Benign positional vertigo appears to strongly correlate with osteopenia and osteoporosis in both men and women, researchers in a case-control study have concluded.
Compared with controls, patients with osteopenia were twice as likely to experience positional vertigo, and those with osteoporosis were three times as likely to experience the disorder, Dr. Ji Sook Kim and colleagues wrote.
“These findings suggest a deranged calcium metabolism in idiopathic benign positional vertigo,” Dr. Kim of the Seoul National University College of Medicine, Korea, said in an interview.
“Restoring normal calcium metabolism may prevent recurrences of BPV.”
The study compared bone mineral density in 209 patients with a diagnosis of idiopathic benign positional vertigo (BPV) and 202 controls. Most of the patients (142) were female; their mean age was 60 years.
Among female patients, only 28% had normal bone mineral density, while 47% had osteopenia (T score > −2.5 and < −1.0) and 25% had osteoporosis (T score = −2.5). Among female controls, normal bone mass was found in 57%; 33% had osteopenia and 9% had osteoporosis. (Percentages do not add up to 100% due to rounding.) The differences were significant at all points measured (Neurology 2009;72:1069–76).
In male patients, 48% had normal bone mass, while 40% had osteopenia and 12% had osteoporosis. Among male controls, 67% had normal bone mass, 27% had osteopenia, and 6% had osteoporosis. The differences were significant at the femur and first lumbar vertebra, but not at the other lumbar measurements.
Recurrent attacks of BPV (defined as at least two previous attacks at least 1 month apart) had occurred in 40% of patients. Compared to patients with new-onset BPV, patients with recurrent BPV were older (62 vs. 60 years) and more likely to be women (77% vs. 62%).
In women older than 45 years, the mean lowest T-scores were lower in the recurrent group than in the new-onset group (-2.1 vs. −1.6). There were no between-group T score differences in younger patients. This finding supports the premise that estrogen deficiency may contribute to the development of BPV by weakening the bond of otoconia to the utricle, they wrote. In men, the weakening may be due to bone loss initiated by a combination of hormone deficiency, poor nutrition, and decreased physical activity.
BPV occurs when otoconia dislodge from the utricle and lodge in the semicircular canals. During head movement, the otoconia can stimulate the canals, which is interpreted as a sense of whirling dizziness and unbalance.