The Relationship Between Obesity and Amputation-free Survival in Patients Undergoing Lower-limb Revascularisation for Chronic Limb-threatening Ischaemia: A Retrospective Cohort Study

Ann Vasc Surg. 2022 Jan:78:288-294. doi: 10.1016/j.avsg.2021.06.022. Epub 2021 Aug 30.

Abstract

Background: The obesity paradox is a well-documented phenomenon in cardiovascular disease, however it remains poorly understood. We aimed to investigate the relationship between body mass (as measured by body mass index [BMI]) and 1-year amputation-free survival (AFS) for patients undergoing lower limb revascularisation for chronic limb-threatening ischaemia (CLTI).

Methods: A retrospective analysis was undertaken of all consecutive patients undergoing lower limb revascularisation for CLTI at the Leicester Vascular Institute between February 2018-19. Baseline demographics and outcomes were collected using electronic records. BMI was stratified using the World Health Organization criteria. One-year AFS (composite of major amputation/death) was the primary outcome. Kaplan-Meier survival analysis and adjusted Cox's proportional hazard models were used to compare groups to patients of normal mass.

Results: One-hundred and ninety patients were included. Overall, no difference was identified in 1-year AFS across all groups (pooled P = 0.335). Compared to patients with normal BMI (n = 66), obese patients (n = 43) had a significantly lower adjusted combined risk of amputation/death (aHR 0.39, 95% CI 0.16-0.92, P = 0.032), however no significant differences were observed for overweight (aHR 0.89, 95% CI 0.47-1.70, P = 0.741), morbidly obese (aHR 1.15, 95% CI 0.41-3.20, P = 0.797) and underweight individuals (aHR 1.86, 95% CI 0.56-6.20, P = 0.314).

Conclusions: In the context of CLTI, obesity is potentially associated with favourable amputation-free survival at 1 year, compared to normal body mass. The results of this study support the notion of an obesity paradox existing within CLTI and question whether current guidance on weight management requires a more patient-specific approach.

Keywords: Amputation; Body Mass Index; Obesity; Peripheral Arterial Disease; Vascular Surgical Procedures.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Amputation, Surgical*
  • Female
  • Humans
  • Ischemia / complications
  • Ischemia / diagnosis
  • Ischemia / mortality
  • Ischemia / surgery*
  • Limb Salvage*
  • Lower Extremity / blood supply*
  • Male
  • Middle Aged
  • Obesity / complications*
  • Obesity / diagnosis
  • Obesity / mortality
  • Peripheral Arterial Disease / complications
  • Peripheral Arterial Disease / diagnosis
  • Peripheral Arterial Disease / mortality
  • Peripheral Arterial Disease / surgery*
  • Progression-Free Survival
  • Protective Factors
  • Retrospective Studies
  • Risk Assessment
  • Risk Factors
  • Time Factors
  • Vascular Surgical Procedures* / adverse effects
  • Vascular Surgical Procedures* / mortality