Association Between Cigarette Smoking and Diabetic Foot Healing: A Systematic Review and Meta-Analysis

Influence of quitting smoking on diabetes-related complications: A scoping review with a systematic search strategy

INTRODUCTION

Smoking in people with diabetes markedly elevates their risk of developing complications and increases the likelihood of cardiovascular mortality. This review is the first to specifically provide evidence-based analysis about the influence of quitting smoking on diabetes-related complications in people with type 2 diabetes.

METHOD

The present review was carried out according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Extension for Scoping Reviews. All human clinical studies assessing the effects of stopping smoking cessation on diabetes-related complications were included. PubMed and Embase were screened until January 2024. References of primary studies and principal peer-reviewed scientific journals in the field were manually screened.

RESULTS

We identified a total of 1023 studies. Only 26 met the criteria for eligibility. In general quitting smoking is associated with decreased risks of myocardial infarction and ischemic stroke. Regarding microvascular complications, the strongest evidence for the beneficial effects of smoking cessation is observed in diabetic nephropathy. However, the relationship between smoking cessation and retinopathy, neuropathy, diabetic foot complications and diabetic-related erectile dysfunction, is poorly investigated.

CONCLUSION

Quitting smoking offers significant advantages in managing diabetes-related complications, significantly lowering the risks of myocardial infarction, ischemic stroke, and diabetic nephropathy. This underscores the importance of cessation. Providing evidence-based information on the benefits of stopping smoking for people with type 2 diabetes who smoke, can bolster smoking cessation efforts in the context of diabetes management.

Two-year incidence and risk factors of diabetic foot ulcer: second phase report of Ahvaz diabetic foot cohort (ADFC) study

AIM/INTRODUCTION

This study was designed as the second phase of a prospective cohort study to evaluate the incidence and risk factors of diabetic foot ulcers (DFU).

MATERIALS AND METHODS

The study was conducted in a university hospital in Iran. Each participant was checked and followed up for two years in terms of developing newfound DFU as ultimate outcome. We investigated the variables using univariate analysis and then by backward elimination multiple logistic regression.

RESULTS

We followed up 901 eligible patients with diabetes for two years. The mean age of the participants was 53.24 ± 11.46 years, and 58.53% of them were female. The two-year cumulative incidence of diabetic foot ulcer was 8% (95% CI 0.071, 0.089) [Incidence rate: 49.9 /1000 person-years]. However, the second-year incidence which was coincident with the COVID-19 pandemic was higher than the first-year incidence (4.18% and 1.8%, respectively). Based on our analysis, the following variables were the main risk factors for DFU incidence: former history of DFU or amputation [OR = 76.5, 95% CI(33.45,174.97), P value < 0.001], ill-fitting foot-wear [OR = 10.38, 95% CI(4.47,24.12), P value < 0.001], smoking [OR = 3.87,95%CI(1.28, 11.71),P value = 0.016], lack of preventive foot care [OR = 2.91%CI(1.02,8.29),P value = 0.045], and insufficient physical activity[OR = 2.25,95% CI(0.95,5.35),P value = 0.066].

CONCLUSION

Overall, the two-year cumulative incidence of diabetic foot ulcer was 8% [Incidence rate: 49.9 /1000 person-years]; however, the second-year incidence was higher than the first-year incidence which was coincident with the COVID-19 pandemic (4.18% and 1.8%, respectively). Independent risk factors of DFU occurrence were prior history of DFU or amputation, ill-fitting footwear, smoking, lack of preventive foot care, and insufficient physical activity.

The burden of costs on health services by patients with neuro-ischaemic ulcers in Singapore

The economic burden of neuro-ischaemic ulcers (NIU) is expected to increase because of rising prevalence of comorbidities in an aging population. We aim to estimate healthcare resources consumed by NIU patients, and to quantify the extent to which factors explain variation in cost-related outcomes. We analysed retrospective patient-level cohort data for NIU patients from a tertiary hospital registry in Singapore, from 2013 to 2017, using generalised linear regression models. The outcome variables were the length of stay per admission; inpatient and outpatient bill per admission; and, if they had an Emergency Department visit. Cost outcomes were reported in Singapore dollars (S$). A total of 1682 patients were included, and the mean age was 69.9 years (±13.0). An average patient incurred a length of stay of 38.7 days, 7.9 inpatient dressing sessions, an inpatient bill of S$33 096, 11.3 outpatient dressing sessions, and an outpatient bill of S$8780. Inpatient services per patient cost 73.5% higher than outpatient services. NIU patients with multiple (>3) comorbid conditions, peripheral artery disease, or chronic kidney disease incurred longer hospitalisation and higher inpatient bill. Patients with diabetes mellitus and coronary artery disease had higher odds of incurring an ED visit. Patients with coronary artery disease, hyperlipidaemia, kidney complications, or obesity incurred higher outpatient bills. NIU treatment imposes a significant economic burden, especially with inpatient services.

