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2242 IMPACT OF AGE ON 24 HOUR URINE RESULTS IN CALCIUM STONE FORMERS
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THE JOURNAL OF UROLOGY姞
Vol. 187, No. 4S, Supplement, Wednesday, May 23, 2012
Stone Disease: Evaluation & Medical Management II Moderated Poster Wednesday, May 23, 2012
10:30 AM-12:30 PM
2241 IS ONE 24-HOUR URINE COLLECTION SUFFICIENT FOR METABOLIC STONE WORK-UP? VARIATIONS AMONG TWO 24-HOUR URINE COLLECTIONS Madhur Nayan, Mohamed Elkoushy*, Sero Andonian, Montreal, Canada INTRODUCTION AND OBJECTIVES: There is considerable debate whether one or two 24-hour urine collections are required for complete metabolic work-up of patients with recurrent urolithiasis. Therefore, the aim of the present study was to compare two consecutive 24-hour urine collections in patients with a history of urolithiasis presenting to a tertiary stone clinic. METHODS: A retrospective review of 188 patients who had two 24-hour collections upon presentation between January 2009 and December 2010. Samples were collected on consecutive days and examined for the following 11 urinary parameters: volume, creatinine, sodium, calcium, uric acid, citrate, oxalate, potassium, phosphorous, magnesium, and urea nitrogen. For each parameter, the absolute value of the difference between the two samples rather than the direct difference was compared with zero. This avoids positive and negative differences of individual patients from negating each other when determining the mean. Similarly, percent difference between samples was calculated for each parameter. RESULTS: The means of the absolute difference between the two samples were significantly different from the value 0 for all 11 urinary parameters (p⬍0.0001). The percent difference for all urinary parameters ranged from 20.5% to 34.2%. Furthermore, 17.1% to 47.6% of patients had a change from a value within normal limits to an abnormal value, or vice-versa. Significance was maintained when patients with incomplete or over-collections were excluded. CONCLUSIONS: Significant variations among the two 24-hour urine collections were observed in all of the 11 urinary parameters analyzed. This variation may change clinical decision making in up to 47.6% of patients if only a single 24-hour urine collection is obtained. The present study supports the Canadian Urological Association’s guidelines of performing two 24-hour urine collections.
2242 IMPACT OF AGE ON 24 HOUR URINE RESULTS IN CALCIUM STONE FORMERS Joseph Pugh*, Shahab Bozorgmehri, Benjamin Canales, Muna Canales, Ramona Ilie, Joseph Villavicencio, Vincent Bird, Gainesville, FL INTRODUCTION AND OBJECTIVES: Hypertension (HTN), diabetes mellitus (DM), and obesity/high body mass index (BMI) may be independently associated with urinary lithiasis, and may increase with age. The association between patient age and 24 hour (hr) urine metabolic risk factors is not known. We investigate impact of age on 24 hr urine parameters in calcium stone formers. METHODS: We prospectively enrolled patients with two or more lifetime kidney stones in an IRB approved database. Struvite and pure uric acid stone formers were excluded. Only patients with adequate 24 hr urine collection by creatinine/kg criteria were included. We studied demographics, urine pH, urine volume, calculated supersaturations, and 24-hour excretion of urinary constituents stratified by decade of life (18-29, 30-39, 40-49, 50-59, 60-69, 70⫹). Well recognized cutoff values for calcium, oxalate, citrate, uric acid, and sodium were used in accordance with reference laboratory standards. Linear regression or chi-square tests were performed to compare means for continuous and categorical variables, respectively, by category of age. RESULTS: From our database, 193 met criteria for inclusion. Mean age (SD) was 50 (15). Age group (%) distribution was: 1829(12.4), 30-39(11.4), 40-49(19.1), 50-59(29.5), 60-69(18.6), 70⫹ (8.81). Prevalence of HTN and mean BMI increased with increasing age to 69 years (yr), then decreased in the 70⫹ group (p⬍0.001 and p⫽0.004, respectively); prevalence of DM peaked at 28% in age ranges 50-69 (p⫽0.004); and prevalence of CAD increased with age (p⫽0.003). Mean urine volume in liters (SD) by increasing age category was 1.6 (1.0), 1.6 (0.9), 1.8 (1.0), 2.0 (0.9), 2.0 (0.9), 