No apparent impact of increased post-operative blood glucose levels on clinical outcome in kidney transplant recipients

Early Post-Renal Transplant Hyperglycemia

CONTEXT

Though posttransplant diabetes mellitus (PTDM, occurring > 45 days after transplantation) and its complications are well described, early post-renal transplant hyperglycemia (EPTH) (< 45 days) similarly puts kidney transplant recipients at risk of infections, rehospitalizations, and graft failure and is not emphasized much in the literature. Proactive screening and management of EPTH is required given these consequences.

OBJECTIVE

The aim of this article is to promote recognition of early post-renal transplant hyperglycemia, and to summarize available information on its pathophysiology, adverse effects, and management.

METHODS

A PubMed search was conducted for "early post-renal transplant hyperglycemia," "immediate posttransplant hyperglycemia," "post-renal transplant diabetes," "renal transplant," "diabetes," and combinations of these terms. EPTH is associated with significant complications including acute graft failure, rehospitalizations, cardiovascular events, PTDM, and infections.

CONCLUSION

Patients with diabetes experience better glycemic control in end-stage renal disease (ESRD), with resurgence of hyperglycemia after kidney transplant. Patients with and without known diabetes are at risk of EPTH. Risk factors include elevated pretransplant fasting glucose, diabetes, glucocorticoids, chronic infections, and posttransplant infections. We find that EPTH increases risk of re-hospitalizations from infections (cytomegalovirus, possibly COVID-19), acute graft rejections, cardiovascular events, and PTDM. It is essential, therefore, to provide diabetes education to patients before discharge. Insulin remains the standard of care while inpatient. Close follow-up after discharge is recommended for insulin adjustment. Some agents like dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 receptor agonists have shown promise. The tenuous kidney function in the early posttransplant period and lack of data limit the use of sodium-glucose cotransporter 2 inhibitors. There is a need for studies assessing noninsulin agents for EPTH to decrease risk of hypoglycemia associated with insulin and long-term complications of EPTH.

Development of a Predictive Model for Hyperglycemia in Nondiabetic Recipients After Liver Transplantation

Background

Posttransplant hyperglycemia has been associated with increased risks of transplant rejection, infections, length of stay, and mortality.

Methods

To establish a predictive model to identify nondiabetic recipients at risk for developing postliver transplant (LT) hyperglycemia, we performed this secondary, retrospective data analysis of a single-center, prospective, randomized, controlled trial of glycemic control among 107 adult LT recipients in the inpatient period. Hyperglycemia was defined as a posttransplant glucose level greater than 200 mg/dL after initial discharge up to 1 month following surgery. Candidate variables with P less than 0.10 in univariate analyses were used to build a multivariable logistic regression model using forward stepwise selection. The final model chosen was based on statistical significance and additive contribution to the model based on the Bayesian Information Criteria.

Results

Forty-three (40.2%) patients had at least 1 episode of hyperglycemia after transplant after the resolution of the initial postoperative hyperglycemia. Variables selected for inclusion in the model (using model optimization strategies) included length of hospital stay (odds ratio [OR], 0.83; P < 0.001), use of glucose-lowering medications at discharge (OR, 3.76; P = 0.03), donor female sex (OR, 3.18; P = 0.02) and donor white race (OR, 3.62; P = 0.01). The model had good calibration (Hosmer-Lemeshow goodness-of-fit test statistic = 9.74, P = 0.28) and discrimination (C-statistic = 0.78; 95% confidence interval, 0.65-0.81, bias-corrected C-statistic = 0.78).

Conclusions

Shorter hospital stay, use of glucose-lowering medications at discharge, donor female sex and donor white race are important determinants in predicting hyperglycemia in nondiabetic recipients after hospital discharge up to 1 month after liver transplantation.

Role of glycemic control on hospital-related outcomes in patients with diabetes mellitus undergoing renal transplantation

OBJECTIVE

To compare length of stay (LOS) and incidence of hypoglycemic events and infections in hospitalized patients with diabetes mellitus (DM) undergoing renal transplantation, among groups of patients defined by admission glucose and mean inpatient daily glucose.

METHODS

A retrospective analysis of 190 charts of patients with DM who underwent renal transplantation over a 2-year period was conducted. Patients were grouped according to admission glucose and mean inpatient daily glucose (≤140 mg/dL, 141-180 mg/dL, and >180 mg/dL).

