Inflammatory biomarkers, glycemic variability, hypoglycemia, and renal transplant outcomes: results of a randomized controlled trial

Intensive glucose control during the perioperative period for diabetic patients undergoing surgery: An updated systematic review and meta-analysis

STUDY OBJECTIVE

To evaluate the impact of intensive glucose control on diabetic patients undergoing surgery.

DESIGN

A systematic review and meta-analysis of randomized controlled trials. PubMed, CENTRAL, EMBASE, ISI Web of Science, and CINAHL databases were searched from inception to 13 December 2020.

SETTING

Operating room, postoperative recovery area and ward, up to 30 days after surgery.

PATIENTS

Diabetic patients undergoing surgery.

INTERVENTIONS

We used Review Manager 5.4 to pool the data with a random-effects model. The quality of evidence was rated using the Grading of Recommendations, Assessment, Development and Evaluation system.

MEASUREMENTS

The primary outcomes were infectious complications, postoperative mortality, and hypoglycaemia. The secondary outcomes included atrial fibrillation, myocardial infarction, stroke, delirium, renal failure, postoperative mechanical ventilation time, length of intensive care unit (ICU) stay, and hospital stay.

MAIN RESULTS

Thirteen studies involving 1582 participants were included. Compared with conventional glucose control, intensive glucose control was associated with a lower risk of infectious complications (risk ratio [RR], 0.35; 95% confidence interval [CI], 0.19-0.63; low-quality evidence), atrial fibrillation (RR, 0.55; 95% CI, 0.42-0.71; high-quality evidence), and renal failure (RR, 0.38; 95% CI, 0.15-0.95; moderate-quality evidence), as well as a shorter length of stay in the ICU (mean difference (MD), -0.55 day; 95% CI, -1.05 to -0.05 days; very-low-quality evidence) and hospital (MD, -1.61 days; 95% CI, -2.78 to -0.44 days; very-low-quality evidence). However, intensive glucose control was associated with a higher risk of hypoglycaemia (RR, 3.00; 95% CI, 1.97-4.55; high-quality evidence). There were no significant differences in postoperative mortality, myocardial infarction, stroke, delirium, or postoperative mechanical ventilation time.

CONCLUSIONS

Intensive glucose control in diabetic patients is associated with a reduction in some adverse postoperative outcomes including infectious complications, but also appears to increase the risk of hypoglycaemia. Further well-designed studies may be needed to determine appropriate regimens to reduce hypoglycaemia incidence.

PROSPERO REGISTRATION NUMBER

CRD42021226138.

Glucose-lowering agents for treating pre-existing and new-onset diabetes in kidney transplant recipients

BACKGROUND

Kidney transplantation is the preferred management for patients with end-stage kidney disease (ESKD). However, it is often complicated by worsening or new-onset diabetes. The safety and efficacy of glucose-lowering agents after kidney transplantation is largely unknown. This is an update of a review first published in 2017.

OBJECTIVES

To evaluate the efficacy and safety of glucose-lowering agents for treating pre-existing and new onset diabetes in people who have undergone kidney transplantation.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 16 January 2020 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

All randomised controlled trials (RCTs), quasi-RCTs and cross-over studies examining head-to-head comparisons of active regimens of glucose-lowering therapy or active regimen compared with placebo/standard care in patients who have received a kidney transplant and have diabetes were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Four authors independently assessed study eligibility and quality and performed data extraction. Continuous outcomes were expressed as post-treatment mean differences (MD) or standardised mean difference (SMD). Adverse events were expressed as post-treatment absolute risk differences (RD). Dichotomous clinical outcomes were presented as risk ratios (RR) with 95% confidence intervals (CI).

