title: Association of estimated glomerular filtration rate with 24-h urinalysis and stone composition.
abstract: The aim of this study is to determine the association of estimated glomerular filtration rate (eGFR) with 24-h urine analysis and stone composition. We performed a retrospective review of 1060 stone formers with 24-h urinalysis, of which 499 had stone composition analysis available. Comparisons of baseline patient characteristics and urinary abnormalities across eGFR groups (<60, 60-89.9, ≥90 mL/min/1.73 m(2)) were performed using Fisher's exact test for categorical data and analysis of variance for continuous variables. Analyses of 24-h urinalysis and stone composition across eGFR groups were performed using linear regression with eGFR groups as a continuous variable to evaluate trends. Of the 1060 patients in the study, 595 (56 %) were males. The mean age was 53.8 years. A total of 38 (4 %), 77 (7 %), and 945 (89 %) patients had eGFR <60, 60-89.9, and ≥90 mL/min/1.73 m(2), respectively. Lower eGFR was associated with older age, lower body-mass index, and female gender (all P < 0.05). Lower eGFR was also associated with lower urinary volume, calcium, citrate, uric acid, sodium, magnesium, phosphorus, sulfate, and creatinine on both univariable and multivariable analyses, adjusted for demographics, comorbidities and medication use (all P < 0.05). The prevalence of hypocitraturia and hypomagnesuria was associated with decreased eGFR, while hypercalciuria, hyperoxaluria, hyperuricosuria and hyperphosphaturia were associated with higher eGFR (all P < 0.05). Stone composition was similar across eGFR groups (all P > 0.05). In conclusion, lower eGFR was associated with lower excretion of urinary elements in a routine 24-h urinalysis, but similar stone composition.
authors.affiliation: Department of Urology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA. moreira.daniel@mayo.edu.
authors.forename: Daniel M
authors.identifier: http://orcid.org/0000-0003-4517-244X
authors.initials: DM
authors.lastname: Moreira
authors.affiliation: Department of Urology, Fox Chase/Einstein Urologic Institute and Einstein Healthcare Network, Philadelphia, PA, USA.
authors.forename: Justin I
authors.initials: JI
authors.lastname: Friedlander
authors.affiliation: The Arthur Smith Institute for Urology, Hofstra North Shore-LIJ School of Medicine, New Hyde Park, NY, USA.
authors.forename: Christopher
authors.initials: C
authors.lastname: Hartman
authors.affiliation: Department of Urology, Mayo Clinic, 200 First Street SW, Rochester, MN, 55905, USA.
authors.forename: Boris
authors.initials: B
authors.lastname: Gershman
authors.affiliation: The Arthur Smith Institute for Urology, Hofstra North Shore-LIJ School of Medicine, New Hyde Park, NY, USA.
authors.forename: Arthur D
authors.initials: AD
authors.lastname: Smith
authors.affiliation: The Arthur Smith Institute for Urology, Hofstra North Shore-LIJ School of Medicine, New Hyde Park, NY, USA.
authors.forename: Zeph
authors.initials: Z
authors.lastname: Okeke
mesh_terms: D000368:Aged; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007669:Kidney Calculi / Q000737:chemistry / Q000503:physiopathology* / Q000652:urine*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013997:Time Factors; D016482:Urinalysis / Q000379:methods
keywords: Calcium oxalate; Glomerular filtration rate; Kidney calculi; Renal insufficiency; Urinalysis