What is decreased bone density?
Decreased bone density, also known as osteopenia or osteoporosis, is a condition where the bones become less dense and more porous over time. This leads to the bones becoming more brittle and prone to fractures.
Some key points about decreased bone density:
- It often develops without any symptoms, so many people don't realize they have it until a fracture occurs
- It is usually caused by an imbalance between bone resorption (breakdown) and bone formation. As we age, bone tends to be resorbed faster than it is formed
- Risk factors include:
- Advanced age
- Family history
- Low calcium intake
- Lack of physical activity
- Smoking
- Certain medications (e.g. steroids)
- Decreased estrogen levels during menopause accelerate bone loss in women
- Fractures most often occur in the wrist, spine, and hip
- Treatments focus on slowing/preventing further bone loss and include weight-bearing exercise, calcium, vitamin D, and in some cases, drug therapies
How is decreased bone density diagnosed?
Decreased bone density is often diagnosed using a bone mineral density (BMD) test such as a dual-energy X-ray absorptiometry (DXA) scan. This allows the density of the bones to be measured precisely. The results determine whether the patient has normal bone density, osteopenia, or osteoporosis based on how many standard deviations (SD) below young adult peak BMD they are:
- Normal: Less than 1 SD below
- Osteopenia: 1 to 2.5 SD below
- Osteoporosis: More than 2.5 SD below
Understanding and monitoring changes in BMD over time is crucial for assessing fracture risk and guiding treatment decisions.