Bone Loss and Aging
Bone loss and aging are inseparable: “The skeleton is a systemically regulated mass of mineralized material that is born, grows, reaches a more or less high peak, and then declines faster or slower as to develop a correspondingly high or low fracture risk”(Ferretti et al. 2003). Musculoskeletal aging—declining bone and muscle mass, increasing joint pain and stiffness, and decreasing physical mobility—is a normal part of aging. However, how rapidly or slowly bone mass declines depends on different factors. While genetic abnormalities account for 70% of the variance in skeletal strength (Rizzoli 2014), other factors—like hormones, nutrition, physical activity and toxins—play crucial roles in developing bone and losing it.
Understanding bone loss starts with distinguishing between the two basic diagnoses: osteopenia (low bone mass) and osteoporosis (advanced loss of bone tissue). Then, the smart thing to do is learn about risk factors and preventive measures.
Osteopenia vs. Osteoporosis
More clients may come to you with a diagnosis of osteopenia than with the better-known osteoporosis. Osteopenia points to low bone mass when overall bone mineral density hasn’t fallen far enough to cause serious concern. It’s critical to note that an osteopenia diagnosis does not mean osteoporosis is inevitable. However, if a client mentions this diagnosis, you have an excellent opportunity to explain that physical activity and nutrition are important modifiable factors that can prevent further decline.
We distinguish between osteopenia and osteoporosis via the T-score system, which quantifies BMD (Karaguzel & Holick 2010). Because the T-score measures bone loss, it is expressed as a negative number. A T-score between -1
and -2.5 is defined as osteopenia, while a T-score below -2.5 is defined as osteoporosis.
There are two types of osteoporosis, both characterized by weakened bone and increased risk for fracture: primary (bone loss through aging) and secondary (caused by a variety of diseases, medications and toxic agents). We will focus only on primary osteoporosis since it is the more common type and also the type that fitness professionals can help clients with through physical activity and nutrition.
Osteoporosis is often called the “silent disease” because it’s usually not diagnosed until after a fracture (Porter et al. 2016). Indeed, nearly 80% of older adults who suffer bone breaks have never been tested or treated for osteoporosis (NOF 2016). Following a fracture, the risks of mortality and disability accelerate: 1 in 5 hip fracture patients end up in a nursing home (OSG 2004), and 24% of hip fracture patients over 50 die in the year after the fracture (NOF 2016).
Thus, fitness professionals who help older exercisers confront the risk factors of osteoporosis can be lifesavers.
To read more about the workings of the skeleton and the risks of bone loss, please see “Bone Health: A Primer” in the online IDEA Library or in the June 2018 print issue of IDEA Fitness Journal. If you cannot access the full article and would like to, please contact the IDEA Inspired Service Team at (800) 999-4332, ext. 7.
References
Bonewald, L.F. 2006. Mechanosensation and transduction in osteocytes. Bonekey Osteovision, 3 (10), 7–15.
Chiba, R., et al. 2016. Human upright posture control models based on multisensory inputs; in fast and slow dynamics. Neuroscience Research, 104, 96–104.
Ferretti, J.L., et al. 2003. Bone mass, bone strength, muscle-bone interactions, osteopenias and osteoporoses. Mechanisms of Ageing and Development, 124 (3), 269–79.
Giangregorio, L.M., et al. 2014. Too fit to fracture: Exercise recommendations for individuals with osteoporosis or osteoporotic vertebral fracture. Osteoporosis International, 25 (3), 821–35.
Gilbert, S.F. 2000. Developmental Biology (6th ed.). Sunderland, MA: Sinauer Associates.
Hernandez C.J., Beaupre, G.S., & Carter, D.R. 2003. A theoretical analysis of the relative influences of peak BMD, age-related bone loss and menopause on the development of osteoporosis. Osteoporosis International, 14, 843–7.
IOF (International Osteoporosis Foundation). 2017. Facts and statistics. Accessed Mar. 3, 2018: iofbonehealth.org/facts-statistics.
Karaguzel, G., & Holick, M.F. 2010. Diagnosis and treatment of osteopenia. Reviews in Endocrine and Metabolic Disorders, 11 (4), 237–51.
Lacour, M., Bernard-Demanze, L., & Dumitrescu, M. 2008. Posture control, aging, and attention resources: Models and posture-analysis methods. Neurophysiologie Clinique, 38 (6), 411–21.
Laskowski, E.R. 2012. The role of exercise in the treatment of obesity. PM & R: The Journal of Injury, Function, and Rehabilitation, 4 (11), 840–44.
Lerner, U.H. 2012. Osteoblasts, osteoclasts, and osteocytes: Unveiling their intimate-associated responses to applied orthodontic forces. Seminars in Orthodontics, 18 (4), 237–48.
McMillan, L.B., et al. 2017. Prescribing physical activity for the prevention and treatment of osteoporosis in older adults. Healthcare, 5 (4), e85.
NIH (National Institutes of Health). n.d. Trabecular bone. Accessed Mar. 19, 2018: ncbi.nlm.nih.gov/pubmedhealth/PMHT0022808/.
NOF (National Osteoporosis Foundation). 2016. Accessed Mar. 19, 2018: nof.org.
ODPHP (Office of Disease Prevention and Health Promotion). 2018. Physical activity. Accessed Mar. 19, 2018: healthypeople.gov.
OSG (Office of the Surgeon General). 2004. Bone health and osteoporosis: A report of the Surgeon General. Accessed Mar. 3, 2018: ncbi.nlm.nih.gov/books/NBK45513/.
Porter, J., et al. 2016. The effect of dietary interventions and nutritional supplementation on bone mineral density in otherwise healthy adults with osteopenia: A systematic review. Nutrition Bulletin, 41 (2), 108–21.
Rizzoli, R. 2014. Nutritional aspects of bone health. Clinical Endocrinology & Metabolism, 28 (6), 795–808.
Tagliaferri, C., et al. 2015. Muscle and bone, two interconnected tissues. Ageing Research Reviews, 21, 55–70.
Watson, S.L., et al. 2015. Heavy resistance training is safe and improves bone, function, and stature in postmenopausal women with low to very low bone mass: Novel early findings from the LIFTMOR trial. Osteoporosis International, 26 (12), 2889–94.
Wright, N.C., et al. 2014. The recent prevalence of osteoporosis and low bone mass in the United States based on bone mineral density at the femoral neck or lumbar spine. Journal of Bone Mineral Research, 29 (11), 2520–26.
Maria Luque, PhD, MS, CHES
Maria Luque, PhD, is a health educator, fitness expert, presenter, writer and USAF veteran. She created Fitness in Menopause, a company dedicated to helping women navigate the challenges and rewards of menopause. Her course “Menopausal Fitness: Training the Menopausal Client” is NASM-, AFAA- and ACE- accredited. She holds graduate and postgraduate degrees in health sciences and teaches at the College of Health and Human Services at Trident University International.
