A DEXA scan is one of the latest diagnostic tools that can help in the diagnosis of bone diseases including osteopenia and osteoporosis. It is considered superior to most other diagnostic techniques because it provides a detailed assessment of bone mineral density in different parts of the body.
This is also the reason why the results of a DEXA scan need to be evaluated carefully. A DEXA scan may show different results for each part of the body and these results must be interpreted in a specific way to be able to determine your risk of bone diseases.
Let’s take a look at the reasons why a DEXA scan shows different results for each scanned area and the right ways to evaluate the results.
What is A DEXA scan?
DEXA scan, or Dual-energy X-ray absorptiometry scan, measures your bone density. It can also be used for determining body composition, including the percentage of fats and lean muscle mass in different parts of the body. [1] [2]
The results of a DEXA scan show the relative composition of bone tissues and soft tissues such as muscle and fats.
This is the primary reason why a DEXA scan may show different results in different parts of the body.
How does DEXA scan work?
This is an imaging technique that provides an estimate of the three main body components including muscles, fat, and bone minerals in the whole body as well as in specific parts of the body.
A DEXA scan uses 2 low-energy X-ray beams that are directed toward specific parts of the body. The use of dual-energy levels helps to separate the images into 2 components, including bone and soft tissues.
This scan can help to detect the amount of bone mass in an area in comparison to the amount of soft tissues in the same area. The results of this test can help to assess the risk of osteoporosis and osteopenia.
The results of a DEXA scan indicate the severity of bone mineral density loss and allows the doctor to determine your risk of developing a fracture.
The DEXA scan is considered more accurate and more sensitive than typical X-rays as it can detect the smallest changes in bone loss. It is also considered very reliable when used for calculating the body fat percentages.
Additionally, a series of DEXA scans can detect loss or improvement in bone mineral density. This means a DEXA scan can help you know if your bone mineral density is improving or declining compared to previous results.
Improvement in bone mineral density can also ensure that the treatment you are receiving is working effectively. A DEXA scan can help predict the prognosis of patients at risk of bone diseases.
While assessing body composition, the DEXA scan results may also help in determining the amount of visceral fat stores around specific internal organs.
Depending on the part of the body and the presence or absence of visceral organs in the region, the results of the scan can differ. [3]
The healthcare experts at the National Osteoporosis Foundation have recommended having a bone density test like DEXA scans in the following conditions [4]
- In woman, if the age is 65 or older
- In man, if the age is 70 or older
- If you break a bone after you are 50 years old
- If you are a woman of menopausal age with risk factors
- If you are a postmenopausal woman under age 65 with risk factors
- If you are a man age 50-69 with risk factors.
What is the purpose of DEXA scans?
DEXA scans are most commonly used for the diagnosis of osteoporosis, a condition that occurs due to gradual loss of bone mass making bones fragile, thinner, porous, and more likely to break.
DEXA scans also help in assessing the risk factors for other diseases such as cancer, rheumatoid arthritis, chronic hepatic or renal diseases, respiratory diseases, and inflammatory bowel disease. [5] [6]
In some patients, a variant of the DEXA scan called VFA (Vertebral Fracture Assessment) is recommended for determining the risk of vertebral osteoporosis. It involves directing low-dose x-ray beams on the spinal region. [7]
This test is usually recommended for older patients, when:
- They experience unexplained back pain
- Have lost more than one inch of height
- The DEXA scan shows borderline readings
- The DEXA scan images of the spine show a vertebral fracture or deformity
How is a DEXA scan performed?
DEXA scan focuses on 2 main areas: the spine and the hip. In some cases, a DEXA scan can also be performed on the forearm.
During the procedure, a scanning arm is passed over your body to measure the bone mineral density in the skeleton.
A narrow beam of X-rays will also be passed through specific parts of your body being examined. As bone mineral density varies in different bones, more than one part of the body needs to be scanned.
This is also why the results of the DEXA scan vary depending on which part of the skeleton was scanned during the procedure.
How to interpret the results of a DEXA scan?
The results of a DEXA scan has 2 scores: The T-score and the Z-score.