1.7 (0.8). Likelihood of hypercalciuria peaked at 40-60y (p⫽0.03) while the likelihood of high urine sodium was similar across all age groups (p⫽0.16). Patients aged 18-40 yr were most likely to have hypocitraturia (p⫽0.03). Odds of hyperoxaluria increased with older age (p⫽0.005). Hyperuricosuria was most likely among those age 40-70 yr, but no statistically significant difference was noted (p⫽0.13). Younger patients were more likely to be supersaturated for brushite and those age 50-59 were more likely to be supersaturated for calcium oxalate and uric acid but no statistically significant differences were noted (p⬎0.1 for all). CONCLUSIONS: In our cohort, we found that stone former age has a significant impact on urinary calcium, oxalate and citrate. Further study in larger patient populations is required to corroborate these findings. These findings may be useful in further evaluation of those at risk for recurrent calcium stone formation. Source of Funding: None
2243 EFFECT OF AGE ON THE CLINICAL PRESENTATION OF INCIDENT SYMPTOMATIC UROLITHIASIS IN THE GENERAL POPULATION Amy Krambeck*, John Lieske, Xujian Li, Eric Bergstralh, L Melton, Andrew Rule, Rochester, MN
Source of Funding: This work was supported in part by the Northeastern AUA Young Investigator Award and Montreal General Hospital Foundation Award to Sero Andonian.
INTRODUCTION AND OBJECTIVES: The goal of our study was to assess the effect of age on the presentation and outcome of incident kidney stone disease in the general population. METHODS: A random subset (3473) of all Olmsted County, MN residents with a first-time ICD-9 code for nephrolithiasis between the years 1984-2004 were selected for further study. Their medical records were reviewed to validate incident kidney stone formers, and to obtain presenting symptoms, laboratory results, comorbidities, interventions, and outcomes. RESULTS: There were 1633 validated incident symptomatic stone formers, with mean age 43 (range: 0.7-96) years. Surgical intervention was required in 524 (32.1%). Those requiring surgery were
THE JOURNAL OF UROLOGY姞
Vol. 187, No. 4S, Supplement, Wednesday, May 23, 2012
Stone Disease: Evaluation & Medical Management II Moderated Poster Wednesday, May 23, 2012
10:30 AM-12:30 PM
2241 IS ONE 24-HOUR URINE COLLECTION SUFFICIENT FOR METABOLIC STONE WORK-UP? VARIATIONS AMONG TWO 24-HOUR URINE COLLECTIONS Madhur Nayan, Mohamed Elkoushy*, Sero Andonian, Montreal, Canada INTRODUCTION AND OBJECTIVES: There is considerable debate whether one or two 24-hour urine collections are required for complete metabolic work-up of patients with recurrent urolithiasis. Therefore, the aim of the present study was to compare two consecutive 24-hour urine collections in patients with a history of urolithiasis presenting to a tertiary stone clinic. METHODS: A retrospective review of 188 patients who had two 24-hour collections upon presentation between January 2009 and December 2010. Samples were collected on consecutive days and examined for the following 11 urinary parameters: volume, creatinine, sodium, calcium, uric acid, citrate, oxalate, potassium, phosphorous, magnesium, and urea nitrogen. For each parameter, the absolute value of the difference between the two samples rather than the direct difference was compared with zero. This avoids positive and negative differences of individual patients from negating each other when determining the mean. Similarly, percent difference between samples was calculated for each parameter. RESULTS: The means of the absolute difference between the two samples were significantly different from the value 0 for all 11 urinary parameters (p⬍0.0001). The percent difference for all urinary parameters ranged from 20.5% to 34.2%. Furthermore, 17.1% to 47.6% of patients had a change from a value within normal limits to an abnormal value, or vice-versa. Significance was maintained when patients with incomplete or over-collections were excluded. CONCLUSIONS: Significant variations among the two 24-hour urine collections were observed in all of the 11 urinary parameters analyzed. This variation may change clinical decision making in up to 47.6% of patients if only a single 24-hour urine collection is obtained. The present study supports the Canadian Urological Association’s guidelines of performing two 24-hour urine collections.
