Evaluation of urolithiasis: a link between stone formation and diabetes mellitus?

ABSTRACT

INTRODUCTION: The pathogenesis of calcium oxalate stone formation is not completely understood. Recently, an influence of vascular phenomena like arteriosclerosis on the crystallization process was hypothesized. Thus, stone formation should be more common in patients with diabetes mellitus (DM) who are at risk of developing angiopathy. The aim of the study was to determine the prevalence of urolithiasis (UL) in patients with DM and to identify specific risk factors. MATERIAL AND METHODS: 350 patients with DM were evaluated with respect to DM-related history, and a total of 179 patients was included (83 female, 96 male; age 23-84 years). All patients were interviewed to assess the history of stone formation. These data were compared to epidemiological data in Germany. RESULTS: The overall prevalence of UL in the diabetic group was 7.82% (vs. 4.73% in Germany, p = 0.0485; binominal test). The prevalence was significantly higher in patients with coronary heart disease (25%; p < 0.0001; Fisher's exact test). We could not demonstrate an increased prevalence of UL for patients with occlusive arterial disease or arterial hypertension as diabetic nephropathy was not a risk factor for developing urinary lithiasis (p = 0.7184, p = 1.000, p = 0.6266, respectively; Fisher's exact test). Thiazide medication lowered the prevalence of stone formation (p = 0.0399; Fisher's test). Calcium or magnesium supplementation did not influence stone formation significantly (p = 0.5279; p = 1.000; respectively; Fisher's test). CONCLUSIONS: In Germany, patients with DM are at higher risk of UL compared with patients without diabetes. We demonstrated a significantly higher prevalence of urinary stones in patients with coronary heart disease. These findings are consistent with the hypothesis that urinary stone formation has a vascular pathogenesis in part.