Diabetes mellitus after renal transplantation: as deleterious as non-transplant-associated diabetes?

Results of an international, randomized trial comparing glucose metabolism disorders and outcome with cyclosporine versus tacrolimus

DIRECT (Diabetes Incidence after Renal Transplantation: Neoral C(2) Monitoring Versus Tacrolimus) was a 6-month, open-label, randomized, multicenter study which used American Diabetes Association/World Health Organization criteria to define glucose abnormalities. De novo renal transplant patients were randomized to cyclosporine microemulsion (CsA-ME, using C(2) monitoring) or tacrolimus, with mycophenolic acid, steroids and basiliximab. The intent-to-treat population comprised 682 patients (336 CsA-ME, 346 tacrolimus): 567 were nondiabetic at baseline. Demographics, diabetes risk factors and steroid doses were similar between treatment groups. The primary safety endpoint, new-onset diabetes after transplant (NODAT) or impaired fasting glucose (IFG) at 6 months, occurred in 73 CsA-ME patients (26.0%) and 96 tacrolimus patients (33.6%, p = 0.046). The primary efficacy endpoint, biopsy-proven acute rejection, graft loss or death at 6 months, occurred in 43 CsA-ME patients (12.8%) and 34 tacrolimus patients (9.8%, p = 0.211). Mean glomerular filtration rate (Cockcroft-Gault) was 63.6 +/- 20.7 mL/min/1.73 m(2) in the CsA-ME cohort and 65.9 +/- 23.1 mL/min/1.73 m(2) with tacrolimus (p = 0.285); mean serum creatinine was 139 +/- 58 and 133 +/- 57 mumol/L, respectively (p = 0.005). Blood pressure was similar between treatment groups at month 6, but total cholesterol, LDL-cholesterol and triglyceride levels were significantly higher with CsA than with tacrolimus (total cholesterol:HDL remained unchanged). The profile and incidence of adverse events were similar between treatments. The incidence of NODAT or IFG at 6 months post-transplant is significantly lower with CsA-ME than with tacrolimus without a significant difference in short-term outcome.

Diabetic Complications Associated With New-Onset Diabetes Mellitus in Renal Transplant Recipients

BACKGROUND

Data are scarce regarding the incidence and risk factors for complications of new-onset diabetes mellitus (NODM) in renal transplant patients.

METHODS

United States Renal Data System (USRDS) data from primary renal transplant recipients during 1995-2001 who developed NODM was used to examine diabetic complications over the first three years posttransplant. Prognostic models were used to evaluate patient characteristics and treatment choices associated with risk of each class of complications. Propensity scores for choice of calcineurin inhibitor were included in multivariate analyses.

RESULTS

The analysis included 21,489 patients, of whom 4,105 developed NODM by 3 years posttransplant. One or more NODM complications developed in 2,393 patients (58.3% of all patients with NODM), comprising ketoacidosis (334, 8.1%), hyperosmolarity (131, 3.2%), renal complications (1,286, 31.3%), ophthalmic complications (340, 8.3%), neurological complications (665, 16.2%), peripheral circulatory disorders (170, 4.1%) and hypoglycemia/shock (301, 7.3%). Complications developed within a mean of 500 to 600 days from diagnosis of NODM. Multivariate analysis showed that increased recipient age, higher body mass index, African-American race, hepatitis C infection, hypertension as cause of end-stage renal disease, cold ischemia >or=30 hours, and use of tacrolimus each increased risk of complications.

CONCLUSION

NODM is associated with similar complications to those seen in the general population, but these appear to develop at an accelerated rate. Obesity and use of tacrolimus are the only modifiable factors that appear to affect risk of NODM or its complications.

