Stressful life events and risk of symptomatic kidney stones.

BACKGROUND It has been reported that a substantial proportion of cases of hypercalciuria and nephrolithiasis are idiopathic. Several studies suggested that stressful life events increase lithogenic urinary constituents (calcium, oxalate and uric acid). OBJECTIVE To test the hypothesis that there is an association between stressful life events and symptomatic kidney stone. METHODS A case-control study of 200 symptomatic kidney stone cases and 200 matched controls was designed to test the hypothesis. In this study, the stressors include those life events that the subjects perceived as highly stressful and inflicted upon them an intense emotional impact with apprehension and distress for at least one week in duration. RESULTS Ten of eleven (91%) categories and 41 of 60 (68%) subcategories of stressful events occurred more frequently among cases than controls. Eighteen stressful events had odds ratios of 1.5 or greater. Of the seven significant (P < 0.05) variables that were entered into a multivariate logistic regression model, the following three remained statistically significant between cases and controls: annual family income (lower for cases); stressful morgage problems; and emotional life events. CONCLUSION The overall prevalence rate of stressful life events was significantly (P < 0.00001) higher among cases than controls. The data support the hypothesis that there is an association between stressful life event(s) and symptomatic kidney stones.