Insulin resistance after renal transplantation: the effect of steroid dose reduction and withdrawal

Management of cardiovascular disease in renal transplant recipients

Cardiovascular disease is a major cause of graft loss and the leading cause of death in renal transplant recipients. Although there are robust data on the frequency of risk factors and their contributions to cardiovascular disease in this population, few trials have demonstrated the benefit of modifying these risk factors to reduce cardiovascular events. Nevertheless, it is widely accepted that the clinical acumen filtered through the best available studies in the general population be used to treat individual renal transplant recipients given their high cardiovascular mortality. Transplant task forces and the Kidney Disease Outcomes Quality Initiative have created guidelines for this purpose. This review examines the data available for prevention and treatment of major risk factors contributing to cardiovascular disease in renal transplant recipients. The contribution of immunosuppressive agents to each risk factor and the evidence to support lifestyle modification as well as drug therapy are examined. Reducing cardiovascular risk factors requires an integrative approach that is best accomplished by a team of health care professionals. It creates a significant challenge but one that must be met if allograft survival is to improve.

New-onset diabetes mellitus in the kidney recipient: diagnosis and management strategies

Advancing care has markedly improved survival after kidney transplantation, leaving patients susceptible to the effects of chronic transplant-associated morbidities. New-onset diabetes mellitus (NODM) is common in kidney recipients, threatening health and longevity by predisposing to microvascular and cardiovascular disease and by reducing graft survival. A strong rationale therefore exists for the aggressive treatment of NODM in kidney recipients to limit these complications. Screening for diabetes should be systematic and should span the pre- and posttransplantation periods. Once NODM is diagnosed in the kidney transplant patient, a comprehensive plan of therapy should be used to achieve treatment targets. As in the general population, treatment includes lifestyle modification and drug therapy as needed, but transplant-specific factors add complexity to the care of kidney recipients. Among these, minimizing immunosuppression-related toxicity without compromising graft outcomes is of paramount importance. Preexisting allograft functional impairment and the potential for significant interactions with immunosuppressive agents mandate that the expanding armamentarium of hypoglycemic agents be used with care. A team-oriented treatment approach that capitalizes on the collective expertise of transplant physicians, diabetologists, nurse-educators, and dieticians will optimize both glycemic control and the overall health of hyperglycemic kidney recipients.

Transplante de pâncreas e ilhotas em portadores de diabetes melito

O transplante simultâneo de pâncreas/rim tem indicações específicas, riscos e benefícios. O procedimento, cada vez mais realizado, traz vantagens se comparado ao paciente em diálise, em relação à qualidade de vida, anos de vida ganhos e evolução das complicações crônicas. Se o paciente tiver a opção de realizar o transplante de rim com doador vivo, que apresenta sobrevida semelhante do enxerto e do paciente aos dez anos, o procedimento deverá ser considerado. O transplante de pâncreas após rim, quando efetivo, pode melhorar a evolução das complicações cardiovasculares, mas em contrapartida provoca maior mortalidade nos primeiros meses após a cirurgia. O transplante isolado de pâncreas também ocasiona a maior mortalidade pós-operatória, resultado da complexidade do procedimento e da imunossupressão. O transplante de ilhotas tem sua indicação para um seleto grupo de diabéticos com instabilidade glicêmica.

New-onset diabetes after kidney transplantation: risk factors

New-onset diabetes after transplantation (NODAT) contributes to the risk for cardiovascular disease and infection, reducing graft and patient survival. For improvement of the outcome of kidney transplant recipients, it is of great interest to know precisely the risk factors that contribute to NODAT development. Nonmodifiable risk factors for development of NODAT are age, race, genetic background, family history of diabetes, and previous glucose intolerance. Modifiable risk factors are obesity and overweight, hepatitis C virus and cytomegalovirus infections, and immunosuppressive drugs. Both steroids and calcineurin inhibitors influence the appearance of NODAT, whereas the role of sirolimus in glucose metabolism currently is controversial.

