Researchers led by Steven J. Jacobsen, MD, of Kaiser Permanente Southern California, wanted to find out if there is any connection between 5-alpha reductase inhibitors and hip fractures. Examples of these drugs include Proscar and Avodart.
These drugs treat BPH in part by blocking testosterone from converting to dihydrotestosterone. The researchers write that other studies "suggest that dihydrotestosterone might have a role in bone metabolism, but no clear evidence exists to support this theory."
The researchers gathered data on 7,076 men (45 years and older) from 1997 to 2006, all who had hip fractures. They compared them with a group of 7,076 similar men who did not have a hip fracture.
109 of the men with hip fractures had taken a 5-alpha reductase inhibitor
141 of the men without hip fractures had taken a 5-alpha reductase inhibitor
Their conclusion: 5-alpha reductase inhibitors are not linked to an increased risk of hip fracture; instead, they may decrease risk of hip fracture.
Interestingly, the researchers also found a modest increase in hip fracture risk in the men who took alpha-blockers. There was more use of alpha-blockers (32%) in men with hip fractures vs. men without hip fractures (30%). Since this was not a primary focus of the study, the researchers write that this finding warrants further investigation.