MONDAY, Sept. 12, 2005 (HealthDay News) -- Contradicting some previous research, a new study finds that frequent use of painkillers including nonsteroidal anti-inflammatory drugs (NSAIDs) does not substantially increase a healthy man's risk of developing hypertension.
The findings, which appear in the Sept. 12 issue of Archives of Internal Medicine, may muddy the picture more than clarify it.
"It's inconclusive," said Dr. Joel S. Bennett, a spokesman for the American Heart Association who is with the division of hematology/oncology at the University of Pennsylvania School of Medicine. "Most epidemiological studies have to be done multiple times before you can be sure."
Past research involving women had suggested there might be a link between pain relievers and hypertension, also known as high blood pressure.
"We don't know what all the answers are," conceded senior author Dr. J. Michael Gaziano, a cardiologist and epidemiologist at Brigham and Women's Hospital in Boston. "We need to better understand what's going on in larger observational studies and randomized trials. We need careful additional study of the question."
Hypertension is a major risk factor for cardiovascular disease, including stroke, heart attack and heart failure, as well as for kidney disease.
While the authors of this study stated that obesity is probably the major contributing factor to an increased risk for heart disease, they pointed to suspicions that other factors, such as NSAID use, may also play a role. NSAIDs inhibit production of prostaglandin, which helps regulate blood pressure.
The study researchers looked at 8,229 healthy male physicians aged 53 to 97 enrolled in the Physicians' Health Study. None of the participants had hypertension at the beginning of the trial. All completed detailed questionnaires about use of analgesics (pain relievers) and blood pressure over a six-year period.
After about six years of follow-up, there appeared to be no association between use of painkillers and hypertension. Specifically, the study looked at three types of pain relievers: NSAIDs, aspirin and the non-NSAID acetaminophen (Tylenol).
When a more detailed analysis was performed, the data indicated there might be a small-to-moderate increase of hypertension risk tied to acetaminophen use, the study found.
The study was funded by the National Institutes of Health and by an unrestricted research grant from McNeil Consumer & Specialty Pharmaceuticals, the maker of Tylenol. It was concerned only with the disease of hypertension and not with transient changes in blood pressure that these drugs can cause.
Despite the contradictory findings involving women, the study authors don't believe that gender affects reaction to the drugs.
"We don't think that women and men are different," said Gaziano, who serves as a consultant for McNeil Consumer & Specialty Pharmaceuticals. "This is observational epidemiology. A lot of people might conclude incorrectly that men must be different than women, and rather than that conclusion, we don't fully know the whole story of analgesics and their ability to cause hypertension in men or women."
It's possible, however, that pain relievers might heighten the risk of hypertension in certain groups of people. "These were healthy men and some of those blood pressure changes seen in other trials may be more pronounced in susceptible populations," Gaziano said.
Gaziano believes that short-term use of over-the-counter pain killers is probably safe, as long as the drugs are taken as indicated.
"Even if there are going to be any effects on blood pressure, they're going to be transient and are not going to translate into any meaningful risk," he said.
But, he added, "we really need better trial data on the long-term consequences."
Bennett said, "This suggests that over the long term, these analgesics are not going to cause hypertension."
The American Heart Association has more on hypertension.