New onset diabetes mellitus after solid organ transplantation

This article presents an overview of the literature on the current diagnostic criteria for new onset diabetes mellitus after transplantation (NODAT) and discusses suggested risk factors for the development of NODAT, its potential pathogenic mechanisms, and its impact on post-transplant outcomes after solid organ transplantation. Suggested guidelines for early identification and management of NODAT are also discussed.

Comprehensive management of post-transplant diabetes mellitus: from intensive care to home care

Post-transplant diabetes mellitus (PTDM) is a common complication of solid organ and hematopoietic transplantation. This clinically oriented review article briefly summarizes the pathophysiology of PTDM, then presents a comprehensive clinical approach to diagnosis and therapy. Topics include the key clinical aspects of PTDM screening, diagnosis, and management during all phases following transplantation from the intensive care unit, to the inpatient ward, to the outpatient arena.

EULAR evidence-based recommendations on the management of systemic glucocorticoid therapy in rheumatic diseases

OBJECTIVE

To develop evidence-based recommendations for the management of systemic glucocorticoid (GC) therapy in rheumatic diseases.

METHODS

The multidisciplinary guideline development group from 11 European countries, Canada and the USA consisted of 15 rheumatologists, 1 internist, 1 rheumatologist-epidemiologist, 1 health professional, 1 patient and 1 research fellow. The Delphi method was used to agree on 10 key propositions related to the safe use of GCs. A systematic literature search of PUBMED, EMBASE, CINAHL, and Cochrane Library was then used to identify the best available research evidence to support each of the 10 propositions. The strength of recommendation was given according to research evidence, clinical expertise and perceived patient preference.

RESULTS

The 10 propositions were generated through three Delphi rounds and included patient education, risk factors, adverse effects, concomitant therapy (ie, non-steroidal anti-inflammatory drugs, gastroprotection and cyclo-oxygenase-2 selective inhibitors, calcium and vitamin D, bisphosphonates) and special safety advice (ie, adrenal insufficiency, pregnancy, growth impairment).

CONCLUSION

Ten key recommendations for the management of systemic GC-therapy were formulated using a combination of systematically retrieved research evidence and expert consensus. There are areas of importance that have little evidence (ie, dosing and tapering strategies, timing, risk factors and monitoring for adverse effects, perioperative GC-replacement) and need further research; therefore also a research agenda was composed.

Do Anti-CD25 Monoclonal Antibodies Potentiate Posttransplant Diabetes Mellitus?

Anti-CD25 monoclonal antibodies (MAbs) are directed against the IL-2 (CD-25) receptor, which is associated with the pathogenesis of diabetes mellitus (DM). Measuring CD25 on peripheral blood lymphocytes could be a new immunologic marker to identify patients with prediabetes.

OBJECTIVE

The study aimed to analyze whether administration of anti-CD25 MAbs was an independent risk factor for posttransplant diabetes mellitus (PTDM) in kidney transplant (KT) patients at 3 months after transplantation.

PATIENTS AND METHODS

Seventy-four stable, nondiabetic KT patients were included in the study. The overall sex distribution was 70% men and mean overall age, 52 +/- 10 years. Thirty-eight subjects where treated with anti-CD25 antibodies (basiliximab). The diagnosis of PTDM was made if patients required insulin or oral antidiabetic drugs and/or had glycemia >200 mg/dL at 120 minutes after an oral glucose tolerance test (75 g glucose). We determined the age, weight, body mass index, acute rejection, chronic hepatitis C virus (HCV) infection, and type of calcineurin inhibitor.

RESULTS

Thirty-four percent of patients developed PTDM. Patients treated with anti-CD25 antibodies were older (P = .022) and showed a greater incidence of PTDM (P = .041). The logistic regression analysis (dependent variable: PTDM; independent variables: age, anti-CD25, tacrolimus vs cyclosporine) showed that treatment with anti-CD25 is an independent risk factor for PTDM (P = .041; OR 3.28; CI 95% 1.04-10.31).

CONCLUSION

Patients treated with anti-CD25 MAbs showed greater incidence of PTDM.

