Demystifying Osteoporosis
If you are older than 60, and especially if you are a woman, chances are you have heard your doctor talk to you about osteoporosis. Osteoporosis, or chronic bone density loss, can be a serious condition. It can put you at a higher risk of future spinal and hip fractures and breaks than normal. These fractures, if not treated properly can then lead to further complications, so It’s important to understand what your risk really is, and what causes it, so steps can be taken to prevent and treat it. But to understand how osteoporosis affects us, we must first understand how bones function under normal, healthy circumstances.
Healthy Bone Function
Throughout life, bone is constantly being broken down and rebuilt in a process called remodeling. It involves two main types of cells: osteoblasts, which are responsible for bone formation, and osteoclasts, which are responsible for bone resorption or breakdown. (National Library of Medicine (1))
Osteoblasts are cells in your body that are responsible for producing and secreting the organic components of the matrix that makes up your bones. This matrix serves as a framework or scaffold upon which mineralization occurs, and is primarily made of collagen. Once the bone matrix is formed, mineralization begins. Calcium and phosphate ions are deposited onto the collagen matrix, forming hydroxyapatite crystals. This mineralization process gives bone its strength and rigidity.
Osteoclasts are large cells that break down bone tissue by secreting acids and enzymes, which dissolve the minerals in bone and break it apart to be reabsorbed by the blood. This resorption phase is crucial for removing old or damaged bone tissue and for maintaining proper calcium levels in the blood.
Osteocytes are a third major cell involved in bone growth. Osteocytes are mature bone cells that are derived from osteoblasts, the cells responsible for bone formation. Once osteoblasts have laid down the bone matrix, some of them become trapped within this matrix and differentiate into osteocytes. These cells are embedded within the bone tissue and play a crucial role in sensing mechanical stresses on bones.
When you injure your bone, whether it’s tiny microfractures caused by exercise, or larger breaks caused by a traumatic incident, Osteocytes then produce molecules that signal for the osteoclasts and osteoblasts to begin bone remodeling in response to these stresses. The body then uses both osteoclasts and osteoblasts in the repair process, first to remove the damaged bone and to re-apply new bone. Your regular daily activities will also contribute to how your bone grows, as your body is constantly recalibrating the need for bone in different areas depending on the stresses applied to it. The adage “Use it or lose it” really applies to your whole body, right down to the individual cell.
The Hormones Essential for Healthy Bones
In addition to physical stresses on your bones, bone is also remodeled depending on the levels of hormones secreted by the body. These hormones include Growth Hormone (GH), Parathyroid Hormone (PTH), Estrogen, Calcitonin, Glucocorticoids, and thyroid hormones. PTH, for example, is essential in sensing how much calcium there is in your bloodstream, and sending signals to break down or build up bone depending on what your levels are. Estrogen is another important hormone that actually hinders the production of osteoblasts, helping to keep bone remodeling process stable, and when estrogen levels are low in the body due to things like menopause, there may be more osteoclasts than osteoblasts, which can means less building and more breaking down of healthy bone tissue, leading to weaker bones. (National Library of Medicine(2))
What is Osteoporosis?
Osteoporosis is one of the most common forms of disorders relating to bone growth, and is defined as the chronic weakening of bone tissue due to either too much bone degradation, not enough new bone growth, or both. This weakening of bones can result in fractures even from minor falls or injuries. Osteoporosis commonly affects older adults, particularly postmenopausal women, but it can also occur in men and younger individuals. It is often referred to as a “silent disease” because it progresses without symptoms until a fracture occurs.
As we discussed, there are many different factors in regulating healthy bones, so the causes of osteoporosis can also be complicated, but for the majority of people with osteoporosis (women over age 60) the cause is frequently decreased Estrogen, which in younger women suppresses the actions of osteoclasts, keeping bones strong and quick to regrow. Other risk factors for osteoporosis include aging, female sex, family history, hormonal changes (such as menopause), inadequate nutrition (particularly low calcium and vitamin D intake), sedentary lifestyle, certain medications, and certain medical conditions.
How Do I Know if I have Osteoporosis?
Your doctor may assess your risk of osteoporosis depending on your age, sex, physical activity, diet, and other factors. If they determine you to be a higher risk than normal, your doctor may choose to use a technique called Dual-energy X-ray absorptiometry (DEXA). Also known as bone densitometry, DEXA is a diagnostic imaging technique used to measure bone mineral density (BMD). It is the most widely used method for assessing bone density, and is the most common and reliable way of determining whether you have osteoporosis. (National Library of Medicine (3)) Ultrasound has also been used to measure bone density at certain points in the body, but usually these ultrasound screenings are used as tool to determine overall risk, and determine if an individual would benefit from a more thorough, DEXA screening.
After DEXA screening, a T-score and/or a Z-score is applied. A T-score compares your BMD to that of a healthy young adult (ages 25-35) of the same sex. A T-score of -1.0 or higher is considered normal, while scores between -1.0 and -2.5 indicate low bone density (osteopenia), and scores of -2.5 or lower indicate osteoporosis. (Harvard Heath Publishing)
A Z-score is a comparison of your BMD as compared to a healthy adult of your same sex and age group. This may be very helpful as it’s important to understand what normal aging looks like in the average healthy body, but many times only a T-score is used, which may lead to a diagnosis of osteoporosis, even if your BMD is normal for someone of your same age.
A diagnosis of osteoporosis is characterized by having a bone density measuring more than 2.5 standard deviations (SD) below the mean for young adults. This is measured as a T-score or Z-score of -2.5. If you have a family history of individuals of your same age and sex being diagnosed, or have experienced prior fractured or other bone injuries, this may also contribute to your diagnosis.
Osteoporosis – Early Detection
Osteoporosis poses a significant risk, especially for older individuals, particularly women over the age of 60. Understanding the intricate process of bone growth and the role of hormones is crucial in comprehending the development of this condition. Early detection through methods like DEXA scans is essential for timely intervention. If you’re concerned about osteoporosis or seeking more information on its prevention and treatment, we encourage you to explore our dedicated article (link to prevention and treatment article #4) covering these aspects in detail. By staying informed and proactive, you can take steps to safeguard your bone health and reduce the risk of fractures associated with osteoporosis.
Learn more about our Bioidentical Hormone Replacement services to treat osteoporosis here.
