Stone screening profile

The Stone screening profile or Supersaturation profile-urine measures the Calcium, Magnesium, Uric Acid, Oxalate, Citrate, and Phosphorous levels in the urine.

• Patients with diagnosed stones should undergo stone testing to know the type of stone detected and the stone content.

Patients with the following clinical symptoms should also undergo testing:

• Lower abdominal pain radiating to back
• Pain while urinating
• Blood in urine
• Previous history of stones.
• Chronic inflammatory gastrointestinal disorders

• The test is done in patients with stones to analyse the type of stone detected
• To analyse the mineral and organic content in the stones detected.
• In patients with previous history of kidney stones to know the likelihood of recurrent stones.
• To know the risk of kidney stones in patients with metabolic disorders, kidney diseases or uncontrolled diabetes.

This test requires a urine sample. Patient will be explained how to collect mid-stream urine sample in a sterile container.

No special precautions required.

Calcium, Urine

High calcium levels in urine may occur in cases of calcium stones. This may occur due to due to faulty calcium absorption from the intestines or bones or due to lack of regulation of calcium excretion by the kidneys, or even in inflammatory bowel diseases. Depending on the composition, the calcium stones may be classified as calcium oxalate or calcium monohydrate stones.

Magnesium and Phosphorus, Urine

High levels of magnesium and phosphorus in urine may be found in certain types of stones.

Uric Acid

Increased levels of uric acid in urine may occur due to formation of uric acid stones. This may also cause the ph to be highly acidic.

Oxalate, Urine

Increased levels may occur due to oxalate rich foods, gastrointestinal disorders, or metabolic disorders Decreased excretion is associated with hyperglycinaemia and hyperglycosuria.

Citrate Urine

Hypocitraturia may occur due renal tubular acidosis which also increases calcium levels in the blood. Other causes could be potassium or magnesium deficiency, urinary tract infection, kidney failure and chronic diarrhoea.

• Stone test
• Supersaturation Urine test

Calcium stones mainly occur as a result of excess calcium excretion in the urine, known as hypercalciuria. This may be due to faulty calcium absorption from the intestines or bones or due to lack of regulation of calcium excretion by the kidneys.

Uric acid stones mainly occur due to high uric acid levels in the urine. Uric acid is mainly formed by protein breakdown. When the urine becomes highly acidic (ph<5.5) uric acid levels may also increase leading to stone formation.

Magnesium is also a by-product of metabolism and its excretion in urine may signify faulty metabolism.

Oxalate in urine may arise either as an end product of intermediary metabolism or from dietary sources. Oxalate excretion may mainly occur due to consumption of oxalate rich foods.

Urinary citrate inhibits stone formation by forming soluble complexes with calcium. Excretion is reduced in the calcium stone-forming population. Urinary citrate measurement may be of value in the assessment of stone-forming risk.