High levels of uric acid may be associated with high blood pressure

August 26, 2008

Reducing levels of uric acid in blood lowered blood pressure to normal in most teens in a study designed to investigate a possible link between blood pressure and the chemical, a waste product of the body's normal metabolism, said researchers at Baylor College of Medicine in a report that appears in the current issue of the Journal of the American Medical Association.

"If you reduce uric acid, at least in some patients, you may be able to reduce blood pressure," said Dr. Daniel Feig, associate professor of pediatrics-renal at BCM and chief of the pediatric hypertension clinics at Texas Children's Hospital. "This could be one way people develop hypertension and may allow us to develop new therapies."

Understanding how people develop high blood pressure gives scientists new tools for understanding the disorder and developing drugs to prevent and treat it.

Uric acid builds up when the body makes too much of it or fails to excrete it. It is a waste product resulting from the metabolism of food. Too much uric acid can cause gout, which occurs when uric acid crystals accumulate in the joints. In this study, researchers used allopurinol to reduce high uric acid levels. Allopurinol is usually used to treat gout, but Feig said its potential side effects rule it out as a treatment for high blood pressure.

In the JAMA study, Feig and his colleagues treated teens with newly diagnosed high blood pressure and elevated levels of uric acid in their blood with allopurinol. In the study, half of the 30 teen-agers with newly diagnosed high blood pressure and higher than normal levels of uric acid in their blood underwent treatment with allopurinol twice a day for four weeks. The other half received a placebo (an inactive drug) on the same schedule. They then went without either drug for two weeks before receiving the opposite treatment for another four weeks.

The treatment not only reduced uric acid levels, it also reduced blood pressure in most of the teens, said Feig. In fact, he said, blood pressures decreased to normal in 20 of the 30 teens when they were on allopurinol. By contrast, only 1 of the 30 teens had normal blood pressure when receiving placebo.

"This is far from being a reasonable therapeutic intervention for high blood pressure, but these findings indicate a first step in understanding the pathway of the disease," said Feig. "You cannot prevent a disease until you know the cause. This study is way of finding that out."

Studies in rats had indicated previously that high levels of uric acid could be associated with the development of high blood pressure through a proven pathway, said Feig. However, he and his colleagues needed to determine if this was true for humans as well.

"The antihypertensive therapies available to patients are well proven and safe," said Feig. "Currently available antihyperuricemic therapies (treatments that lower uric acid) are not safe enough to be used as first line therapy for most people with high blood pressure."

Side effects could include nausea, diarrhea, vomiting, liver problems and even a very rare, potentially life-threatening reaction known as Steven-Johnson syndrome. While only 1 in 3,000 people develop this problem, the risk is too great to prescribe the drug on a routine basis to people with high blood pressure, a problem that affects 30 to 35 percent of adults.

Currently available therapies are effective but are not solving the problem in everyone. Optimal blood pressures are achieved in only 40 percent of people who are treated for the problem. Understanding the cause of high blood pressure could lead to better treatments and even methods of prevention.

Animal studies indicate that early in the disease, the extra uric acid activates the renin angiotensin system of the body, shrinking key blood vessels and causing high blood pressure. Eventually, however, the small vessels in the kidney are permanently affected, making the blood pressure sensitive to salt or sodium. Too much salt causes the pressure to rise.
-end-
Others who took part in this work include Beth Soletsky, RN, also of BCM and Dr. Richard J. Johnson of the University of Florida at Gainesville.

Funding for this work came from the National Institutes of Health.

After the embargo lifts, the full article can be found at www.jama.com.

For more science news from Baylor College of Medicine, go to www.bcm.edu/fromthelab.

Baylor College of Medicine

Related Blood Pressure Articles from Brightsurf:

Children who take steroids at increased risk for diabetes, high blood pressure, blood clots
Children who take oral steroids to treat asthma or autoimmune diseases have an increased risk of diabetes, high blood pressure, and blood clots, according to Rutgers researchers.

High blood pressure treatment linked to less risk for drop in blood pressure upon standing
Treatment to lower blood pressure did not increase and may decrease the risk of extreme drops in blood pressure upon standing from a sitting position.

Changes in blood pressure control over 2 decades among US adults with high blood pressure
National survey data were used to examine how blood pressure control changed overall among U.S. adults with high blood pressure between 1999-2000 and 2017-2018 and by age, race, insurance type and access to health care.

Transient increase in blood pressure promotes some blood vessel growth
Blood vessels are the body's transportation system, carrying oxygen and nutrients to cells and whisking away waste.

Effect of reducing blood pressure medications on blood pressure control in older adults
Whether the amount of blood pressure medications taken by older adults could be reduced safely and without a significant change in short-term blood pressure control was the objective of this randomized clinical trial that included 534 adults 80 and older.

Brain blood flow sensor discovery could aid treatments for high blood pressure & dementia
A study led by researchers at UCL has discovered the mechanism that allows the brain to monitor its own blood supply, a finding in rats which may help to find new treatments for human conditions including hypertension (high blood pressure) and dementia.

Here's something that will raise your blood pressure
The apelin receptor (APJ) has been presumed to play an important role in the contraction of blood vessels involved in blood pressure regulation.

New strategy for treating high blood pressure
The key to treating blood pressure might lie in people who are 'resistant' to developing high blood pressure even when they eat high salt diets, shows new research published today in Experimental Physiology.

Arm cuff blood pressure measurements may fall short for predicting heart disease risk in some people with resistant high blood pressure
A measurement of central blood pressure in people with difficult-to-treat high blood pressure could help reduce risk of heart disease better than traditional arm cuff readings for some patients, according to preliminary research presented at the American Heart Association's Hypertension 2019 Scientific Sessions.

Heating pads may lower blood pressure in people with high blood pressure when lying down
In people with supine hypertension due to autonomic failure, a condition that increases blood pressure when lying down, overnight heat therapy significantly decreased systolic blood pressure compared to a placebo.

Read More: Blood Pressure News and Blood Pressure Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.