Multiple factors predict longer and shorter time-to-ulcer-free in people with diabetes-related foot ulcers: Survival analyses of a large prospective cohort followed-up for 24-months

AIMS

To investigate factors independently associated with time-to-(being)-ulcer-free, time-varying effects and predict adjusted ulcer-free probabilities, in a large prospective cohort with diabetes-related foot ulcers (DFU) followed-up for 24 months.

METHODS

Patients presenting with DFU(s) to 65 Diabetic Foot Services across Queensland, Australia, between July-2011 and December-2017 were included. Demographic, comorbidity, limb, ulcer, and treatment factors were captured at presentation. Patients were followed-up until ulcer-free (all DFU(s) healed), amputation, death or two years. Factors associated with time-to-ulcer-free were investigated using both Cox proportional hazards and flexible parametric survival models to explore time-varying effects and plot predicted adjusted ulcer-free probability graphs.

RESULTS

Of 4,709 included patients (median age 63 years, 69.5% male), median time-to-ulcer-free was 112 days (IQR:40->730), with 68.4% ulcer-free within two years. Factors independently associated with longer time-to-ulcer-free were each year of age younger than 60 years, living in a regional or remote area, smoking, neuropathy, peripheral artery disease (PAD), ulcer size >1 cm², deep ulcer and mild infection (all p < 0.05). Time-varying effects were found for PAD and ulcer size limiting their association to six months only. Shorter time-to-ulcer-free was associated with recent DFU treatment by a podiatrist and receiving knee-high offloading treatment (both p < 0.05). Predicted adjusted ulcer-free probability graphs reported largest differences in time-to-ulcer-free over 24-months for geographical remoteness and PAD factors.

CONCLUSIONS

Multiple factors predicted longer and shorter time-to-ulcer-free in people presenting with DFUs. Considering these factors, their time-varying effects and adjusted ulcer-free probability graphs, should aid the prediction of the likely time-to-(being)-ulcer-free for DFU patients.

Free Triiodothyronine and Free Triiodothyronine to Free Thyroxine Ratio Predict All-Cause Mortality in Patients with Diabetic Foot Ulcers

PURPOSE

Free triiodothyronine (FT3) and FT3/free thyroxine (FT4) ratio have been associated with mortality in various diseases. However, no study to date has identified a link between FT3, FT3/FT4 ratio and all-cause mortality in patients with diabetic foot ulcers (DFUs). This study aimed to investigate this relationship.

METHODS

This retrospective cohort study included 726 patients diagnosed with DFUs in a public hospital from January 2015 to October 2019. Patients were classified by the optimal cut-off values of the FT3 and FT3/FT4 ratio, respectively. The association of FT3 and FT3/FT4 ratio with all-cause mortality was evaluated in a multivariable cox regression model. Directed acyclic graphs were used to assess the minimally sufficient sets of confounding variables.

RESULTS

Log rank tests indicated that patients with low FT3 and FT3/FT4 ratio had lower overall survival rates (all p < 0.001). The adjusted HRs for all-cause mortality were 0.48 (95% CI: 0.32-0.73, P = 0.001) when comparing high versus low FT3 and 0.47 (95% CI: 0.32-0.70, P < 0.001) when comparing high versus low FT3/FT4 ratio. Subgroup analyses showed that these associations existed only in elderly patients (≥65 years) and women, after adjustment. In men, only high FT3/FT4 ratio was associated with low all-cause mortality, after adjustment.

CONCLUSION

Routine assessment of FT3 and FT3/FT4 ratio may be a simple and effective way to identify high-risk patients with DFUs, especially in elderly patients and women.

Enhanced Expression of miR-34c in Peripheral Plasma Associated with Diabetic Foot Ulcer in Type 2 Diabetes Patients

OBJECTIVE

To explore the correlation between the expression of miR-34c in peripheral blood of patients with type 2 diabetes mellitus (T2DM) and the onset of diabetic foot ulcer (DFU) and diabetic foot osteomyelitis (DFO).

METHODS

Sixty newly diagnosed patients with T2DM without DFU (T2DM group), 112 T2DM patients with DFU (DFU group) and 60 controls with normal glucose tolerance (NC group). The DFU group patients were subdivided into DFO (n=64) and NDFO (n=48) groups. Quantitative real-time PCR (qRT-PCR) method was used to determine miR-34c expression levels in the peripheral blood of subjects to analyze the clinical characteristics of DFU and DFO risk factors.

