All-cause and cardiovascular mortality in a consecutive series of patients with diabetic foot osteomyelitis

Risk factors for foot ulcer recurrence in patients with comorbid diabetic foot osteomyelitis and diabetic nephropathy: A 3-year follow-up study

This study aimed to explore the risk factors for foot ulcer recurrence in patients with comorbid diabetic foot osteomyelitis (DFO) and diabetic nephropathy (DN). This is a prospective cohort study. Between May 2018 and May 2021, we selected 120 inpatients with comorbid severe diabetic foot infection (PEDIS Grade 3 or above) and DN for inclusion in our study. All cases were followed up for 36 months. The study outcomes were whether foot ulcer recurred and the time to recurrence. The risk factors of ulcer recurrence were analysed by comparing the data of the three groups. According to the recurrence of foot ulcer, the participants were divided into three groups: Group A (no foot ulcer recurrence, n = 89), Group B (foot ulcer recurrence within 12-36 months, n = 19) and Group C (foot ulcer recurrence within 6-12 months, n = 12). The multivariate Cox regression analysis showed that urine albumin-creatinine ratio (UACR) (HR: 1.008, 95% CI: 1.005-1.011, P < .001) and vibration perception threshold (VPT) (HR: 1.064, 95% CI: 1.032-1.096, P < .001) were identified as independent risk factors. Kaplan-Meier curves showed a significant positive association between UACR or VPT and the risk of foot ulcer recurrence (log rank, all P < .05). Areas under the ROC curves for UACR, VPT and the combination of UACR and VPT were 0.802, 0.799 and 0.842, respectively. The best cut-off values of UACR and VPT were 281.51 mg/g and 25.12 V, respectively. In summary, elevated UACR and VPT were independent risk factors. The best clinical cut-off values of UACR and VPT for prediction of foot ulcer recurrence were 281.51 mg/g and 25.12 V, respectively. Besides, our results suggested that microcirculation disorders rather than macrovascular complications play a major role in the recurrence of foot ulcer in patients with comorbid DFO and DN.

Decreased accuracy of erythrocyte sedimentation rate in diagnosing osteomyelitis in diabetic foot infection patients with severe renal impairment: A retrospective cross-sectional study

BACKGROUND

Rapid diagnosis and treatment of diabetic foot osteomyelitis (DFO) could reduce the risk of amputation and death in patients with diabetic foot infection (DFI). Erythrocyte sedimentation rate (ESR) is considered the most useful serum inflammatory marker for the diagnosis of DFO. However, whether severe renal impairment (SRI) affects its diagnostic accuracy has not been reported previously.

OBJECTIVE

To investigate the accuracy of ESR in diagnosing DFO in DFI patients with and without SRI.

METHODS

This was a retrospective cross-sectional study. From the inpatient electronic medical record system, the investigators extracted demographic information, diagnostic information, and laboratory test results of patients with DFI who had been hospitalized in Longhua Hospital from January 1, 2016 to September 30, 2021. Logistic regression was performed to analyze the interaction between ESR and SRI with adjustment for potential confounders. The area under the curve (AUC), cutoff point, sensitivity, specificity, prevalence, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LR+), and negative likelihood ratio (LR-) were analyzed by receiver operating characteristic (ROC) curve analysis and VassarStats.

RESULTS

A total of 364 DFI patients were included in the analysis. The logistic regression analysis results showed that elevated ESR increased the probability of diagnosing DFO (adjusted odds ratio [OR], 2.40; 95% confidence interval [CI], 1.75-3.28; adjusted P < 0.001); SRI was not associated with the diagnosis of DFO (adjusted OR, 3.20; 95% CI, 0.40-25.32; adjusted P = 0.271), but it had an obstructive effect on the diagnosis of DFO by ESR (adjusted OR, 0.48; 95% CI, 0.23-0.99; adjusted P = 0.048). ROC analysis in DFI patients without SRI revealed that the AUC of ESR to diagnose DFO was 0.76 (95% CI, 0.71-0.81), with the cutoff value of 45 mm/h (sensitivity, 67.8%; specificity, 78.0%; prevalence, 44.7%; PPV, 71.3%; NPV, 75.0%; LR+, 3.08; LR-, 0.41). In contrast, in patients with SRI, the AUC of ESR to diagnose DFO was 0.57 (95% CI, 0.40-0.75), with the cutoff value of 42 mm/h (sensitivity, 95.0%; specificity, 29.2%; prevalence, 45.5%; PPV, 52.8%; NPV, 87.5%; LR+, 1.34; LR-, 0.17).

