151. Can a Simplified 12-Hour Nighttime Urine Collection Predict Urinary Stone Risk?
- Author
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Ignacio Granja, Manoj Monga, Bryan Hinck, Sri Sivalingam, Vishnuvardhan Ganesan, Juan Calle, John R. Asplin, and Sarah Tarplin
- Subjects
Calcium Phosphates ,Male ,medicine.medical_specialty ,Urology ,Urinary stone ,030232 urology & nephrology ,Urinalysis ,Nephrolithiasis ,First morning void ,Urine collection device ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Predictive Value of Tests ,Internal medicine ,medicine ,Humans ,Prospective Studies ,Ohio ,Urine Specimen Collection ,Calcium Oxalate ,business.industry ,Incidence ,Middle Aged ,Uric Acid ,Surgery ,Patient burden ,chemistry ,030220 oncology & carcinogenesis ,Uric acid ,Female ,business ,Follow-Up Studies ,Urine collection - Abstract
Objective To determine if there is correlation between nighttime 12-hour and traditional 24-hour urine collection in regard to chemistry values and the supersaturations of calcium oxalate, calcium phosphate, and uric acid for the metabolic evaluation of nephrolithiasis. Materials and Methods Ninety-five patients were prospectively enrolled from 2013 to 2015. Patients >18 years of age who presented to a tertiary stone clinic and who would normally be counseled for 24-hour urine collection were eligible for the study. Participants completed 24-hour urine collections twice, with each divided into 2 separate 12-hour collections. Day-time collection began after the first morning void and continued for 12 hours. The night collection proceeded for the next 12 hours through the first morning void. Results Forty-nine 24-hour samples from 35 patients met inclusion criteria and were included in the analysis. Overall, there was strong correlation between the night 12-hour and the 24-hour urine collections with R2 ranging from 0.76 for pH to 0.96 for Citrate. In our analysis of variability, the nighttime 12-hour collection differed from the 24-hour collection by 30% in 1-9 patients (2.0%-18.4%) based on individual chemistry value. Diagnosis of underlying metabolic abnormalities was concordant in 92% of patients. Conclusion A 12-hour nighttime collection has strong correlation with 24-hour urine collection. As such, simplifying the metabolic evaluation to a 12-hour overnight collection may be feasible—improving compliance and decreasing patient burden.
- Published
- 2017