Predictors of new onset diabetes after renal transplantation

The development of new onset diabetes after transplantation (NODAT) is associated with increased cardiovascular morbidity and mortality. This study aimed at identifying risk factors for the development of NODAT. We performed a retrospective review of 787 renal transplants performed between 1994 and 2004 at a single centre. NODAT was diagnosed in patients who had two random plasma glucose concentrations >11.1 mmol/L after the first month post-transplant or patients who required treatment for hyperglycaemia within the first month and continued treatment thereafter. The incidence of NODAT was 7.7%. The incidence of NODAT requiring either insulin or oral hypoglycaemic agents was 4.5%. Risk factors for the development of NODAT were older age (HR 1.04, 95% CI: 1.01-1.07, p < 0.01), heavier weight at time of transplantation (HR 1.04, 95% CI: 1.02-1.07, p < 0.01), higher mean pre-transplant random plasma glucose concentrations (HR 1.54, 95% CI: 1.14-2.08, p < 0.01), higher plasma glucose within the first seven d post-transplant (HR 1.27, 95% CI: 1.09-1.47, p < 0.01) and use of tacrolimus (HR 3.70, 95% CI: 1.61-8.46, p < 0.01). Ten yr actuarial patient survival was 67.1% in patients with NODAT compared with 81.9% for those without diabetes and 65.3% in patients known to have diabetes pre-transplant. There was no difference in graft survival. We have identified a high-risk group in which attempts should be made to reduce the incidence of NODAT by tailoring immunosuppression, lifestyle modification and selecting non-diabetogenic medications. Improvements in management of patients at higher risk of NODAT may help reduce the incidence of deaths with a functioning graft.

The Impact of Living Donor Kidney Transplantation on Markers of Cardiovascular Risk in Chronic Kidney Disease Patients

BACKGROUND

Kidney transplant (Tx) patients present a reduced cardiovascular (CV) mortality in comparison to the dialysis population, but in comparison to the general population, it is still several-fold higher.

METHODS

We studied risk factors for CV disease in a group of 38 patients (50% males, median age 36 years) who underwent a living donor Tx at the baseline and after 3 +/- 1 and 9 +/- 2 months.

RESULTS

The prevalence of overweight increased from 26 to 54% after Tx (p < 0.001). The mean systolic blood pressure decreased significantly after the Tx (148 +/- 27.6 vs. 126 +/- 12.7 mm Hg). There was a significant increase in LDL (97 +/- 30 vs. 114 +/- 35) and hematocrit (33.8 +/- 4.4 to 42 +/- 5.7%) levels and a significant reduction in fibrinogen levels (394 +/- 91 vs. 366 +/- 100 mg/dl) after 9 months as compared to the baseline. Obesity and dislipidemia were significantly correlated with inflammation. Significant changes in left ventricle mass index (293 +/- 116 vs. 241 +/- 96) were observed after the Tx. Patients with a low glomerular filtration rate (GFR) in the follow-up evaluation presented higher LDL (128 +/- 7 vs. 99 +/- 7 mg/dl; p < 0.05) and higher fibrinogen levels (399 +/- 21 vs. 332 +/- 22 mg/dl; p < 0.05) compared to patients with a high GFR.

CONCLUSION

Most of the risk factors analyzed (particularly the uremia-related) improved after the renal Tx, which could justify the positive impact of Tx on the development of CV disease. Inflammation and dyslipidemia were related to renal dysfunction after the Tx, suggesting that complete restoration of renal function may have an impact on reducing CV mortality in CKD patients treated with renal Tx.

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.

Risk factors associated with the onset and progression of posttransplantation diabetes in renal allograft recipients

OBJECTIVE

The aim of this study was to assess the incidence of posttransplantation diabetes mellitus (PTDM) in renal allograft recipients and to investigate factors contributing to the onset and progression of PTDM and its underlying pathogenic mechanism(s).

RESEARCH DESIGN AND METHODS

A total of 77 patients with normal glucose tolerance (NGT) were enrolled in this study. An oral glucose tolerance test was performed 1 week before transplantation and repeated at 1 and 7 years after transplantation.

RESULTS

The overall incidence of PTDM was 39% at 1 year and 35.1% at 7 years posttransplantation. The incidence for each category of PTDM was as follows: persistent PTDM (P-PTDM) (patients who developed diabetes mellitus within 1 year of transplantation and remained diabetic during 7 years), 23.4%; transient PTDM (T-PTDM) (patients who developed diabetes mellitus during the 1st year after transplantation but eventually recovered to have NGT), 15.6%; late PTDM (L-PTDM) (patients who developed diabetes mellitus later than 1 year after transplantation), 11.7%; and non-PTDM during 7 years (N-PTDM7) (patients who did not develop diabetes mellitus during 7 years), 49.3%. Older age (> or = 40 years) at transplantation was a higher risk factor for P-PTDM, whereas a high BMI (> or = 25 kg/m2) and impaired fasting glucose (IFG) at 1 year posttransplantation were higher risk factors for L-PTDM. Impaired insulin secretion rather than insulin resistance was significantly associated with the development of P- and L-PTDM.

