The researchers compared 209 people with benign positional vertigo with no known causes -- such as ear surgery or head trauma -- with 202 people with no history of dizziness. Compared to participants with normal bone density, those with osteoporosis (low bone density) were three times more likely to have vertigo and those with osteopenia (the stage before osteoporosis) were two times more likely to have vertigo.
Among women, 25 percent of those with vertigo had osteoporosis, compared to 9 percent of those without vertigo, and 47 percent of those with vertigo had osteopenia, compared to 33 percent of those without vertigo. Among men, 12 percent of those with vertigo had osteoporosis, compared to 6 percent of those without vertigo, and 40 percent with vertigo had osteopenia, compared to 27 percent of those without vertigo.
The study will be published in the March 24 issue of Neurology.
"These findings suggest a problem with calcium metabolism in people with vertigo," Dr. Ji Soo Kim, of the Seoul National University College of Medicine, said in a journal news release.
"Women most often have their first case of vertigo in their 50s, when they are also having a drop in bone mass due to loss of estrogen. Estrogen is one of the main hormones that influence calcium and bone metabolism," Kim said.
The role that estrogen plays in vertigo hasn't been determined. Since this study also found an association between osteoporosis and vertigo in men, other factors must also play a role, Kim noted.
-- Robert Preidt
SOURCE: American Academy of Neurology, news release, March 23, 2009