The tests you need to know for bone health

Whenever a client tells me her doctor says she should take osteoporosis medications, I always respond with the following comment… “If the problem is serious enough to warrant the use of strong bone drugs, then it is serious enough to warrant an investigation into the possible causes of the supposed bone weakening.”

The truth is that many times when we take a closer look, we find there actually isn’t excessive bone weakening, just regular age-related bone loss!  That’s why a health practitioner’s  suggestion — or often demand —  that a patient use bone drugs offers a good opportunity to do a standard medical workup searching for the possible cause of bone loss.

In part 3 of my Better Bones Empowerment Video Series Uncovering the hidden causes of bone loss — medical tests you should know about, I explain which tests you should know about so you can discuss them with your practitioner. There are many baseline medical tests commonly used to help uncover hidden causes of bone weakening or osteoporosis and this Empowerment Series discussion details over a dozen of them including:

• Vitamin D Blood 25(OH)D Test

• Intact Parathyroid Hormone (iPTH) Blood Test

• Ionized Calcium Test

• 24-Hour Urine Calcium Excretion Test

• Celiac Disease and gluten sensitivity

Remember, osteoporosis always has a cause and the best path to life-long bone health is uncovering and correcting the underlying causes of the bone weakening. Empowering yourself with knowledge about these tests is especially important when you already have signs of excessive bone loss or have experienced a low-trauma fracture.

Finally, a few comments regarding your medical records: make it your personal responsibility to obtain copies of all your test results and try to understand, or find out, what they mean. Make sure to keep the medical test reports with your personal records. No one else cares about your bone health as much as you do and no one will suffer the consequences of neglecting your bone health as much as you will. But it is also crucial to remember we all have options and control when it comes to our bone health.

Watch this blog as a video or purchase Uncovering the hidden causes of bone loss — medical tests you should know about now.

 

Tests included in the medical workup for osteoporosis

The other day, I had an e-mail from a 70-year-old woman who is following the Better Bones approach. She was obviously very frustrated by what she considered a lack of progress. “I’m doing everything I’m supposed to,” she said, noting that she was eating alkaline and testing her pH, exercising daily with weights, meditating, and taking her vitamin supplements religiously. But she’d just had a DEXA scan and was upset because nothing had changed. Her bone density was no different than it had been the last time she’d had her bone density measured 2 years ago, and she couldn’t understand why it hadn’t improved.

At first, this struck me as a little bit funny. She clearly didn’t understand something very important. For a woman after menopause, keeping bone density stable is a big accomplishment! Keep in mind that the average in her 60’s and 70’s loses 1 or 2% of her bone mass every two years. That means that over the course of 3 years, this particular woman had maintained her bone density instead of losing the 1-2% she might normally have expected to lose just from the average wear-and-tear of aging. Compared to a lot of her peers, she’s doing pretty well! In light of the fact that the average women loses as much as 47% bone of her bone mass by her late 80’s, this client’s stability of bone as she ages is a real sign of success.

Then I reconsidered. I thought, “this woman thinks she’s failing at something when she’s succeeding — that’s a problem!” Here she was, beating the odds and keeping her bones stable year after year, yet she felt like she wasn’t doing enough. I did not want her to walk away feeling defeated when she’d just won a wonderful victory. But how to get that point across to her and others like her?

Well, here’s a small analogy for you. Many personal trainers will tell someone they’re helping to lose weight to pay no attention to what the scale says, but instead gauge their weight loss success by how their clothes fit. It’s somewhat the same with bone health. For many of us, “optimal bone health” might mean results not visible to the naked eye or even to a DEXA scan — a strengthening of bone that leaves it more flexible and less prone to fracture, but that doesn’t increase its overall density. Some might also find their bone density stabilizes, as the woman who wrote me did (even if she didn’t recognize this stability for the achievement it is). Some see small gains in bone density, and a few see significant increases in bone density. But for most, the improvement might not really show up on any measurement made by a DEXA scanner.

What you do often get with a natural bone health program is a visible improvement in overall health — stronger nails, more supple skin, healthier teeth and gums, often better digestive health — that signifies that the body is getting what it needs and therefore doesn’t need to tap the bones for resources. Like a pair of suddenly loose pants on a person whose bathroom scale says she hasn’t lost a pound, sometimes the measuring device should be disbelieved if the body itself says that good changes are happening.

