Mortality risk of Charcot arthropathy compared with that of diabetic foot ulcer and diabetes alone.

OBJECTIVE

The purpose of this study was to compare mortality risks of patients with Charcot arthropathy with those of patients with diabetic foot ulcer and those of patients with diabetes alone (no ulcer or Charcot arthropathy).

RESEARCH DESIGN AND METHODS

A retrospective cohort of 1,050 patients with incident Charcot arthropathy in 2003 in a large health care system was compared with patients with foot ulcer and those with diabetes alone. Mortality was determined during a 5-year follow-up period. Patients with Charcot arthropathy were matched to individuals in the other two groups using propensity score matching based on patient age, sex, race, marital status, diabetes duration, and diabetes control.

RESULTS

During follow-up, 28.0% of the sample died; 18.8% with diabetes alone and 37.0% with foot ulcer died compared with 28.3% with Charcot arthropathy. Multivariable Cox regression shows that, compared with Charcot arthropathy, foot ulcer was associated with 35% higher mortality risk (hazard ratio 1.35 [95% CI 1.18-1.54]) and diabetes alone with 23% lower risk (0.77 [0.66-0.90]). Of the patients with Charcot arthropathy, 63% experienced foot ulceration before or after the onset of the Charcot arthropathy. Stratified analyses suggest that Charcot arthropathy is associated with a significantly increased mortality risk independent of foot ulcer and other comorbidities.

CONCLUSIONS

Charcot arthropathy was significantly associated with higher mortality risk than diabetes alone and with lower risk than foot ulcer. Patients with foot ulcers tended to have a higher prevalence of peripheral vascular disease and macrovascular diseases than patients with Charcot arthropathy. This finding may explain the difference in mortality risks between the two groups.