CONCLUSIONS

Impaired insulin secretion may be the main mechanism for the development of PTDM. Older age at transplantation seems to be associated with P-PTDM, whereas a high BMI and IFG at 1 year after transplantation were associated with L-PTDM.

The burden of new-onset diabetes mellitus after transplantation

The clinical impact of new-onset diabetes mellitus (NODM) is frequently underestimated by clinicians. NODM occurs in approximately 15-20% of renal transplant patients and 15% of liver transplant recipients. Diabetes after transplantation is a leading risk factor for cardiovascular events, with a higher prognostic value than in the non-transplant population. NODM also appears to have a negative influence on graft function, and graft survival rates after renal transplantation are significantly lower in patients who develop diabetes than in controls. Patient mortality following renal transplantation is generally found to be higher in patients with NODM, due to increased cardiovascular and peripheral vascular disease, accelerated graft deterioration and diabetes-related complications, notably infection. A renal registry analysis has reported an increase of 87% in risk of death following onset of NODM. There is also limited evidence that NODM is associated with increased risk of death in liver transplant patients. The relative incidence and severity of diabetic complications in transplant recipients have not been assessed rigorously in a clinical trial but registry data indicate that 20% of renal transplant patients with NODM experience at least one clinically significant diabetic complication within three years. Financially, the additional healthcare costs incurred over the first two years following onset of NODM amount to 21,500 dollars. Routine pre-transplant assessment of diabetic risk, with requisite modification of lifestyle, glycaemic monitoring and immunosuppressive regimens, and coupled with standardized, aggressive hypoglycaemic management as necessary, offers an important opportunity to alleviate the burden of NODM for transplant patients.

Review article: medical management of the liver transplant recipient - a primer for non-transplant doctors

BACKGROUND

Survival 10 years after orthotopic liver transplantation now approaches 65%. Consequently, community doctors must manage the metabolic and neoplastic complications of orthotopic liver transplantation in an ageing population.

AIMS

To review common sources of morbidity and mortality in long-term orthotopic liver transplantation recipients, and to make evidence-based recommendations regarding their management.

METHODS

Pertinent studies and reviews were identified by literature search through PubMed. Where evidence-based recommendations could not be gleaned from the literature, expert opinion was obtained from syllabi of national meetings.

RESULTS

The two most common causes of morbidity and mortality in orthotopic liver transplantation recipients are atherosclerotic vascular disease and de novo malignancy. The pathogenesis of many complications begins before orthotopic liver transplantation, and many are potentially modifiable. Most complications, however, can be directly ascribed to immunosuppressive agents. Despite improvements in our understanding of the pathogenesis and epidemiology of the metabolic and neoplastic complications of orthotopic liver transplantation, remarkably few randomized-controlled studies exist to define their optimal management.

CONCLUSIONS

Orthotopic liver transplantation recipients experience and succumb to the same afflictions of old age as non-transplant patients, but with greater frequency and at an earlier age. Most recommendations regarding surveillance for, and treatment of, medical complications of orthotopic liver transplantation remain based upon expert opinion rather than evidence-based medicine.

Risk factors for new-onset diabetes mellitus following liver transplantation and impact of hepatitis C infection : an observational multicenter study

