Time trends (2001–2019) and sex differences in incidence and in-hospital mortality after lower extremity amputations among patients with type 1 diabetes in Spain

BACKGROUND: We examined trends in incidence (2001–2019), clinical characteristics, and in-hospital outcomes following major and minor lower extremity amputations (LEAs) among type 1 diabetes mellitus (T1DM) patients in Spain and attempted to identify sex differences. METHODS: Retrospective cohort study using data from the Spanish National Hospital Discharge Database. We estimated the incidence of the LEA procedure stratified by type of LEA. Joinpoint regression was used to estimate incidence trends, and logistic regression was used to estimate factors associated with in-hospital mortality (IHM). RESULTS: LEA was coded in 6011 patients with T1DM (66.4% minor and 33.6% major). The incidence of minor LEA decreased by 9.55% per year from 2001 to 2009 and then increased by 1.50% per year, although not significantly, through 2019. The incidence of major LEA decreased by 13.39% per year from 2001 to 2010 and then remained stable through 2019. However, incidence increased in men (26.53% per year), although not significantly, from 2017 to 2019. The adjusted incidence of minor and major LEA was higher in men than in women (IRR 3.01 [95% CI 2.64–3.36] and IRR 1.85 [95% CI 1.31–2.38], respectively). Over the entire period, for those who underwent a minor LEA, the IHM was 1.58% (2.28% for females and 1.36% for males; p = 0.045) and for a major LEA the IHM was 8.57% (10.52% for females and 7.59% for males; p = 0.025). IHM after minor and major LEA increased with age and the presence of comorbid conditions such as peripheral arterial disease, ischemic heart disease or chronic kidney disease. Female sex was associated with a higher IHM after major LEA (OR 1.37 [95% CI 1.01–1.84]). CONCLUSIONS: Our data show a decrease in incidence rates for minor and major LEA in men and women with T1DM and a slight, albeit insignificant, increase in major LEA in men with T1DM in the last two years of the study. The incidence of minor and major LEA was higher in men than in women. Female sex is a predictor of IHM in patients with T1DM following major LEA. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12933-022-01502-y.