Osteoporosis, in which bones get dangerously thin, is most common among postmenopausal women. But it can also strike men in advanced age.
"One third of all osteoporotic fractures occur in men," write Christian Meier, MD, of Switzerland's University Hospital Basel, and colleagues.
Meier's team analyzed data on 609 men older than 60 in Australia. The men got a bone mineral density test and had their blood levels of testosterone checked.
The men were followed for almost six years, on average. During that time, 113 men sustained at least one osteoporosis bone fracture.
Men with osteoporosis bone fractures were more likely than other men to have had low testosterone levels at the study's start, regardless of other factors including age, weight, bone mineral density, smoking, and calcium intake.
But the researchers caution that the observational study doesn't prove that low testosterone causes bone fractures or osteoporosis in men. And they aren't ready to recommend hormone therapy to help men avoid osteoporosis bone fractures.
If such therapies are proven safe and effective at preventing fractures in healthy older men, "it is most likely to be justified only in those with the most severe testosterone deficiency," Meier and colleagues write in the Archives of Internal Medicine.