Elevated Uric Acid Blood Levels May Lead to High Blood Pressure With Sjögren’s
Higher-than-normal blood levels of uric acid, a body waste product, significantly raise the risk of hypertension among people with primary Sjögren’s syndrome (pSS), a study found.
Findings suggest that monitoring uric acid levels may be one way to manage hypertension, or high blood pressure, to avoid cardiovascular problems arising later in these patients, the researchers noted.
Previous studies have shown that people with primary Sjögren’s are at a higher risk of cardiovascular diseases compared with the general population, and high blood pressure is a known major risk factor for cardiovascular disease.
“Therefore, the management of hypertension is an important issue for the prevention of [cardiovascular] events in pSS,” the researchers wrote.
Levels linked in Sjögren group to high blood pressure
In the general population, elevated blood levels of uric acid have been associated with hypertension.
Uric acid is a normal waste product formed when the body breaks down purines — compounds found in cells, and in foods that include liver, shellfish, sardines, and alcohol. While uric acid is thought to have antioxidant activity, excessive levels are also thought to raise blood pressure by mediating inflammatory responses in blood vessels.
Researchers in China assessed whether blood uric acid levels might associate with hypertension in primary Sjögren’s patients.
They analyzed data covering 351 pSS patients with no history of hypertension treated at the Affiliated Hospital of Southwest Jiaotong University from May 2011 to May 2020.
Patients, 322 women and 29 men, had a mean age of 60.34. Their blood pressure was monitored every six months.
After a mean 3.91 years of follow-up, nearly half of these patients — 166 people; 47.3% of group — had developed hypertension, defined as reported higher-than-normal blood pressure or the use of hypertension medications.
Several clinical characteristics at study’s start significantly differed between those who developed hypertension and those who did not.
Hypertensive patients were older, with a mean age of 68.01 compared with 53.47 among those who maintained a normal blood pressure. Those with hypertension also had higher blood pressure at study’s start, as well as higher levels of uric acid, some immune cells, inflammatory markers, and blood sugar.
Uric acid blood levels were found to significantly and independently associate with hypertension among these Sjögren’s patients. This relationship remained constant after adjusting for potential influencing factors, including other cardiovascular risk factors, inflammatory markers, and medication use.
Patients with higher-than-normal uric acid levels were at a significantly higher risk of hypertension than those with normal levels, further analyses found.
A unique dose-response relationship between blood uric acid levels and hypertension was also seen, in which higher levels were significantly associated with an increasing risk of hypertension.
Notably, this association resembled the shape of the letter J, meaning that the lowest uric levels were linked to a higher risk than slightly higher levels, likely representing normality, in which uric acid’s antioxidant effects may protect from hypertension, the team noted.
With increasing levels, however, uric acid’s antioxidant effects may be surpassed by its negative effects on blood vessels, the researchers suggested.
Study results overall “suggested that higher SUA [serum uric acid] levels were associated with incident hypertension in pSS, as they do in the general population, and the relationship remained constant after adjusting for related confounding [factors],” the researchers concluded.
Given the evident “relationship between SUA and hypertension” among Sjögren’s patients, uric acid blood levels should be considered when managing cardiovascular risk factors in these patients, they added.