RESULTS

MiR-34c expression level in the T2DM group was marked higher than the NC group [2.99 (1.45-6.22) vs 1.01 (0.89-1.52)] (P < 0.05). However, the expression level of miR-34c in the DFU group was significantly higher than the T2DM group [9.65 (6.15-18.63) vs 2.99 (1.45-6.22)] (P < 0.01). Compared with the NDFO group, the expression level of miR-34c in the DFO group was also obviously increased [13.46 (8.89-19.11) vs 6.02 (5.93-14.72)] (P < 0.01). The expression level of miR-34c in DFU patients was positively correlated with the amputation rate of foot ulcers (P=0.030) and was negatively correlated with the healing rate of foot ulcers after eight weeks (P=0.025). Multifactorial logistic regression analysis showed that increased expression of miR-34c was an independent risk factor for DFU and DFO (OR_DFU=3.47, OR_DFO=4.25, P < 0.01). Meanwhile, the ROC curve analysis indicated that the AUC of miR-34c for the diagnosis of DFU and DFO was 0.803 and 0.904, the optimum sensitivity being was 100% and 98.7%, the optimum specificity was 98.4% and 98.4%, respectively.

CONCLUSION

The increased expression of miR-34c in peripheral blood of T2DM patients is closely related to the occurrence, development and prognosis of DFU and DFO.

Autologous non-cultured keratinocyte cell suspension in non-healing diabetic ulcers: A preliminary study

Background:

Diabetic ulcers are a common morbidity associated with poorly controlled glycemic status. Most patients often have neuropathy and vasculopathy as the etiology behind such ulcers. These factors not only lead to poor wound healing but also nonhealing ulcers. Nonhealing ulcers pose therapeutic challenges as they are usually not amenable to be treated with simple wound care and hence require newer modalities to effectively cure this condition that leads to a plethora of poor health outcomes. This study was conducted to see the effect of autologous noncultured keratinocyte cell suspension in chronic nonhealing diabetic ulcers that failed to normal wound care.

Material and Methods:

It was an observational pilot study. A total of 05 patients with nonhealing ulcers, attending the tertiary care teaching hospital in North India, were included in the study. Inclusion criteria was type 2 DM with more than 5 years duration of diabetes mellitus and glycated hemoglobin (HbA1c) <9 g%. History was taken in detail; name, age, sex, address, duration of disease and various other treatments taken from outside were noted; and size of ulcer was recorded as per Proforma.

Results:

A total of 5 patients were enrolled in the study, three (60%) and two (40%) patients were male and female, respectively. Three (60%) patients were habitual for tobacco use. Mean age of patients was 45 ± 6.51 years. Mean duration of ulcers was 4.8 ± 1.48 months. Area of ulcers ranged from 31.2 to 122.2 cm². Majority of cases, three (60%) of diabetic foot ulcers, were improved at 9–12 weeks and remaining two cases with large size of ulcer were healed at 13–16 weeks and 17–20 weeks, respectively. Majority (80%) of patients revealed >50% reduction in the size of ulcer within 2 weeks.

Conclusion:

Noncultured keratinocytes are useful in healing of nonhealing diabetic ulcer.

Active smoking is associated with higher rates of incomplete wound healing after endovascular treatment of critical limb ischemia

The association between active smoking and wound healing in critical limb ischemia (CLI) is unknown. Our objective was to examine in a retrospective cohort study whether active smoking is associated with higher incomplete wound healing rates in patients with CLI undergoing endovascular interventions. Smoking status was assessed at the time of the intervention, comparing active to no active smoking, and also during follow-up visits at 6 and 9 months. Cox regression analysis was conducted to compare the incomplete wound healing rates of the two groups during follow-up. A total of 264 patients (active smokers: n = 41) were included. Active smoking was associated with higher rates of incomplete wound healing in the 6-month univariate Cox regression analysis (hazard ratio (HR) for incomplete wound healing: 4.54; 95% CI: 1.41-14.28; p = 0.012). The 6-month Kaplan-Meier (KM) estimates for incomplete wound healing were 91.1% for the active smoking group versus 66% for the non-current smoking group. Active smoking was also associated with higher rates of incomplete wound healing in the 9-month univariable (HR for incomplete wound healing: 2.32; 95% CI: 1.11-4.76; p = 0.026) and multivariable analysis (HR for incomplete wound healing: 9.09; 95% CI: 1.06-100.0; p = 0.044). The 9-month KM estimates for incomplete wound healing were 75% in the active smoking group versus 54% in the non-active smoking group. In conclusion, active smoking status at the time of intervention in patients with CLI is associated with higher rates of incomplete wound healing during both 6- and 9-month follow-up.

To Smoke or Not To Smoke: Cigarettes Have a Negative Effect on Wound Healing of Diabetic Foot Ulcers

Diabetic foot ulcers (DFUs) have a complex pathophysiology and require an expert multidisciplinary treatment. There are several, both systemic and local, risk factors for DFUs. A recent meta-analysis of 18 studies has now provided robust evidence on the detrimental effect of smoking on healing of DFUs. Indeed, healing rates were consistently lower among smokers than among nonsmokers. Based on this new evidence, it is reasonable to consider the utility of smoking cessation programs. Incorporation of the latter into the holistic therapeutic strategy for DFUs may be anticipated to improve healing rates, but this remains to be shown.