Using the Bone Loss Assay for Osteoporosis Treatment

by Ronald B. Keys, JD, PhD May 1, 1997

Introduction

Osteoporosis literally means "porous bone" and has been called "the silent thief" because there are usually no symptoms or warning signs until a fracture occurs. There is usually a balance between the bone producing cells called osteoblasts and the osteoclasts which are bone cells that break down and reabsorb the bone matrix. When osteoclastic activity (bone break down) exceeds osteoblastic activity (new bone growth) resulting in the exaggerated loss of bone mass and poor bone quality, osteoporosis begins. Most typical are fractures of the hip and wrist and collapse fractures of the spine which can produce deformity, functional decline and loss of height. It is a major health problem in the United States and elsewhere when the mean life span is climbing with the accelerated development of life extension technologies. It affects 1 in 3 postmenopausal women, but it is not only found in this age group. Men, younger women and otherwise healthy, active individuals can experience rapid bone loss and the debilitating effects of its progression.

The rate of bone loss is highly variable from one individual to another. Those who suffer from rapid bone resorption--both men and women, are at greater risk and will best benefit from therapeutic intervention using this simple urine test.

Sound bone maintenance requires individualized patient management to find the right balance between osteogenesis (bone growth) and osteolysis (bone resorption). Part of this is the new and easy test to identify, profile and monitor bone loss with this new, simple and cost effective urine test (with urine collection at home or office with free overnight delivery to our special laboratory). Arrangements may be made through Dr. Keys' office for the home delivery of the BONE LOSS ASSAY. This assay is more sensitive and specific than previous biochemical markers. The BONE LOSS ASSAY shows present bone activity by detecting specific biomarkers which reflect present remodeling bone activity. It detects bone loss earlier than x-ray. It is an excellent monitor for testing the effectiveness of a bone loss therapy. Serial bone scans are costly and do not give insight into present bone activity; they only measure changes in bone density over a six to twelve month period.

Who needs to be tested? Are you listed here?

Men and women over 50
All peri-menopausal women
All women who have had hysterectomies
Heavily exercising women of all ages
Women with a family history of osteoporosis
Women recently pregnant or nursing
Women with thin, petite or small frames
People who use anti-ulcer medication
All people who inadequately exercise or have sedentary life styles or occupations
People who consume excessive amounts of caffeine or soft drinks
Smokers and heavy alcohol users
Men and women with lactose intolerance or dairy allergy
All people using steroids (i.e. for asthma, arthritis or cancer)
Women who have had surgically induced menopause

How does the bone loss assay work?

Previous, more expensive and invasive testing has included the following:

QCT (Quantitiative Computed Tomography) of the spine, a low-dose radiation technique using the familiar CAT scanner, in which cross-sections of your vertebrae are imaged and then the mineral content of each slice is measured.
DXA (Dual X-ray Absorptiometry), imaging whole body parts (of the spine, hip or both), the extremely low radiation dosage has in the past made it a popular screening tool among clinicians.
SPA (Single Photon Absorptiometry) of the radius, a measurement of the bone density of the forearm or of the heel; usually used in conjunction with the QCT.

Now, no radiation is necessary for routine bone resorption studies because the BONE LOSS ASSAY is non-invasive and just an overnight urine study. The bone remodeling process is reflected in body fluids by the presence of various molecules that are excreted either from the bone matrix or from the cells that are actively involved in the bone resorption or formation. Simply stated, this test looks at special metabolic byproducts such as analyte, solute and metabolites in urine. There is no reason to doubt its usefullness even in patients with metabolic bone disease (See: Gamero P, et al., Assessment of bone resorption with a new marker of collagen degradation in patients with metabolic bone disease. J. CLIN ENDOCRINOL & METAB, 1994, 79(3): 780-785, supra). The protein matrix of bone upon which its mineral structure is accumulated consists of Type I collagen. Special peptide sequences such as pyridinoline and deoxypyridinoline, are involved in cross-linking for greater structural stability. Active bone resorption requires a breakdown of this protein structure. By immunoassay, the peptide fragments from this breakdown are excreted in the urine and quantified. The amount of peptide found in the second morning urine provides an accurate measure of the rate of bone resorption at the time of collection because bone resorption is a relatively constant process. High levels in the urine, without unnecessary radiation exposure to the patient, indicate rapid bone resorption.

Repeated tests every 6 to 12 weeks are recommended to monitor the effectiveness of therapeutic intervention. This permits the timely adjustment of individualized, patient-appropriate, therapeutic interventions. Contact Dr. Keys' office to arrange for this test and for follow-up management.

REFERENCES

Bonde M., et al., Immunoassay for quantifying type I collagen degradation products in urine evaluated. CLIN CHEM, 1994, 40;2022-2025

Burgeson RE. New Collagen, new concepts. ANNU REV CELL BIOL, 1988, 4:552-577

Delmas, PD. Biochemichal markers of bone turnover. J BONE MINER. RES. 1993, 8(Suppl 2): 549-555

Gamero P, et al. Assessment of bone resorption with a new marker of collagen degradation in patients with metabolic bone disease. J CLIN ENDOCRINOL & METAB, 1994, 79:780-785

Gertz BJ, et al.. Monitoring bone resorption in early postmenopausal women by an immunoassay for cross-linked collagen peptides in urine. J BONE MINER RES, 1994, 9(2):134-142

Hanson DA, et al., A specific immunoassay for monitoring human bone resorption: quantitation of type I collagen cross-linked N-telopeptides in urine. J BONE MINER RES 1992, 7:1251-1258

Kleerekoper, M. Bone mass, bone remodeling and biochemical markers. CLIN LAB NEWS. 1994, 20(11):5

Risteli J, et al., Radioimmunoassay for the pyridinoline cross-linked carboxy-terminal telopeptide of type I collagen: a new serum marker of bone collagen degradation. CLIN CHEM 1993, 39: 635-60

Contact Dr. Ronald B. Keys at (954) 448-1515 or e-mail at rkeysphd@brainlink.com.
After all, it's only your life.