THURSDAY, Jan. 18, 2007 (HealthDay News) -- Some common blood pressure drugs can substantially increase the risk of diabetes, especially among those already at risk for the condition, U.S. researchers report.
According to the report, angiotensin-receptor blockers (ARBs) and angiotensin-converting-enzyme (ACE) inhibitors are the blood pressure drugs least associated with diabetes. These are followed by calcium-channel blockers.
Beta blockers and diuretics are the drugs most associated with the condition.
"There are differences across the various types of drugs that we use to treat high blood pressure in people who develop diabetes," said study author Dr. William Elliott, from the department of preventive medicine at Rush University Medical Center, Chicago.
The report is published in the Jan. 20 issue of The Lancet.
In the study, Elliott and his colleague Peter Meyer looked at 22 clinical trials that included more than 143,000 people. These people had high blood pressure but did not have diabetes at the start of the trials. In each trial, the participants received long-term treatment with each class of blood pressure drugs or placebo.
The traditional medicines used to treat high blood pressure in the United States are diuretics and beta blockers, Elliott said. "It so happens that they are the two drug classes that are most likely to precipitate diabetes. It turns out the two of the new classes of drugs -- ACE inhibitors and ARBs -- are the two that have the least amount of diabetes associated with them. In the middle, we have calcium-channel blockers," he said.
Elliott noted that your risk of getting diabetes while taking diuretics and beta blockers depends on a number of factors. These include how long you are on the medication, your weight, your family history of diabetes, whether or not you have recently gained weight, and other risk factors, he said.
How doctors should be prescribing these drugs in light of these findings isn't clear cut, Elliott said. "In Britain, they have issued new guidelines, where, in fact, the diuretic and beta blocker combination are not to be used together because of the excess risk of diabetes," he said.
Doctors who take a patient's risk for diabetes into account might be better off prescribing an ACE inhibitor or an ARB, rather than a beta blocker or a diuretic as first-line treatment, Elliott said.
"However, if you have a patient who has high blood pressure, kidney disease and had a major heart attack recently -- there is no question they are going to get the beta blocker to protect them from another heart attack," he said. "They are also going to get diuretic, because of the kidney disease. If they get diabetic, you just accept that and move on. You are not going deny them the medicines they need today over the risk of diabetes down the road," he said.
One diabetes expert thinks that doctors should take a patient's risk for diabetes into account when prescribing blood pressure medications.
"Individualization of therapy is important," said Dr. Stuart Weiss, an endocrinologist at New York University Medical Center. "With the explosion of diabetes in the country, we need to take that into consideration when providing patients with their initial antihypertensive."
Weiss thinks that those people who are at risk for diabetes should not be started on beta blockers or diuretics. "With all the data about the long-term use of ACEs and ARBs and their lower risk for diabetes, it's a good thing to get these drugs in early in somebody who is even at modest risk for type 2 diabetes," he said.
A cardiologist agreed that treatment needs to be tailored to individual patient needs.
"Since doctors generally have many drug options to lower blood pressure, it makes sense to tailor the drug choice to the patient who may be at higher risk for certain diseases," said Dr. Byron K. Lee, an assistant professor of medicine at University of California San Francisco, Division of Cardiology.
"For example, those at higher risk for diabetes may be given an ACE inhibitor or ARB, whereas those at higher risk for heart attacks may be given a beta blocker," Lee said.
In related news, changing to a healthier lifestyle also appears to be at least as effective as taking prescription drugs in reducing the risk of developing type 2 diabetes, according to a study published in this week's issue of the British Medical Journal.
Researchers from Leicester reviewed studies that measured the effects of different interventions -- lifestyle, diabetes drugs and anti-obesity drugs -- on people with impaired glucose tolerance. They found that lifestyle changes, such as switching to a healthier diet and increasing exercise, were at least as effective as taking drugs. On average, the study found, lifestyle changes helped to reduce the risk of developing type 2 diabetes by around half and were also less likely to have adverse side effects.
There's more on diabetes and heart disease at the American Heart Association.