It’s also true that one might have such gains but not see them, since (as I’ve commented in earlier blogs) DEXA machines are notorious for having poor accuracy from one scan to another. A DEXA scan must show a change in density of at least 5-6%, according to noted bone researcher Susan Ott, to indicate a definite change in bone density; anything less than that could just be variation in the scanner or operator skill. The woman who e-mailed me, for example, could very well have had an increase in bone density of 1% from year to year, but the variability in DEXA measurements might have masked the increase.

So there are two points I’d like everyone to take away from this. One is that your success might not be measurable or quantifiable in terms of increased bone density—but that doesn’t mean you should discount it. Having stable bone mass as we age is something to celebrate! The other is that the point of a Better Bones Health Package and the approach I’ve long advocated is not to make sure everyone has bones equivalent in density to a 25-year-old athlete, but to give the bones — and the body, too — the resources they need to obtain optimal health.

 

Mysteries of bone breakdown revealed: the RANK, RANK-L and OPG system

Each minute, within the skeleton, more than a million sites of old worn-out bone are being eaten away by osteoclast cells, while new fresh bone is laid down by other specialized build-up cells known as osteoblasts. Just how this process of bone recycling and rebuilding is controlled has long been a question of scientific speculation.

Here is where RANK, RANK-L, and OPG enter the picture. Scientific breakthroughs have identified these three strange-sounding proteins and how they participate in the bone turnover process — and thereby identified a new place where science and pharmacology can intervene to prevent bone breakdown.

This insight into the nature of bone breakdown has led to the development of a different kind of osteoporosis drug — Prolia, a monoclonal antibody that was approved for postmenopausal osteoporosis by the FDA on June 1st. Prolia works on the RANK, RANK-L, and OPG proteins, but its mechanisms are unfamiliar to most people. So I thought I would familiarize you with what these acronyms mean:

RANK is short for “receptor activator of NF-kB” — a receptor sitting on bone breakdown osteoclast cells waiting to be activated. Once activated, RANK signals osteoclasts to mature, get active, and to begin breaking down bone.

RANK-L is a molecule that binds to RANK, activating it, and initiating the bone-recycling process. In essence, it turns RANK on.

OPG, short for osteoprotegerin, is a competitor of RANK-L. OPG binds to RANK and does not activate the bone breakdown cells. OPG keeps RANK-L from locking on to osteoclasts, and thus limits the bone breakdown activity of the osteoclasts.

So for someone in good health, the RANK/RANK-L/OPG system is a key regulator of bone breakdown, allowing the body to refresh and renew bone without excessive bone breakdown or excessive bone build-up.

Now for the quiz . . . if you want to reduce bone breakdown what would you do? Well, you could either:

  1. Increase OPG so that it would bind to the RANK receptor on the bone breakdown cells and thus deactivate them; or
  2. You could inhibit the ability of RANKL to bind to RANK, thus avoiding the activation of the bone breakdown cells.

The bone drug Prolia takes the second route, inhibiting RANK-L. Sound good? Well it sure can be in some cases, but there is always a price to pay when you interfere with a mechanism of disease instead of addressing the causes of the disease. Two logical questions arise: What other role(s) does activated RANK play in the rest of the body  — roles that taking Prolia might interfere with? And is it good for overall health to inhibit RANK-L? In an upcoming article, I will talk more about this new osteoporosis medication. For now, you can be ahead of the crowd — you know about RANK, RANK-L and OPG.

 

Who needs a medical osteoporosis workup?

Here at the Center for Better Bones, we often say that it is difficult to solve a problem you do not fully understand. If you have a bone health problem — or if you or your doctor just suspect you might have a serious bone concern — an osteoporosis medical work-up is in order. As I always say, if it is serious enough for your physician to prescribe an osteoporosis drug, it is serious enough to merit medical testing to look for any hidden causes of the bone loss.

