Risk factors for amputation in diabetic foot ulcers: A retrospective analysis

We read with great interest the article ‘Risk Factors for Amputation in Diabetic Foot Ulcers: A Retrospective Analysis’ by Zhang et al., published in your esteemed journal.¹ This study has investigated several risk factors for diabetic foot ulcer (DFU) amputation. However, we believe some methodological weaknesses and limitations warrant further investigation.

Firstly, a more thorough classification of the wounds should be conducted based on their anatomical locations, such as under and inner metatarsal heads and malleoli. Detailed differentiation between major and minor amputations, especially concerning wound locations, would enhance the categorization of patients.

Secondly, the study mentions that microvascular disease (e.g., retinopathy and neuropathy) is a systemic phenomenon, where diagnosis in one capillary bed suggests systemic microvascular dysfunction. Microvascular disease, peripheral artery disease (PAD) and diabetes mellitus are known to be associated with lower limb outcomes and nontraumatic amputations. However, the relationship between vascular involvement and amputations remains inadequately explored in the current research. Future studies should address this gap to understand better the vascular factors contributing to amputations.²

The Wagner classification system, commonly used for grading diabetic foot ulcers, was employed in this study. Nonetheless, other classification tools, such as the PEDIS classification—which includes factors like perfusion, extent, depth, infection and sensation—offers a more comprehensive assessment.³ The severity of each PEDIS subcategory is linked to various adverse outcomes of diabetic foot ulcers, and incorporating this system could provide deeper insights into patient prognosis.

Additionally, the study's omission of several comorbidities, such as kidney disease, congestive heart failure and mental illness, is a significant oversight. These comorbidities significantly influence the outcomes of diabetic foot complications and should be accounted for in future research.

While the study correctly identifies the neutrophil-to-lymphocyte ratio (NLR) as a marker for systemic inflammation, it would have been beneficial also to investigate other inflammatory markers, such as the platelet-to-lymphocyte ratio (PLR) and the monocyte-to-lymphocyte ratio (MLR).⁴ Including these markers could provide a more comprehensive view of the inflammatory processes involved.

In conclusion, although the study provides valuable insights into risk factors for amputation, addressing the limitations mentioned above would substantially strengthen the article and guide future studies. We hope the authors and the journal will consider these points and propose feasible solutions to the highlighted issues.

The authors declare no conflicts of interest.