MAIN RESULTS

Ten studies (21 records, 603 randomised participants) were included - three additional studies (five records) since our last review. Four studies compared more intensive versus less intensive insulin therapy; two studies compared dipeptidyl peptidase-4 (DPP-4) inhibitors to placebo; one study compared DPP-4 inhibitors to insulin glargine; one study compared sodium glucose co-transporter 2 (SGLT2) inhibitors to placebo; and two studies compared glitazones and insulin to insulin therapy alone. The majority of studies had an unclear to a high risk of bias. There were no studies examining the effects of biguanides, glinides, GLP-1 agonists, or sulphonylureas. Compared to less intensive insulin therapy, it is unclear if more intensive insulin therapy has an effect on transplant or graft survival (4 studies, 301 participants: RR 1.12, 95% CI 0.32 to 3.94; I² = 49%; very low certainty evidence), delayed graft function (2 studies, 153 participants: RR 0.63, 0.42 to 0.93; I² = 0%; very low certainty evidence), HbA1c (1 study, 16 participants; very low certainty evidence), fasting blood glucose (1 study, 24 participants; very low certainty evidence), kidney function markers (1 study, 26 participants; very low certainty evidence), death (any cause) (3 studies, 208 participants" RR 0.68, 0.29 to 1.58; I² = 0%; very low certainty evidence), hypoglycaemia (4 studies, 301 participants; very low certainty evidence) and medication discontinuation due to adverse effects (1 study, 60 participants; very low certainty evidence). Compared to placebo, it is unclear whether DPP-4 inhibitors have an effect on hypoglycaemia and medication discontinuation (2 studies, 51 participants; very low certainty evidence). However, DPP-4 inhibitors may reduce HbA1c and fasting blood glucose but not kidney function markers (1 study, 32 participants; low certainty evidence). Compared to insulin glargine, it is unclear if DPP-4 inhibitors have an effect on HbA1c, fasting blood glucose, hypoglycaemia or discontinuation due to adverse events (1 study, 45 participants; very low certainty evidence). Compared to placebo, SGLT2 inhibitors probably do not affect kidney graft survival (1 study, 44 participants; moderate certainty evidence), but may reduce HbA1c without affecting fasting blood glucose and eGFR long-term (1 study, 44 participants, low certainty evidence). SGLT2 inhibitors probably do not increase hypoglycaemia, and probably have little or no effect on medication discontinuation due to adverse events. However, all participants discontinuing SGLT2 inhibitors had urinary tract infections (1 study, 44 participants, moderate certainty evidence). Compared to insulin therapy alone, it is unclear if glitazones added to insulin have an effect on HbA1c or kidney function markers (1 study, 62 participants; very low certainty evidence). However, glitazones may make little or no difference to fasting blood glucose (2 studies, 120 participants; low certainty evidence), and medication discontinuation due to adverse events (1 study, 62 participants; low certainty evidence). No studies of DPP-4 inhibitors, or glitazones reported effects on transplant or graft survival, delayed graft function or death (any cause).

AUTHORS' CONCLUSIONS

The efficacy and safety of glucose-lowering agents in the treatment of pre-existing and new-onset diabetes in kidney transplant recipients is questionable. Evidence from existing studies examining the effect of intensive insulin therapy, DPP-4 inhibitors, SGLT inhibitors and glitazones is mostly of low to very low certainty. Appropriately blinded, larger, and higher quality RCTs are needed to evaluate and compare the safety and efficacy of contemporary glucose-lowering agents in the kidney transplant population.

Ensuring Patient Safety During the Transition to ESRD

Patients with chronic kidney disease (CKD) are at risk for complications both inherent to the disease and as a consequence of its treatment. The dangers that CKD patients face change across the spectrum of the disease. Providers who are well-versed in these safety threats are best poised to safeguard patients as their CKD progresses.

Glucose-lowering agents for treating pre-existing and new-onset diabetes in kidney transplant recipients

BACKGROUND

Kidney transplantation is the preferred form of kidney replacement therapy for patients with end-stage kidney disease (ESKD) and is often complicated by worsening or new-onset diabetes. Management of hyperglycaemia is important to reduce post-transplant and diabetes-related complications. The safety and efficacy of glucose-lowering agents after kidney transplantation is largely unknown.

