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The overtreatment of ‘mild’ hypertension is causing more harm than good, say experts

“Evidence suggests no net benefit from drug treatment of mild hypertension in people without the higher risks of diabetes or chronic kidney disease,” the authors write.

High blood pressure is defined as a systolic pressure of 160 or higher and a diastolic pressure of 100 or higher.
REUTERS/Lucy Nicholson

Millions of people around the world are being treated unnecessarily with drugs for “mild” hypertension (high blood pressure), exposing them to more potential harm than good and wasting health care resources, according to a recent commentary in the journal BMJ.

The commentary, whose authors include Dr. Stephen Martin of the University of Massachusetts Medical School and Dr. James Wright of the University of British Columbia, who is also a coordinating editor of the Cochrane Hypertension Review Group, was published last week in conjunction with BMJ’s ongoing “Too Much Medicine” campaign.

As Martin and Wright point out, the concept of “mild” hypertension has only been around for about a decade, and the idea that otherwise low-risk patients should be treated with blood-pressure-lowering drugs is controversial.

“Evidence suggests no net benefit from drug treatment of mild hypertension in people without the higher risks of diabetes or chronic kidney disease,” they write. “Nevertheless, most people with mild hypertension are treated with drugs.”

A lack of good evidence

Mild (or stage 1) hypertension is defined as a systolic pressure of 140 to 159 and a diastolic pressure of 90 to 99. High blood pressure is defined as a systolic pressure of 160 or higher and a diastolic pressure of 100 or higher. A person is considered at “low risk” if he or she does not have existing heart disease, diabetes or kidney disease.

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As Martin and Wright note in their commentary, hypertension is being diagnosed — and treated — at progressively lower blood pressures. Today, up to 40 percent of adults worldwide are said to have hypertension, although more than 60 percent of those cases fall into the mild category.

And more than half of the people with mild hypertension are treated with blood-pressure-lowering drugs. Yet, “analyses of absolute cardiovascular risk show that drug treatment based on blood pressure alone is likely to have little individual effect in low risk patients with mild hypertension,” write Martin and Wright.

A 2012 Cochrane review (co-authored by Wright) found, for example, that treating mild hypertension with an antihypertensive drug had no beneficial effect on patient outcomes, including the rates at which patients developed heart disease or had a stroke.

Yet each year, billions of dollars are spent on treating mild hypertension. Here in the U.S., the annual cost is $32 billion — more than 1 percent of the country’s annual healthcare costs and more than one-third of its total national expenditures on public health, Martin and Wright point out.

Not without risk

Antihypertensive drugs are not risk-free. They can cause fatigue and muscle weakness, and are associated with an increased risk of serious, injury-causing falls, particularly among older people. People being treated with antihypertensive drugs are also more likely to be admitted to a hospital for medical issues related to the medications, and they tend to rate themselves as being in poorer physical and mental health than people with similar blood pressure measurements who are not taking the medications.

In addition, say Martin and Wright, taking antihypertensive drugs increases the risk that people will not be advised to make heart-healthy lifestyle changes, such as losing weight, increasing physical activity, quitting smoking and reducing alcohol consumption.

Write the two doctors (with British spellings):

For patients with mild hypertension, the focus on drug treatment reduces emphasis on lifestyle changes. Unlike drug treatment, lifestyle changes are free of side effects and provide benefits beyond reduced blood pressure. The health benefits of lifestyle interventions have been known for decades, yet the medical system does not adequately support these approaches.

Comments are often made about lack of adherence to advice about behaviour change, but 50-80% of patients are non-adherent with antihypertensive drugs.

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Misdiagnoses — and missed opportunities

The commentary also talks about the need to measure blood pressure more accurately to avoid “white coat” hypertension — the phenomenon in which blood pressure spikes to abnormally high (and thus unrepresentative) levels while the patient is in the doctor’s office. Studies suggest that as many as 20 percent of people diagnosed with high blood pressure may actually have white coat hypertension.

“Blood pressure must be measured more accurately to ensure patients are correctly identified,” urge Martin and Wright. “Consideration should be strongly given to home measurement as the default.”

And for patient with mild hypertension, “doctors should be open about the lack of known benefits for drug treatment and the benefits of lifestyle improvements,” they add.

You’ll find an abstract of the commentary on the BMJ website, but, unfortunately, the full commentary is behind a paywall.