CONCLUSIONS

The accuracy of ESR in diagnosing DFO in DFI patients with SRI is reduced, and it may not have clinical diagnostic value in these patients.

Major Amputation In Non-Healing Ulcers: Outcomes and Economic Issues. Data from a Cohort of Patients with Diabetic Foot Ulcers

Background: Foot ulcers have a relevant economic impact on Health Care Systems and the cost-effectivenesseffectiveness of options is not clear. The aim of this study was the assessment of costs for ulcers treatment after 6, 12, and 18 months of follow-up, compared to those for major amputation. Methods: A retrospective study was carried out on 196 types 2 diabetic patients with foot ulcers. The principal endpoints were 1) the proportion of recovered patients among those with ulcers not healed after 6 and 12 months; 2) the assessment of direct costs for treatment of ulcers 6, 12, and 18 months of follow-up, as compared to the cost of major amputation. The economic evaluation was performed considering the perspective of the local health system. Results: Out of 196 patients, 85(46.2%), 131(71.6%), and 140(85.9%) healed within 6, 12, and 18 months, respectively. The average health cost during the 18-month follow-up was 5402€ per patient. We calculated hypothetical costs for three different scenarios, in which patients who did not heal within 6 months underwent a major amputation at 6, 1,2, or 18 months. Costs for the standard of care for all these scenarios (6,094, 7,256, and 7649€ for 6, 12, or 18 months, respectively) were significantly lower than that for major amputations (21,065€). Conclusions: A conservative approach appears more convenient than major amputations in ulcers not healing after 6 months, irrespective of the estimated risk of individual patients.

Expanding the definition beyond surveillance criteria reveals a large burden of osteomyelitis caused by group B Streptococcus in the United States Veterans Health Administration

Background

Population-based surveillance studies may underestimate osteomyelitis caused by Group B Streptococcus (GBS). We analyzed cases of GBS osteomyelitis, including patients diagnosed using an expanded case definition that incorporates cultures from non-sterile sites, as well as cultures from normally sterile sites.

Methods

We retrospectively examined a cohort of veterans with the diagnosis of osteomyelitis between 2008 and 2017. Cases of definite GBS osteomyelitis required GBS isolation from normally sterile sites, (e.g., blood or bone). Cases of probable GBS osteomyelitis permitted GBS isolation from non-sterile sites (e.g., surgical sites, wounds). We compared comorbid conditions, lower extremity amputation and mortality rates in these groups.

Results

Among 1281 cases of GBS osteomyelitis, the median age was 63 years, 87% had diabetes mellitus and 37% had peripheral vascular disease. Similar characteristics were found in 768 (60%) cases classified as definite and 513 (40%) classified as probable GBS osteomyelitis. Polymicrobial infection was less frequent in patients with definite than with probable GBS osteomyelitis (45% vs. 85%; P < 0.001). Mortality rates within 1-year were similar for definite and probable GBS osteomyelitis (12% vs. 10%). Amputation within 1-year occurred in 21% of those with definite and 10% of those with probable GBS osteomyelitis of the lower extremity, with comparable rates in the subset with monomicrobial infection.

Conclusions

Expanding the definition of GBS osteomyelitis to include cases with cultures from non-sterile sites may be warranted, increasing the estimated burden of GBS osteomyelitis. This can help guide preventive efforts to reduce the impact of GBS osteomyelitis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-022-07238-0.

Gender Differences in the Risk of Adverse Outcomes After Incident Diabetic Foot Hospitalization: A Population Cohort Study

BACKGROUND

Diabetic Foot Disease (DFD) is more prevalent among males and is associated with an excess risk of cardiovascular events or mortality.

