Broken hip tied to increased risk of stroke

While suffering a stroke is already known to raise the risk of breaking your hip, new research shows that the reverse might also be true; something seen previously in other studies. The study out of Taiwan found that patients with a broken hip had more than a 50 percent increased risk of having a stroke within a year of their injury compared to similar patients with no fractures.

Hip fractures account for more than 320,000 hospital admissions every year in the U.S., but can they actually cause a stroke -- the nation's third leading cause of death."

It is known that the risk of hip fracture is high in those with strokes. We thought that was because strokes lead to falls and bone loss," Dr. Steven Cummings of the University of California, San Francisco, told Reuters Health in an e-mail.

"This new study makes me think that both hip fractures and strokes are partly due to an underlying cause of aging," added Cummings, who was not involved in the current research but recently led a separate study of hip fractures.

Jiunn-Horng Kang of National Taiwan University, in Taipei, and his colleagues studied about 8,400 Taiwanese patients averaging 64 years old. Among 256 patients who suffered a stroke over the course of a year, 4.1 percent had broken their hips previously, compared to 2.7 percent of those who hadn't. That translated into more than a 50 percent increased risk of stroke after the injury. The difference in vulnerability held after accounting for other stroke risk factors such as diabetes and heart disease.

Still, what might be responsible for the added risk remains unclear, report the researchers in the journal Stroke. They point to the potential roles of physical inactivity and psychological distress that comes after a broken hip, and the complications that can arise during hospitalization and surgery. However, a "common hidden cause" might also underlie both broken hips and stroke, noted Cummings. "We know that those with cardiovascular disease have lower bone density and most studies, like ours, show that low bone mineral density is associated with a greater risk of dying of stroke," he said. The study is published online ahead of print in the December 23, 2010 issue of the journal Stroke.