CITR - Clinical: Citrate Excretion, 24 Hour, Urine

Test Catalog

Test ID: CITR    
Citrate Excretion, 24 Hour, Urine

Useful For Suggests clinical disorders or settings where the test may be helpful

Diagnosing risk factors for patients with calcium kidney stones

 

Monitoring results of therapy in patients with calcium stones or renal tubular acidosis

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Urinary citrate is a major inhibitor of kidney stone formation due in part to binding of calcium in urine. Low urine citrate levels are considered a risk for kidney stone formation.

 

Several metabolic disorders are associated with low urine citrate. Any condition that lowers renal tubular pH or intracellular pH may decrease citrate (eg, metabolic acidosis, increased acid ingestion, hypokalemia, or hypomagnesemia).

 

Low urinary citrate promotes kidney stone formation and growth, and is subject to therapy by correcting acidosis, hypokalemia, or hypomagnesemia by altering diet or using drugs such as citrate and potassium.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

0-19 years: not established

20 years: 150-1,191 mg/24 hours

21 years: 157-1,191 mg/24 hours

22 years: 164-1,191 mg/24 hours

23 years: 171-1,191 mg/24 hours

24 years: 178-1,191 mg/24 hours

25 years: 186-1,191 mg/24 hours

26 years: 193-1,191 mg/24 hours

27 years: 200-1,191 mg/24 hours

28 years: 207-1,191 mg/24 hours

29 years: 214-1,191 mg/24 hours

30 years: 221-1,191 mg/24 hours

31 years: 228-1,191 mg/24 hours

32 years: 235-1,191 mg/24 hours

33 years: 242-1,191 mg/24 hours

34 years: 250-1,191 mg/24 hours

35 years: 257-1,191 mg/24 hours

36 years: 264-1,191 mg/24 hours

37 years: 271-1,191 mg/24 hours

38 years: 278-1,191 mg/24 hours

39 years: 285-1,191 mg/24 hours

40 years: 292-1,191 mg/24 hours

41 years: 299-1,191 mg/24 hours

42 years: 306-1,191 mg/24 hours

43 years: 314-1,191 mg/24 hours

44 years: 321-1,191 mg/24 hours

45 years: 328-1,191 mg/24 hours

46 years: 335-1,191 mg/24 hours

47 years: 342-1,191 mg/24 hours

48 years: 349-1,191 mg/24 hours

49 years: 356-1,191 mg/24 hours

50 years: 363-1,191 mg/24 hours

51 years: 370-1,191 mg/24 hours

52 years: 378-1,191 mg/24 hours

53 years: 385-1,191 mg/24 hours

54 years: 392-1,191 mg/24 hours

55 years: 399-1,191 mg/24 hours

56 years: 406-1,191 mg/24 hours

57 years: 413-1,191 mg/24 hours

58 years: 420-1,191 mg/24 hours

59 years: 427-1,191 mg/24 hours

60 years: 434-1,191 mg/24 hours

>60 years: not established

Interpretation Provides information to assist in interpretation of the test results

Any value less than the mean for 24 hours represents a potential risk for kidney stone formation and growth. Patients with low urinary citrate, and new or growing stone formation, may benefit from adjustments in therapy known to increase urinary citrate excretion. (See Clinical Information)

 

Very low levels (<150 mg/24 hours) suggest investigation for the possible diagnosis of metabolic acidosis (eg, renal tubular acidosis).

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Drugs that lower systemic pH, potassium, and/or magnesium, lower urine citrate and are to be avoided in patients with a tendency to form calcium stones.

 

Conversely, drugs that raise systemic pH, potassium, and/or magnesium, may raise urine citrate and should be considered in treating patients or interpreting results.

Clinical Reference Provides recommendations for further in-depth reading of a clinical nature

Hosking DH, Wilson JW, Liedtke RR, et al: The urinary excretion of citrate in normal persons and patients with idiopathic calcium urolithiasis (abstract). Urol Res 1984;12:26

Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test