AIMS

This study aimed at exploring the risk of cardiovascular events, renal failure, and all-cause mortality after incident DFD hospitalizations, separately in males and females, to detect any gender difference in a cohort of 322,140 people with diabetes retrospectively followed up through administrative data sources in Tuscany, Italy, over the years 2011-2018.

METHODS

The Hazard Ratio (HR) for incident adverse outcomes after first hospitalizations for DFD, categorized as major/minor amputations (No.=449;3.89%), lower limbs' revascularizations (LLR: No.=2854;24.75%), and lower-extremity-arterial-disease (LEAD) with no procedures (LEAD-no proc: No.=6282;54.49%), was compared to the risk of patients having a background of DFD (ulcers, infections, Charcot-neuroarthropathy: No.=1,944;16.86%).

RESULTS

DFD incidence rate was higher among males compared to females (1.57(95% CI:1.54-1.61) vs. 0.97(0.94-1.00)/100,000p-years]. After DFD, the overall risk of coronary artery disease was significantly associated with the male gender and of stroke with the female gender. LEAD-no proc and LLR were associated with the risk of stroke only in females, whereas they were found to be associated with the risk of coronary artery disease among females to a significantly greater extent compared to males. The incident of renal failure was not associated with any DFD category. Amputations and LEAD-no proc significantly predicted high mortality risk only in females, while LLR showed reduced risk in both genders. Moreover, females had a greater risk of composite outcomes (death or cardiovascular events). Compared to the background of DFD, the risk was found to be 34% higher after amputations (HR: 1.34(1.04-1.72)) and 10% higher after LEAD-no proc (HR:1.10(1.03-1.18)), confirming that after incident DFD associated with vascular pathogenesis, females are at an increased risk of adverse events.

CONCLUSION

After incident DFD hospitalizations, females with DFD associated with amputations or arterial disease are at a greater risk of subsequent adverse cardiovascular events than those with a DFD background.

Association of continuous glucose monitoring-derived time in range with major amputation risk in diabetic foot osteomyelitis patients undergoing amputation

OBJECTIVE

The metrics generated from continuous glucose monitoring (CGM), such as time in range (TIR), are strongly correlated with diabetes complications. This study explored the association of perioperative CGM-derived metrics with major amputation risk in patients with diabetic foot osteomyelitis (DFO).

METHODS

This study recruited 55 DFO patients with grade 3-4 wounds according to the Wagner Diabetic Foot Ulcer Classification System, all of whom underwent CGM for 5 days during the perioperative period. The CGM-derived metrics were defined in accordance with the most recent international consensus recommendations.

RESULTS

Patients with major amputation had significantly less TIR and higher time below range (TBR) (all p < 0.05). In binary logistic regression analyses, a lower TIR was associated with the risk of major amputation (odds ratio: 0.83 (95% confidence interval: 0.71-0.99), p = 0.039). This association remained statistically significant after adjustments for age, sex, body mass index, type of diabetes, smoking, drinking, durations of diabetes and DFU, ankle-brachial index, albumin, estimated-glomerular filtration rate, Society for Vascular Surgery wound, ischemia, and foot infection (WIfi) stage, multidrug-resistant organisms, and hemoglobin A1c. Further adjustment for the mean amplitude of glycemic excursion (MAGE) reduced this association. TBR was also independently associated with the risk of major amputation (odds ratio: 1.60 (95% confidence interval: 1.17-2.18), p = 0.003); this association persisted after adjustment for MAGE.

CONCLUSION

Perioperative TIR (3.9-10.0 mmol/L) and TBR (<3.9 mmol/L) were significantly associated with major amputation in hospitalized patients with DFO.

Retrospective Matched Case-Control Study on the Use of CO2 Laser for the Treatment of Nonhealing Diabetic Foot Ulcers: The DULCIS-2 (Diabetic ULcer, CO2 Laser, and Infections) Study

PURPOSE

Infection, which is one of the possible complications of diabetic foot ulcers (DFUs), makes the treatment of ulcers challenging because of its negative impact on healing processes and the high prevalence of multiresistant germs. This study is aimed at verifying the effect of a surgical CO₂ laser (which reduces the bacterial load and allows a more accurate debridement), as compared with the traditional lancets, on the healing rate of DFU.

