Watch Out for Gout

Gout risk higher in high blood pressure patients

(RxWiki News) Sometimes treating one problem can put you at a higher risk for a different health condition. For example, some blood pressure medications can increase the risk of gout.

A recent study looked at how common gout is among those with high blood pressure. Gout is a type of arthritis where patients experience joint inflammation and pain due to the build up of uric acid in the blood and joints.

The researchers found higher rates of gout in those with high blood pressure and other heart disease risk factors than in the general population.

This finding means patients should be aware of an even higher risk of gout with certain blood pressure medications called diuretics.

"Ask your cardiologist about Rx side effects."

The study, led by Stephen P. Juraschek, of the Department of Epidemiology at Johns Hopkins Bloomberg School of Public Health in Baltimore, aimed to understand how common gout is among those with high blood pressure or other heart disease risk factors.

Having too much uric acid in the blood by itself is called hyperuricemia. This condition becomes diagnosed as gout when inflammation and pain in the joints is present due to these elevated uric acid levels.

The researchers pulled data from the 1988-1994 and 1999-2010 National Health and Nutrition Examination Surveys, which included a total of 47,476 adults aged 18 and older.

The researchers looked for which patients had hyperuricemia, gout, high blood pressure and three heart disease risk factors: obesity, reduced glomerular filtration rate and dyslipidemia.

Glomerular filtration rate has to do with how well the kidneys filter the blood. Dyslipidemia refers to having too many or too few lipids in the blood. Lipids include both cholesterol and fat.

Women were classified as having high levels of uric acid, or hyperuricemia, if they had more than 6 mg/dL of uric acid in their blood. Men had hyperuricemia if they had more than 7 mg/dL. Patients were recorded as having gout if they had been diagnosed with it by a doctor.

The researchers identified patients with "uncontrolled blood pressure" (high blood pressure that is not being adequately treated) as those with systolic pressure (top number) at 140 mmHg or higher and diastolic pressure (bottom number) at 90 mmHg or higher.

Overall, 2.6 percent of adults had gout in the 1988-1994 survey, and 3.75 percent had gout in the 2007-2010 surveys.

About 6 to 8 percent of adults with a normal blood pressure and no cardiovascular disease risk factors were found to have hyperuricemia, and 1 to 2 percent had gout.

Among those who had high blood pressure but no other heart disease risk factors, 10 to 15 percent had hyperuricemia and 4 to 5 percent had gout. Among those with uncontrolled blood pressure and one other cardiovascular disease risk factor, 22 to 25 percent had hyperuricemia and 6 to 8 percent had gout.

Finally, among those with uncontrolled blood pressure and two other heart disease risk factors, 34 to 37 percent had hyperuricemia and 8 to 12 percent had gout.

Hyperuricemia was also much more common among those who were obese: 31 to 37 percent of obese participants had hyperuricemia, compared to 7 to 8 percent of those with a healthy weight.

For the years 2007 to 2010, the researchers looked at the risk of having hyperuricemia and gout among those with no risk factors for heart disease and those with both high blood pressure and two other risk factors.

They found that individuals with uncontrolled blood pressure and two other cardiovascular disease risk factors were four and a half times more likely to have hyperuricemia or gout than those with no heart disease risk factors.

Therefore those with high blood pressure and additional heart disease risk factors were also at a higher risk for gout. The medications used to treat high blood pressure include diuretics, which make individuals have to urinate more often.

But diuretics can also increase the risk of gout. Therefore, individuals with high blood pressure and other cardiovascular risk factors need to consider the added risks of gout with certain medications they might take to control their blood pressure.

The study was published February 27 in the journal PLOS ONE. The research was funded by the National Institutes of Health Heart, Lung and Blood Institute. The authors declared no conflicts of interest.

Review Date: 
March 22, 2013