There’s no doubt that high blood pressure is a major risk factor for cardiovascular disease. But there’s plenty of doubt about when to start blood pressure medication in someone with low-risk, mild hypertension.
Mild hypertension is typically considered a systolic blood pressure between 140 and 159 or a diastolic blood pressure between 90 and 99. The most recent guidelines from the American Heart Association and the American College of Cardiology state that anyone with risk factors for cardiovascular disease and a blood pressure of 130/80 or higher should be treated. They also say to treat everyone with a blood pressure of 140/90 or higher even without any risk factors.
The problem? These guidelines are primarily based on the Systolic Blood Pressure Intervention Trial (SPRINT). SPRINT was a large study, but most of the patients were already being treated and they were not low risk. “Low risk” usually means no history of cardiovascular disease, family history of early heart disease and no evidence of heart enlargement, atrial fibrillation, diabetes or chronic kidney disease.
To specifically investigate the risks and benefits of treating low-risk, mild hypertension, researchers from Oxford University in the UK used data extracted from the UK Clinical Practice Research Datalink between 1998 and 2015, a database of electronic medical records that represents the entire population of the UK. They focused on a group of more than 38,000 patients who fit the description. Half of the patients were treated with hypertensive medications within 12 months of diagnosis and half were not. The researchers followed them for about six years to see how the risks and benefits of treatment compared between the two groups.
The results: There was no evidence of benefit for the patients taking medication. Treatment was not associated with a lower risk for death, heart attack, stroke or heart failure.
Treatment was, however, associated with significantly higher risk for low blood pressure, syncope (dizziness), electrolyte imbalances and sudden kidney damage. Although the overall risk of such adverse events was low, they were about 30% to 70% more likely to occur in the treated patients.
The dilemma: US guidelines recommend drug treatment to lower blood pressure more quickly than other countries. In the UK, low-risk patients with mild hypertension are given lifestyle advice rather than medication. Elsewhere in Europe, lifestyle advice is recommended for a number of months before medication is considered. This study has some limitations, namely that patients were not randomly allocated to a treatment or no treatment group, which could bias the results. However, it would take even larger and longer studies than this one to arrive at a treatment consensus, and the cost of conducting such a trial would be so high that it may never be undertaken.
So how can you use this new information? If you or a loved one is trying to figure out the best treatment for mild, low-risk hypertension, first recognize that there is no one-size-fits-all approach. Weigh the pros and cons of treatment in view of your personal risk factors, including your age. Recently, a separate study done in the US found that people with elevated blood pressure in their 40s had greater heart risks later in life if they didn’t take early steps to lower it. (The average age of patients in the UK study was 55.)
The one “treatment” that should be part of every person’s plan to manage blood pressure involves adopting known lifestyle changes—a more healthful diet, not smoking, exercising more and reducing stress, none of which are associated with the risks of medication.