What Is Bone Mineral Density?
Bone mineral density (BMD) or bone density refers to the amount of bone minerals like calcium present in bone tissue. Bone mineral density is an indicator of bone health. Bone health is essential for daily activities and protecting our body. Bones provide support, help us move, protect our brain, heart, and other organs.
Testing Bone Mineral Density
The BMD test measures the amount of minerals like calcium present in your bone. This is one of the best ways to keep track of your bone health. The results of this test can tell you how strong or weak your bones are, your risk of weak bones and osteoporosis, whether your osteoporosis treatment is working, and your bones are recovering.
The BMD test is also referred to as Dual Energy X-ray Absorptiometry(DXA).
This test measures your BMD and compares it to a standard established, and gives you a score called the T-score and the Z-score.
A T-score of 0 means your BMD is equal to that of the standard norms set for a healthy young adult and your bones are healthy. Differences between your BMD and the standard norm are reported in terms of standard deviation. A score between -1 and +1 is considered healthy. A score between -1 and -2.5 means you have low bone density or osteopenia. Scores below -2.5 indicate osteoporosis. The more negative the score is, the weaker your bones are, and the more severe your osteoporosis is.
A T or Z-score above +2.5 is an indicator of high BMD.
Once your scores are obtained, your doctor may use a risk assessment tool called FRAX. This is an online fracture risk assessment tool that can calculate a person’s absolute fracture risk. It can also tell you if you have a greater chance of breaking a bone.
Genetics and Bone Mineral Density
The VDR Gene
The VDR genecarries instructions for the production of the vitamin D receptor. This receptor binds to the active form of vitamin D and modulates several functions in the cell. Vitamin D is essential for the maintenance of bone health by aiding in the absorption of calcium.
*rs7311236 *
rs7311236 is a single nucleotide polymorphism or SNP in the VDR gene. People with the T allele of this SNP tend to have lower BMD than those with the CC type.
The FGF2 Gene
TheFGF2 gene carries instructions for the production of basic fibroblast growth factor protein. This protein is involved in several biological processes, including wound healing, limb and nervous system development, and tumor growth.
rs1048201
rs1048201 is an SNP in the FGF2 gene. Carriers of the T allele were found to have a lower spine BMD than those with the CC type.
The LRP5 Gene
The LRP5 gene carries instructions for the production of LDL receptor-related protein 5. This protein is present in the outer membrane of several types of cells and is involved in the development and maintenance of certain tissues. It helps regulate BMD.
rs4988321
rs4988321is an SNP in the LPR5 gene. People with the A allele were found to have reduced spine BMD and an increased risk of osteoporosis.
Non-Genetic Factors That Influence Bone Mineral Density
Gender
Women, especially after menopause, are found to be at an increased risk of developing low BMD.
Age
The risk of low BMD and osteoporosis increases with age.
Physical activity
A sedentary lifestyle increases the risk of developing osteoporosis.
Size
An extremely thin person or people with a smaller body frame are at greater risk of developing low BMD.
Diet
You may be at higher risk of developing low BMD if you do not include enough calcium in your diet to meet your body’s requirements.
Smoking and alcohol
The use of tobacco and regular consumption of alcohol can increase the risk of osteoporosis.
Hormone levels
Excess of thyroid hormone can lead to bone loss. The levels of estrogen decrease after menopause, and this can increase the risk of low BMD. Low testosterone levels in men can also lead to bone loss.
Medication
Corticosteroid medications can increase the risk of bone damage on prolonged use. Certain drugs like aromatase inhibitors used to treat breast cancer, anti-seizure medications may increase the risk of developing osteoporosis.
High Bone Mineral Density
Scelorisng bone dysplasias and osteopetroses are a group of rare genetic disorders with skeletal effects that can lead to a high BMD value. A high bone density may be associated with conditions that increase fracture risk, or it may mask low BMD and affect measurements of fracture risk.
Low Bone Mineral Density
Without proper care, bones can become weaker, and the risk of injury increases. It can lead to fractures which can take time to heal. It can also lead to long-lasting health problems.
When your bone density is lower than normal, it can be an indicator of deteriorating bone health. This means that you have an increased risk of developing osteoporosis. Osteoporosis is a condition in which your bones become weak and brittle. It occurs when the body loses too much bone or makes very little bone to make up for the bone loss. Lower bone density also increases the risk of fractures.
Recommendations
Diet
Make sure you include enough calcium in your diet to meet your body’s requirements and keep your bones healthy. Dietary sources of calcium include almonds, broccoli, dairy products, sardines, and soy products. Your doctor may also recommend supplements if you cannot meet your calcium needs through diet. Other minerals essential for bone health include phosphate and magnesium.
Vitamin D is essential for the proper absorption of calcium. Get enough sun exposure and include Vitamin-D rich foods in your diet. There are supplements available.
Reduce your alcohol consumption and avoid the use of tobacco.
Physical activity
Get active and include some physical activity in your schedule. This helps keep your bones healthy and strong. Physical activity can help manage body weight also.
Summary
- Bone mineral density(BMD) refers to the amount of bone minerals like calcium present in bone tissue. It is an indicator of bone health. Certain genetic disorders may lead to increased BMD. Low BMD can increase the risk of fractures and lead to osteoporosis.
- The Bone Mineral Density(BMD) test measures the amount of minerals like calcium present in your bone. This is one of the best ways to keep track of your bone health.
- Variations in genes can increase the risk of low BMD and osteoporosis. Some genes associated with BMD are VDR, FGF2, and LRP5.
- Gender, age, physical activity, size, and diet are some of the factors that influence BMD apart from variations in genes.
- A healthy, balanced diet with a good source of calcium, phosphorous, magnesium, and protein is essential for maintaining bone health. Exercising can help keep your bones strong and healthy.
References
https://medlineplus.gov/bonedensity.html
https://www.healthline.com/health/bone-mineral-density-test
https://medlineplus.gov/ency/article/007197.htm
https://www.webmd.com/osteoporosis/guide/bone-mineral-density
https://www.bones.nih.gov/health-info/bone/bone-health/bone-mass-measure
https://www.nof.org/patients/diagnosis-information/bone-density-examtesting/
https://americanbonehealth.org/bone-density/understanding-the-bone-density-t-score-and-z-score/
https://www.mayoclinic.org/healthy-lifestyle/adult-health/in-depth/bone-health/art-20045060