Tests included in the medical workup for osteoporosis

  • Vitamin D (25[OH]D) blood test
  • Ionized calcium test
  • Intact parathyroid hormone blood test (iPTH)
  • 24-hour urine calcium excretion test
  • Thyroid hormone function test (TSH)
  • Markers of bone resorption tests (NTx, Dpd, CTX)
  • Vertebral deformity assessment
  • Free cortisol test (blood or saliva)
  • DHEA test (blood or saliva)
  • C-reactive protein test (high sensitivity if possible).
  • Homocysteine test (plasma or serum)
  • Celiac disease and gluten sensitivity tests
  • Sex hormone tests

A good osteoporosis medical work-up can include a variety of tests such as the ones listed here. Over and over again we find that such simple medical tests can often reveal important causes of bone loss, such as inadequate vitamin D or a loss of calcium in the urine — problems that can be corrected, leading to improved bone health.

The medical osteoporosis work-up is so important that I have taken the time to write about 13 key tests that will help uncover any hidden medical issues that can cause or contribute to excessive bone loss. In addition, I also provide a discussion on understanding the results of these tests.

Everyone is an individual, and your reasons for bone loss are unique to you as well. Following my “Take Heart and Take Action” slogan, I suggest you print off this information on medical testing, read it, take it to your doctor, and check to see if these tests are appropriate for you.

 

How often should a low-risk individual get a bone density test? Canadian authorities say only every 5 years.

If you are thinking that you should have a bone mineral density retest every year or two, you should know that Canadian osteoporosis authorities might disagree. Summer 2008 findings from the large Canadian Multicentre Osteoporosis Study led researchers to suggest that bone density testing in middle-aged and older adults can be delayed for intervals of up to five years in the absence of risk factors for bone loss, unless a therapeutic intervention is being monitored.

As the researchers report, while current guidelines recommend that measurements of bone density be repeated once every two or three years, their data suggest that, at this rate of testing, the average person would exhibit changes well below the margin of error. “Consequently … repeat measurements of bone density could be safely delayed for intervals of up to 5 years unless a therapeutic intervention is being monitored or there are additional clinical risk factors for bone loss, such as corticosteroid use.”

The study included 4,433 women and 1,935 men, and interestingly enough, bone loss was found to begin earlier in men—between 25 and 39 years of age. Bone loss in women appeared to begin between ages 40 and 44, with the greatest rate of decline between ages 50 and 54, followed by a slower decline. Then from age 70 onwards both women and men experienced another phase of accelerated bone loss.

And what about those at high risk for excessive bone loss and/or fracture?

We at the Center for Better Bones monitor high-risk individuals on our natural bone-building programs with regular bone resorption tests every six months or so and bone density testing at 2 to 3 year intervals.

For details on testing the success of your bone building program using bone resorption markers see my articles, Bone testing – assessing bone breakdown and bone loss, and Bone density testing.

Finally, if you wonder whether you are at high risk for osteoporosis, check into our interactive Bone Fracture Risk Assessment Questionnaire.

 

Reference:
Berger, C. et al. 2008. Change in bone mineral density as a function of age in women and men and association with use of anti-resorptive agents. CMAJ, 178(13):1660-8.

 

How accurate is a DEXA bone density test?

Nearly every day I see women and physicians themselves getting very worried when a woman’s bone density tests show even a small 1-2% decline. Women are often told their fracture risk has greatly increased and that they should immediately begin osteoporosis drug therapy. For many women, the growing “osteoporosis fear” is fueled by small reductions in bone density. But what do these small changes really mean, and just how accurate are the DEXA bone density tests anyway?

Thanks to the excellent work of the University of Washington osteoporosis specialist, Dr. Susan Ott, we now know that the common bone density test is rather imprecise and large changes in density are needed to assure that bone loss is indeed occurring, much less significant in nature. A thoughtful scientist, Dr. Ott had 300 patients get two bone density measurements: one when they came into the room, and the second after walking around the room for a while. With this simple experiment she showed that repeat measurements on the same day may show as much as 7% difference in bone mineral density. Breaking down the data she found that while a 4-6% change in bone mineral density indicates a “probably change” it takes more than a 6% change to fully guarantee a statistically significant change in bone density.

The Better Bones perspective on bone density testing: Bone density testing can be useful, especially when spaced over many years, but small changes are not significant and certainly not a basis for beginning bone drug therapy.

 

Reference:

Dr. Susan Ott’s website: http://courses.washington.edu/bonephys/opBMDp.html