Bone Up on Bones - Understanding Osteoporosis Screening

Osteoporosis is a condition that weakens an individual’s bone integrity. The word comes from two Greek roots; “osteo”, which means “bone”, and “poro” which means “porous”. As the name would suggest, the bone from a person with osteoporosis has less supporting structure, which means that the bone is weaker. 

^{Image credit: Google images / McMaster University}

The way healthy bone stays structurally sound is by constantly breaking down and rebuilding existing bone. This is performed by specialized cells called osteoclasts (which break down bone) and osteoblasts (which create new bone). Another important part of making bones strong is the mineralization of bone, which is accomplished by a calcium-based deposit. Osteoporosis develops when bone is being broken down at a higher rate than it is being rebuilt. 

You don’t feel osteoporosis happening. It’s not painful, and the shape and size of your bones doesn’t change. Often, people only realize that they have osteoporosis after their bone has weakened to the point that they suffer a fracture. Risk factors for osteoporotic fractures include a history of hip fracture in one or both parents, excessive alcohol consumption, low body weight, and smoking.¹ In addition, post-menopausal women are at higher risk because of a drop in estrogen levels, as estrogen inhibits bone resorption (breakdown).. Long-term use of certain medications (especially corticosteroids) can also increase this risk. 

It’s estimated that more than 12 million people in the US suffer from osteoporosis.² Hip fractures are the most serious of the fractures that result from this condition, and can cause problems with ambulation and independence, chronic pain, and decreased quality of life. 21-30% of patients who suffer a hip fracture die within 1 year.³ 

Fortunately, the condition is treatable. There are several medications available that can help restore the structural integrity of bone, and prevent fractures. In addition, screening for the condition is possible, so that measures can be taken before problems arise. 

The USPSTF currently recommends that all females 65 and older should be screened for osteoporosis by bone measurement. They also recommend screening for postmenopausal females younger than 65 who are at an increased risk of osteoporosis, as determined by formal clinical risk assessment tools.⁴ The most commonly used clinical risk assessment tools are SCORE and FRAX (links provided).

Once it is determined that you are a candidate for screening, there are three screening methods that could potentially be used. The most studied and most commonly used is the centralized DEXA (dual-energy X-ray absorptiometry) scan.  DEXA scans calculate your “T-score”, which is a measure of the density of your bone. A T-score less than -2.5 is consistent with a diagnosis of osteoporosis.⁵

Other medical societies dedicated to management of osteoporosis have similar recommendations. The National Osteoporosis Foundation and the International Society for Clinical Densitometry recommend the same screenings as USPSTF for women, but additionally recommend screenings for men 70 and older, as well as age 50-69 men if they have elevated risk (by the same risk assessment tools, SCORE and FRAX). 

In their review of evidence, the USPSTF determined that it was convincing that 1) screening can detect osteoporosis and 2) treatment of women with osteoporosis can provide at least a moderate benefit in preventing fractures, specifically the most dangerous “hip” (femoral neck) fractures. The harms of screening on the other hand were found to be very small; essentially just the minor radiation exposure associated with the DEXA scans, and cost.⁴

There are other measures that can be taken to prevent osteoporosis. For one, it is important to consume foods that are an adequate source of calcium and vitamin D. This involves eating a diet that is high in fruits and vegetables, which are important for bone health. If you have a vitamin D deficiency, then supplementation may be required. In addition, avoiding smoking and abstaining from more than 2-3 alcoholic beverages per day also helps prevent risk. Lastly, regular exercise, especially weightlifting or resistance training, help to maintain strong, healthy bones.⁶ 

In conclusion, bone health is yet another important consideration in maintaining overall health. Keeping yourself healthy with diet, exercise, and avoidance of smoking are important in prevention. And for those whom it’s appropriate, undergoing screening and subsequent treatment also decreases the risk of fracture. Keep yourself and those closest to you upright and active! 

Pass this on to someone that you know and love, and help to promote healthy bones!

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