Corticosteroid withdrawal in kidney transplantation: the present status

Corticosteroids (CS) have played a vital role in organ transplantation, both for prevention and treatment of allograft rejection. However, the use of CS is associated with a wide range of adverse effects. With advances in immunosuppressive drug therapy, attempts have been made to minimize the use of CS to avoid or alleviate their side effects. Withdrawal of CS months after transplantation has transitioned to days. In low to intermediate risk renal allograft recipients, use of induction therapy and modern maintenance drug combinations allows safe withdrawal of CS within the first week of transplantation. In other groups, existing potent maintenance agents permit tapering of CS to low doses over the first few months. Withdrawal of these small doses may not add to the benefits.

Posttransplant metabolic acidosis: a neglected factor in renal transplantation?

PURPOSE OF REVIEW

The occurrence and pathogenesis of metabolic acidosis after renal transplantation is reviewed. Posttransplant acidosis is shown to be a key mechanism for major metabolic complications in mineral and muscle metabolism, and for anemia, discussed in the context of both acidosis and renal transplantation.

RECENT FINDINGS

Continuous improvement in kidney transplant survival has shifted attention to long-term outcomes, specifically to disorders linked to cardiovascular disease, physical capacity and quality of life. Metabolic acidosis is gaining growing acceptance as a clinical entity and has occasionally come into focus in the context of renal transplantation. The possible link to metabolic disturbances resulting in impairment of musculoskeletal disorders and physical limitations, however, has not been considered specifically.

SUMMARY

Available evidence suggests a high prevalence of (compensated) metabolic acidosis after renal transplantation, presenting as low serum bicarbonate and impaired renal acid excretion. This condition is associated with relevant disorders in mineral metabolism and muscle function. Current knowledge about the effects of acidosis on renal electrolyte handling, mineral metabolism and protein synthesis suggests that acid/base derangements contribute to the muscle and bone pathology, as well as anemia, encountered after kidney transplantation. Consequently, posttransplant acidosis may be a relevant factor in the causal pathway of impaired physical capacity observed in this patient group.

Atherosclerosis is accelerated in patients with long-term well-controlled systemic lupus erythematosus (SLE)

BACKGROUND

It is uncertain whether atherosclerosis is accelerated in premenopausal and postmenopausal patients with long-term well-controlled systemic lupus erythematosus (SLE).

METHODS

We measured the intima-media thickness (IMT) of the carotid arteries and the cardio-ankle vascular index (CAVI) in 39 women with SLE and in age- and sex-matched controls.

RESULTS

In the premenopausal state, carotid plaque was detected only in SLE patients (36%). In the postmenopausal state, the maximum IMT was about 2-fold greater in SLE patients than in control subjects (1.3+/-0.7 vs. 0.7+/-0.2 mm, p<0.001). CAVI was higher in both the premenopausal and postmenopausal SLE patients. The serum amyloid A protein (SAA) was higher in SLE patients in the premenopausal state (p=0.025), while remnant like particle-cholesterol (RLP-C), the homeostasis model assessment of insulin resistance (HOMA-IR), and SAA were significantly increased in postmenopausal SLE patients (p=0.001, p<0.001 and p<0.05, respectively). Multiple regression analysis revealed that the maximum IMT was associated with cumulative PSL dosage (p=0.027) and SAA (p=0.074) in the premenopausal SLE patients, and with HOMA-IR (p<0.001) in the postmenopausal SLE patients.

CONCLUSION

Atherosclerosis is accelerated in long-term well-controlled SLE. More attention should be given to subclinical inflammation and insulin resistance in the management of SLE patients.

Polycystic kidney disease is a risk factor for new-onset diabetes after transplantation

BACKGROUND

Data from matched historical cohort studies suggest that autosomal-dominant polycystic kidney disease (ADPKD) may be a risk factor for new-onset diabetes after transplantation (NODAT).

METHOD

A retrospective study of 429 renal allografts transplanted from 1990 through 2004 in nondiabetic patients was performed. A multivariate analysis of risk factors for NODAT was performed with focus on ADPKD.

