Association between dietary iron intake and hyperuricemia in U.S. adults: a cross-sectional study

Elevating blood iron levels may increase the risk of hyperuricemia. However, the association between dietary iron intake and hyperuricemia remains unclear. This study examines the association between dietary iron and hyperuricemia.

The data for this cross-sectional study came from the 2011-2020 National Health and Nutrition Examination Survey (NHANES), which included adults aged 20 and above in the United States. Detailed information on their demographics, dietary iron intake, serum uric acid, and other variables were gathered. This study employs a multifactorial logistic regression method to assess the relationship between dietary iron intake and hyperuricemia. Additionally, it utilizes Restricted Cubic Spline analysis to determine whether there is a non-linear relationship between dietary iron and hyperuricemia. Furthermore, sub-group analyses are conducted to further validate the robustness of this correlation.

This study included 11,441 patients, with a prevalence of hyperuricemia at 14.96%. Regardless of whether confounding factors were adjusted for, there was a positive correlation between dietary iron intake and hyperuricemia. In Model III, after adjusting for age, gender, race, educational background, body mass index, hypertension, carbohydrate intake, dietary fiber intake, total saturated fatty acid intake, vitamin K intake, vitamin C intake, marital status, poverty income ratio, smoking status, drinking status, work activity, diabetes, sodium intake, energy intake, protein intake, zinc intake, copper intake, selenium intake and total sugars intake, we found that compared to the lowest quintile of dietary iron intake (Q1, ≤ 8.03 mg/day), the odds ratios (ORs) for hyperuricemia in the second (Q2, 8.04-11.07 mg/day), third (Q3, 11.08-14.27 mg/day), fourth (Q4, 14.28-19.33 mg/day), and fifth quintiles (Q5, ≥ 19.34 mg/day) were 1.05 (95% confidence interval: 0.79-1.40), 1.30 (95% confidence interval: 0.99-1.73), 1.39 (95% confidence interval: 1.02-1.89), and 1.36 (95% confidence interval: 0.95-1.97), respectively. The study results indicate that a higher dietary iron intake is significantly positively associated with the likelihood of hyperuricemia.

In the adult population of the United States, there is a positive correlation between dietary iron intake and hyperuricemia, with higher dietary iron intake associated with an increased likelihood of hyperuricemia.