OBJECTIVES

To evaluate the efficacy and safety of pharmacological interventions for lowering glucose levels in patients who have undergone kidney transplantation and have diabetes.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Specialised Register to 15 April 2016 through contact with the Information Specialist using search terms relevant to this review. Studies contained in the Specialised Register are identified through search strategies specifically designed for CENTRAL, MEDLINE, and EMBASE; handsearching conference proceedings; and searching the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

All randomised controlled trials (RCTs), quasi-RCTs and cross-over studies examining head-to-head comparisons of active regimens of glucose-lowering therapy or active regimen compared with placebo/standard care in patients who have received a kidney transplant and have diabetes were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study eligibility and quality and performed data extraction. Continuous outcomes were expressed as post-treatment mean differences (MD) or standardised mean difference (SMD). Adverse events were expressed as post-treatment absolute risk differences (RD). Dichotomous clinical outcomes were presented as risk ratios (RR) with 95% confidence intervals (CI).

MAIN RESULTS

We included seven studies that involved a total of 399 kidney transplant recipients. All included studies had observed heterogeneity in the patient population, interventions and measured outcomes or missing data (which was unavailable despite correspondence with authors). Many studies had incompletely reported methodology preventing meta-analysis and leading to low confidence in treatment estimates.Three studies with 241 kidney transplant recipients examined the use of more intensive compared to less intensive insulin therapy in kidney transplant recipients with pre-existing type 1 or 2 diabetes. Evidence for the effects of more intensive compared to less intensive insulin therapy on transplant graft survival, HbA1c, fasting blood glucose, all cause mortality and adverse effects including hypoglycaemia was of very low quality. More intensive versus less intensive insulin therapy resulted in no difference in transplant or graft survival over three to five years in one study while another study showed that more intensive versus less intensive insulin therapy resulted in more rejection events over the three year follow-up (11 events in total; 9 in the more intensive group, P = 0.01). One study showed that more intensive insulin therapy resulted in a lower mean HbA1c (10 ± 0.8% versus 13 ± 0.9%) and lower fasting blood glucose (7.22 ± 0.5 mmol/L versus 13.44 ± 1.22 mmol/L) at 13 months compared with standard insulin therapy. Another study showed no difference between more intensive compared to less intensive insulin therapy on all-cause mortality over a five year follow-up period. All studies showed either an increased frequency of hypoglycaemia or severe hypoglycaemia episodes.Three studies with a total of 115 transplant recipients examined the use of DPP4 inhibitors for new-onset diabetes after transplantation. Evidence for the treatment effect of DPP4 inhibitors on transplant or graft survival, HbA1c and fasting blood glucose levels, all cause mortality, and adverse events including hypoglycaemia was of low quality. One study comparing vildagliptin to placebo and another comparing sitagliptin to placebo showed no difference in transplant or graft survival over two to four months of follow-up. One study comparing vildagliptin to placebo showed no significant change in estimated glomerular filtration rate from baseline (1.9 ± 10.3 mL/min/1.73 m2, P = 0.48 and 2.1 ± 6.1 mL/min/1.73 m2, P = 0.22) and no deaths, in either treatment group over three months of follow-up. One study comparing vildagliptin to placebo showed a lower HbA1c level (mean ± SD) (6.3 ± 0.5% versus versus 6.7 ± 0.6%, P = 0.03) and trend towards a greater lowering of fasting blood glucose (-0.91 ± -0.92 mmol/L versus vs -0.19 ± 1.16 mmol/L, P = 0.08) with vildagliptin. One study comparing sitagliptin to insulin glargine showed an equivalent lowering of HbA1c (-0.6 ± 0.5% versus -0.6 ± 0.6%, P = NS) and fasting blood glucose (4.92 ± 1.42 versus 4.76 ± 1.09 mmol/L, P = NS) with sitagliptin. For the outcome of hypoglycaemia, one study comparing vildagliptin to placebo reported no episodes of hypoglycaemia, one study comparing sitagliptin to insulin glargine reported fewer episodes of hypoglycaemia with sitagliptin (3/28 patients; 10.7% versus 5/28; 17.9%) and one cross-over study of sitagliptin and placebo reported two episodes of asymptomatic moderate hypoglycaemia (2 to 3.9 mmol/L) when sitagliptin was administered with glipizide. All three studies reported no drug interactions between DPP4 inhibitors and the immunosuppressive agents taken.Evidence for the treatment effect of pioglitazone for treating pre-existing diabetes was of low quality. One study with 62 transplant recipients compared the use of pioglitazone with insulin to insulin alone for treating pre-existing diabetes. Pioglitazone resulted in a lower HbA1c level (mean ± SD) (-1.21 ± 1.2 versus 0.39 ± 1%, P < 0.001) but had no effects on fasting blood glucose (6.58 ± 2.71 versus 7.28 ± 2.78 mmol/L, P = 0.14 ), and change in creatinine (3.54 ± 15.03 versus 10.61 ± 18.56 mmol/L, P = 0.53) and minimal adverse effects (no episodes of hypoglycaemia, three dropped out due to mild to moderate lower extremity oedema, cyclosporin levels were not affected).

