Gout —a common, painful form of arthritis that causes swollen, red, hot, and stiff joints — may be more common in people with ankylosing spondylitis (AS) than in the general population, a study suggests.
Among people with AS, this association is particularly likely in patients ages 40-60, men, and those who are not overweight.
The study, titled “The coexistence of gout in ankylosing spondylitis patients: a case control study,” was published in the journal Rheumatology International. It was led by scientists at Tel Aviv University in Israel.
AS and gout are two forms of inflammatory arthritis that affect the joints, causing pain and physical disability. Few studies have explored their coexistence, and the ones that did reported that any association is uncommon.
Yet, prior research suggests that chronic cases of gout, or the use of nonsteroidal anti-inflammatory drugs (NSAIDs) by AS patients with the concurrent condition, “may mask the acute inflammation and accompanying pain of gout.”
“Due to this difficulty, the true prevalence of co-coexisting gout and AS may be underestimated,” the researchers in that study said.
To address this gap, the researchers conducted a population-based study using data from adults with AS that had been stored in the Clalit Health Services medical database, the largest in Israel.
For each AS patient included in the study, researchers added five age- and sex-matched individuals without the disease and whose clinical data was retrieved from the same database. In total, the study involved 3,763 people with AS and 19,214 controls.
Several parameters were compared between the two groups, including the presence of gout, high blood pressure and body mass index (BMI). The researchers also assessed socioeconomic status and whether the participants smoked.
Results revealed that gout was more prevalent among people with AS (73 patients, 1.94%) than in the general population (107 individuals, 0.56%).
In addition, the researchers found that gout was 3.7 times more common among men with AS and had more than a five-fold prevalence in patients ages 40-60, Gout also was shown to be 2.64 times more likely in people with AS with a BMI lower than 25 kg/m2 (underweight or normal weight).
After eliminating possible confounding factors, the team found that AS was independently associated with gout, suggesting that both conditions may be found in the same individual more frequently than previously thought.
“In conclusion, our study suggests that gout is not less common in AS patients than in the general population, and that it might even be more common in AS patients. We hope that this new information would assist physicians in the future when diagnosing new arthritic events in AS patients,” the researchers said.