RESULTS

Admission glucose was not associated with LOS. A mean inpatient daily glucose of ≤140 mg/dL was associated with a longer LOS compared to a mean inpatient daily glucose of >180 mg/dL (p=0.03). Patients with an admission glucose of ≤140 mg/dL had approximately half the rate of hypoglycemic events compared to those with admission glucose of 141-180 mg/dL (odds ratio [OR]=2.1; p=0.02) or >180 mg/dL (OR=1.9; p=0.04). However, patients whose mean daily glucose was ≤140 mg/dL had approximately twice the rate of hypoglycemic events than those whose mean daily glucose was 141-180 mg/dL (OR=0.4; p=0.01) or >180 mg/dL (OR=0.4; p=0.004). The incidence of infections was low and was not associated with admission or mean daily glucose levels.

CONCLUSION

Lower mean daily inpatient glucose levels (≤140 mg/dL) are associated with longer LOS and greater incidence of hypoglycemic episodes in diabetes patients undergoing renal transplantation. Our findings suggest that target blood glucose levels of 140-180 mg/dL may be appropriate in this specific population. Additional prospective research is needed to confirm these findings.

The Effect of Different Glycaemic States on Renal Transplant Outcomes

Background. Optimal glycaemic targets following transplantation are unknown. Understanding the impact of DM and posttransplant diabetes mellitus (PTDM) may improve patient and graft survival in transplant recipients. Aim. To determine the perioperative and one-year outcomes after renal transplantation and whether these outcomes are affected by preexisting DM, PTDM, or glycaemia during transplant admission. Method. Adult recipients of renal transplants from a single centre over 5.5 years were retrospectively reviewed. Measured outcomes during transplant admission included glycaemia and complications (infective complications, acute rejection, and return to dialysis) and, at 12 months, glycaemic control and complications (cardiovascular complication, graft failure). Results. Of 148 patients analysed, 29 (19.6%) had DM and 27 (18.2%) developed PTDM. Following transplantation, glucose levels were higher in patients with DM and PTDM. DM patients had a longer hospital stay, had more infections, and were more likely return to dialysis. PTDM patients had increased rates of acute rejection and return to dialysis. At 1 year after transplant, there were more cardiovascular complications in DM patients compared to those without DM. Conclusions. Compared to patients without DM, patients with DM or PTDM are more likely to suffer from complications perioperatively and at 12 months. Perioperative glycaemia is associated with graft function and may be a modifiable risk.

Perioperative Hyperglycemia and Glucose Variability in Gynecologic Laparotomies

BACKGROUND

The glycemic response and its relation to postoperative complications following gynecologic laparotomies is unknown, although these surgeries carry a substantial risk for postoperative morbidity. Therefore, our objective was to assess the prevalence of perioperative hyperglycemia and glucose variability in women undergoing a gynecologic laparotomy.

METHODS

In this prospective cohort study, capillary glucose was measured every hour during the perioperative period. The primary outcome measures were the proportion of patients with postoperative hyperglycemia (glucose >180 mg d l(-1)) and the glucose variability in the intra- and postoperative period. Postoperative complications were assessed as secondary outcome measure.

RESULTS

We included 150 women undergoing a gynecologic laparotomy. Perioperative hyperglycemia occurred in 33 patients without diabetes (23.4%) and in 8 patients with diabetes (89%). Glucose variability was significantly higher (mean absolute glucose change [MAG] 11 mg dl(-1) hr(-1) [IQR 8-18]) in the intraoperative compared to the postoperative period (MAG 10 mg dl(-1) hr(-1) [IQR 3-16], P = .03). Neither hyperglycemia nor glucose variability was associated with postoperative complications.

CONCLUSIONS

Hyperglycemia and glucose variability seem to be a minor problem during gynecologic laparotomy. Based on the current data, we would not advocate standardized glucose measurements in every patient without diabetes undergoing gynecologic laparotomy.

