Back to Bone Health and Osteoporosis
Definitions, Situation of Osteoporosis in Canada and Risk Factors
Osteoporosis is a disease with its roots in childhood, as bone size, strength, and mineralization peak in one's 20s. Since bone mass declines with advancing age and menopause, individuals who attain optimal peak bone mass during their younger years will have an advantage as they get older. Although it is largely genetically predetermined, peak bone mass is not always attained due to inadequate calcium and vitamin D intakes, poor overall nutrition, lack of physical activity, and other factors such as smoking.1
Definitions
Osteoporosis is defined as a “systemic skeletal disorder characterized by a low bone mineral density (BMD) and micro-architectural deterioration of bone tissue, leading to enhanced bone fragility and a consequent increase in fracture risk.”1 Since we currently do not have a reliable way of measuring bone quality, osteoporosis tends to be diagnosed based on low bone density alone. The World Health Organization defines a fragility fracture as a “fracture caused by injury that would be insufficient to fracture normal bone”2 In other words, it is a fracture that would not otherwise occur to normal, healthy bone.
The situation in Canada
Osteoporosis is a major health problem in Canada, and its prevalence is increasing as the population ages.1 According to results from bone mineral density assessments in the Canadian Multicentre Osteoporosis Study (CaMOS), the prevalence of osteoporosis in Canadian women aged 50 years and over is:3
- 12.1% at the lumbar spine,
- 7.9% at the femoral neck,
- Combined prevalence of 15.8%.
According to Osteoporosis Canada, one in four women and at least one in eight men over the age of fifty suffers from osteoporosis.4 The prevalence of osteoporosis increases with age: 6% at 50 years to greater than 50% above 80 years. This disease is therefore likely to become an even bigger problem in the future as the population continues to age.1
The major public health and clinical impact of osteoporosis lies in the fractures caused by the disease. About 20% of women and 40% of men die within 1 year after a hip fracture. It has been estimated that 50% of women who sustain a hip fracture become functionally dependent in their daily activities, and 19% require long-term nursing home care.1 Osteoporosis Canada recommends that all postmenopausal women older than 50 years be assessed for the presence of risk factors for osteoporosis, as outlined in Table 1.1
Table 1: Risk factors that identify who should be assessed for osteoporosis
| Major Risk Factors | Minor Risk Factors |
| Age 65 years | Rheumatoid arthritis |
| Vertebral compression fracture | Past history of clinical hyperthyroidism |
| Fragility fracture after age 40 | Chronic anticonvulsant therapy |
| Family history of osteoporotic fracture | Low dietary calcium intake |
| Systemic glucocorticoid therapy 3 months | Smoker |
| Malabsorption syndrome | Excessive alcohol intake |
| Primary hyperparathyroidism | Weight < 57 kg |
| Propensity to fall | Weight loss > 10% of weight at age 25 |
| Osteopenia apparent on X-ray film | Chronic heparin therapy |
| Hypogonadism | |
| Early menopause (before age 45) |
Canadian Consensus Conference on Osteoporosis 2006.1
As childhood habits have an impact on this disease, the best approach is prevention via the attainment and maintenance of optimal bone health.
References
- Brown JP, Fortier M. Canadian Consensus Conference on Osteoporosis, 2006 update. J Ostete Gynaecol Can 2006;28(special edition 1):S95-S112.
- Brown JP et al. 2002 clinical practice guidelines for the diagnosis and management of osteoporosis in Canada. CMAJ 2002;167(10 suppl):S1-S33.
- Tenenhouse A et al. Estimation of the prevalence of low bone density in Canadian women and men using a population-specific DXA reference standard: The Canadian Multicentre Osteoporosis Study (CaMos). Osteoporos Int 2000;11:897-904.
- Osteoporosis Canada. Breaking barriers not bones: 2008 report on osteoporosis care. 2008:1-33.
Keywords: osteoporosis, health studies
Scientific Evidence Keywords
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