Smoking is among the few modifiable risk factors that touches nearly every pathway leading to diabetic foot complications: nerve damage, arterial disease, and impaired tissue repair. Yet it is often overshadowed in discussions of glycemic control and footwear. This article summarizes what peer-reviewed research shows about tobacco use and the diabetic foot, and what the evidence says about the benefits of quitting.
How Smoking Harms the Diabetic Foot
A 2019 review by Xia and colleagues in the Journal of Diabetes Investigation described three main routes by which cigarette smoking may contribute to diabetic foot ulcers: worsening peripheral neuropathy, promoting vascular damage, and impairing wound healing. The authors proposed that smoking-induced oxidative stress within cells may underlie these effects, while noting that the direct relationship between smoking and ulceration is still not fully defined and needs further study.
The vascular pathway is the best documented. In a 2023 narrative review in Frontiers in Cardiovascular Medicine, Behrooz and colleagues reported that smoking carries a three- to four-fold increased risk of developing peripheral artery disease (PAD), and that about 22% of people with clinical PAD are current smokers. Because PAD reduces the blood flow needed to heal even minor foot wounds, tobacco-related arterial disease is a direct threat to limb survival in people with diabetes.
Smoking and Amputation Risk
A meta-analysis by Liu and colleagues, published in Experimental and Therapeutic Medicine in 2018, pooled eight studies (five cohort and three case-control) and found that smoking was associated with a higher risk of diabetic foot amputation, with a pooled odds ratio of 1.65 (95% CI 1.09–2.50) compared with non-smokers. The analysis did not detect a significant difference between minor and major amputation among smokers, and tests did not suggest publication bias. As with all observational pooled data, the estimate shows association rather than proof of causation, and the confidence interval is wide, reflecting variation between the included studies.
Smoking also affects the outcome of revascularization. Behrooz and colleagues noted that smoking after lower-limb bypass was associated with roughly a three-fold increase in graft failure risk. This matters because revascularization is often the central step in saving a limb with a diabetic foot ulcer and PAD.
What Happens When Patients Quit
Armstrong and colleagues followed 739 patients with claudication or critical limb ischemia who underwent peripheral angiography, as reported in the Journal of Vascular Surgery in 2014. At angiography, 204 patients (28%) were active smokers, and 61 of them (30%) quit and remained abstinent through one year. Compared with continued smokers, those who quit had lower all-cause mortality (14% versus 31%; hazard ratio 0.4) and better amputation-free survival (81% versus 60%; hazard ratio 0.43). The differences persisted after multivariable adjustment. This was an observational study, so patients who quit may differ from those who continued in ways not fully captured, but the size and consistency of the effect are notable.
Sex may also influence risk. A 2024 systematic review and meta-analysis by Xu and colleagues in PLOS One found that the relative risk of lower-extremity PAD in current smokers was 5.30 (95% CI 3.17–8.87) in women and 3.30 (2.46–4.42) in men, and the authors concluded that both sexes should be equally encouraged to quit.
Evidence-Based Cessation Support
The 2022 Canadian Cardiovascular Society guideline for peripheral arterial disease makes strong recommendations for smoking cessation to prevent PAD and to reduce major adverse cardiovascular events and major adverse limb events in those who have it. It supports intensive counselling, nicotine replacement therapy, bupropion, varenicline, and in some cases nicotine e-cigarettes, with varenicline and combination nicotine replacement showing the strongest efficacy and counselling of at least six sessions associated with better cessation outcomes. The guideline advises asking about smoking status at every clinical visit.
Despite this, treatment appears underused. Behrooz and colleagues reported that fewer than one in five smokers with PAD received cessation counselling and only about one in ten received pharmacologic treatment.
Key Takeaways
Smoking is associated with greater amputation risk in people with diabetes, damages the arterial supply that wound healing depends on, and worsens outcomes after revascularization. Observational data suggest that sustained abstinence is linked to lower mortality and better amputation-free survival in people with symptomatic PAD. Guideline-supported counselling and pharmacotherapy are effective but underused. Evidence specific to diabetic foot ulcer healing remains less robust than evidence in PAD generally, and further trials are needed.
References
- Liu M, Zhang W, Yan Z, Yuan X. Smoking increases the risk of diabetic foot amputation: a meta-analysis. Experimental and Therapeutic Medicine. 2018.
- Xia N, Morteza A, Yang F, Cao H, Wang A. Review of the role of cigarette smoking in diabetic foot. Journal of Diabetes Investigation. 2019.
- Armstrong EJ, et al. Smoking cessation is associated with decreased mortality and improved amputation-free survival among patients with symptomatic peripheral artery disease. Journal of Vascular Surgery. 2014.
- Behrooz L, Abumoawad A, Rizvi SHM, Hamburg NM. A modern day perspective on smoking in peripheral artery disease. Frontiers in Cardiovascular Medicine. 2023.
- Xu Y, Pouncey AL, Zhou Z, Woodward M, Harris K. Smoking as a risk factor for lower extremity peripheral artery disease in women compared to men: a systematic review and meta-analysis. PLOS One. 2024.
- Canadian Cardiovascular Society. Guidelines for the management of peripheral arterial disease. 2022.
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