Drug Treatment of Pre-Hypertension
Can Drug Treatment of Prehypertension Prevent Hypertension?
What is the problem and what is known about it so far?
High blood pressure, also called hypertension, is defined as a blood pressure greater than 140/90. High blood pressure puts people at increased risk for cardiovascular disease (CVD) including heart attack and stroke. People, who have blood pressure higher than normal, but lower than what is considered hypertension, have "prehypertension". Prehypertension blood pressures range between 130/80 and 140/90. People with prehypertension are also at a greater risk for CVD, and they usually go on to develop hypertension. Current guidelines recommend lifestyle changes rather than drugs for the management of prehypertension. Examples of lifestyle changes include exercise, weight loss, and eating a low salt diet. While lifestyle changes offer some benefit, the occurrence of prehypertension is increasing, and the condition is now present in 70 million Americans. In rats with hypertension, a short treatment with anti-hypertension drugs results in the lifelong reduction in blood pressure. No one has studied if using similar drugs for a short amount of time to treat people with prehypertension might prevent or delay the onset of hypertension.
Why did the researchers do this particular study?
To determine whether two years of treatment with an anti-hypertension drug (candesartan) in patients with prehypertension reduces the chance of their developing hypertension, even after stopping the drug.
Who was studied?
About 800 men and women from several different medical centers, ages 30 to 65 years, with untreated prehypertension.
How was the study done?
Participants were randomly assigned to receive either blood pressure medication or no treatment for two years. Both groups were also instructed to make lifestyle changes geared toward reducing blood pressure. After this time, both groups received no treatment and were simply followed for another two years. Researchers measured blood pressure at set times through out the study period.
What did the researchers find?
After two years, 154 participants who received no medication and 53 taking the drug developed hypertension. This means that those taking the drug had only a three out of ten risk of developing hypertension. After four years (or two years after participants stopped taking the drug), hypertension had developed in 240 people in the no medication group and 208 in the drug group. In other words, people who had taken the drug two years previously had an eight out of ten risk of developing hypertension.
What were the limitations of the study?
The study did not test if the treatment made any differences in the long-term development of hypertension (beyond two years after stopping the drug). The study was also too short to determine if treating prehypertension actually affects long-term problems such as heart disease or stroke. The issue of the cost of such treatment was not addressed.
What were the implications of the study?
Treating prehypertension with medicine for a short period offers a decrease in the development of hypertension even after the drug is stopped. Further research is needed to see if this effect lasts beyond two years, which types of patients will benefit the most, and the price of such benefits in terms of both patient safety and money.
Summarized by Sahir Kalim, College of Medicine, University of Vermont
Summarized from "Feasibility of treating prehypertension with an angiotensin-receptor blocker." Julius S. et al. New England Journal of Medicine, April 20, 2006, Volume 354, Number 16, Pages 1685-97.