AUTHORS' CONCLUSIONS

Evidence concerning the efficacy and safety of glucose-lowering agents for treating pre-existing and new-onset diabetes in kidney transplant recipients is limited. Existing studies examine more intensive versus less intensive insulin therapy, and the use of DPP4 inhibitors and pioglitazone. The safety and efficacy of more intensive compared to less intensive insulin therapy is very uncertain and the safety and efficacy of DPP4 inhibitors and pioglitazone is uncertain, due to data being limited and of poor quality. Additional RCTs are required to clarify the safety and efficacy of current glucose-lowering agents for kidney transplant recipients with diabetes.

INPATIENT HYPOGLYCEMIC EVENTS IN A COMPARATIVE EFFECTIVENESS TRIAL FOR GLYCEMIC CONTROL IN A HIGH-RISK POPULATION

OBJECTIVE

Inpatient hypoglycemia (glucose ≤70 mg/dL) is a limitation of intensive control with insulin. Causes of hypoglycemia were evaluated in a randomized controlled trial examining intensive glycemic control (IG, target 140 mg/dL) versus moderate glycemic control (MG, target 180 mg/dL) on post-liver transplant outcomes.

METHODS

Hypoglycemic episodes were reviewed by a multidisciplinary team to calculate and identify contributing pathophysiologic and operational factors. A subsequent subgroup case control (1:1) analysis (with/without) hypoglycemia was completed to further delineate factors. A total of 164 participants were enrolled, and 155 patients were examined in depth.

RESULTS

Overall, insulin-related hypoglycemia was experienced in 24 of 82 patients in IG (episodes: 20 drip, 36 subcutaneous [SQ]) and 4 of 82 in MG (episodes: 2 drip, 2 SQ). Most episodes occurred at night (41 of 60), with high insulin amounts (44 of 60), and during a protocol deviation (51 of 60). Compared to those without hypoglycemia (n = 127 vs. n = 28), hypoglycemic patients had significantly longer hospital stays (13.6 ± 12.6 days vs. 7.4 ± 6.1 days; P = .002), higher peak insulin drip rates (17.4 ± 10.3 U/h vs. 13.1 ± 9.9 U/h; P = .044), and higher peak insulin glargine doses (36.8 ± 21.4 U vs. 26.2 ± 24.3 U; P = .035). In the case-matched analysis (24 cases, 24 controls), those with insulin-related hypoglycemia had higher median peak insulin drip rates (17 U/h vs. 11 U/h; P = .04) and protocol deviations (92% vs. 50%; P = .004).