RESULTS

A total of 6.5% of all patients developed NODAT and a further 11% developed impaired glucose tolerance. NODAT developed in 13.4% of patients with ADPKD compared with 5.2% of non-ADPKD patients (P=0.01). There were significant univariate associations between NODAT and recipient age (P=0.001) and weight (P<0.0001). There was no association between NODAT and recipient gender, human leukocyte antigen mismatch, acute rejection, or cumulative methylprednisolone dose. In a multivariate analysis, ADPKD was a strong risk factor for the development of NODAT (odds ratio [OR]=2.41, P=0.035) after correction for recipient age, weight, gender, ethnicity, and tacrolimus use. Age (OR=1.06), weight (OR=1.04), and nonwhite race (OR=5.04) were the other significant variables.

CONCLUSION

We conclude that ADPKD is a significant risk factor for the development of NODAT. This may influence the follow up and management choices of these patients in the future.

Metabolic and nutritional complications of renal transplantation

Renal transplantation is the gold standard therapy for patients with end-stage renal disease. However, renal transplantation is associated with various metabolic and nutritional complications. This review focuses primarily on factors that have a significant impact on cardiovascular disease, namely, hyperlipidemia, posttransplant diabetes mellitus, and hyperhomocysteinemia. The prevalence of hyperlipidemia in renal transplant patients is estimated at 80% to 90%. Corticosteroids, cyclosporine, and sirolimus are commonly associated with hyperlipidemia. The incidence of posttransplant diabetes mellitus is estimated to be 24% at 36 months post transplant. Glucocorticoids induce metabolic changes that result in hyperglycemia. Calcineurin inhibitors have direct islet cell toxicity and induced alterations in the transcriptional regulation of insulin. Hyperhomocysteinemia is common in renal transplant recipients and is an independent risk factor for cardiovascular disease.

Transplant-associated hyperglycemia: a new look at an old problem

New-onset diabetes has long been recognized as a common complication of kidney transplantation, promoting cardiovascular disease, death, and graft failure. Studies in recent years have begun to highlight the very high posttransplantation prevalence of the prediabetic states of impaired fasting glucose and impaired glucose tolerance and the significant repercussions of these states on cardiovascular health. Therefore, the overall burden of transplant-associated hyperglycemia (TAH), which encompasses new-onset diabetes and the prediabetic states, is far greater than previously appreciated. The kidney transplant population is predisposed to insulin resistance and to additional insults of hypertension and hyperlipidemia that, together with hyperglycemia, compose the metabolic syndrome and promote atherosclerosis. When recipients with an underlying, frequently nonmodifiable predisposition to glucose dysregulation encounter transplant-specific, often modifiable, diabetogenic exposures, TAH manifests. Aggressive screening will effectively detect TAH, whereas risk factor modification, lifestyle intervention, and, when appropriate, drug therapy may decrease its impact. Topics of future investigation should include the use of emerging diabetes therapies and avenues for the prevention and reversal of TAH.

Determinants of Insulin Resistance in Renal Transplant Recipients

BACKGROUND

Insulin resistance is considered to play an important role in the development of cardiovascular disease, which limits long-term renal transplant survival. Renal transplant recipients are more insulin-resistant compared with healthy controls. It is not known to date which factors relate to this excess insulin resistance. Therefore, we investigated which factors are related to insulin resistance long-term after renal transplantation.

METHODS

All renal transplant recipients at our outpatient clinic with a functioning graft for more than one year were invited to participate. We excluded diabetic recipients. Recipient, donor, and transplant characteristics were collected as putative determinants. We used fasting insulin, homeostasis model assessment index, and McAuley's index as valid estimates of insulin resistance. Linear regression models were created to investigate independent determinants of all indexes.

RESULTS

A total of 483 recipients (57% male, 50+/-12 years) were analyzed at a median (interquartile range) time of 6.0 (2.6-11.6) years posttransplant. The most consistent determinants across all three indices were body mass index (P<0.001), waist-to-hip ratio (P<0.001), and prednisolone dose (P<0.05). Independent associations were present for total cholesterol (P<0.001), high-density lipoprotein cholesterol (P<0.001), creatinine clearance (P<0.05), recipient age (P<0.001), and gender (P< or =0.002). No independent associations were present for transplant-related factors such as acute rejection treatment or cytomegalovirus seropositivity.

