I have a copy of my recent lab test results. For the N telepeptide/creatinine (urine test) ratio is rated as high. Mine was 75 and the normal range is from 5-65. Does anyone know what that means? The values for creatinine and N telepeptide separately are not identified so I don't know if the individual tests are abnormal or not but it looks like the ratio is. Also, on the same date I had many blood tests ordered by a different doctor and on that test the Creatinine test (blood) is within the range ok. There's no ratio mentioned.

I'll be talking with the doctor this week but I'm just wondering if I should be worried about the ratio being abnormal. Any replies about this would be helpful. Thanks

I have a copy of my recent lab test results. For the N telepeptide/creatinine (urine test) ratio is rated as high. Mine was 75 and the normal range is from 5-65. Does anyone know what that means? The values for creatinine and N telepeptide separately are not identified so I don't know if the individual tests are abnormal or not but it looks like the ratio is. Also, on the same date I had many blood tests ordered by a different doctor and on that test the Creatinine test (blood) is within the range ok. There's no ratio mentioned.

I'll be talking with the doctor this week but I'm just wondering if I should be worried about the ratio being abnormal. Any replies about this would be helpful. Thanks

I don't know what the telepeptide test reveals but creatinine is a protein and a measure of kidney function.

N-telepeptide (NTx) is a bone marker used as an indicator of human bone resorption which can be used to predict and confirm the effect of antiresorptive therapy.

As near as I can determine a reduction in N-telepeptide/creatinine serum markers is a good thing for those w/osteoporosis, I assume the same would hold true for urinary levels. It is also spelled telopeptide.

Thanks for the information. My doctor called today but I missed her call. I'll hopefully talk with her tomorrow.

Taape, how were the rest of your test results, other than the ones you mentioned?

PatNJ,
My Calcium test was normal. All of the other tests I had in Metabolic panel were fine as well as CBC, etc, the normal ones you usually get during a physical. The only other one I had a question about was the Carbon Dioxide was one number above the range so it was considered high. I don't understand what that test was for.

That's good to hear, taape.

I think CO2 is part of a routine blood chemistry panel. I wouldn't worry about it.

Hope your doctor will be able to shed some light on the N t/c test.

The nurse called me back today. She said that the N-telepetide is an enzyme that is present in urine that detects bone loss, and that with the Forteo medication she would expect this enzyme to be elevated which means the medicaton is working. Perhaps, she meant it detects bone reformation? I still don't quite understand if this is good or bad news.

The only thing I can think of is that Forteo does increase bone resorption, particularly in the first six months of treatment--before the bone mineralization mechanism "kicks in" and becomes the more dominant process. But I believe it's a constant tug-of-war between bone resorption and mineralization throughout treatment.

Perhaps the enzyme is elevated because it is reflecting bone resorption, which must mean that bone mineralization is also occurring?

Well, serum creatinine is used to evaluate kidney function. If kidney function is abnormal, creatinine levels will increase in the blood, due to decreased excretion of creatinine in the urine. Creatinine clearance has to be measured by urine collection (usually 12 or 24 hours). It is a more precise estimate of kidney function than serum creatinine since it does not depend on the amount of muscle one has. Creatinine is a waste product, that is, it cannot be used by cells for any constructive purpose. The daily production of creatine, and subsequently creatinine, depends on muscle mass, which fluctuates little in most normal people over long periods of time.

There seems to be an issue of how long the bisphosphonates are safe, and whether long-term use could possibly lead to brittle bone. I've seen several recommendations of just 5 years of use. It has been suggested if one has been taking a bisphosphonate properly (a urine N-telopeptide might be helpful, it should be less than 30) and has good vitamin D levels, no high PTH, cancer, malabsorption, renal failure, hyperthyroidism, etc) intermittent Forteo could be considered.

If urine N-telopeptide is suppressed, less than 30 (preferabley less than 25) one could be considered a candidate for Forteo rather than a bisphosphonate. It appears that urinary N-telopeptide can indicate if there is enhanced bone resorption but I really am not finding anything about the N-telopeptide/creatinine ratio. I do keep seeing the recommendation of 25(OH)vitamin D, and a 24-hour urine collection for calcium, creatinine, N-telopeptide and protein electrophoresis. These can all be done on the same collection.

In other words, I haven't found diddley-squat to really answer your question or to satisfy my curiosity your question has aroused!!!

ChronieToo,
Thanks for the information that you did give me. My blood creatinine level was fine, it's just this ratio from the urine test I don't quite understand. I'm going to send my doctor an email asking about the test results. When I find out I'll post it.

This is the first ratio test I've been given. I've never done a 24 hour urine but I did read that doing the second void of the morning is an alternative to the 24 hour urine for this test. So, there must be some information about the ratio of N-T and creatinine because it's done many times after the 24 urine is collected.