Remote Ischemic ConditioningPromising Potential in Wound Repair in Diabetes?

Application Value of Limb Ischemic Preconditioning in Preventing Intradialytic Hypotension during Maintenance Hemodialysis

INTRODUCTION

The aim of this study was to investigate the efficacy and safety of limb ischemia preconditioning (LIPC) in the treatment of intradialytic hypotension (IDH) in patients with maintenance hemodialysis (MHD).

METHODS

This was a single-center, prospective, and randomized controlled case study. A total of 38 patients with MHD who met the inclusion criteria from September 2021 to August 2022 were selected from the Blood Purification Center of our hospital. They were randomly divided into the LIPC group (n = 19) and the control group (n = 19). For patients in the LIPC group, the femoral artery blood flow was blocked with an LIPC instrument for 5 min (pressurized to 200 mm Hg) before each dialysis, and they were reperfused for 5 min. The cycle was repeated five times, with a total of 50 min for 12 weeks. The control group was pressurized to 20 mm Hg with an LIPC instrument, and the rest was the same as the LIPC group. The blood pressure of 0 h, 1 h, 2 h, 3 h, 4 h, and body weight before and after hemodialysis were measured in the two groups during hemodialysis, the incidence of IDH and the changes of serum troponin I (TNI) and creatine kinase isoenzyme MB (CK-MB) levels before and after the intervention were observed, and the ultrafiltration volume and ultrafiltration rate were recorded.

RESULTS

At the 8th and 12th week after intervention, the MAP in the LIPC group was higher than that in the control group (103.28 ± 12.19 mm Hg vs. 93.18 ± 11.11 mm Hg, p = 0.04; 101.81 ± 11.36 mm Hg vs. 91.81 ± 11.92 mm Hg, p = 0.047). The incidence of IDH in the LIPC group was lower than that in the control group (36.5% vs. 43.1%, p = 0.01). The incidence of clinical treatment in IDH patients in the LIPC group was lower than that in the control group (6.3% vs. 12.4%, p = 0.00). The incidence of early termination of hemodialysis in the LIPC group was lower than that in the control group (1.6% vs. 3.8%, p = 0.01). The levels of TNI and CK-MB in the LIPC group after the intervention were lower than those in the control group (322.30 ± 13.72 ng/dL vs. 438.50 ± 24.72 ng/dL, p = 0.00; 159.78 ± 8.48 U/dL vs. 207.00 ± 8.70 U/dL, p = 0.00). The changes of MAP before and after the intervention were negatively correlated with the changes of TNI and CK-MB before and after the intervention (r = -0.473, p = 0.04; r = -0.469, p = 0.04). There were no differences in dry body mass and ultrafiltration rate between the two groups before and after the LIPC intervention (p > 0.05). Multiple linear regression analysis shows that TNI is the main influencing factor of ΔMAP. No LIPC-related adverse events were found during the study period.

CONCLUSION

LIPC can effectively reduce the incidence of IDH in patients with MHD and may be associated with the alleviation of myocardial damage.

Impact of repeated remote ischemic conditioning on diabetic foot ulcers: A proof-of-concept study

Patients with a diabetic foot ulcer (DFU) suffer disabilities and are at increased risk for lower extremity amputation. Current standard of care includes debridement, topical antibiotics, and weight off-loading-still resulting in low rates of healing. Previous small-scale research has indicated that repeated remote ischemic conditioning (rRIC) is a novel modality that delivers significantly higher DFU healing rates. This proof-of-concept study was performed to expand the research on the utility of rRIC as an adjunctive treatment in the healing of chronic DFUs. Forty subjects (41 wounds) received rRIC treatment three times weekly in addition to standard of care for 12 weeks. Subjects that did not heal in this time frame but had a significant reduction in wound size were eligible to continue for an 8-week extension period. By the end of the extension period, 31 of the 41 DFU wounds (75.6%) in this study were determined to be healed. This compares favourably to the 25-30% standard of care average healing rate. For additional comparison, another group of patients receiving standard of care alone, by the same investigator, was selected and matched by wound size at baseline and wound location. For this matching cohort, after 20 weeks of treatment, only 15 of the 41 DFU comparison wounds (36.6%) were determined to be healed, in line with other standard of care results. In the rRIC treatment group, the 10 wounds that did not heal, experienced an average reduction in wound area of 54.3%. The results of this proof-of-concept study reinforce earlier evidence that the addition of rRIC to local wound care significantly improves the healing of chronic diabetic foot ulcers.

Impaired dermal microvascular reactivity and implications for diabetic wound formation and healing: an evidence review

Diabetic foot ulcers (DFUs) are among the most consequential and costly complications faced by patients with diabetes and the global healthcare system. Acknowledged risk factors for DFUs include diabetic peripheral neuropathy (DPN), peripheral arterial disease (PAD), microtrauma and foot deformities. Research on additional risk factors for DFUs has recently focused on dysregulated, autonomic vasomotor control in the skin of patients with DPN. In particular, impaired dermal microvascular reactivity (IDMR) with its attendant reduction in nutritive capillary blood flow has been identified as an emerging risk factor. This especially relates to refractory wounds noted in patients without overt PAD signs. In this paper, evidence will be reviewed supporting the evolving understanding of IDMR and its impact on DFU formation and healing. Advances in diagnostic instrumentation driving this research along with the most promising potential therapies aimed at improving microvascular function in the diabetic foot will be discussed in brief.

Remote ischemic conditioning: A potential therapeutic strategy of type 2 diabetes

Type 2 diabetes (T2D) is one of the major public diseases which is characterized by peripheral insulin resistance (IR) and progressive pancreatic β-cell failure. While in the past few years, some new factors, such as inflammation, oxidative stress, immune responses and other potential pathways, have been identified to play critical roles in T2D, and thereby provide novel promising targets for the treatment of T2D. Remote ischemic conditioning (RIC) is a non-invasive and convenient operation performed by transient, repeated ischemia in distant place. Nowadays, RIC has been established as a potentially powerful therapeutic tool for many diseases, especially in I/R injuries. Through activating a series of neural, humoral and immune pathways, it can release multiple protective signals, which then regulating inflammation, oxidative stress, immune response and so on. Interestingly, several recent studies have discovered that the beneficial effects of RIC on I/R injuries might be abolished by T2D, wherein the higher basal levels of inflammation and oxidative stress, dysregulation of immune system and some potential pathways secondary to hyperglycemia may play critical roles. In contrast, a higher intensity of conditioning could restore the protective effects. Based on the overlapped mechanisms RIC and T2D performs, we provide a hypothesis that RIC may also play a protective role in T2D via targeting these signaling pathways.