Beta blocker drugs protect against heart attacks and thiazide diuretics are commonly used to treat high blood pressure. But these drugs may have another benefit, say scientists from Switzerland; they could help maintain strong bones.

What the researchers wanted to know: Do beta blockers, taken alone or with thiazide diuretics, help prevent bone fractures?

What they did: The researchers used data from a huge study being done in the United Kingdom to assess the general health of the population. The researchers identified all of the participants between the ages of 30 and 79 who had broken a bone between January 1993 and December 1999, totaling 30,601 people in all. They then looked at whether these people were taking beta blockers and thiazide diuretics. They compared people with fractures to a similar-age control group.

What they found: Beta blockers did seem to protect against fractures in the short term; people who had been using beta-blockers for less than five years were 37 percent less likely to have suffered a fracture than people who were not. But for people who had been taking beta blockers for more than five years, the risk of fracture rose; these people were only 17 percent less likely to fracture their bones. However, the authors say this finding is not consistent with the rest of their data and could be a chance result. Using beta blockers with thiazide diuretics also reduced risk of fracture: People taking both were about 29 percent less likely to fracture their bones than those who did not take the drugs.

What it means to you: Previous studies have shown that thiazide diuretics can help build strong bones by reducing the amount of calcium that is released in urine. However, this study shows that beta blockers may also help build bone mass, either alone or in combination with thiazide diuretics. The authors write that this study could be most useful for senior patients, who often struggle with both heart and bone diseases.

Caveats: The authors tried to control for many different factors but had no information on participants' physical activity, diet, or socioeconomic status, variables that could have skewed the data.

Find out more: The National Institutes of Health has information on the combination of beta blockers and thiazide diuretics, which are usually used to reduce hypertension.

The researchers took their data from the General Practice Research Database.

Read the article: Schlienger, R.G. et al. "Use of Beta-Blockers and Risk of Fractures." Journal of the American Medical Association. Sept. 15, 2004, Vol. 292, No. 11, pp. 1326-1332.

Abstract online: http://jama.ama-assn.org