Can We Slow Down and Reverse Osteoporosis?
Scientists from Barcelona and Madrid have discovered a way of reducing the risk of osteoporosis and slowing down the process in the early stages following diagnosis by reinforcing bone mass.
Researchers from the National Cardio-Vascular Investigation Centre (CNIC) in the two cities, together with their counterparts in Belgium and France have discovered a way of monitoring the cells which 'eat' bone mass.
They are studying the use of a drug normally employed in treating surface lymphomas – Bexarotene – as a way of blocking the formation of osteoclasts, the cells which 'attack' bone mass.
According to the team led by Dr Mercedes Ricote, whose main researchers are Dr María Piedad Menéndez and Dr Tomás Roszer, the formation and spread of osteoclasts can be controlled by a protein found in the bone cells known as a retinoid X-receptor, or RXR, which carries vitamin A derivatives and lipids, or fat cells.
RXR controls the development, immunity and metabolism of bone cells as well as the presence of a key molecule, known as a MAFB, which generates osteoclasts.
Laboratory tests on genetically-modified mice has shown that the loss of RXR gives rise to 'gigantic' osteoclasts, and have worked out how to control the 'bone-eating' function in these by doctoring the amount of RXR fed into them.
This way, they have discovered how male mice, in normal physiological conditions, develop much denser bones, and have ascertained how to protect bone mass in female mice when this diminishes as a result of loss of oestrogen after their fertile era has ended.
Osteoporosis is particularly common in post-menopausal women due to the loss of oestrogen, the female reproductive hormone, but a significant minority of men of a similar age suffer it, explains the team.
Every year, millions of osteoporosis patients suffer fractures and deformities.
The risk of osteoporosis increases with age and is also linked to diet and body weight.
Malnutrition in youth or early adulthood - such as in women with eating disorders - and, conversely, excess body weight are risk factors, as is a diet low in calcium.
Physical exercise, particularly weight-bearing, or strengthening activities such as Pilates, are helpful defences against osteoporosis.
Spanish researchers warn that with the ageing population in the country caused by people living longer and a lower birth rate, patients being treated for fractures and disabling deformities could rise in number over the next few decades given how osteoporosis is more common in old age.