Risk factors for diffuse idiopathic skeletal hyperostosis: a case-control study

Objective. Diffuse idiopathic skeletal hyperostosis (DISH) is a skeletal disease characterized by ligamentous ossification of the anterolateral side of the spine. The aim of this study was to characterize risk factors associated with DISH. Methods. Subjects were recruited for participation in a screening survey of vertebral osteoporosis. The cases were 69 men and 62 women with DISH and the controls were 69 men and 62 women with spondylosis over the age of 50 yr. Cases and controls were matched for age and sex. Radiographs were taken according to a standardized protocol and DISH was classified using the Resnick criteria. Laboratory parameters and an interviewer-administered questionnaire were used to obtain data about exposure. Results. The mean ages of the populations with DISH and spondylosis were 65.2+/-8.8 and 65.0+/-9.1 yr respectively. Compared with controls, patients with DISH had a greater body mass index (27.8 vs 26.0 kg/m(2), P<0.05) and a higher serum level of uric acid (308 vs 288 mu mol/l, P<0.05) and were more likely to have had diabetes mellitus (19.8 vs 9.1%, P<0.05). Conclusion. DISH is clearly a distinct disorder with risk factors that distinguish it from other spinal degenerative diseases.