CONCLUSION

Peak insulin requirements and protocol deviations were correlated with hypoglycemia.

ABBREVIATIONS

DM = diabetes mellitus ICU = intensive care unit IG = intensive glycemic control MELD = Model for End-stage Liver Disease MG = moderate glycemic control SQ = subcutaneous.

Hyperglycemia and Diabetes Mellitus Following Organ Transplantation

Hyperglycemia is common following organ transplantation, regardless of the pre-transplant diabetes status. Transient post-transplant hyperglycemia and/or new-onset diabetes after transplantation (NODAT) are common and are associated with increased morbidity and mortality. NODAT and type 2 diabetes share similar characteristics, but the pathophysiology may differ. Immunosuppressive agents and steroids play a key role in the development of NODAT. Glycemic control is challenging in this population due to fluctuating renal/end-organ function, immunosuppressive dosing, nutritional status, and drug-drug interactions. A proactive and multidisciplinary approach is essential, along with flexible protocols to adjust to patient status, type of organ transplanted, and corticosteroid regimens. Insulin is the preferred agent for hospitalized patients and during the early post-transplant period; optimal glycemic control (BG < 180 mg/dl with minimal hypoglycemia [<70 mg/dl]) is desired.

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.

Hyperglycemia and Acute Kidney Injury During the Perioperative Period

Hyperglycemia and acute kidney injury (AKI) are frequently observed during the perioperative period. Substantial evidence indicates that hyperglycemia increases the prevalence of AKI as a surgical complication. Patients who develop hyperglycemia and AKI during the perioperative period are at significantly elevated risk for poor outcomes such as major adverse cardiac events and all-cause mortality. Early observational and interventional trials demonstrated that the use of intensive insulin therapy to achieve strict glycemic control resulted in remarkable reductions of AKI in surgical populations. However, more recent interventional trials and meta-analyses have produced contradictory evidence questioning the renal benefits of strict glycemic control. Although the exact mechanisms through which hyperglycemia increases the risk of AKI have not been elucidated, multiple pathophysiologic pathways have been proposed. Hypoglycemia and glycemic variability may also play a significant role in the development of AKI. In this literature review, the complex relationship between hyperglycemia and AKI as well as its impact on clinical outcomes during the perioperative period is explored.

Improvement of β-cell function ameliorated glycemic variability in patients with newly diagnosed type 2 diabetes after short-term continuous subcutaneous insulin infusion or in combination with sitagliptin treatment: a randomized control trial

Glycemic variability (GV) has been proposed as contributor to diabetes-related macrovascular complications. This randomized control trial evaluated a new combination therapy with continuous subcutaneous insulin infusion (CSII) plus sitagliptin (CSII + sitagliptin) vs. CSII only in terms of metabolic control, GV and β-cell function in patients with newly diagnosed type 2 diabetes (T2DM). 217 patients were randomized to two weeks of CSII (n = 108) or CSII + sitagliptin (n = 109) therapy. As a measure of GV, the coefficient of variation (CV) was computed from capillary blood glucose during the first and second week, respectively. β-cell function before and after treatment was determined with the Insulin Secretion-Sensitivity Index-2 (ISSI-2). Good metabolic controls were established with both therapies. CSII + sitagliptin therapy resulted in greater improvements in CV and ISSI-2 than CSII alone (all P = 0.000). For each group, change in CV was inversely correlated with change in ISSI-2 (r = -0.529, P = 0.000 and r = -0.433, P = 0.000, respectively). The multivariate regression analysis demonstrated that improved ISSI-2 was the only independent contributor to reduced CV in both groups (standardized β = -0.388, P = 0.004 and standardized β = -0.472, P = 0.000, respectively). Correction of β-cell function in newly diagnosed T2DM patients via use of either CSII or CSII + sitagliptin therapy was feasible in controlling GV to prevent secondary complications of T2DM. Moreover, CSII + sitagliptin therapy was superior to CSII monotherapy in terms of GV.