The difference between the measurement of your bone density and that of a young healthy adult is called the T-score. The deviation between your bone density and that of someone of your age is called the Z-score. [8]
A T-score above 1 is normal while a score from -1 to -2.5 SD is considered as mildly reduced bone density. A T-score below -2.5 SD is indicative of osteoporosis. [9]
A Z-score of less than -2 indicates your bone density is lower than what it should be for a person of your age. [10]
Serial BMD Measurements
Serial BMD testing including DEXA scans for different parts of the body can help to assess the prognosis of patients receiving treatment for osteoporosis.
According to the International Society For Clinical Densitometry, “Serial BMD testing can be used to determine whether treatment should be started on untreated patients, because significant loss may be an indication for treatment. Serial BMD testing can monitor response to therapy by finding an increase or stability of bone density. Follow-up BMD testing should be done when the expected change in BMD equals or exceeds the least significant change (LSC).” [10]
Conclusion
A DEXA scan is one of the most accurate tests to check your bone mineral density. It is commonly used for the diagnosis of osteopenia and osteoporosis. It can also help to assess the prognosis of patients receiving treatment for these diseases.
Assessing the deviation in the bone density compared to that of normal individuals as well as the patient’s own earlier reports can help the physician determine whether the current treatment needs to be continued or modified.
References:
- https://dapa-toolkit.mrc.ac.uk/anthropometry/objective-methods/whole-body-dexa-scan
- https://www.northshore.org/nuclear-medicine/diagnostic-tests/bone-density-scan-dexa/
- https://clinicalcenter.nih.gov/drd/nucmed/patientinfo.html
- https://www.nof.org/patients/diagnosis-information/bone-density-examtesting/
- https://www.cancerresearchuk.org/about-cancer/cancer-in-general/tests/bone-density-scan-DEXA-DXA
- https://www.radiologyinfo.org/en/info.cfm?pg=dexa
- https://www.radiologyinfo.org/en/info.cfm?pg=dexa
- https://www.webmd.com/osteoporosis/guide/dexa-scan#
- https://www.bones.nih.gov/health-info/bone/bone-health/bone-mass-measurement-what-numbers-mean#c
- http://www.who.int/en/
- https://www.iscd.org/official-positions/2015-iscd-official-positions-adult/
Strong bones form the foundation of a stable framework for your body. It is important to maintain optimum bone health to be able to live a physically active life.
Bone health is also important to avoid diseases that can occur due to the loss of bone mineral density. Read on to know the best supplements you can use to promote bone health.
Top 8 supplement women can use to improve bone health
1. Calcium
Calcium is the building block of the bones. It is the most important mineral the body needs to form the bone mass. The requirement of calcium for adult women is about 1000 to 1200 mg per day. [1]
The daily requirement may be higher in menopausal women who experience faster bone loss due to the hormonal changes that put them at risk of osteopenia and osteoporosis. [2]
The use of calcium supplements would promote the bone formation processes in menopausal women and make their bones stronger and denser. [3]
Women can start using calcium supplements in a lower dose initially, especially if they are prone to develop frequent gastric upsets. They may increase the dose gradually as the stomach gets used to it.
Also, for adults, the maximum limit for calcium intake is 2000 mg. Using a very high dose of calcium supplements may increase the risk of kidney stones. Women should keep in mind these factors and use calcium supplements as recommended to improve bone health. [4]
2. Vitamin D
Vitamin D plays a vital role in improving bone health. It facilitates the absorption of calcium in the gut and increases its availability to the bones. Vitamin D is also needed for the physiological processes involved in bone growth, development, and remodeling.
Hence, it is advisable to use calcium supplements in combination with vitamin D to derive better results. [5]
3. Vitamin K
Vitamin K, particularly vitamin K2, is essential for bone health. Vitamin K2 (menaquinone) can act as a coenzyme for certain proteins that are required in bone formation and remodeling processes.
Vitamin K also helps calcium to bind to the bones more efficiently and inhibits the loss of minerals from the bones.
Research studies have shown that vitamin K2 supplements can also support bone health in menopausal and postmenopausal women and reduce their risk of osteoporosis. [6]
The recommended dosage of vitamin K is 150 micrograms per day. However, it should be noted that vitamin K can interfere with the action of blood-thinning drugs and increase the risk of bleeding.
