New US guidelines on hypertension take a stronger approach, reclassifying “high normal” blood pressure as “pre-hypertension” and calling for aggressive treatment, firstly by changing lifestyle and then with drugs.
The National Heart, Lung, and Blood Institute of the National Institutes of Health, 39 professional, public, and voluntary agencies, and seven federal agencies issued the seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC 7).
The report was presented at the American Society of Hypertension meeting in New York last week and is being published in the Journal of the American Medical Association(2003;289: 2560-7212748199). Related guidelines from the National Heart, Lung, and Blood Institute are on the institute's website (www.nhlbi.nih.gov/guidelines/hypertension).
The new guidelines categorise blood pressure as normal (<120/80 mm Hg), pre-hypertension (120/80 to 139/89), stage 1 hypertension (140/90 to 159/99), and stage 2 hypertension (≥160/100 or higher). In people aged over 50 years high systolic blood pressure (above 140 mm Hg) is considered a greater risk factor for cardiovascular disease than high diastolic blood pressure.
“The risk of cardiovascular disease begins at 115/75 mm Hg and doubles with each increment of 20/10 mm Hg; individuals who are normotensive at 55 years of age have a 90% lifetime risk for developing hypertension,” the guidelines say.
The guidelines recommend that patients with pre-hypertension should lose weight, exercise, drink less alcohol, reduce sodium intake, and change their diet to the “DASH” diet (high in fruits and vegetables, potassium, and calcium). They say that the first line treatment for patients with uncomplicated hypertension should be thiazide diuretics, with other drugs added as needed to control pressure. Most patients will need two drugs to lower their blood pressure to <140/90 mm Hg (or <130/80 mm Hg for patients with diabetes or chronic kidney disease).
Dr Thomas Kottke, professor of medicine at the Mayo Clinic, Rochester, Minnesota, who wrote an accompanying editorial in JAMA, told the BMJ that getting patients to change lifestyles was difficult. “Yapping at people doesn't help,” he said.
At the Mayo Clinic several team approaches were being used to encourage patients who have hypertension but no symptoms to understand that changes now could prevent stroke or heart attack later, Dr Kottke added.
At the New York meeting doctors questioned the new guidelines. One physician said he used to tell patients their blood pressure was normal at 120/80 mm Hg and send them home happy. Now, was he supposed to tell them they had pre-hypertension, which they would interpret as a disease?
Other doctors questioned the use of thiazide diuretics as the basic treatment and then adding other drugs. Switching patients to a different single drug might control hypertension, they said. Other doctors questioned recommending drugs that might cause impotence in men. The guidelines say that doctors' judgment of treatment is important.
Professor Alberto Zanchetti, professor of medicine at the University of Milan and director of the university's Centre for Clinical Physiology and Hypertension, said that the European Society of Hypertension's definitions were more flexible.