High uric acid levels are associated with a significantly increased risk of atrial fibrillation (AFib), according to new findings published in the Journal of the American Heart Association.[1]
“Uric acid is the final product of purine metabolism, catalyzed by xanthine oxidase,” wrote first author Mozhu Ding, PhD, a researcher with the Karolinska Institute in Sweden, and colleagues. “Its role in cardiovascular disease and cardiometabolic disorders is gaining increasing importance, and elevated uric acid is associated with a higher risk of hypertension, diabetes and coronary heart disease (CHD) in large studies.”
To explore the potential relationship between elevated uric acid and AFib, Ding et al. examined data from nearly 340,000 patients who were free of cardiovascular condition. Each participant’s uric acid was measured at baseline and then repeatedly for five years; they were then tracked for a mean follow-up period of 25.9 years.
The team identified more than 46,000 AFib cases over the course of the study. Nearly 70% of those patients also developed hypertension, diabetes, heart failure or CHD.
Patients were separated into four different quartiles based on their uric acid levels, but those groups were different for male and female patients. The first quartile served as the study’s reference group (≤282 μmol/L for men and ≤205 μmol/L for women). The second quartile corresponded to levels of 283 to 319 μmol/L for men and 206 to 236 μmol/L for women. The third quartile corresponded to levels of 320 to 361 μmol/L for men and 237 to 273 μmol/L for women, and the final quartile corresponded to levels of ≥362 μmol/L for men and ≥274 μmol/L for women.
Overall, uric acid levels in the second, third and fourth quartiles were all associated with a heightened AFib risk. This risk was present in both patients who went on to develop other cardiovascular conditions and those who did not, suggesting that these high uric levels may directly contribute to the onset of AFib as opposed to simply being “a reflection of cardiometabolic burden.”
The team also found that BMI was strongly associated with a higher AFib risk. Curious about this detail, they performed an additional analysis adjusted for BMI, and the link between uric acid levels and AFib was still present.
“High uric acid not only operates through cardiovascular disease and cardiovascular risk factors to increase the risk of AFib, it may also have a direct influence on the development of AFib via other mechanisms,” the authors wrote. “Future studies are needed to further elucidate the mechanism by which uric acid may increase the risk of AFib and in controlled randomized studies examine whether lowering uric acid levels may prevent the development of AFib in a general population setting.”
Michael has more than 16 years of experience as a professional writer and editor. He has written at length about cardiology, radiology, artificial intelligence and other key healthcare topics.