52-OR: Risk Factors and Incidence over Time for Lower Extremity Amputations in Persons with Type 1 Diabetes: An Observational Cohort Study of 46,008 Patients from the Swedish National Diabetes Registry

Background: Lower extremity amputations in people with diabetes is a major source of disability and distress and it constitutes a significant financial burden for the healthcare system. Risk factors and current risks for amputation in persons with type 1 diabetes have not been extensively studied. Methods: Persons with type 1 diabetes registered in the Swedish National Diabetes Registry with no previous amputation from 1998 and followed until 2019 were included. Time-updated Cox regression and gradient of risk per SD were used to evaluate the impact of risk factors on the incidence of amputation. Age and sex adjusted incidences were estimated over time. Findings: Of 46,008 persons with type 1 diabetes with no previous amputation and a mean age of 32.5 years (SD 14.5) and 25 354 (55%) male, 1,519 (3.3%) underwent amputation. Median follow-up was 12.4 years. The age and sex adjusted incidence for any amputation decreased over time. The standardized incidence was 1998-2001 2.84 (95% CI 2.32-3.36) per 1000 patient years and decreased to 1.64 (95% CI 1.38-1.90) in 2017-2019 along with improved glycaemic control (0.02% [95% CI 0.02-0.02] per year) and renal function (0.23 ml/min/1.73m² [95% CI 0.21-0.24] per year). Risk factors for amputations were hyperglycemia, renal dysfunction, older age, male gender, cardiovascular comorbidities, smoking and hypertension. Interpretation: Prognosis has improved considerably regarding the risk of amputations in persons with type 1 diabetes while glycaemic control and renal function improved which were the most prominent risk factors. Disclosure S. Hallstrom: None. A. Svensson: None. A. Pivodic: None. A. F. Olafsdottir: None. M. Londahl: Advisory Panel; Self; Abbott, Speaker’s Bureau; Self; AstraZeneca, Boehringer Ingelheim International GmbH, Lilly Diabetes, Novo Nordisk, Sanofi. H. Wedel: None. M. Lind: Consultant; Self; AstraZeneca, Eli Lilly and Company, Other Relationship; Self; Novo Nordisk, Research Support; Self; Dexcom, Inc. Funding Novo Nordisk Foundation; Swedish State