Test Code SULFU Sulfate, 24 Hour, Urine
Reporting Name
Sulfate, 24 Hr, UUseful For
Assessing the nutrition intake of animal protein
The calculation of urinary supersaturation of various crystals or stones
Performing Laboratory
Mayo Clinic Laboratories in RochesterSpecimen Type
UrineNecessary Information
24-Hour volume (in milliliters) is required.
Specimen Required
Supplies: Sarstedt 5 mL Aliquot Tube (T914)
Container/Tube: Plastic, 5-mL urine tube
Specimen Volume: 4 mL
Collection Instructions:
1. Collect urine for 24 hours.
2. Collection instructions with no preservative:
-Specimen must be kept refrigerated during and after collection.
3. Collection instructions with preservative:
 a. If preservative is not added before collection, the specimen must be kept refrigerated until preservative is added.
 b. Preservative must be added within 4 hours of the end of collection.
4. Specimen pH should be between 4.5 and 8 and will stay in this range if kept refrigerated. Specimens with pH >8 indicate bacterial contamination, and testing will be cancelled. Do not attempt to adjust pH as it will adversely affect results.
Additional Information: See Urine Preservatives-Collection and Transportation for 24-Hour Urine Specimens for multiple collections.
Specimen Minimum Volume
1 mL
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Urine | Refrigerated (preferred) | 14 days | |
Frozen | 14 days |
Special Instructions
Reference Values
7-47 mmol/24 hours
Day(s) Performed
Monday through Friday
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
84392
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
SULFU | Sulfate, 24 Hr, U | 26889-6 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
SLF_U | Sulfate, 24 Hr, U | 26889-6 |
TM89 | Collection Duration | 13362-9 |
VL71 | Urine Volume | 3167-4 |
SUL_C | Sulfate Concentration, 24 Hr, U | 12920-5 |
Clinical Information
Urinary sulfate is a reflection of dietary protein intake, particularly meat, fish, and poultry, which are rich in sulfur-containing amino acids methionine and cysteine. Urinary sulfate can be used to assess dietary protein intake for nutritional purposes. A protein-rich diet has been associated with an increased risk for stone formation, possibly due, in part, to an increase in urinary calcium excretion caused by acid production from metabolism of sulfur-containing amino acids.(1,2) Indeed, urinary sulfate excretion is higher in patients who have kidney stones than in individuals who do not form stones. Thus, urinary sulfate excretion may provide an index for protein-induced calciuria.(1)
Sulfate is a major anion in the urine that has significant affinity for cations and modulates the availability of cations for reacting with other anions in the urine. It thus is an important factor of urinary supersaturation(3) for various crystals or stones such as calcium oxalate, hydroxyapatite, and brushite. For example, a high sulfate concentration may modulate the availability of calcium for reacting with oxalate and thus affect the propensity for calcium oxalate stone or crystal formation. Urinary sulfate also has a major impact on buffering or providing hydrogen ions and as such modulates the supersaturation of uric acid.
Interpretation
Urinary sulfate is a reflection of dietary protein intake, particularly of meat, and thus can be used as an index of nutritional protein intake.
It also is used in the calculation of urinary supersaturation of various crystals or stones.
Cautions
No significant cautionary statements
Clinical Reference
1. Rodgers A, Gauvin D, Edeh S, et al. Sulfate but not thiosulfate reduces calculated and measured urinary ionized calcium and supersaturation: implications for the treatment of calcium renal stones. PLoS ONE. 2014;9(7):e103602. doi:10.1371/journal.pone.0103602
2. Magee EA, Curno R, Edmond LM, Cummings JH. Contribution of dietary protein and inorganic sulfur to urinary sulfate: toward a biomarker of inorganic sulfur intake. Am J Clin Nutr. 2004;80(1):137-142
3. Houterman S, van Faassen A, Ocke MC, et al. Is urinary sulfate a biomarker for the intake of animal protein and meat?. Cancer Lett. 1997;114(1-2):295-296
Method Description
A high pressure ion chromatography system (HPICS) utilizes an anion exchange column to separate sulfate from other anions present in urine. Detection of sulfate is done by conductivity change as eluent flows through a conductivity cell of a conductivity detector. The Thermo IC system is operated through a PC computer using thermo Chromeleon 7 software.(Christison T, Lopez L. Determination of Inorganic Anions in Acid Rain Using a Dedicated High-Pressure Capillary Ion Chromatography System. Technical Note 124 Thermo Scientific; 2016)
Report Available
1 to 3 daysSpecimen Retention Time
7 daysReject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Method Name
High-Pressure Ion Chromatography (HPIC)
Secondary ID
606479Forms
If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.