Hyperuricemia associated with increased risk for hypertension

People with hyperuricemia are at an increased risk for high blood pressure, according to research presented at the Nov 2010, American College of Rheumatology Annual Scientific Meeting in Atlanta.

Hyperuricemia is an abnormally high level of uric acid in the blood that can lead to gout - a painful and potentially disabling form of arthritis that has been recognized since ancient times.

It has long been known that people with high levels of uric acid in the blood can also have high blood pressure. However, it is unknown if these two conditions simply tend to occur together or if one condition actually precedes the other. Researchers recently set out to establish whether excessive uric acid increases the risk for future development of hypertension. They reviewed all previously published studies related to this topic and combined the outcomes of those studies into one overall analysis.

To do this, they searched major electronic databases using specific medical terms associated with hyperuricema and high blood pressure and evaluated hypertension studies that measured the impact of serum uric acid levels. They conducted an analysis of 18 studies that included at least 100 participants of all ages who were studied for at least one year and who did not have high blood pressure at the beginning of the study in which they participated.

According to Peter Grayson MD, a rheumatologist at the Boston Medical Center and lead investigator in the study, most of the studies his team reviewed accounted for factors that are traditionally known to increase the likelihood of developing high blood pressure - such as age, family history, weight and tobacco use. By doing this, Dr. Grayson and his team were able to determine if uric acid independently increases the risk for hypertension.

Among the 18 studies analyzed, there was data from 55,607 participants, including 13,025 participants with high blood pressure. The researchers noted that participants with hyperuricemia were more than 40 percent more likely to later develop high blood pressure than participants without hyperuricemia. Women with the highest uric acid levels and people who develop high levels of uric acid at a relatively young age are especially at risk for developing high blood pressure.

Additionally, race may play an important role, and the researchers noted that black people with hyperuricemia may also be at particularly increased risk.

"The results of this study show that people with elevated uric acid levels are at an increased risk for the future development of hypertension, but this does not mean that uric acid directly causes elevated blood pressure. More studies are needed to clarify that question," explains Dr. Grayson. "Medications that lower uric acid levels in the blood may potentially be useful in the prevention or treatment of hypertension. Randomized trial data, with particular attention paid to gender, age, and racial subgroups, would be valuable to address this issue."