Management of the hospitalized transplant patient

Significant hyperglycemia is commonly observed immediately after solid organ and bone marrow transplant as well as with subsequent hospitalizations. Surgery and procedures are well known to cause pain and stress leading to secretion of cytokines and other hormones known to aggravate insulin action. Immunosuppression required for transplant and preexisting risk are also major factors. Glucose control improves outcomes for all hospitalized patients, including transplant patients, but is often more challenging to achieve because of frequent and sometimes unpredictable changes in immunosuppression doses, renal function, and nutrition. As a result, risk of hypoglycemia can be greater in this patient group when trying to achieve glucose control goals for hospitalized patients. Key to successful management of hyperglycemia is regular communication between the members of the care team as well as anticipating and rapidly implementing a new treatment paradigm in response to changes in immunosuppression, nutrition, renal function, or evidence of changing insulin resistance.

Acute hyperglycemic exacerbation of lung ischemia-reperfusion injury is mediated by receptor for advanced glycation end-products signaling

The effects of acute hyperglycemia on lung ischemia-reperfusion (IR) injury and the role of receptor for advanced glycation end-products (RAGE) signaling in this process are unknown. The objective of this study was twofold: (1) evaluate the impact of acute hyperglycemia on lung IR injury; and (2) determine if RAGE signaling is a mechanism of hyperglycemia-enhanced IR injury. We hypothesized that acute hyperglycemia worsens lung IR injury through a RAGE signaling mechanism. C57BL/6 wild-type (WT) and RAGE knockout (RAGE (-/-)) mice underwent sham thoracotomy or lung IR (1-h left hilar occlusion and 2-h reperfusion). Acute hyperglycemia was established by dextrose injection 30 minutes before ischemia. Lung injury was assessed by measuring lung function, cytokine expression in bronchoalveolar lavage fluid, leukocyte infiltration, and microvascular permeability via Evans blue dye. Mean blood glucose levels doubled in hyperglycemic mice 30 minutes after dextrose injection. Compared with IR in normoglycemic mice, IR in hyperglycemic mice significantly enhanced lung dysfunction, cytokine expression (TNF-α, keratinocyte chemoattractant, IL-6, monocyte chemotactic protein-1, regulated upon activation, normal T cell expressed and secreted), leukocyte infiltration, and microvascular permeability. Lung injury and dysfunction after IR were attenuated in normoglycemic RAGE (-/-) mice, and hyperglycemia failed to exacerbate IR injury in RAGE (-/-) mice. Thus, this study demonstrates that acute hyperglycemia exacerbates lung IR injury, whereas RAGE deficiency attenuates IR injury and also prevents exacerbation of IR injury in an acute hyperglycemic setting. These results suggest that hyperglycemia-enhanced lung IR injury is mediated, at least in part, by RAGE signaling, and identifies RAGE as a potential, novel therapeutic target to prevent post-transplant lung IR injury.

Sodium, potassium and glucose management in organ transplantation

PURPOSE OF REVIEW

To present current knowledge about the metabolic management of patients undergoing solid organ transplantation, and potential organ donors.

RECENT FINDINGS

Appropriate management of electrolytes and glucose improves outcome after transplantation, although conflicting evidence exists. Patients with cirrhosis-induced hyponatremia can be successfully transplanted but are at increased risk of postoperative complications. A new class of drugs, the vaptans, that antagonizes arginine vasopressin may be an effective treatment for hyponatremia in transplant candidates. Recent literature has documented the implications, predictors and potential therapies for perioperative hyperkalemia in the transplant population. The debate over appropriate targets for serum glucose in perioperative and critically ill patients has been lively. The documented risk of hypoglycemia associated with 'intensive insulin therapy' has led to the adoption of more conservative glycemic targets. Studies of glycemic control in transplant recipients are limited.

SUMMARY

In patients undergoing solid organ transplants, sodium management should aim to minimize an acute change in sodium concentration. Vaptans may be of future use in optimizing patients with cirrhosis prior to transplantation. Pending further studies, a perioperative 'middle ground' target glucose of between 140 and 180 mg/dl seems reasonable at this time.

Glycemic control and organ transplantation

A discussion of hyperglycemia during organ transplantation is a broad topic that includes patients with a known history of diabetes pretransplant, those at risk for post-transplant diabetes, those with stress-induced hyperglycemia, those with hyperglycemia related to immunosuppressive therapy, and hyperglycemia in the deceased organ donor. In contrast to the plethora of articles and studies describing perioperative and critical care management of hyperglycemia in cardiac, trauma, and medical/surgical intensive care unit patients, relatively few published articles in the field of organ transplantation can be found. This article consists of a review of available literature in the form of publications and abstracts, and a preliminary report of the authors' work with liver transplantation and deceased organ donors.