Largest ever Canadian study on osteoporosis informs health policy

Dr David Goltzman and his team from the Research Institute of the McGill University Health Centre (RI MUHC) and McGill University – along with colleagues from across Canada – have issued new recommendations to public health authorities about how to best cope with osteoporosis, a bone disease which leads to increased risk of fracture, particularly in the elderly. Their recommendations derive from the latest results of the Canadian Multicentre Osteoporosis Study (CaMos), which will be published June 16 in the Canadian Medical Association Journal (CMAJ). Osteoporosis results from reduced bone mineral density (BMD), disrupted bone microarchitecture and alteration in the distribution and variety of non-collagenous proteins in bone, all of which serve to place sufferers at far greater risk of bone fractures, which can be life-threatening in the elderly. The measure of BMD is the main predictive marker of the disease.

"Osteoporosis has enormous impact on public health and on the quality of life of patients," Dr. Goltzman said.

The latest CaMos results confirm that, for women, menopause is a critical period during which bone mineral density decreases in all the bones studied. More specifically: an average decrease of 6.8% over 5 years was observed in the hip. Significant BMD loss also occurs after age 70, mainly in the hip bone. In men, BMD decreases more gradually, although it starts earlier, around the age of 40.

The fact that rapid BMD loss occurs after menopause was already known but had never been previously quantified, while the second period of BMD decline after age 70 is a completely new discovery.

"These findings provide new insight into the public health impact of osteoporosis," Dr. Goltzman explained. "Population aging combined with the potential human and financial consequences of fractures, notably hip fractures represent a major challenge. However, knowing the age at which bone loss is more likely to occur opens up new avenues for preventive measures."

The CaMos study involves nine other centres across Canada that are coordinated from the MUHC in Montreal. It has recruited more than 10,000 participants since 1996. The long duration and the national scale of the project have enabled researchers to determine that participants' BMD varies very slowly in the absence of other risk factors.

"The scope of the CaMos study means that we can produce data that are representative of the entire Canadian population, in order to help improve official recommendations, and to enhance the prevention, diagnosis and treatment of osteoporosis," said Dr Goltzman.

"In light of our results, we think that, in the absence of other risk factors, BMD should be measured every five years, instead of every two years, as is currently the case," he continued. "Of course, this frequency should be modified if the person does have other risk factors.

Source: McGill University Health Centre