Incidence rates of amputations in patients with diabetes in Denmark have been decreasing continuously for the last four decades, but further reduction is still needed

Abstract

Worldwide, a patient with diabetes is amputated every 30 s, and patients with diabetes fear amputation, with the loss of limbs and mobility, more than any other late diabetic complication, including death.¹

The incidence of lower extremity amputations (LEA) in patients with diabetes has been much higher than in patients without diabetes, with a 12-fold higher risk in the UK in the early 1990s.² The Saint Vincent Declaration from Europe, 1989, aimed for a reduction by half of LEA within 5 years in patients with diabetes.

In the United States, there has been a resurgence of LEA in patients with diabetes,³ which has caused the American Heart Association to set a goal of reducing the incidence rate of LEA by 20% by 2030.⁴ Furthermore, a new declaration for feet's sake: halving the global diabetic foot disease burden, from 2% to 1% with next-generation care, has recently been suggested by members of the International Working Group on the Diabetic Foot.⁵

In 2022 in Denmark, an ‘Amputation Scandal’, where patients had been amputated unnecessarily, was described by Danish Press. The reason was a high frequency of LEA in the Central Region of Jutland compared with other Regions of Denmark, caused by cuts in budgets for vascular surgery. A later analysis also showed regional differences, where the annual rate of LEA was halved in the Capital Region, but was increased by 10% in Region Zealand, from 2016 to 2021,⁶ probably due to differences in socioeconomic and health status, as well as access to health services and general practitioners. However, the impact of diabetes was not reported.

Several studies have examined the incidence rates of LEA in patients with diabetes in Denmark (Table 1).⁷ As shown in Table 1, significant decreases in the incidence rates of LEA in patients with diabetes have occurred in all the studies over the past 40 years. Several of the studies in the table suggest that the reasons for the significant decrease in incidence rates of LEA in patients with diabetes are increased vascular surgical treatment, establishment of multidisciplinary teams to handle foot ulcers in patients with diabetes, better treatment of metabolic and lifestyle factors, improved organization of diabetes foot clinics, better and more aggressive early prevention and treatment of foot ulcers, and improved patient education.

In the latest national study of non-traumatic LEA in Denmark from 1997 to 2017, 60% had diabetes.⁸ The total number of LEA had increased, both in people with and without diabetes, probably because the number of elderly and people with diabetes in Denmark had increased. However, the incidence rate of major LEA decreased by 2–9% per year and minor LEA by 6–7% per year in patients with diabetes. In people without diabetes, the incidence rate of both major and of minor LEA decreased by about 1% per year. In 2017, the incidence rate (per 100,000 patient-years) of transfemoral amputations, transtibial amputations and minor LEA was approximately 70, 40 and 120 in patients with type 2 diabetes; 10, 20 and 120 in patients with type 1 diabetes, and 20, 15 and 30 for individuals without diabetes. Thus, the risk of LEA for an individual patient with diabetes has decreased but was still two to four times higher than in individuals without diabetes.

The time interval from vascular surgical intervention to LEA had increased from 1997 to 2017, from under 6 months to 2 years for minor LEA, 3 years for transtibial amputations and 4 years for transfemoral amputations, and was similar for patients with and without diabetes.⁸ Thus, Danish patients with diabetes who undergo vascular surgery have the same effect of the procedure as patients without diabetes, with a ‘lifetime’ of the limb of up to 4 years without amputation.

One-year mortality rates in patients with diabetes were approximately 50%, 30% and 20% after transfemoral amputation, transtibial amputation and minor LEA, respectively, while the 5-year mortality rates were approximately 75%, 67% and 45%.⁸ Advanced age and comorbidity, but not diabetes, were associated with increased mortality.^{9, 10}

Evidence-based guidelines from the International Working Group on Diabetic Foot (www. iwgdfguidelines.org) have recently been updated and are recommended to further reduce LEAs in patients with diabetes. In Denmark, the National Treatment Guideline for the treatment of diabetic foot disease from the Danish Endocrinology Society is recommended. However, monitoring the quality of care is important. The Danish Adult Diabetes Database report for 2021–2022, shows that only 71% of patients with diabetes in hospital-based diabetes outpatient clinics had undergone the recommended annual preventive foot examination, whereas in general practice, 30% of patients with diabetes had undergone the preventive annual foot examination. The low percentage receiving the annual preventive foot examination is far from the goal.

This underscores the need for continuously ongoing monitoring of quality of care and treatment of diabetic foot diseases.

The author has no potential conflict of interest relevant to this letter.