Media Release: 09 November 2010
Beta-blocker use increases bone density and reduces risk of osteoporotic fracture by around 50% in men and women, say Australian researchers.
Not only that, a global trend towards prescribing other hypertensive agents, which may lack the protective effect, could lead to a significant increase in fractures.
Beta-blockers, a class of drug that reduces the effects of stress hormones, are widely used to treat heart problems, hypertension and some anxiety disorders.
PhD student Shuman Yang and Professor Tuan Nguyen from Sydney’s Garvan Institute of Medical Research used data collected from the long-running Dubbo Osteoporosis Epidemiology Study to demonstrate that people on beta-blockers have lower risk of fracture and better bone density. Their findings are now online in the international journal, Bone.
“The thing that spurred this study was a remarkable finding from a research group at Columbia University a few years ago which showed that mice treated with beta-blockers have increased bone mass,” said project leader Professor Nguyen.
“That was very significant, as it showed that the sympathetic nervous system has an effect on bone.”
“So we set out to test the hypothesis that ‘if mice treated with beta blockers have increased bone mass, and we know that increased bone mass is associated with reduced fracture risk, then people on beta blockers should have reduced fracture risk’.”
“We found that indeed it was the case – beta-blockers reduced the risk of fracture by about 50% in men and women, which is dramatic. Drugs used specifically for treating osteoporosis also reduce fracture by around the same magnitude.”
“Extrapolating this finding, we suggest that the use of beta-blockers over the past four decades may have contributed towards a lack of increase in osteoporotic fractures.”
“We estimate that in Australia, North America, Europe and Japan, where rising levels of obesity and high blood pressure have been treated with beta-blockers, fracture risk may have been reduced by as much as 29%.”
“The worrying factor is that we are starting to see a drift away from beta-blockers as the preferred treatment for hypertension. They are gradually being replaced by other drugs that may not have their protective effect on bone.”
As around 45% of women and 20% of men over 60 will develop osteoporosis during their remaining lifetime, the public health ramifications are clear.
The current project was based on 3488 participants in the Dubbo study, 2203 women and 1285 men, who were first seen between 1989 and 1993. Bone Mineral Density measurements were taken at the first visit, and have been measured biennally since then.
Dubbo data over a 20-year period was used to compare fractures among beta-blocker users and non-users.