Kidney stones are a growing problem in the United States, new data suggest.
Researchers who analyzed data from 12,110 participants in the 2007-2010 National Health and Nutrition Examination Survey (NHANES) found that 8.8% of respondents reported a history of kidney stones, up from 5.2% reported by 1994 NHANES respondents, according to an online report in European Urology. According to the investigators, “the increase is likely related to dietary and lifestyle factors.”
The prevalence increased for men and women. The 2007-2010 data revealed that 10.6% of men and 7.1% of women reported having kidney stones, up from 6.3% and 4.1%, respectively, in 1994.
Kidney stones were more common among obese individuals than among normal-weight subjects (11.3% vs. 6.1%). Compared with normal-weight individuals, obese respondents had a 55% increased risk of kidney stones.
“Presuming obesity as a marker for the metabolic syndrome, which is linked epidemiologically and physiologically to risk of kidney stones, the epidemic of obesity in the United States is a likely explanation for the dramatic rise in the prevalence of stone disease,” the researchers observed.
The investigators, led by Charles D. Scales Jr., MD, of the University of California-Los Angeles, also found that non-Hispanic blacks and Hispanics were 63% and 40% less likely than whites to report a history of kidney stones.
The last nationally representative assessment of kidney stone prevalence in the United States occurred in 1994. After a 13-yr hiatus, the National Health and Nutrition Examination Survey (NHANES) reinitiated data collection regarding kidney stone history.
The prevalence of kidney stones was 8.8% (95% confidence interval [CI], 8.1–9.5). Among men, the prevalence of stones was 10.6% (95% CI, 9.4–11.9), compared with 7.1% (95% CI, 6.4–7.8) among women. Kidney stones were more common among obese than normal-weight individuals (11.2% [95% CI, 10.0–12.3] compared with 6.1% [95% CI, 4.8–7.4], respectively; p < 0.001). Black, non-Hispanic and Hispanic individuals were less likely to report a history of stone disease than were white, non-Hispanic individuals (black, non-Hispanic: odds ratio [OR]: 0.37 [95% CI, 0.28–0.49], p < 0.001; Hispanic: OR: 0.60 [95% CI, 0.49–0.73], p < 0.001). Obesity and diabetes were strongly associated with a history of kidney stones in multivariable models. The cross-sectional survey design limits causal inference regarding potential risk factors for kidney stones. Kidney stones affect approximately 1 in 11 people in the United States. These data represent a marked increase in stone disease compared with the NHANES III cohort, particularly in black, non-Hispanic and Hispanic individuals. Diet and lifestyle factors likely play an important role in the changing epidemiology of kidney stones. ### Charles D. Scales Jr., Alexandria C. Smith, Janet M. Hanley, Christopher S. Saigal, Urologic Diseases in America Project
Additionally, respondents with a history of gout had a nearly twofold increased likelihood of kidney stones.
“Given the temporary disability imposed by a symptomatic stone event, these findings have important implications for a disease that burdens a primarily working-age population,” the authors concluded. “These findings suggest that the direct and indirect costs of kidney stones will continue to rise in the United States, and efforts should be directed toward ameliorating the burden of urinary stone disease.”
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Jody A. Charnow
