Thiazide Diuretics and Hip Fracture Risk

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The summary below is from the full report titled "Thiazide Diuretics and the Risk for Hip Fracture." It is in the 16 September 2003 issue of Annals of Internal Medicine (volume 139, pages 476-482). The authors are M.W.C.J. Schoofs, M. van der Klift, A. Hofman, C.E.D.H. de Laet, R.M.C. Herings, T. Stijnen, H.A.P. Pols, and B.H.Ch. Stricker.

What is the problem and what is known about it so far?

Broken hips (hip fractures) are common injuries in older people. Older people have increased risks for hip fractures because bones become weaker and thinner as people age. Several drugs may prevent weakening of bones and hip fractures. Thiazide diuretics are drugs often used to treat high blood pressure. They also reduce calcium loss in the urine and may prevent age-related bone loss. However, whether these drugs actually reduce the risk for hip fracture isn't clear.

Why did the researchers do this particular study?

To see whether hip fractures occurred less frequently in older people who took thiazide diuretics than in those who didn't take thiazides.

Who was studied?

7891 people 55 years of age and older.

How was the study done?

In the early 1990s, the researchers asked older people living near Rotterdam, the Netherlands, to participate in a follow-up study. They interviewed and examined people who agreed to participate and followed them for 8 to 9 years. During this time, the researchers routinely communicated with doctors and reviewed medical records to see which persons had hip fractures. The researchers also looked at computerized pharmacy records to see which persons were given thiazide diuretics. They counted the days that the diuretics were prescribed and noted when diuretics were stopped. The researchers then compared numbers of hip fractures among the people given and not given diuretics.

What did the researchers find?

281 first hip fractures occurred during the study. People who took thiazide diuretics for more than 1 year had a much lower risk (about 50% less) for hip fracture than people who never took thiazides. They also found that the risk for hip fracture returned to its pretreatment value within 4 months of stopping thiazides.

What were the limitations of the study?

The researchers accounted for many medical conditions that increase risk for hip fracture, but they did not ask people about exercise. Because few men had fractures, the researchers couldn't assess whether thiazides affect men and women differently. Thiazide use was based on pharmacy records. Some people who were given thiazides may not have taken them.

What are the implications of the study?

Thiazide diuretics given for longer than 1 year may reduce hip fractures. Whether they have effects similar or additive to those of other drugs that prevent hip fracture merits study.