Collagen Cross‑Linked N‑Telopeptide (NTx), 24‑Hour Urine
Also known as: N-Telopeptide or NTx
Use
NTx (collagen cross‑linked N‑telopeptide) in 24‑hour urine is useful in assessing bone resorption in patients with metabolic bone disease and in monitoring therapy aimed at slowing or halting osteoporotic bone loss. A decline of approximately 30% or more in NTx over a six‑month period is indicative of effective therapy. Reference ranges vary by age and sex, typically expressed as nM bone collagen equivalents per mM creatinine. These results are used primarily for monitoring treatment response in osteoporosis or similar metabolic bone disorders. ([jdos.nicholsinstitute.com](https://jdos.nicholsinstitute.com/dos/prismahealth/test/909418?utm_source=openai))
Special Instructions
Do not include the first morning void—discard it. Collect all subsequent voids for the next 24‑hour period, including the first morning specimen the following day at the same time as the prior day’s first voiding. Mix well. Record total volume on the container and test requisition. The specimen must be unpreserved and kept refrigerated during collection. Acidified specimens are not acceptable. ([rchsd.org](https://www.rchsd.org/lab-test/collagen-cross-linked-n-telopeptide-ntx-24-hour-urine-36421/?utm_source=openai))
Limitations
NTx results are affected by diurnal variation, which may influence interpretation. ([jdos.nicholsinstitute.com](https://jdos.nicholsinstitute.com/dos/prismahealth/test/909418?utm_source=openai))
Methodology
Immunoassay (Chemiluminescence)
Biomarkers
Result Turnaround Time
1 day
Related Documents
For more information, please review the documents below
Specimen
Urine
Volume
2 mL
Minimum Volume
1 mL
Container
24‑Hour Urine Container
Collection Instructions
Do not include first morning void. Collect all subsequent voids for a 24‑hour period; the last sample should be the first morning specimen the next day at the same time as the previous morning’s first voiding. Mix well. Record total volume on container and requisition. Keep refrigerated; acidified specimen not acceptable.
Storage Instructions
Refrigerated during collection
Causes for Rejection
Acidified specimens; preserved specimens; room‑temperature collection
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | 72 Hours |
| Refrigerated | 5 Days |
| Frozen | 30 Days |