CONCLUSIONS

Our results indicate that obesity, distribution of obesity, and prednisolone treatment are the predominant determinants of insulin resistance long term after transplantation. Insulin resistance after renal transplantation could be managed favorably by weight and prednisolone dose reduction, which may reduce cardiovascular disease.

Immunosuppression in pediatric solid organ transplantation: opportunities, risks, and management

The pediatric transplant community stands at a time of unprecedented choice of immunosuppressive agents - and with a legacy of morbidity from those agents used in the previous two decades. This review considers the clinical utility and side-effect profiles of immunosuppressants used widely in current practice (e.g., glucocorticoids, azathioprine, ciclosporin, tacrolimus, mycophenolate, and sirolimus) and those agents which are in increasing use or in evaluation (e.g., IL-2 receptor antibodies, everolimus, FTY720, LEA29Y, and deoxyspergualin). Further consideration is given to the wider drug interactions likely during the use of new immunosuppressant regimens and to our growing awareness of the influences of genetic heterogeneity on drug efficacy and handling. Finally, we consider the new demands being placed on the use of drug monitoring to regulate dosage of this new repertoire of immunosuppressants.

Long-term patient survival: strategies to improve overall health

The use of potent immunosuppressant therapy has led to an increase in number of patients with successful long-term kidney transplants. These individuals come to kidney transplantation with varying levels of comorbidity associated with end-stage renal disease and are susceptible to immunologic and nonimmunologic comorbidities that arise late after transplantation, including cardiovascular disease, infection, malignancy, and bone disease, which negatively impact on patient and graft survival. In addition, nonadherence to immunosuppressant regimens increases with time after transplantation, which further augments the risk for late-term graft failure and mortality. Consistent and frequent follow-up of kidney transplant recipients beyond the first year permits early diagnosis and successful treatment of many posttransplantation comorbidities. Implementation of preventive practices and aggressive management of risk factors throughout the life of the transplant improves overall health and long-term outcomes. Establishment and maintenance of close relationships among transplant centers, physicians, patients, and their families improves patient adherence to medications and reduces the risk for morbidity and mortality.

Steroid Sparing in Kidney Transplantation: Changing Paradigms, Improving Outcomes, and Remaining Questions

The widely known adverse effects of long-term therapy with corticosteroids have motivated increasing interest in steroid-free immunosuppression for kidney transplant recipients. Results from recent trials that used newer immunosuppressants to facilitate elimination of steroids suggest better short-term results than were achieved in an earlier era. However, the best results have been reported in uncontrolled trials of low-risk patients or in randomized trials with relatively short periods of follow-up. Increasingly, the therapeutic paradigm has shifted from late withdrawal of steroids to very early withdrawal after transplantation or even complete avoidance. Induction antibody therapy has been used routinely in the most successful trials that involved early steroid withdrawal or avoidance. Although the outcomes of kidney transplant recipients who are treated with steroid-free immunosuppression are improving steadily, there still is room for concern in recommending this strategy as a standard of practice.

Hypoadiponectinemia is associated with insulin resistance and glucose intolerance after renal transplantation: impact of immunosuppressive and antihypertensive drug therapy

The objectives of this analysis were (1) to assess whether low serum adiponectin concentrations are associated with insulin resistance, metabolic syndrome, and new-onset posttransplantation diabetes mellitus (PTDM) and (2) to examine the possible effects of immunosuppressive and antihypertensive therapies on circulating adiponectin levels after renal transplantation. A total of 172 consecutive previously nondiabetic renal transplant recipients were examined 3 mo after transplantation, the majority (n = 167) with an oral glucose tolerance test. Serum adiponectin was measured by an in-house time-resolved immunofluorometric assay. Insulin secretion and insulin sensitivity were estimated by previously validated oral glucose tolerance test-derived indexes. One- and 6-yr follow-up data were available in subgroups of patients. Lower adiponectin levels were significantly associated with insulin resistance but not with insulinopenia. Patients with low adiponectin levels (first quartile) had significantly higher odds of PTDM (odds ratio [OR] 3.6; 95% confidence interval [CI] 1.1 to 12.7; P = 0.049) and metabolic syndrome (OR 3.9; 95% CI 1.6 to 9.5; P = 0.003) than patients in the upper (fourth) quartile. The increased risk for PTDM in patients with low adiponectin levels remained significant after adjustment for age, steroid dose, and family history of diabetes. Treatment with beta blockers was independently associated with lower serum adiponectin levels, and total steroid dose was associated with higher serum adiponectin levels. Low baseline adiponectin levels were also associated with significantly higher odds of PTDM at 6 yr (OR 6.9; 95% CI = 1.1 to 41.8; P = 0.037). Serum adiponectin levels correlate with posttransplantation insulin sensitivity and glucose tolerance. Glucocorticoids and beta blockers seem to have opposite effects on circulating adiponectin levels.

