Background/Purpose: Gout can cause uric acid deposition in joints, soft tissues, and organs (1) and is associated with heart disease, kidney disease, hypertension, hyperlipidemia, diabetes, and metabolic syndrome (2). Infected tophi, osteomyelitis, and diabetic ulcers can appear clinically similar which can cause clinical challenges in diagnosis and treatment (3). Uncontrolled gout can lead to amputation, but amputations in patients with gout are rarely described in the literature. It is well known that patients with diabetes are at increased risk for requiring amputation procedures, along with subsequent adverse health sequelae and mortality (4,5). The current population-based study assessed and compared amputation risk in populations with gout, diabetes, and concomitant gout and diabetes to investigate a potential association between gout and increased risk of amputation. Patients without gout or diabetes were examined as a control group.

Methods: The TriNetX “Diamond” network is a large U.S. claims database that contains data from 190 million patients. Data were used to examine the occurrence of amputation procedural codes (foot, toes, hand, fingers) in adult patients with gout and in those with diabetes. Groups were further stratified into patients with diabetes only, gout only, both diabetes and gout, and neither diabetes nor gout (control).

Results: A total of 4,467,721 patients with gout and 25,972,726 patients with diabetes were identified. Amputation rate in patients with diabetes (regardless of gout comorbidity) and gout (regardless of diabetes comorbidity) was comparable at 0.484% and 0.434%, respectively. However, non-overlapping gout and diabetes cohorts had different amputation rates (gout only: 0.162%, n=2,471,430; diabetes only: 0.461%, n=23,976,435), but both were higher than in the control population (no gout or diabetes: 0.035%, n=144,705,645; 4.6- and 13.2-fold higher, respectively). Patients with both gout and diabetes (n=1,996,291) had the highest amputation rate of 0.770%, which was 1.7-fold higher than the diabetes only population and 22.0-fold higher than the control population. The amputation rate in all groups differed significantly from the control (p< 10^-16).

Conclusion: This large population-based study demonstrated that patients with gout only, diabetes only, and comorbid gout and diabetes had amputation rates 4.6, 13.2, and 22.0 times higher than patients without gout or diabetes, respectively. These findings indicate that increased risks of amputation incurred by patients with diabetes and gout are independent and synergistic. Given that both conditions are associated with cardiovascular, renal, and metabolic complications, independent risk was expected, but additive risk was not. More research is needed to understand prognostic patient features underlying this amputation rate increase.

References:

1. Becker MA, Jolly M. In: Arthritis and Allied Conditions: A Book of Rheumatology. 2005:2303-40
2. Dalbeth N, et al. Nature Reviews Disease Primers, 2019;5(69):1-17
3. Kunkel G. JCR 2020;16(6):295-297
4. Geiss LS, et al. Diabetes Care, 2019;42:50-54
5. Moulik PK, et al. Diabetes Care, 2003;26:491-494

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/gout-is-an-independent-risk-factor-for-undergoing-an-amputation-procedure/