New-onset diabetes mellitus (NODM) remains a common complication of liver transplantation (LT). We studied incidence and risk factors in 211 French patients who had undergone a primary LT between 6 and 24 months previously. This is a cross-sectional and retrospective multicenter study. Data were collected on consecutive patients at a single routine post-LT consultation. Demographic details, immunosuppressive regimens, familial and personal histories, hepatitis status, and cardiovascular risk were analyzed to compare those who developed NODM (American Diabetes Association/World Health Organization criteria) with the others. The overall incidence of NODM was 22.7%: 24% in tacrolimus (Tac)-treated patients (n = 175; 82.9%) and 16.7% in cyclosporine-treated patients (n = 36; 17.1%). A total of 81% of the cases were diagnosed within 3 months of LT (M3). Among hepatitis C virus (HCV)-infected (HCV(+)) patients, NODM incidence was 41.7% whereas among those patients negative for this virus (HCV(-)), the incidence was only 18.9% (P = 0.008). In Tac-treated patients, the incidence of NODM in the HCV(+) patients was significantly higher than in the HCV(-) patients (46.7% and 19.3%, respectively, P = 0.0014). Only 1 of 6 (16.7%) of the HCV(+) patients developed NODM on cyclosporine. Other independent pretransplantation risk factors for NODM included impaired fasting glucose (IFG) and a maximum lifetime body-mass index (BMI) over 25 kg/m2. In conclusion, emergence of NODM after LT is related to risk factors that can be detected prior to the graft, like maximum lifetime BMI, IFG, and HCV status. Tac induced a significantly higher incidence of NODM in the HCV(+) compared to the HCV(-) patients. The treatment should therefore be tailored to the patient's risk especially in case of HCV infection.

Relative risk of new-onset diabetes during the first year after renal transplantation in patients receiving tacrolimus or cyclosporine immunosuppression

Clinical trials have consistently shown a higher incidence of new-onset diabetes mellitus with tacrolimus than cyclosporine. However, in protocol-driven studies steroid doses are comparable in both treatment arms, while in clinical practice steroid dose used in conjunction with tacrolimus or cyclosporine may differ. This retrospective study analysed renal transplant recipients without pre-existing diabetes receiving tacrolimus (n = 100) or cyclosporine (n = 100) for whom one-year follow-up data were available. Diabetes was defined as use of insulin or oral hypoglycemic agents; fasting glucose >6.9 mmol/L; or non-fasting glucose >11 mmol/L on three consecutive occasions. Tacrolimus-treated patients were significantly older than cyclosporine-treated patients (49 +/- 14 vs. 44 +/- 13 yr, p < 0.05) and received a significantly lower cumulative dose of corticosteroids over the first three months post-transplant (1284 +/- 379 vs. 1714 +/- 486 mg, p < 0.0001). At 3, 6, 9 and 12 months significantly more tacrolimus-treated patients had new-onset diabetes than cyclosporine- treated patients. At 12 months, 18 patients receiving tacrolimus and two receiving cyclosporine had diabetes (p < 0.0001). There was a clear relationship between age and incidence of new-onset diabetes at three months in the tacrolimus cohort. After stratifying patients by age group, the frequency of diabetes was significantly higher with tacrolimus than with cyclosporine in patients aged 40-60 yr [8/46 (17.4%) vs. 2/48 (4.2%), p < 0.05] and >60 yr [9/28 (32.1%) vs. 0/14 (0%), p < 0.05]. The mean tacrolimus trough level during the first three months was similar in patients with diabetes (13.1 +/- 2.3 ng/mL) or without diabetes (13.0 +/- 2.8 ng/mL, n.s.). These results indicate that new-onset diabetes is strongly and significantly associated with tacrolimus vs. cyclosporine in renal transplant recipients, even when steroid dosing is lower with tacrolimus.

The impact of early-diagnosed new-onset post-transplantation diabetes mellitus on survival and major cardiac events

The impact of early-diagnosed new-onset post-transplantation diabetes mellitus (PTDM) on cardiovascular (CV) disease is not well described. The objectives of the present prospective single-center observational study were to assess the long-term effects of early-diagnosed new-onset PTDM on major cardiac events (MCE; cardiac death or nonfatal acute myocardial infarction) and patient survival. Diabetic status and CV risk factors were assessed in 201 consecutive renal allograft recipients 3 months after transplantation (baseline) during a period of 16 months (1995-96). Follow-up data until January 1, 2004 were obtained from the Norwegian Renal Registry. The 8-year (range 7-9 years) cumulative incidence of MCEs was 7% (nine out of 138) in recipients without diabetes, 20% (seven out of 35) in patients with new-onset PTDM and 21% (six out of 28) in patients with diabetes mellitus before transplantation (DM). Proportional hazards regression analyses (forward stepwise regression) revealed that patients with PTDM had an approximately three-fold increased risk of MCEs as compared with nondiabetic patients (hazard ratio (HR)=3.27, 95% confidence interval (CI)=1.22-8.80, P=0.019). A total of 61 patients (30%) died. Eight-year patient survival was 80% in the nondiabetic group, 63% in the PTDM group and 29% in the DM group, respectively. Pretransplant diabetes (HR=5.09, 95% CI=2.60-9.96, P<0.001), age (HR=1.03, 95% CI=1.01-1.05, P=0.016), cytomegalovirus (CMV) infection (HR=2.66, 95% CI=1.27-5.53, P=0.009), and creatinine clearance (HR=0.98, 95% CI=0.96-1.00, P=0.046), but not PTDM (HR=1.20, 95% CI=0.58-2.49, P=0.621), were independent predictors of death in the multiple Cox regression model. Early-diagnosed PTDM is a predictor of MCEs, but not of all-cause mortality, the first 8 years after renal transplantation.

