Michele Kohli, BSc, MSc
The Osteoporosis Society of Canada estimates that 1.4 million Canadians have osteoporosis (OP). As discussed in the Clinical Practice Guidelines for the diagnosis and management of osteoporosis,1 the Society recommends several treatments to improve bone mineral density (BMD) and decrease an individual's risk of fracture.1 Since BMD loss occurs in all people as they age, the challenge is to decide which individuals have a low enough BMD to warrant preventive treatment. The Osteoporosis Society of Canada endorses using the World Health Organization definition of OP to decide whether or not BMD loss is significant enough to increase the risk of fracture. This definition utilizes the spectrum, or distribution, of BMDs found in young adults. Any individual whose BMD is at least 2.5 standard deviations below the mean for this distribution is said to have OP.1
Several risk factors for OP and OP-related fractures have been identified, including: older age, female gender, low body weight, cigarette smoking, family history of fracture, history of fragility fractures, loss in height, hyperthyroidism, immobility/ inactivity, calcium or vitamin D deficiency, use of certain pharmaceutical agents (benzodiazepines, anticonvulsants, corticosteroids, heparin) and alcoholism. These risk factors only account for about one third of the risk of having an OP-related fracture.