Association between rheumatoid arthritis and hyperuricemia among adults: a cross-sectional study based on NHANES data

This study aimed to explore the relationship between rheumatoid arthritis (RA) and hyperuricemia among adults. All the data were from the National Health and Nutrition Examination Survey (NHANES 1997-2018) database. Linear regression, logistic regression, and restricted cubic spline (RCS) analyses were used to investigate the association between RA and hyperuricemia. Subgroup analysis and interaction tests were conducted to assess the influence of various subgroups on their association. This study included 41,460 patients, among whom 2603 had RA. The RA group had higher uric acid levels compared with the non-RA group (P < 0.001). Linear regression showed that RA was significantly related to uric acid levels among several adjusted models (all P < 0.05). Logistic regression analysis also indicated the independent association between RA and hyperuricemia in a positive relationship (P < 0.05). Subgroup analysis revealed significant association in the subgroups of females, age ≥ 60 years, non-Hispanics, individuals with hypertension and antihypertensive drugs use, and those with BMI ≥ 30 kg/m2 (all P < 0.05). The interaction test showed that there was no interaction effect between baseline features and RA (all interaction P > 0.05). RCS analysis further found that the course of RA, rather than the age of diagnosis, was related to hyperuricemia (P < 0.05). Furthermore, we found that the association between RA and hyperuricemia was mainly observed in populations with 15-30-year course of RA (P < 0.05). RA was associated with hyperuricemia and their association was still stable even after adjusting for several variables, suggesting that uric acid levels should be routinely tested to detect hyperuricemia at an early stage in patients with RA. Key Points • Revealing association between rheumatoid arthritis (RA) and hyperuricemia risk: This study initially explored the association between RA and hyperuricemia, finding that RA was positively related to the higher uric acid levels and hyperuricemia risk. • Reflecting the role of RA course on their association: Our study found that their association was mainly observed in population with RA course of 15-30 years.