Presentation Authors: Carter Boyd*, Dustin Whitaker, Omotola Ashorobi, William Poore, Robert Oster, John Knight, Ross Holmes, Dean Assimos, Kyle Wood, BIRMINGHAM, AL
Introduction: Age, sex, and race are all known to influence kidney stone risk. Previous literature has demonstrated a clear link between kidney stone disease, obesity, and diabetes. Our objective was to examine in a multivariate analysis the associations between various demographic factors and systemic diseases on stone risk parameters in a stone forming population.
Methods: A retrospective chart review of adult kidney stone patients who completed 24-hour urine collections from April 2004 through August 2015 was performed. Demographic information was captured including age at collection, sex, race, and BMI. Chart review was performed to assess for a diagnosis of diabetes and hypertension. The results of CT Imaging, and renal/abdominal ultrasonography, performed with Â±6 months were reviewed for a diagnosis of fatty liver disease. Statistical analysis included Pearson correlation analysis, Spearman correlation analysis, and linear and logistic regression analyses, both univariate and multivariate.
Results: There were 589 patients included in the study. Numerous urinary parameters were significant in association with demographic factors or systemic diseases in a multivariate analysis. Older age was associated with decreased calcium (Ca) excretion (p=0.0214), decreased supersaturation of calcium oxalate (SSCaOx) (p=0.0262), decreased supersaturation of calcium phosphate (SSCaP) (p < .0001), and decreased urinary pH (p=0.0201). Males excreted more Ca (p=0.0015) and oxalate (Ox) (p=0.0010), had lower urine pH (p=0.0269), and higher supersaturation of uric acid (SSUA) (p < .0001) than women. For race, African Americans had lower urine volume (p=0.0023), less Ca excretion (p=0.0142), less Ox excretion (p=0.0074), and higher SSUA (p=0.0049). Diabetes was associated with more Ox excretion (p < .0001), lower SSCaP (p=0.0068), and lower urinary pH (p=0.0153). There were positive correlations between BMI and Ca excretion (p=0.0386), BMI and Ox excretion (p=0.0177), and BMI and SSUA (p=0.0045).
Conclusions: These results demonstrate that both demographic factors and systemic disease are independently associated with numerous risk factors for kidney stones. These results highlight that there are differential risks for individuals to develop kidney stones based on these associations. The mechanisms responsible for these associations and disparities (racial differences) need to be further elucidated.
Source of Funding: AUA Research Scholar/Medical Student Summer Fellowship; NORC Intramural Grant; K-08