The association of chronic, enhanced immunosuppression with outcomes of diabetic foot infections

Abstract

In the past few decades, the number of scientific publications concerning diabetic foot infections (DFI) has increased exponentially. 1,2 These have uncovered several clinical variables that are associated with failure of treatment for DFI, especially severe peripheral arterial disease, presence of osteomyelitis, insufficient surgical debridement and inadequate weight off-loading. 1,2 It is known that diabetes mellitus is associated with defects in immune responses of both innate (including dysfunction of neutrophils and macrophages) and adaptive (including T cells) types. 3 Patients with diabetes can also suffer from a chronic, 'enhanced' immunosuppressed state when they also are afflicted with various serious co-morbidities. To our knowledge, there are no data assessing the influence of this type of immune suppression on the outcome of treatment for DFI. In our tertiary referral medical centre, we have been seeing an increasing number of patients with DFI who are afflicted with complex comorbidities and immune-compromised states. Thus, we investigated the potential effects of these complications on the likelihood of successful treatment for their DFI.

Nutritional Interventions May Improve Outcomes of Patients Operated on for Diabetic Foot Infections: A Single-Center Case-Control Study

“…Clinical failures were noted in 255 episodes (25%). Microbiologically proven recurrence of the index infection was noted in only 47 episodes (5% of the study population; 18% of the failures) [ 6 ]. Table 1 demonstrates a comparison of episodes of clinical failure with those of remission, including for nutrition-related parameters.…”

“…Of note, all 1.2, 0.9-1.5 2.0, 0.6-7.2 Body mass index at admission 1.0, 1.0-1.0 0.9, 0.9-1.0 Regular alcohol consumption 1.3, 0.9-1. The main strengths of our study are the large database of over 1,000 DFI patients and the long duration of follow-up in a specialized, academic diabetic foot unit [6,10]. The main limitations are the varied case-mix, retrospective nature of the study, arbitrary indication for requesting nutrition counselling (compared to a general nutrition counselling for every DFI patient), majority of operated patients (versus mostly conservative DFI therapies), lack of formal proof of a causal relationship between nutrition and therapeutic failures, and lack of an artificial variable "malnutrition" that may include a variety of nutritional parameters.…”

“…We used a DFI registry that we developed, which lists all episodes occurring since the year 2000 [ 6 ]. One author (VT) completed the registry for his master degree, with five additional variables: an internationally validated nutrition score [ 7 ], a history of involuntary weight loss, treatment with vitamin substitutions or other nutritional interventions by our professional nutritionists, and the serum albumin level on admission (if available).…”

“…Infections. Among 1,013 DFI episodes in 586 patients (78% males; median age 67 years) occurring during the study period, 882 (87%) had DFO, 388 (38%) had a disorder associated with enhanced immunosuppression (beyond their diabetes mellitus) [6], and 753 (74%) were insulin-treated diabetes cases. At presentation, the patients' overall median duration of diabetes was 19 years.…”

Correction of hyperglycemia after surgery for diabetic foot infection and its association with clinical outcomes

“…These intervention variables included the duration of the antibiotic therapy [ 7 ], the number of surgical debridements undertaken [ 7 ], and the use of hyperbaric oxygen [ 7 ]. It appears that only selected chronic, patient-related parameters that are causative or contributive to the DFI, such as limb ischemia, enhanced immune suppression [ 8 ], or the anatomic localization of the infection in the foot [ 9 ], make a significant difference in multivariate analyses. Hence, our finding of a lack of a immediate benefit from achieving rapid glycemic control is consistent with the results of our prior studies.…”