The association of prevalent kidney stone disease with mortality in US adults: the National Health and Nutrition Examination Survey III, 1988-1994

Abstract

Background: Kidney stone disease is associated with hypertension, diabetes, metabolic syndrome, kidney function decline, and increased cardiovascular (CV) events. However, its association with all-cause and CV mortality is unclear.

Methods: We used the Third National Health and Nutrition Examination Survey, a large US population-based study with mortality data through 2006 determined via linkage to the National Death Index to examine kidney stone disease in relation to all-cause and CV mortality risks.

Results: Among 14,879 men and women over 18 years of age who were eligible for analysis, 683 participants reported a history of kidney stones. There was a total of 3,590 all-cause and 1,608 CV deaths during a median follow-up of 14.9 years. Stone formers had a significantly higher risk for all-cause mortality [hazard ratio (HR): 1.95, 95% CI: 1.64-2.33, p < 0.0001) and CV mortality (HR: 2.05, 95% CI: 1.60-2.62, p < 0.0001) in unadjusted analyses. However, after multivariate adjustment for age, gender, race, and poverty, stone formers no longer had increased risk for all-cause mortality (HR: 1.08, 95% CI: 0.93-1.26, p = 0.3) and CV mortality (HR: 1.07, 95% CI: 0.84-1.36, p = 0.6). Results remain unchanged after further adjustment for other clinical variables including history of hypertension, diabetes, and CV disease.

Conclusion: The increased risk of all-cause and CV mortality in kidney stone formers is likely a reflection of unique demographics and associated comorbidities. There is no independent association of prevalent kidney stone disease with all-cause and CV mortality.

Figure 1

Kaplan-Meier estimates for all-cause mortality (unadjusted)

Figure 2

Kaplan-Meier estimates for cardiovascular mortality (unadjusted)