Menopause, Bone Remodeling, and Osteoporosis - How to Be Proactive
As women age, we go through a physiological change called menopause. This occurs when there is a depletion of eggs due to aging.
After a woman goes through menopause they are no longer fertile and will not have monthly menstrual cycles. This typically happens between the ages of 45-55.
There is, however, an unfortunate consequence of menopause which is a drastic drop in estrogen levels.
Estrogen has many functions, but an important function is that it aids in keeping our bone remodeling in homeostasis. This means that helps maintain a normal level of bone formation and bone resorption. When this hormone is not found in its normal amounts our bone density can be heavily affected.
How Does Bone Remodeling Work?
Bone remodeling is a continuous process by which old bone is resorbed into the body and new bone is laid down. Bone resorption is crucial in maintaining calcium levels in the body and is carried out by cells called osteoclasts. Bone formation helps to maintain a stable skeletal structure.
The cells that are responsible for laying down new bone are called Osteoblasts. These cells secrete proteins which are eventually converted to mineralized bone.
As children, our osteoblasts typically out function our osteoclasts which is why we see such large growth spurts in children and adolescents. Peak bone mass is typically reached around age 30. After this point, women’s bone mass does not vary until they reach menopause.
A woman's peak bone mass can give insight into whether she is at risk for osteoporosis later in life.
How Does Menopause Alter Bone Remodeling?
The function of osteoclasts in bone resorption is directly related to estrogen levels. Estrogen acts as an inhibitor of osteoclasts. Without estrogen present to inhibit its function, the lifespan of osteoclasts increases, and these cells can continue resorbing bone for a longer period.
When bone resorption increases we also see an increase in bone formation. This results in an increased turnover rate which puts us at risk for decreased bone density.
This means that our bones are not as stable as they previously were and are more liable to fracture. Since estrogen levels decrease after menopause, women are at a high risk for developing osteoporosis.
Be Proactive and Decrease Risk for Osteoporosis?
Resistance training has been proven to be an influential option in maintaining bone mineral density. It is the primary recommended treatment to prevent osteoporosis by many physicians.
Resistance training programs, regardless of intensity, increase bone density in the lumbar spine whereas progressive overload training has been shown to increase bone density within the femur. Load-bearing activity can help stimulate the cells within the bones to maintain a strong frame.
Not only is this important for post-menopausal women, but it has also been shown to increase bone density in adolescent females. A study done by Blimkie et. al. shows that just 13 weeks of resistance training had significant increases in bone density of the lumbar spine within adolescence.
When adolescent females increase their peak bone density it puts them at decreased risk for developing osteoporosis later in life. In other words, it is encouraged that young females begin a resistance training program. This does not mean they need to be hitting one rep max’s every other week, but it is a good idea to start teaching them basic lifts with lower weight and higher rep counts.
Resistance training and load bearing activities are beneficial in preventing osteoporosis in pre and post-menopausal women. It helps to increase our peak bone mass when we are young which decreases the risk for osteoporosis later in life. It also helps post-menopausal women increase or maintain their bone density. Increasing our bone density can significantly decrease our risk of fracture as we age.
It is worth your while to be proactive about this issue as fractures in the elderly can have detrimental effects on health and acts of daily living. The older we get the longer it takes our fractures to heal and the more difficult it is to fully recover from fractures. Ensuring a high peak bone mass can help prevent common falls from turning into hospital visits.