4438 Twenty-four-hour Urinary Sodium Excretion Estimated from a Spot Urine Sample May Be Used as an Indicator of Intake in CKD Patients

OBJECTIVES/GOALS: Sodium (Na) intake can elevate blood pressure and is a factor in developing chronic kidney disease (CKD). Twenty-four-hour urinary Na (24hUNa) is the gold standard for assessing Na intake but is burdensome. Validated equations estimate 24hUNa (e24hUNa) from a spot urine sample, but these estimations are not validated against a known Na intake in CKD. METHODS/STUDY POPULATION: The current study is a secondary analysis of a 9-day controlled feeding study in moderate CKD patients matched to healthy adults. Only CKD patients were used for the current analyses (n = 8). Participants consumed a controlled diet for 9 days, providing ~2400 mg Na/d as determined by inductively coupled plasma optical emission spectroscopy (ICP). On days 7 and 8, participants collected all urine in an inpatient setting, beginning with a fasting sample on day 7. Urine sample mineral analyses were performed by ICP and urinary creatinine by the Jaffe reaction. The day 7 fasting urine sample was used to calculate e24hUNa using 6 published equations. Log-transformed Na intake, measured 24hUNa, and e24hUNa were compared by repeated-measures ANOVA with planned contrasts using SAS. RESULTS/ANTICIPATED RESULTS: Fifty percent of the CKD patients (n = 4) were female; 63% (n = 5) were white, and 37% (n = 3) were black. On average, participants were aged 56.6 ± 13.8 y with a BMI of 31.7 ± 9.4 kg/m2 and eGFR of 40.7 ± 7.9 mL/min. Based on actual food intake, average Na intake on day 7 was 2024 ± 388 mg. Average measured 24hUNa was 2529 ± 1334 mg. The main ANOVA was significant (p = 0.02). Results from the planned contrasts found that e24hUNa from the SALTED cohort, an equation developed specifically for CKD patients, was significantly higher than both Na intake (p<0.001) and measured 24hUNa (p = 0.007). For the remaining 5 equations, e24hUNa was not significantly different from measured 24hUNa nor dietary Na intake. DISCUSSION/SIGNIFICANCE OF IMPACT : Our results suggest that e24hUNa calculated using most published equations may provide a reliable and low-burden method of assessing dietary Na intake in moderate CKD patients. These findings should be confirmed in larger samples. Additional studies are needed to validate or dispute the use of the SALTED equation for estimating Na intake.

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The Utility of Spot vs 24-Hour Urine Samples for Metal Determination in Veterans With Retained Fragments

American Journal of Clinical Pathology ◽

10.1093/ajcp/aqaa144 ◽

2020 ◽

Author(s):

Joanna M Gaitens ◽

Clayton H Brown ◽

Frederick G Strathmann ◽

Hanna Xu ◽

Michael R Lewin-Smith ◽

...

Keyword(s):

Urine Sample ◽

Inductively Coupled Plasma ◽

Urine Samples ◽

Metal Exposure ◽

Good Reliability ◽

Spot Urine ◽

Inductively Coupled ◽

Spot Urine Sample ◽

Plasma Mass Spectrometry ◽

Good Agreement

Abstract Objectives The objective of this investigation is to explore the utility of using a spot urine sample in lieu of a 24-hour collection in assessing fragment-related metal exposure in war-injured veterans. Methods Twenty-four veterans collected each urine void over a 24-hour period in separate containers. Concentrations of 13 metals were measured in each void and in a pooled 24-hour sample using inductively coupled plasma mass spectrometry. To assess the reliability of spot sample measures over time, intraclass correlations (ICCs) were calculated across all spot samples. Lin’s concordance correlation coefficient was used to assess agreement between a randomly selected spot urine sample and each corresponding 24-hour sample. Results In total, 149 spot urine samples were collected. Ten of the 13 metals measured had ICCs more than 0.4, suggesting “fair to good” reliability. Concordance coefficients were more than 0.4 for all metals, suggesting “moderate” agreement between spot and 24-hour concentrations, and more than 0.6 for seven of the 13 metals, suggesting “good” agreement. Conclusions Our fair to good reliability findings, for most metals investigated, and moderate to good agreement findings for all metals, across the range of concentrations observed here, suggest the utility of spot urine samples to obtain valid estimates of exposure in the longitudinal surveillance of metal-exposed populations.

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Evaluation of the release of nickel and titanium under orthodontic treatment

Scientific Reports ◽

10.1038/s41598-020-79221-1 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Rafael Velasco-Ibáñez ◽

Edith Lara-Carrillo ◽

Raúl Alberto Morales-Luckie ◽

Elizabeth Teresita Romero-Guzmán ◽

Víctor Hugo Toral-Rizo ◽

...