2242 IMPACT OF AGE ON 24 HOUR URINE RESULTS IN CALCIUM STONE FORMERS Joseph Pugh*, Shahab Bozorgmehri, Benjamin Canales, Muna Canales, Ramona Ilie, Joseph Villavicencio, Vincent Bird, Gainesville, FL INTRODUCTION AND OBJECTIVES: Hypertension (HTN), diabetes mellitus (DM), and obesity/high body mass index (BMI) may be independently associated with urinary lithiasis, and may increase with age. The association between patient age and 24 hour (hr) urine metabolic risk factors is not known. We investigate impact of age on 24 hr urine parameters in calcium stone formers. METHODS: We prospectively enrolled patients with two or more lifetime kidney stones in an IRB approved database. Struvite and pure uric acid stone formers were excluded. Only patients with adequate 24 hr urine collection by creatinine/kg criteria were included. We studied demographics, urine pH, urine volume, calculated supersaturations, and 24-hour excretion of urinary constituents stratified by decade of life (18-29, 30-39, 40-49, 50-59, 60-69, 70⫹). Well recognized cutoff values for calcium, oxalate, citrate, uric acid, and sodium were used in accordance with reference laboratory standards. Linear regression or chi-square tests were performed to compare means for continuous and categorical variables, respectively, by category of age. RESULTS: From our database, 193 met criteria for inclusion. Mean age (SD) was 50 (15). Age group (%) distribution was: 1829(12.4), 30-39(11.4), 40-49(19.1), 50-59(29.5), 60-69(18.6), 70⫹ (8.81). Prevalence of HTN and mean BMI increased with increasing age to 69 years (yr), then decreased in the 70⫹ group (p⬍0.001 and p⫽0.004, respectively); prevalence of DM peaked at 28% in age ranges 50-69 (p⫽0.004); and prevalence of CAD increased with age (p⫽0.003). Mean urine volume in liters (SD) by increasing age category was 1.6 (1.0), 1.6 (0.9), 1.8 (1.0), 2.0 (0.9), 2.0 (0.9), 1.7 (0.8). Likelihood of hypercalciuria peaked at 40-60y (p⫽0.03) while the likelihood of high urine sodium was similar across all age groups (p⫽0.16). Patients aged 18-40 yr were most likely to have hypocitraturia (p⫽0.03). Odds of hyperoxaluria increased with older age (p⫽0.005). Hyperuricosuria was most likely among those age 40-70 yr, but no statistically significant difference was noted (p⫽0.13). Younger patients were more likely to be supersaturated for brushite and those age 50-59 were more likely to be supersaturated for calcium oxalate and uric acid but no statistically significant differences were noted (p⬎0.1 for all). CONCLUSIONS: In our cohort, we found that stone former age has a significant impact on urinary calcium, oxalate and citrate. Further study in larger patient populations is required to corroborate these findings. These findings may be useful in further evaluation of those at risk for recurrent calcium stone formation. Source of Funding: None
2243 EFFECT OF AGE ON THE CLINICAL PRESENTATION OF INCIDENT SYMPTOMATIC UROLITHIASIS IN THE GENERAL POPULATION Amy Krambeck*, John Lieske, Xujian Li, Eric Bergstralh, L Melton, Andrew Rule, Rochester, MN
Source of Funding: This work was supported in part by the Northeastern AUA Young Investigator Award and Montreal General Hospital Foundation Award to Sero Andonian.
INTRODUCTION AND OBJECTIVES: The goal of our study was to assess the effect of age on the presentation and outcome of incident kidney stone disease in the general population. METHODS: A random subset (3473) of all Olmsted County, MN residents with a first-time ICD-9 code for nephrolithiasis between the years 1984-2004 were selected for further study. Their medical records were reviewed to validate incident kidney stone formers, and to obtain presenting symptoms, laboratory results, comorbidities, interventions, and outcomes. RESULTS: There were 1633 validated incident symptomatic stone formers, with mean age 43 (range: 0.7-96) years. Surgical intervention was required in 524 (32.1%). Those requiring surgery were