The association between gout and nephrolithiasis: The National Health and Nutrition Examination Survey III, 1988-1994

Background: Gout, an inflammatory arthritis, reportedly afflicts more than 2 million men and women in the United States. Previous reports have suggested an association between gout and kidney stone disease; however, these studies did not adjust for such important potential confounders as obesity and the presence of hypertension. To our knowledge, no published study has examined the independent association between gout and kidney stone disease. Methods: We used a national probability sample of the US population to determine the independent association between reported gout and history of kidney stone disease. Results: Among men and women 20 years and older, 5.6% (10 million) reported the previous passage of a kidney stone and 2.7% (5.1 million) reported a diagnosis of gout by a physician. Moreover, 8.6% of individuals who reported the passage of a kidney stone on two or more occasions had a history of gout. Conversely, the prevalence of previous kidney stones in subjects with reported gout was 13.9%. In the age-adjusted model, gout was associated with an increased odds ratio (OR) for previous kidney stones (OR, 1.97; 95% confidence interval [CI], 1.37 to 2.83). After further adjustment for sex, race, body mass index, and presence of hypertension, the OR for previous kidney stones in individuals with gout decreased to 1.49 (95% CI, 1.04 to 2.14). Conclusion: Showing an independent association between kidney stone disease and gout strongly suggests that they share common underlying pathophysiological mechanisms. Identification of these mechanisms may lead to improved preventive strategies for both conditions. (C) 2002 by the National Kidney Foundation, Inc.