The effect of pancreas transplantation on peripheral vascular disease complications

Hyperbaric Oxygen Therapy and Vascular Complications in Diabetes Mellitus

Vascular complications in patients with diabetes mellitus (DM) are common. Since impaired oxygen balance in plasma plays an important role in the pathogenesis of chronic DM-associated complications, the administration of hyperbaric oxygen therapy (HBOT) has been recommended to influence development of vascular complications. Hyperbaric oxygen therapy involves inhalation of 100% oxygen under elevated pressure from 1.6 to 2.8 absolute atmospheres in hyperbaric chambers. Hyperbaric oxygen therapy increases plasma oxygen solubility, contributing to better oxygen diffusion to distant tissues and preservation of the viability of tissues reversibly damaged by atherosclerosis-induced ischemia, along with microcirculation restoration. Hyperbaric oxygen therapy exerts antiatherogenic, antioxidant, and cardioprotective effects by altering the level and composition of plasma fatty acids and also by promoting signal transduction through membranes, which are impaired by hyperglycemia and hypoxia. In addition, HBOT affects molecules involved in the regulation of nitric oxide synthesis and in that way exerts anti-inflammatory and angiogenic effects in patients with DM. In this review, we explore the recent literature related to the effects of HBOT on DM-related vascular complications.

Follow-up of secondary diabetic complications after pancreas transplantation

PURPOSE OF REVIEW

Successful pancreas transplantation restores physiologic glycemic and metabolic control. Its effects on overall patient survival (especially for simultaneous pancreas-kidney transplantation) are clear-cut. We herein review the available literature to define the impact of pancreas transplantation on chronic complications of diabetes mellitus.

RECENT FINDINGS

With longer-term follow-up, wider patient populations, and more accurate investigational tools (clinical and functional tests, noninvasive imaging, histology, and molecular biology), growing data show that successful pancreas transplantation may slow the progression, stabilize, and even favor the regression of secondary complications of diabetes, both microvascular and macrovascular, in a relevant proportion of recipients.

SUMMARY

Patients who are referred for pancreas transplantation usually suffer from advanced chronic complications of diabetes, which have classically been deemed irreversible. A successful pancreas transplantation is often able to slow the progression, stabilize, and even reverse many microvascular and macrovascular complications of diabetes. Growing clinical evidence shows that the expected natural history of long-term diabetic complications can be significantly modified by successful pancreas transplantation.

Reamputation after minor foot amputation in diabetic patients: risk factors leading to limb loss

The prevalence of lower extremity reamputation in diabetic patients has been well-documented. We sought to determine the risk factors for major lower extremity amputation (LEA) after minor foot amputation in diabetic patients. We studied 163 diabetic patients who had undergone an initial minor foot amputation and then had undergone at least 1 subsequent major or minor LEA. The patients were separated into a minor LEA group (initial minor LEA followed by at least 1 subsequent minor LEA) and a major LEA group (initial minor LEA followed by at least 1 subsequent major LEA). We then studied the possible risk factors for both groups. The possible risk factors analyzed were age, glycemic control, kidney function, previous kidney or kidney-pancreas transplantation, smoking history, and presence and severity of peripheral arterial disease (PAD). No statistical significance was found between the 2 groups for hemoglobin A1c, smoking status, chronic kidney disease, end-stage renal disease requiring dialysis, kidney or kidney-pancreas transplantation, or vascular intervention (peripheral arterial bypass). In the minor group, 22.23% had severe PAD. In the major group, 71.15% had severe PAD. This was statistically significant (p < .001). The average interval to major amputation in those without PAD, mild to moderate PAD, and severe PAD was 1,180.9, 591.0, and 559.6 days, respectively. This demonstrates the importance of assessing the peripheral vascular status in all diabetic patients with minor LEA. Early referral to a vascular surgeon might delay (or prevent) major LEA.

Kidney transplant in diabetic patients: modalities, indications and results

BACKGROUND

Diabetes is a disease of increasing worldwide prevalence and is the main cause of chronic renal failure. Type 1 diabetic patients with chronic renal failure have the following therapy options: kidney transplant from a living donor, pancreas after kidney transplant, simultaneous pancreas-kidney transplant, or awaiting a deceased donor kidney transplant. For type 2 diabetic patients, only kidney transplant from deceased or living donors are recommended. Patient survival after kidney transplant has been improving for all age ranges in comparison to the dialysis therapy. The main causes of mortality after transplant are cardiovascular and cerebrovascular events, infections and neoplasias. Five-year patient survival for type 2 diabetic patients is lower than the non-diabetics' because they are older and have higher body mass index on the occasion of the transplant and both pre- and posttransplant cardiovascular diseases prevalences. The increased postransplant cardiovascular mortality in these patients is attributed to the presence of well-known risk factors, such as insulin resistance, higher triglycerides values, lower HDL-cholesterol values, abnormalities in fibrinolysis and coagulation and endothelial dysfunction. In type 1 diabetic patients, simultaneous pancreas-kidney transplant is associated with lower prevalence of vascular diseases, including acute myocardial infarction, stroke and amputation in comparison to isolated kidney transplant and dialysis therapy.

CONCLUSION

Type 1 and 2 diabetic patients present higher survival rates after transplant in comparison to the dialysis therapy, although the prevalence of cardiovascular events and infectious complications remain higher than in the general population.

Peripheral Arterial Disease and Renal Transplantation

It was hypothesized that peripheral arterial disease (PAD) is less frequent after kidney transplantation than among comparable patients who are on the deceased-donor waiting list. The cumulative incidences and risk factors for PAD were compared among 43,427 adult transplant recipients and 53,309 adults who were placed on the renal transplant waiting list between 1995 and 2003. All patients had Medicare primary insurance coverage, and Medicare claims were used to identify PAD. For patients with diabetes, the 3-yr cumulative incidence of de novo PAD was 24% on the waiting list versus 20% after transplantation. For patients without diabetes, the 3-yr cumulative incidence was 9% on the waiting list versus 5% after transplantation. The adjusted relative risk (RR) for PAD among patients without diabetes was 0.73 (95% confidence interval [CI] 0.66 to 0.80; P < 0.0001) in the transplant population versus the waiting list population, whereas among patients with diabetes, it was 0.88 (95% CI 0.82 to 0.96; P = 0.0024). A diagnosis of PAD on the waiting list was associated with an almost three-fold increase in the RR for death for patients without diabetes (2.98; 95% CI 2.71 to 3.27; P < 0.0001) and with diabetes (2.92; 95% CI 2.71 to 3.15; P < 0.0001). After transplantation, de novo PAD increased the RR for death almost two-fold in patients without diabetes (1.92; 95% CI 1.63 to 2.26; P < 0.0001) and with diabetes (1.83; 95% CI 1.58 to 2.12; P < 0.0001). The incidence of PAD is higher on the waiting list than after transplantation and is associated with an increased risk for death among patients with and without diabetes.