A normal blood pressure (BP) reading at the doctor’s clinic should not make you complacent as you could be suffering from masked hypertension like 17 million other Americans, according to a new study by the Columbia University Medical Center (CUMC). Your risk is higher if you are man, aged 45 or older, and have diabetes.
For a hypertension patient, the telltale sign is a BP reading above 140/90 mmHg. However, in masked hypertension, the BP stays within the normal or pre-hypertensive range (systolic BP 120-139 mmHg or diastolic BP between 80-89 mmHg) when the doctor checks it but after a while it stays above 135/85 mmHg. An out-of-office BP reading is called ambulatory BP monitoring (ABPM).
ABPM is done with the help of a small digital device that a person tucks under the belt or wears around the waist as they move around carrying out their routine activities. The devise is connected to a tiny cuff worn around the arm where it measures the BP after every 15-20 minutes around the clock.
Approximately 75 percent million Americans have hypertension and every one in three individuals has pre-hypertension. If we go by the stats of the new study, 17 million Americans may have masked hypertension.
“Having a prevalence estimate is the first step in recognizing the extent of the problem,” said Dr. Daichi Shimbo, an associate professor of medicine and a cardiologist at New York-Presbyterian/Columbia University Medical Center, and the lead author of the study.
“Future research should focus on characterizing the health benefits and net costs of treating people with masked hypertension.”
In an attempt to determine the prevalence of masked hypertension in American citizens, the researchers collected data from an earlier study on 9,316 individuals with normal BP (normotensive), who participated in the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2010.
Using multiple imputation – a statistical technique to analyze incomplete data sets – the researchers came to the conclusion that approximately 17.1 million (12.3 percent) Americans may have masked hypertension. Outside the US, researchers believe that approximately 10-30 percent people have masked hypertension.
The researchers also found that masked hypertension is much more prevalent in males, particularly if they are 45 or above and suffer from at least one additional health risk such as diabetes or pre-hypertension.
The researchers concluded their study by recommending that BP screening be offered to men that fall in the health risk category. The rationale of the screening is that 24-hour ABPM is not feasible. Besides, national health surveys do not include ABPM in their studies, making it difficult to identify individuals with masked hypertension.
“While it may not be practical to perform 24-hour blood pressure monitoring on all adults who have normal clinic blood pressure, our study suggests that it may be prudent to screen men 45+ years of age with diabetes or prehypertension,” said Dr. Joseph Schwartz, PhD, professor of psychiatry and sociology at Stony Brook University School of Medicine and a lecturer at CUMC.
The press release was published on January 20, 2017 on CUMC website.
Why Blood Pressure Matters
Blood pressure is the force with which the blood pushes against the blood vessels, as it moves from the heart to the body and vice versa. The BP surges and falls throughout the day but if it stays high for a long time it can seriously damage your health.
Persistently high blood pressure – or hypertension – is a gateway for several health complications such as heart attack, stroke and coronary heart disease.
Hypertension is a universal disease but in the US, it is more common in some states than others, such as South Caroline, Georgia, Alabama, Mississippi, and Arkansas etc.
Data shows that hypertension is the cause of seven out 10 cases of heart attacks, chronic heart failure and kidney disease, and eight out of 10 cases of stroke.
Everyday 10,000 people die due to hypertension and its complications.
People with masked hypertension share similar cardiovascular health risks as hypertensive patients.
Controlling BP is extremely important to reduce the risk of lethal diseases. An early diagnosis helps the doctor devise a clinical strategy that eases your life and ensures health on long term basis.
The US Centers For Disease Control & Prevention (CDC) recommends several measures to control BP. These include getting biannual (or more frequent) screening for BP, taking medications in time, reducing sodium in diet from 3,400 milligrams (mg) to 2,300 mg per day, quitting smoking and maintaining daily physical activity of at least 30 minutes a day.
Lifestyle changes remarkably reduce BP readings and take the pressure off the heart and other vital organs.