Validation of insulin resistance indexes in a stable renal transplant population

OBJECTIVE

The purpose of this study was to investigate the validity of established insulin resistance indexes, based on fasting blood parameters, in a stable renal transplant population.

RESEARCH DESIGN AND METHODS

Fasting insulin, homeostasis model assessment (HOMA), the quantitative insulin sensitivity check index (QUICKI), and McAuley's index were assessed for correlation and agreement with whole-body glucose uptake (M value) divided by prevailing serum insulin concentrations (I value) assessed during a hyperinsulinemic-euglycemic clamp in 51 stable renal transplant recipients, who were at a median of 7.5 years after transplant. Multivariate linear regression analyses were used to determine independent risk factors for insulin resistance.

RESULTS

The M/I value correlated with fasting insulin concentration (r = -0.56), HOMA (r = -0.53), QUICKI (r = 0.52), and McAuley's index (r = 0.61) (all P < 0.01). Linear regression showed agreement between all indexes and insulin resistance. However, McAuley's index showed the strongest agreement irrespective of age, sex, renal allograft function, and obesity. In multivariate analysis, fasting insulin concentration (beta = -0.59, P = 0.002), fasting triglyceride concentration (beta = -0.33, P = 0.04), and BMI (beta = -1.22, P = 0.05) were independently associated with the M/I value.

CONCLUSIONS

All investigated insulin resistance indexes were valid estimates of insulin resistance in the long-term stable renal transplant population. However, correlation and agreement were strongest for McAuley's index. In addition to fasting insulin and triglyceride concentrations, of which McAuley's index is composed, only BMI seemed to be independently associated with insulin resistance in this population.

Glucose metabolism in renal transplant recipients: effect of calcineurin inhibitor withdrawal and conversion to sirolimus

Cyclosporine A (CsA) and tacrolimus have been associated with an increased risk for diabetes after transplantation, whereas sirolimus is deemed to be devoid of any effect on glucose metabolism. This study was performed to investigate the effect of the withdrawal of calcineurin inhibitors and the switch to sirolimus on peripheral insulin resistance and pancreatic beta cell response. Twenty-six patients who received a kidney transplant and discontinued CsA and were converted to sirolimus and 15 recipients of suboptimal kidneys who were treated with tacrolimus plus sirolimus for the first 3 mo after grafting and thereafter with sirolimus alone were enrolled. All patients underwent an oral glucose tolerance test and intravenous insulin tolerance test before and 6 mo after the conversion to sirolimus-alone therapy. The withdrawal of CsA or tacrolimus was associated with a significant fall of insulin sensitivity (both P = 0.01) and with a defect in the compensatory beta cell response, as measured by the disposition index (P = 0.004 and P = 0.02, respectively). The increase of insulin resistance and the decrease of disposition index significantly correlated with the change of serum triglyceride concentration after the conversion to sirolimus-based therapy (R(2) = 0.30, P = 0.0002; and R(2) = 0.19, P = 0.004, respectively). Clinically, the switch to sirolimus was associated with a 30% increase of incidence of impaired glucose tolerance and with four patients' developing new-onset diabetes. In conclusion, the discontinuation of calcineurin inhibitors and their replacement by sirolimus fail to ameliorate the glycometabolic profile of kidney transplant recipients. Rather, it is associated with a worsening of insulin resistance and an inappropriately low insulin response.