Diagnostic Tests For Osteoporosis

With primary osteoporosis cases simple blood tests like calcium, phosphate, alkaline phosphatase levels, red blood cell sedimentaion rate and serum electophoresis would all be normal.

Type I osteoporosis (click on "causes of osteoporosis" , see table) would show high FSH, low estrogen, low progesterone in women and low testosterone in males. Male and female hormone deficiency (=hypogonadism) is found in this type (see Ref. 8).

Type II osteoporosis is usually associated with vitamin D deficiency and we know from research papers that there is a lowered number of bone building cells in the bone, which leads to a dysbalance between bone production and bone turnover with an overall net bone loss. The ultimate test for determining the amount of bone mass loss is with the help of dual-emission X-ray absorptiometry (for short: DEXA or DXA).

This DEXA scan is done easily at the X-ray department (Ref.1). The results are scored as outlined in the beginning of the chapter, expressed as standard deviations below the norm of a 35-year old control person matched for sex and race.

When Fosamax was developed for osteoporosis treatment by Merck in 1995 there were two independent occurrences that helped the marketing of Fosamax (see Ref. 9). First, WHO came out with a new definition of osteoporosis where the bone density of a 30-year old woman was considered the new reference point. This new criterion immediately declared 30% of postmenopausal women to have osteoporosis. Secondly, Merck subsidized the distribution of machines to test bone density. This bone density test provided the physician a powerful tool to assess the risk for a fracture in the near future.

This relationship would be similar to measuring blood pressure and predicting how likely it would be for the patient to get a stroke. It has been determined in a group of patients with osteoporosis that the difference in probability between the lower density and higher density patients on the DEXA test to develop a hip fracture was 8.5-fold higher (Ref.1). However, there are some problems with Fosamax as will be discussed under "treatment of osteoporosis".

In secondary osteoporosis blood tests would be ordered that would help in distinguishing between the specific hormone imbalance listed in the table under this link (click on "causes of osteoporosis" ,see table). A positive history, for instance, of celiac disease would likely lead to a referral of the patient to the gastroenterologist for a work-up. A rheumatologist might be needed in the case of a patient with an underlying rheumatological disease such as rheumatoid arthritis or ankylosing spondylitis.

A suspicion for cancer would trigger the physician to order a nuclear medicine bone scan, other imaging techniques and other blood tests. Finally, a history of drug use should be taken as they can interfere with bone metabolism. For instance, prednisone side effects for asthma or a rheumatic disease includes osteoporosis; and alcohol and smoking are also powerful negative factors as was mentioned above.

Here is a summary in tabular form of the tests that are done (Ref. 1 and 2) to investigate for osteoporosis.

Disclaimer:

This outline is only a teaching aid to patients and should stimulate you to ask the right questions when seeing your doctor. However, the responsibility of treatment stays in the hands of your doctor and you.

References:

1. ABC of rheumatology, second edition, edited by Michael L. Snaith M.D., BMJ Books, 1999.

2. The Merck Manual, 7th edition, by M. H. Beers et al., Whitehouse Station, N.J., 1999. Chapter 57.

3. B. Sears: "The age-free zone".Regan Books, Harper Collins, 2000.

4. B. Sears: "Zone perfect meals in minutes". Regan Books, Harper Collins, 1997.

5. Goldman: Cecil Textbook of Medicine, 21st ed.(©2000)W.B.Saunders

6. Ferri: Ferri's Clinical Advisor: Instant Diagnosis and Treatment, 2004 ed., Copyright © 2004 Mosby, Inc.

7. Rakel: Conn's Current Therapy 2004, 56th ed., Copyright © 2004 Elsevier

8. Dr. John R. Lee: Natural Progesterone- The remarkable roles of a remarkable hormone", Jon Carpenter Publishing, 2nd edition, 1999, Bristol, England.

9. Michael T. Murray, N.D.: "What the drug companies won't tell you and your doctor doesn't know" - The alternative treatments that may change your life - and the prescriptions that could harm you. Atria Books (subsidiary of Simon & Schuster Inc.), 2009.

Last Modified: March 27, 2012