4. Magnesium
Magnesium is another mineral that is essential for maintaining optimum bone health. Though it is found in natural food sources such as whole grains, green vegetables, and nuts, the use of supplements may be essential for patients who suffer from poor absorption of food in the intestine.
The recommended daily dose of magnesium is about 300 to 500 mg. The requirement may be higher in people whose diet comprises mainly of processed foods or ready meals that are known to have a poor nutritional profile.
5. Herbal supplements
Herbal supplements that possess natural anti-inflammatory, antioxidant, and immunomodulatory properties could help to support bone health.
For example; the use of supplements containing Herba epimedii, Fructus psoraleae, and Fructus ligustri lucidi has been found to improve bone mineral density. [7]
These herbs produce a bone-protective effect, particularly in postmenopausal women, by creating an estrogen-like effect.
The use of black cohosh is recommended for women who suffer from osteoarthritis. The anti-inflammatory and antioxidant properties of black cohosh would reduce damage to the bones and joints and slow down the progress of osteoarthritis. [8]
Similarly, fruits and herbs containing vitamin C such as amla (Indian gooseberry), and oranges may produce antioxidant and immunomodulatory effects and reduce the risk of joint damage due to rheumatoid arthritis. [9]
Herbs such as holy basil and turmeric would help to minimize the risk of infections in the bones such as osteomyelitis by improving immunity and producing a natural antibacterial action.
6. Boron
Most people are not aware that trace elements like Boron also play a vital role in improving bone health. Your body does not need Boron in high amounts. However, it is still important to ensure your bones are not deprived of this mineral as it has the potential to help your body use calcium more efficiently.
Boron can also help in the management of osteoporosis and osteopenia by activating vitamins and minerals essential for bone formation.
The body needs around 3 to 5 mg of boron per day. Boron is found in food sources such as apples, peaches, grapes, nuts, and pears. If you suffer from osteoporosis, you can use a boron supplement to support bone formation and reduce bone loss.
7. Omega 3 fatty acids
Omega 3 fatty acids are revered for their natural anti-inflammatory properties. Supplements containing omega 3 fatty acids would support bone health by minimizing inflammation caused due to osteoarthritis and rheumatoid arthritis.
8. Silicon
Silicon is another trace mineral needed for the growth and development of bones, tendons, and ligaments. It is estimated that taking around 25 to 50 mg of silicon every day might help to prevent osteoporosis.
Why do we need to use supplements to improve bone health?
Most of the nutrients the body needs to support bone health can be derived from our diet. Hence, eating a balanced and nutritious diet is often considered the most effective way to ensure optimum bone health.
However, sometimes, you may have to use supplements to make the bones healthier and stronger.
Factors such as advancing age, menopause, diet restrictions, loss of appetite, and digestive disorders can affect the amount of nutrients your bones receive. As a result, the bones are deprived of the nutrients they need to build strong mass.
In this case, the use of supplements may offer an effective alternative to enhance bone health and prevent diseases caused due to the deficiency of essential vitamins and minerals.
Conclusion
The use of these supplements would protect your bones against several diseases including osteopenia, osteoporosis, osteoarthritis, osteomyelitis, and rheumatoid arthritis. You can choose the best supplement suitable for you depending on your risk factors and tendencies.
References:
- http://www.nejm.org/doi/full/10.1056/NEJM199709043371003
- https://www.endocrine.org/guidelines-and-clinical-practice/clinical-practice-guidelines/osteoporosis-in-postmenopausal-women
- https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/calcium-supplements/art-20047097
- https://ods.od.nih.gov/factsheets/Calcium-Consumer/
- https://www.ncbi.nlm.nih.gov/pubmed/20068257
- https://ods.od.nih.gov/factsheets/vitaminK-HealthProfessional/
- https://www.sciencedirect.com/science/article/pii/S222541101630181X
- https://www.webmd.com/vitamins/ai/ingredientmono-857/black-cohosh
- https://www.hsph.harvard.edu/nutritionsource/vitamin-c/
