Special Feature “ Health & Exercise Forum” with Geisinger Commonwealth School of Medicine the 3rd Monday of every month!
Guest Columnist: Ian Coote
Ian Coote, MD3 originally from Rogersville, PA is a third-year medical student at Geisinger Commonwealth School of Medicine. Ian majored in Biological Sciences at Ohio Northern University before graduating in 2015. He hopes to pursue a career in emergency medicine upon graduating from GCSOM.
Growing old is one of life’s inevitabilities. While growing old is something we all hope to achieve, as we age our bodies start to wear down. Many people start to have more aches and pains as they grow older which can seriously impact their happiness and overall quality of life. It is important for us to take care of our bodies when we are young and to continue to take care of ourselves as we get older. Knowing how to care for our health and being aware of some the things to watch out for as we age is essential. One of the more common issues that people experience as they age is problems with their bones, specifically osteoporosis.
The human skeletal system is made up of 206 bones. Our bones have several functions including physical support, transferring the forces produced by our muscles to allow us to move around the world, protection of our internal organs, mineral regulation, and serve as the location where our red blood cells are made. Each bone in our body is made up of three basic layers. The outermost layer is known as the periosteum and it is a thin fibrous layer that can be thought of as a sort of “plastic wrap” that serves as the outer layer of bone. This periosteum or “plastic wrap” has several purposes; it contains the blood vessels that supply nutrients to the bone, it contains nerves that allow us to feel, and it serves as the attachment point for muscles and tendons which allows us to move our arms and legs. The next layer of bone is called compact bone. It is made from tightly packed minerals and is very strong, stiff, and dense. The compact bone serves to provide support to our bones and to protect our internal organs. The innermost layer of bone is called cancellous bone. The cancellous bone is made up of the exact same minerals as the compact bone but is much more spongy and arranged in a mesh-like pattern. Cancellous bone serves to provide internal support to bones and is the region in which red blood cell production occurs.
Our bones are constantly undergoing a process of being broken down and rebuilt. This means that old, worn-out bone tissue is being degraded and the minerals that make up the old bone are being recycled and made into new, healthier bone. This process is known as bone remodeling and there are two types of cells that are involved, osteoclasts and osteoblasts. The easiest way to understand how osteoclasts work is to think of them as the bone’s inspection and demolition crew. Osteoclasts search around bone to find weak or damaged bone and then release chemicals that dissolve the weak bone. The minerals or building materials of the bone are then recycled. Osteoblasts are the construction crew of the bones. They are constantly laying down the building material of bone and helping it to mature into strong healthy new bone. This process of bone remodeling is happening constantly and it is very important that there is a healthy balance between the activity of the bone demolition crew and the bone construction crew.
Osteoporosis is essentially an imbalance between the osteoclast “demolition crew”, and the osteoblast “construction crew”. In osteoporosis the demolition crew is working much harder and faster than the construction crew. This produces bone that is thinner, less dense, brittle, and overall weaker than normal healthy bone.
The group of individuals that is at the greatest risk for developing osteoporosis is post-menopausal women. The reason that women who have gone through menopause are at increased risk for osteoporosis has to do with estrogen. Estrogen is a naturally produced chemical in the human body that is mainly produced by the ovaries. Estrogen has a role in maintaining bone health in that it inhibits the activity of the osteoclasts, which are the bone demolition crew. With the osteoclasts inhibited, the osteoblasts, the bone construction crew, are able to build strong healthy bone without being overwhelmed by the destruction that the osteoclasts cause. Women who have gone through menopause have decreased activity within their ovaries and therefore much less estrogen present in their bodies. This lack of estrogen means that the osteoclasts are not as inhibited as they were before the woman went through menopause and therefore the bone demolition crew starts to work faster than the bone construction crew. When this occurs, bones become thin and brittle and are much more likely to fracture.
While postmenopausal women are at the greatest risk for developing osteoporosis, they are not the only population at risk. As we age, our osteoblasts, or bone construction crew, become tired and start to slow down. It is also not unusual for older people to stop eating a well-balanced diet which leads to fewer of the essential components that make up bone to be present in the body. Therefore, it is not surprising to learn that 10 million Americans over the age of 50 have osteoporosis and that 2 million of these are men.
NEXT WEEK: Part 2: Ways to Prevent and Treat Osteoporosis
Read Dr. Mackarey’s Health & Exercise Forum – every Monday. This article is not intended as a substitute for medical treatment. If you have questions related to your medical condition, please contact your family physician. For further inquires related to this topic email: firstname.lastname@example.org
Paul J. Mackarey PT, DHSc, OCS is a Doctor in Health Sciences specializing in orthopaedic and sports physical therapy. Dr. Mackarey is in private practice and is an associate professor of clinical medicine at Geisinger Commonwealth School of Medicine.