The Severity of Diabetes and the Risk of Diabetic Foot Amputation: A National Cohort Study

Background: This study aimed to assess whether markers of diabetes severity could serve as predictors for foot amputation risk among patients with type 2 diabetes mellitus. Methods: We analyzed data from the nationally representative Korean National Health Insurance System database, tracking 2,544,077 patients with type 2 diabetes mellitus who participated in routine health check-ups between 2009 and 2012, with follow-up extending through the end of 2018. The parameters used to define the diabetes severity score encompassed diabetes duration, insulin usage, the number of oral glucose-lowering medications, the presence of chronic kidney disease, diabetic retinopathy, and cardiovascular disease. Each factor was assigned one point, yielding a cumulative severity score ranging from 0 to 6. Results: The risk of diabetic foot amputation was predominantly predicted by insulin therapy, diabetic retinopathy, and a prolonged duration of diabetes. The hazard ratios for foot amputation increased with the severity score as follows: 2.31 (95% confidence interval [CI], 2.15 to 2.47) for a score of 1, 4.73 (95% CI, 4.42 to 5.07) for a score of 2, 8.86 (95% CI, 8.24 to 9.53) for a score of 3, 16.95 (95% CI, 15.60 to 18.4) for a score of 4, 23.98 (95% CI, 21.25 to 27.05) for a score of 5, and 37.87 (95% CI, 28.93 to 49.57) for a score of 6. Conclusion: Specific markers of advanced diabetes effectively identified patients at an elevated risk for diabetic foot amputation.