Posttransplant diabetes mellitus in kidney transplant recipients receiving calcineurin or mTOR inhibitor drugs

BACKGROUND

The aim of this study was to evaluate the incidence and risk factors for posttransplant diabetes mellitus (PTDM; defined as new insulin use and/or new hyperglycemia) in 528 kidney recipients using different immunosuppressive agents.

METHODS

Maintenance therapy included mycophenolate mofetil or azathioprine plus glucocorticoids in combination with Group I cyclosporine (263); Group II tacrolimus (60); or Group III sirolimus (205).

RESULTS

The mean follow-up was 39.2 (range 9.0-103.8) months. Overall, the number of patients needing insulin was 7.4% (39/528). The incidences for Groups I, II, and III of 7.6%, 11.7%, and 5.9%, respectively, were not statistically different. Characteristics of patients with PTDM included older age (P=0.007); greater body weight (kg) at transplant, 6 months, and 12 months, respectively (P<0.001); greater BMI (kg/m2) at transplant, 6 months, and 12 months, respectively (P<0.001); more acute rejection episodes 28.2% vs. 13.5% (P=0.012); and increased incidence in African Americans (P=0.03). Multivariable analysis demonstrated increased risk for PTDM (defined as new insulin use) for tacrolimus, (hazard ratio [HR] 3.794, P=0.007); treated rejections (HR 2.491, P=0.0115); age (HR 1.407, P=0.0116); and BMI (HR 1.153, P<0.0001). New insulin use occurred sooner and with less total glucocorticoid dose for tacrolimus patients. If PTDM is defined as all cases of new hyperglycemia, then no immunosuppressive drug group demonstrated an increased risk. CONCLUSION.: The risk for developing PTDM is greatest among older recipients, and those obese at the time of transplant; those given steroid pulse therapy were at exceptionally high-risk. PTDM risk reduction should focus on weight loss in the obese end-stage renal disease population prior to transplant.

Medical Care of Kidney Transplant Recipients after the First Posttransplant Year

Kidney transplantation is the treatment of choice for patients with ESRD. Despite improvements in short-term patient and graft outcomes, there has been no major improvement in long-term outcomes. The use of kidney allografts from expanded-criteria donors, polyoma virus nephropathy, underimmunosuppression, and incomplete functional recovery after rejection episodes may play a role in the lack of improvement in long-term outcomes. Other factors, including cardiovascular disease, infections, and malignancies, also shorten patient survival and therefore reduce the functional life of an allograft. There is a need for interventions that improve long-term outcomes in kidney transplant recipients. These patients are a unique subset of patients with chronic kidney disease. Therefore, interventions need to address disease progression, comorbid conditions, and patient mortality through a multifaceted approach. The Kidney Disease Outcomes Quality Initiative from the National Kidney Foundation, the European Best Practice Guidelines, and the forthcoming Kidney Disease: Improving Global Outcomes clinical practice guidelines can serve as a cornerstone of this approach. The unique aspects of chronic kidney disease in the transplant recipient require the integration of specific transplant-oriented problems into this care schema and a concrete partnership among transplant centers, community nephrologists, and primary care physicians. This article reviews the contemporary aspects of care for these patients.

