Study of peripheral bone mineral density in patients with diffuse idiopathic skeletal hyperostosis.

Diffuse idiopathic skeletal hyperostosis (DISH) is an ossifying systemic enthesopathy which involves not only the spine but which may also appear in other sites. Degenerative, inflammatory and metabolic factors have been reported for a possible pathogenic role in the new bone growth that characterises DISH. In the present study peripheral bone mineral density (BMD) has been measured in patients affected by DISH and the results compared to those of a control group. Forty-two patients (33 females and 9 males) affected by DISH and 84 controls (66 females and 18 males) were examined. All subjects underwent radiological study of the lumbar and dorsal spine and the pelvis. BMD was evaluated using dual-energy X-ray absorptiometry and the examination was performed in the distal radius. In DISH patients the mean value of BMD was significantly higher than in controls (P<0.002), even when it was referred to sex subgroups. Statistical analysis showed significant differences between both the two male groups (P<0.002) and the two female groups (P<0.01). In the two female subgroups (DISH patients and controls) BMD was significantly inversely related to age and to the duration of the postmenopausal period. The present study showed higher BMD in DISH patients than in the control group.