New US guidelines on hypertension take a stronger approach, reclassifying“high normal” blood pressure as “pre-hypertension” andcalling for aggressive treatment, firstly by changing lifestyle and then withdrugs.
The National Heart, Lung, and Blood Institute of the National Institutes ofHealth, 39 professional, public, and voluntary agencies, and seven federalagencies issued the seventh report of the Joint National Committee onPrevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC7).
The report was presented at the American Society of Hypertension meeting inNew York last week and is being published in theJournal of the American MedicalAssociation(2003;289:2560-72 [PubMed] [Google Scholar]). Related guidelines fromthe 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 yearshigh systolic blood pressure (above 140 mm Hg) is considered a greater riskfactor for cardiovascular disease than high diastolic blood pressure.
“The risk of cardiovascular disease begins at 115/75 mm Hg anddoubles with each increment of 20/10 mm Hg; individuals who are normotensiveat 55 years of age have a 90% lifetime risk for developinghypertension,” the guidelines say.
The guidelines recommend that patients with pre-hypertension should loseweight, exercise, drink less alcohol, reduce sodium intake, and change theirdiet to the “DASH” diet (high in fruits and vegetables, potassium,and calcium). They say that the first line treatment for patients withuncomplicated hypertension should be thiazide diuretics, with other drugsadded as needed to control pressure. Most patients will need two drugs tolower their blood pressure to <140/90 mm Hg (or <130/80 mm Hg forpatients 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 theBMJ 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 encouragepatients who have hypertension but no symptoms to understand that changes nowcould prevent stroke or heart attack later, Dr Kottke added.
At the New York meeting doctors questioned the new guidelines. Onephysician said he used to tell patients their blood pressure was normal at120/80 mm Hg and send them home happy. Now, was he supposed to tell them theyhad pre-hypertension, which they would interpret as a disease?
Other doctors questioned the use of thiazide diuretics as the basictreatment and then adding other drugs. Switching patients to a differentsingle drug might control hypertension, they said. Other doctors questionedrecommending drugs that might cause impotence in men. The guidelines say thatdoctors' judgment of treatment is important.
Professor Alberto Zanchetti, professor of medicine at the University ofMilan and director of the university's Centre for Clinical Physiology andHypertension, said that the European Society of Hypertension's definitionswere more flexible.
