yoga, and relaxation training. Some studies suggest that these stress management may reduce cardiovascular risk by lowering blood pressure through decreasing the activity of catecholamines and renin-angiotensin-aldosterone.
VII. Prevention
1.Prevent the main risk factors of hypertension by having a reasonable diet, reducing body weight, limiting alcohol consumption, and performing appropriate physical activities.
2, pay attention to the adjustment of lifestyle and prevention of stress, correct treatment and try to relieve all kinds of psychological stress.