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NBC29 HEALTH SEGMENTS |
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WHITE COAT EFFECT White Coat Effect: when a patient's blood pressure (BP) is 10 mm Hg lower at home than in the doctor's office.
White Coat Hypertension (WCH): when a patient’s blood pressures are elevated in the office but are normal when measured at home. The reasons for WCH are not known.
§ About 15-20% of patients with elevated office blood pressures have normal daytime blood pressures measured by ambulatory-monitoring or home devices. § Patients with WCH have increased emotional reactivity and higher levels of anger, anxiety, or depression, as compared with sustained hypertensive patients. § Often coexists with other cardiovascular risk factors.
Should WCH be treated?
Some evidence suggests these patients have essentially the same cardiovascular risk (chance of coronary artery disease, heart attack, stroke, kidney failure, and eye damage) as patients with no elevated blood pressures.
§ People with WCH have a lower body mass index (BMI) and a better lipid profile than those with sustained hypertension. § Some measures of long-term damage to the heart (LV mass) and kidney (urine albumin excretion) are only elevated in sustained hypertension compared with WCH. § The nervous system acts differently (whole-day sympathetic overactivity) in sustained hypertension than in white coat hypertension. § Increased home BP measurements are more predictive of major cardiovascular events, whether a person is treated or not. § BP that is controlled when measured at home predicts a lower risk of cardiovascular disease. § Problems associated with cardiovascular events are similar in people with WCH and those with normal blood pressures. § Middle-aged people with WCH have lower homocysteine levels than patients with sustained hypertension. o high homocysteine levels have been shown to increase cardiovascular risk.
§ Home BP <130 mmHg systolic and 80 mmHg diastolic may be considered optimal to identify people with WCH at very low risk.
§ Patients should be followed to make sure they don’t develop sustained hypertension.
Other evidence suggests that WCH is a form of pre-hypertension and should be treated.
§ Patients with WCH in the long-term have impaired glucose tolerance, but better than those with sustained hypertension. o Impaired glucose tolerance is a risk factor for diabetes. § Similar abnormalities of heart compliance (diastolic LV function) were identified in the patients with persistent hypertension and those with WCH. § The diameter of the carotid arteries (the arteries that go to your brain) are smaller than when compared w/ normotensives. o Clogged arteries to your brain increase the risk of stroke. § The presence of other risk factors may determine the risks associated with white coat hypertension: if you have other risk factors you are more likely to have complications.
How is WCH treated?
§ The best way to lower BP is with regular exercise and a healthy diet. § One study showed that after only 4 weeks of regular exercise training in patients with WCH, clinic and home BP measurements were significantly reduced and these reductions persisted over the 12-week study. Significant reductions were also found in total cholesterol, LDL (bad cholesterol), and triglycerides. Elevation of HDL (good cholesterol) was noted as well. § If exercise and diet are not enough, there are many different types of medicines used to treat high blood pressure that your doctor can prescribe.
What if my blood pressure is only a little high?
§ Women with high-normal blood pressure (120-140/80-90) are 2.5 times more likely and men are 1.6 times more likely to have a cardiovascular event than those with optimal blood pressure (<120/80).
What if my BP is lower in the doctor’s office than at home?
§ This is called inverse white coat hypertension. § IWCH is associated with increased damage to the heart (LV mass).
By John S. Hong, MD, MS |