Keyword(s):

Metal Ions ◽

Repeated Measures ◽

Inductively Coupled Plasma ◽

Orthodontic Treatment ◽

Optical Emission ◽

Inductively Coupled ◽

Anova Model ◽

Significant Difference ◽

Salivary Ph ◽

Fixed Appliances

AbstractThe metal alloys used in dentistry are made mainly of nickel (Ni), titanium (Ti), and other elements such as molybdenum (Mo), zirconium (Zr), iron (Fe), tin (Sn), chrome (Cr), carbon (C), copper (Cu) and niobium (Nb) which can release metal ions in unstable environments. The aim of this work was determine the salivary pH before and during orthodontic treatment; evaluate the release of metal ions, mainly Ni and Ti, in urine and saliva using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES); and evaluate the corrosion using Scanning Electronic Microscopy (SEM). In this study, we selected 35 individuals under orthodontic treatment, from whom saliva and urine samples were collected in 3 stages: (a) basal, (b) at 3 and (c) 6 months after the placement of the fixed appliances. SEM analyzed the Ni–Ti (0.016″) and stainless steel (SS) (0.016 × 0.022″) archs after 1 month of being in contact with the oral cavity. Statistical analysis was performed with Stata using the ANOVA model of repeated measures with a p < 0.05. A statistically significant difference in the concentration of Ni in saliva were found between 3 and 6 months of intervention and Ti in urine was found 3 and 6 months.

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Using Spot Urine Samples to Estimate Sodium and Potassium intake in Healthy vs CKD Patients: Results from a Controlled Feeding Study

Current Developments in Nutrition ◽

10.1093/cdn/nzaa067_049 ◽

2020 ◽

Vol 4 (Supplement_2) ◽

pp. 1822-1822

Author(s):

Andrea Lobene ◽

Elizabeth Stremke ◽

George McCabe ◽

Sharon Moe ◽

Ranjani Moorthi ◽

...

Keyword(s):

Urine Sample ◽

Mixed Model ◽

Cardiovascular Health ◽

Linear Mixed Model ◽

Secondary Analysis ◽

Urine Samples ◽

Inpatient Setting ◽

Spot Urine ◽

Feeding Study ◽

Funding Sources

Abstract Objectives Evaluating sodium (Na) and potassium (K) intake is important as both have implications for blood pressure and cardiovascular health, especially in individuals with chronic kidney disease (CKD). Spot urine samples may be used to estimate Na and K intake with several published equations, but the accuracy has not been thoroughly explored. Our objective was to compare estimated 24-hour urinary Na and K excretion (e24hUNa and e24hUK), calculated from a spot urine sample using published equations, to measured 24hUNa and 24hUK and Na and K intake, and to determine if there are differences between healthy and CKD participants. Methods This is a secondary analysis of a controlled feeding study in participants with moderate CKD matched to healthy adults (n = 16). Participants consumed a controlled diet for 9 days, providing ∼2400 mg Na/d and ∼3000 mg K/d. On days 7 and 8, participants collected all urine in an inpatient setting. Urine Na and K were analyzed by ICP and urine creatinine by the Jaffe reaction. The day 7 fasting urine sample was used to calculate e24hUNa using 2 equations and e24huK using 1 equation. Log-transformed Na intake, measured 24hUNa, and e24hUNa were compared using a general linear mixed model and partial correlations, and agreement between Na intake and e24hUNa was assessed using Bland-Altman plots. Similar analyses were run for K. Results Participants were aged 54.6 ± 13.0 y, n = 8 were female, n = 6 were black, and n = 10 were white. In CKD participants, eGFR was 40.7 ± 7.9 mL/min. Average Na intake on day 7 was 2138 ± 302 mg and K intake was 2528 ± 254 mg. Na intake, measured 24hUNa, and e24hUNa were not significantly different (P = 0.17) or correlated with each other (all P > 0.20) and there was no significant interaction with CKD status (P = 0.51). However, both e24hUNa were ∼500 mg higher than Na intake. For K, e24hUK was significantly different from K intake (P < 0.001) and measured 24hUK (P = 0.02), with no interaction with CKD (P = 0.53). K intake, measured 24hUK, and e24hUK were not correlated (all P > 0.05). Bland-Altman plots show poor agreement between both e24hUNa and Na intake and e24hUK and K intake. Conclusions Estimated 24hUNa and estimated 24hUK are poor predictors of Na and K intake, respectively, in both healthy and CKD participants. Results should be confirmed in a larger sample. Funding Sources Indiana CTSI (funded by NCATS CTSA program), NIDDK.

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