METHODS

The present case-control retrospective analysis was performed on patients with chronic (>6 months) DFU with Texas grade >1, treated with 80 W surgical CO₂ laser (DEKA SmartXide2 C80, El.En. Group) and compared with a matched sample of patients with similar characteristics, who were treated with a traditional surgical approach. The debridement was performed trying to achieve the complete removal of nonviable tissues. The principal endpoint was the proportion of patients healed at 6 months. All analyses were carried out with SPSS 25.0. The study protocol was approved by the local ethical committee.

RESULTS

This study included 118 patients (59 cases and 59 controls). At 6 months, the proportion of healing patients was 35% and 18% in cases and controls, respectively (P = .034). The corresponding figure at 1 year was 62% and 38% (P = .009), whereas no difference was observed at 1, 2, and 3 months. No serious adverse event was observed.

CONCLUSIONS

In this article, we show for the first time that CO₂ laser treatment, in comparison with traditional surgical approaches, can be associated with an increased healing rate in patients with DFU.

Mortality in Patients with Diabetic Foot Ulcers: Causes, Risk Factors, and Their Association with Evolution and Severity of Ulcer

Background: This study reviews the mortality of patients with diabetic foot ulcers (DFU) from the first consultation with a Multidisciplinary Diabetic Foot Team (MDFT) and analyzes the main cause of death, as well as the relevant clinical factors associated with survival. Methods: Data of 338 consecutive patients referred to the MDFT center for a new DFU during the 2008–2014 period were analyzed. Follow-up: until death or until 30 April 2020, for up to 12.2 years. Results: Clinical characteristics: median age was 71 years, 92.9% had type 2 diabetes, and about 50% had micro-macrovascular complications. Ulcer characteristics: Wagner grade 1–2 (82.3%), ischemic (49.2%), and infected ulcers (56.2%). During follow-up, 201 patients died (59.5%), 110 (54.7%) due to cardiovascular disease. Kaplan—Meier curves estimated a reduction in survival of 60% with a 95% confidence interval (95% CI), (54.7–65.3) at 5 years. Cox regression analysis adjusted to a multivariate model showed the following associations with mortality, with hazard ratios (HRs) (95% CI): age, 1.07 (1.05–1.08); HbA1c value < 7% (53 mmol/mol), 1.43 (1.02–2.0); active smoking, 1.59 (1.02–2.47); ischemic heart or cerebrovascular disease, 1.55 (1.15–2.11); chronic kidney disease, 1.86 (1.37–2.53); and ulcer severity (SINBAD system) 1.12 (1.02–1.26). Conclusion: Patients with a history of DFU have high mortality. Two less known predictors of mortality were identified: HbA1c value < 7% (53 mmol/mol) and ulcer severity.

Predictors of intra-hospital mortality in patients with diabetic foot ulcers in Nigeria: data from the MEDFUN study

BACKGROUND

Diabetic foot ulcers (DFU) are associated with high morbidity and mortality globally. Mortality in patients hospitalized for DFU in Nigeria is unacceptably high. This study was undertaken to determine factors that predict mortality in patients hospitalized for DFU in Nigeria.

METHODS

The current study was part of Multi-centre Evaluation of Diabetic Foot Ulcer in Nigeria (MEDFUN), an observational study conducted in six tertiary healthcare institutions across the 6 geopolitical zones of Nigeria. Consecutive type 1 or 2 diabetic patients hospitalized for DFU who consented to participate were recruited and subjected to relevant clinical, biochemical, and radiological assessments and multidisciplinary care until discharge or death. Data for type 1 diabetes mellitus (DM) patients were expunged from current mortality analysis due to their small number.

RESULTS

Three hundred and twenty-three type 2 DM subjects with mean age and mean duration of DM of 57.2 ± 11.4 years and 8.7 ± 5.8 years respectively participated in this study. The median duration of ulcers was 39 days with a range of 28 to 54 days and the majority (79.9%) presented with advanced ulcers of at least Wagner grade 3. Mortality of 21.4% was recorded in the study, with the highest mortality observed among subjects with Wagner grade 5. Variables significantly associated with mortality with their respective p values were DM duration more than 120 months (p 0.005), ulcer duration > 1 month (p 0.020), ulcer severity of Wagner grade 3 and above (p 0.001), peripheral arterial disease (p 0.005), proteinuria (p < 0.001), positive blood cultures (p < 0.001), low HDL (p < 0.001), shock at presentation (p < 0.001), cardiac failure (p 0.027), and renal impairment (p < 0.001). On Multivariate regression analysis, presence of bacteraemia (OR 5.053; 95% CI 2.572-9.428) and renal impairment (OR 2.838; 95% CI 1.349-5.971) were significantly predictive of mortality independent of other variables.

