Bone Abstracts

Objective: Although metabolic syndrome is common in gout patients, recent reports that bone mineral density may actually be reduced (and falls common) in this group have led researchers to hypothesise that osteoporotic fracture may be more common in subjects with gout than in healthy controls. We tested this hypothesis in a national Danish registry.

Material and Methods: We identified subjects as new users of allopurinol, a proxy for gout, for the years 1996–2010. Each incident user was assigned up to 10 age- and gender matched controls. We used propensity score matching to identify a highly matched control population. Patients with a diagnosis of malignancy in the year prior to the first allopurinol prescription were excluded. The final propensity score model included hospital diagnoses since 1994; Charlson index components; and prior osteoporotic fractures; use of drugs (including osteoporosis medication, prednisolone and HRT) in the last year. Conditional Cox regression modelling was undertaken.

Results: We studied 86 129 patients and the same number of controls (58 129 men and 28 000 women). Thirteen thousand and ninety one cases and 12 188 controls sustained any osteoporotic fracture; the number of major osteoporotic fractures was 5574 in the cases and 4893 in the control group. We found a modest adjusted effect of allopurinol prescription on major osteoporotic fractures; an association with hip fractures just failed to attain statistical significance.

Among patients who were incident allopurinol users and who also had at least one hospital contact with a gout diagnosis (about 20% of allopurinol users, median number of allopurinol rx 12 vs 6 in non-hospital group), we found stronger associations.

Conclusion: These data suggest that gout requiring allopurinol prescription is a risk factor for osteoporotic fracture.