Blood pressure may spike when a doctor performs the reading.
Experts define high blood pressure as a top reading of at least 130 millimeters of mercury (mm Hg) or a bottom reading of 80 mm Hg or higher.
New research finds that white coat hypertension is in itself a significant risk factor for heart disease and cardiovascular death, just like hypertension.
Specifically, untreated white coat hypertension may increase the risk of dying from heart disease by more than 100%, according to a new paper that the Annals of Internal Medicine recently published.
Dr. Jordana B. Cohen, who is an assistant professor in the division of Renal-Electrolyte and Hypertension at the University of Pennsylvania School of Medicine in Philadelphia, is the lead author of the research.
"Studies suggest that about one in five adults may have white coat hypertension. Our findings underscore the importance of identifying people with this condition."
Dr. Jordana B. Cohen
Cardiovascular death risk doubled
Dr. Cohen and colleagues carried out a meta-analysis of 27 observational studies, which included more than 60,000 participants in total. Each of the studies examined the health risks that correlated with white coat hypertension and had a follow-up period of at least 3 years.
Two investigators independently extracted the data from these studies and assessed their quality.
The researchers found that participants who had untreated white coat hypertension were 36% more likely to have heart disease, 33% more likely to die prematurely from any cause, and 109% more likely to die of heart disease.
Treated white coat effect, however, did not correlate with higher cardiovascular risk. Dr. Cohen and colleagues conclude:
"Untreated [white coat hypertension], but not treated [white coat effect], is associated with an increased risk for cardiovascular events and all-cause mortality. Out-of-office [blood pressure] monitoring is critical in the diagnosis and management of hypertension."
"We believe individuals with isolated in-office hypertension — those who are not taking blood pressure medication — should be closely monitored for transition to sustained hypertension, or elevated blood pressure both at home and the doctor's office," emphasizes Dr. Cohen.
She goes on to add that this "pressing need" for constant monitoring is a "nationwide" concern, as are the lifestyle changes that people should make for better cardiovascular health.
"Simultaneously, we advise individuals with untreated white coat hypertension to engage in lifestyle modifications, including smoking cessation, reduction in their alcohol intake, and making improvements to their diet and exercise regimen."
"We also caution providers not to overtreat individuals with white coat hypertension who are already on blood pressure medication, as this could lead to dangerously low blood pressures outside of the office and unnecessary side effects from medication," concludes Dr. Cohen.
Finally, the authors also point to some limitations of their analysis, noting the insufficient number of studies that evaluated isolated cardiac outcomes. Also, the studies did not contain enough information about the participants' race and ethnicity.