Metabolic Workup in Patients Suffering From Kidney Stone Disease and Osteopenia

Metabolic Workup in Patients Suffering From Kidney Stone Disease and Show Osteopenic Bone Changes on Non-contrast CT Scan

Patients suffering from acute renal colic are evaluated by non contrast computerized tomography with excellent identification rates of urinary stones. The scan also covers the bones of the ribs, spine and pelvis, allowing measurements of the bone density and identifying early osteopenic changes. Bone demineralization is associated with metabolic changes such as hypercalcemia or hypercalcuria. In this study the investigators will look for correlation between kidney stones, osteopenic bone changes and metabolic abnormalities.

Kidney stones are a common medical condition found in more then 5% of the adult population. The stones might cause severe pain (due to acute obstruction of a renal unit) , deterioration of renal function and urinary tract infection. One of the causes of kidney stones is metabolic changes such as hypercalcemia or hyperoxaluria. Basic evaluation of kidney stones patients include measurements of calcium, phosphor and uric acid in the serum and is often negative. Thorough metabolic workup including 24 hours urine collection is not cost effective and is reserved for patients with frequent recurrence of stone disease.

Metabolic abnormalities are often associated with bone demineralization, of which the patients are typically unaware. such changes can be detected by the CT scan. On the same scan, performed for identifying the stone, the radiologist can measure bone density, using the Hounsfield units, in the L2 vertebral body of and the acetabular area of the pelvis.

In the study, in all patients undergoing CT scan due to renal colic, the bone density will be measured. Patients with abnormal bone density will undergo a complete metabolic workup including 24 hours collection of urine and measurements of urinary clearance of calcium, phosphorous, uric acid, oxalate and citrate . The investigators will look for correlation between osteopenic changes and metabolic abnormalities.

Inclusion Criteria:

• 18 years or old
• informed consent
• kidney stones
• CT scan positive for stones AND bone changes

Exclusion Criteria:

• under 18
• unable to sign
• no stones detected on scan (even if a stone was expelled recently)
• no bone changes
• pregnancy
• a patient already known to suffer from metabolic bone disease
• a patient with documented osteoporosis
• patients following spinal or pelvic trauma / surgery