A recent study published in Medicine (Baltimore) has identified blood urea nitrogen (BUN) as both an observational and causal risk factor for gout. The findings, based on data from over 31,000 adults in the United States, suggest that this common kidney function marker could serve as a valuable predictor for the painful joint disease.
Researchers analyzed information from 31,245 participants aged 20 years and older across the 2007–2018 National Health and Nutrition Examination Survey (NHANES) cycles, supplementing their work with Mendelian randomization to test causality. In the cross-sectional analysis, each standard deviation increase in BUN was linked to higher gout risk, with an odds ratio of 1.02 (95% CI = 1.01–1.03, P < 0.001) even after adjusting for multiple covariates. The association was particularly pronounced in women and in individuals with hypertension, diabetes, or chronic kidney disease. A restricted cubic spline analysis further revealed a positive non-linear relationship between BUN levels and gout occurrence.
Genetic analyses strengthened these findings. Using a two-sample Mendelian randomization approach, researchers confirmed significant causal relationships between elevated BUN and gout, with odds ratios ranging from 1.43 to 9.12 depending on the statistical model applied.
BUN, a byproduct of protein metabolism formed in the liver and excreted through the kidneys, can fluctuate due to diet, corticosteroid use, gastrointestinal bleeding, or hydration status. While traditionally used to assess kidney function, BUN has also been linked to liver disease, sepsis, cardiovascular disease, chronic obstructive pulmonary disease, Parkinson’s disease, and even mortality risk, highlighting its broader clinical significance.
Adding to this body of evidence, a 2023 study by Zhang et al. reported higher levels of serum creatinine, BUN, and uric acid in patients with adult nephrotic syndrome compared to healthy controls, with the greatest increases seen between ages 45 and 55 years. The study also found a moderate correlation between BUN and uric acid (r = 0.373) in the 41–45 age group, reinforcing the link between nitrogen metabolism and uric acid-related disorders.
These findings suggest that BUN could emerge as a practical biomarker for identifying individuals at greater risk of gout. Such an approach may allow clinicians to implement targeted interventions and preventive strategies, potentially reducing the disease burden in high-risk populations.
Reference
Hong KD, Peng JH, He QD, Zhou JL, Wang SQ, Liu N, Gui TJ, Zhe XW. Association of blood urea nitrogen with gout: Observational and Mendelian randomization analyses. Medicine (Baltimore). 2025 Aug 8;104(32):e43730.