Study: Gout patients more commonly undergo lower-extremity amputations

A study published in early January found that patients with gout more commonly undergo lower extremity amputation.

The study, published in the JAMA Open Network, was funded internally by the UNMC Division of Rheumatology and the Nebraska Arthritis Outcomes Research Center.

UNMC researchers, as well as researchers from the Boston University School of Medicine and Horizon Therapeutics, analyzed a database of 5,924,918 patients, with and without gout, who used U.S. Department of Veterans Affairs services from Jan. 1, 2000, to July 31, 2015. In analyses limited to patients with gout, attributes of serum urate control and treatment with urate-lowering therapy were examined as factors associated with lower-extremity amputation.

"Patients with gout were 20% more likely to undergo lower extremity amputation even after accounting for other health conditions more commonly seen in this group, such as diabetes or peripheral vascular disease," said Ted Mikuls, MD, Stokes Shackleford Professor in the division of rheumatology and first author of the study. "Among those with gout, poor serum urate control, but not the administration of urate-lowering therapy, was associated with a significantly higher incidence of amputation.

"We also found that optimal serum urate (or uric acid) control was associated with a lower rate of amputation, suggesting that among some of these procedures might be preventable if gout is well managed," said Dr. Mikuls, who also sees patients at the Omaha VA Hospital. "Amputation portends to substantial declines in physical function and quality of life for patients undergoing the procedure, so future efforts that might reduce or prevent amputation in this population would obviously be welcome."

Dr. Mikuls said as patients are being evaluated for an amputation, screening individuals for gout or hyperuricemia (the major risk factor for gout) could be an indicator that further evaluation might be needed to rule out gout as a mimic of non-healing ulcer or osteomyelitis, for example, common indications for undergoing amputation.

He said the study found the association of gout with amputation to be similar for different procedure types (eg, toe, transmetatarsal, below and above the knee amputations).

"I would have anticipated seeing the highest risk for toe and transmetarsal amputation, since these are sites more commonly affected by severe gout," Dr. Mikuls said. "These results suggest that amputations may not be driven entirely by tophaceous gout being misclassified as infection or a non-healing wound.

"We don’t know the precise indications for the procedures that were done in this study, so it’s frankly impossible to know the proportion of amputations that could truly be prevented."