CONCLUSIONS

This study showed high intra-hospital mortality among patients with DFU, with the majority of deaths occurring among those with advanced ulcers, bacteraemia, cardiac failure, and renal impairment. Prompt attention to these factors might help improve survival from DFU in Nigeria.

A multicenter randomized placebo controlled trial of rifampin to reduce pedal amputations for osteomyelitis in veterans with diabetes (VA INTREPID)

Background

The prevalence of diabetes mellitus continues to inexorably rise in the United States and throughout the world. Lower limb amputations are a devastating comorbid complication of diabetes mellitus. Osteomyelitis increases the risk of amputation fourfold and commonly presages death.

Antimicrobial therapy for diabetic foot osteomyelitis (DFO) varies greatly, indicating that high quality data are needed to inform clinical decision making. Several small trials have indicated that the addition of rifampin to backbone antimicrobial regimens for osteomyelitis outside the setting of the diabetic foot results in 28 to 42% higher cure rates.

Methods/design

This is a prospective, randomized, double-blind investigation of the addition of 6 weeks of rifampin, 600 mg daily, vs. matched placebo (riboflavin) to standard-of-care, backbone antimicrobial therapy for DFO. The study population are patients enrolled in Veteran Health Administration (VHA), ages ≥18 and ≤ 89 years with diabetes mellitus and definite or probable osteomyelitis of the foot for whom an extended course of oral or intravenous antibiotics is planned. The primary endpoint is amputation-free survival. The primary hypothesis is that using rifampin as adjunctive therapy will lower the hazard rate compared with the group that does not use rifampin as adjunctive therapy. The primary hypothesis will be tested by means of a two-sided log-rank test with a 5% significance level. The test has 90% power to detect a hazard ratio of 0.67 or lower with a total of 880 study participants followed on average for 1.8 years.

Discussion

VA INTREPID will test if a rifampin-adjunctive antibiotic regimen increases amputation-free survival in patients seeking care in the VHA with DFO. A positive finding and its adoption by clinicians would reduce lower extremity amputations and their associated physical and emotional impact and reduce mortality for Veterans and for the general population with diabetic foot osteomyelitis. Given that rifampin-adjunctive regimens are currently employed for therapy for the majority of DFO cases in Europe, and only in a small minority of cases in the United States, the trial results will impact therapeutic decisions, even if the null hypothesis is not rejected.

Trial registration

Registered January 6, 2017 at ClinicalTrials.gov, NCT03012529.

Risk factors for diabetic foot ulcer recurrence: A prospective 2-year follow-up study in Egypt

OBJECTIVES

To determine the frequency of diabetic foot ulcer recurrence and its potential risk factors.

METHODS

This study included 93 patients with type 2 diabetes and followed for 2 years after primary healed foot ulceration. Demographic, diabetes related, comorbid and ulcer related variables were investigated as risk factors. Multiple logistic regression analysis was used to identify independent risk factors.

RESULTS

61.3% of patients had recurrent ulcers particularly in the forefoot (33.3%) and big toe (24.6%). Peripheral neuropathy, peripheral arterial disease or both were reported in 69%, 12% and 19% of feet with recurrent ulcers respectively. In multivariate analysis, the significant independent potential risk factors for recurrence of foot ulcers were smoking (P=0.040), poor glycemic control [HbA1c cutoff of 10%] (P=0.010), peripheral neuropathy with lost ankle reflex (P=0.0001), peripheral arterial disease (P=0.0001) and previous ulcer location (P=0.050).

CONCLUSION

The frequency rate of recurrent diabetic foot ulceration in patients with type 2 diabetes is high particularly in the first year despite regular follow-up and patient education.