Posttransplant Diabetes Mellitus: Impact of Good Blood Glucose Regulation on Renal Transplant Recipient Outcome

Posttransplant diabetes mellitus (PTDM) is a frequent complication among renal transplant recipients. This study sought to compare clinical outcomes of patients with PTDM who had strict glucose control with nondiabetic patients and to identify risk factors for atherosclerotic disease in both groups. We retrospectively examined 204 renal allograft recipients transplanted at our center between 1996 and 2002. Demographic features, dialysis and posttransplantation duration, smoking, body mass index, medications, comorbid diseases, number of HLA mismatches, and laboratory parameters including serum levels of creatinine, albumin, calcium, phosphorus, C-reactive protein, lipid parameters, and parathyroid hormone were analyzed as possible risk factors for atherosclerotic disease. Patients were followed for a mean of 59.7 +/- 23.6 months. PTDM was diagnosed according to the American Diabetic Association criteria or the need for an insulin/oral hypoglycemic agent. Twenty-six patients developed PTDM, and these patients had very good diabetes control. One patient with poorly regulated PTDM was excluded. Adverse events which were documented in 24 patients were more frequent among patients with PTDM. Mean age was found to be an independent risk factor for atherosclerotic disease, whereas PTDM was not. There were no differences regarding other atherosclerosis-related or other risk factors (including serum C-reactive protein levels and lipid profiles) between the groups. Nondiabetic subjects tended to have longer graft survival than patients with PTDM, but this finding was not statistically significant. PTDM is an important risk factor for developing atherosclerotic disease. Good control of blood glucose levels can decrease the high morbidity rates and negative influence of PTDM on patient and graft survival rates in this population.

Utility of HbA1c in the Detection of Subclinical Post Renal Transplant Diabetes

BACKGROUND

We hypothesized that the use of HbA1c testing would help identify postrenal transplant diabetes (PTDM).

METHODS

In all, 199 adult kidney transplant recipients at least 3 months posttransplant without previous history of diabetes or elevated fasting blood sugar were studied. Medical history, a fasting blood glucose, calcineurin inhibitor blood level, and HbA1c were obtained. Primary outcome was the incidence of subjects with HbA1c > or =6.1%. The covariates were use of cyclosporine or tacrolimus, time posttransplant, body mass index (BMI) at transplant and change since transplant, current steroid dose, history of graft rejection, current fasting glucose, age, and race. Proportions were compared between HbA1c <6 and > or =6.1% using Fisher's exact test. Means were compared using Student's t test. Logistic regression was used to identify risk factors associated with elevated HbA1c.

RESULTS

Twenty subjects (10.1%) had an elevated HbA1c. High normal fasting glucose (P=0.003) and African American race (P=0.08, marginally significant) were found to be associated with an elevated HbA1c. Subjects with normal and abnormal HbA1c levels were otherwise similar. There was no difference in HbA1c in tacrolimus versus cyclosporine treated subjects or in the percent of subjects with elevated HbA1c between these groups.

CONCLUSIONS

HbA1c levels were found to be more a more sensitive test than fasting blood glucose levels in PTDM, with 10.1% of all patients and 19.4% of blacks found to have an elevated HbA1c. HbA1c testing should be considered as a screening test for PTDM, especially in African Americans.

Survival Beyond 10 Years Following Heart Transplantation: The Cleveland Clinic Foundation Experience

BACKGROUND

Long-term survival after heart transplantation is a desirable although challenging goal.

METHODS

We analyzed clinical outcomes in the cohort of 170 patients who have undergone heart transplantation at The Cleveland Clinic Foundation and survived >10 years.

RESULTS

We found 10-year and 15-year survival rates of 54% and 41%, respectively, in these patients, but there was also a high incidence of complications, such as hypertension, renal dysfunction, transplant vasculopathy, and malignancy.

CONCLUSIONS

Long-term survival following cardiac transplantation is possible although complications are frequent. Beyond 10 years, malignancy is a major cause of death.

Clinical and Genetic Risk Factors for Posttransplant Diabetes Mellitus in Adult Renal Transplant Recipients Treated with Tacrolimus

BACKGROUND

The present study investigated the incidence of posttransplant diabetes mellitus (PTDM) and calculated the risk of developing PTDM under a tacrolimus-based immunosuppression based on clinical characteristics, tacrolimus pharmacokinetics, and genetic polymorphisms related to tacrolimus pharmacokinetics or diabetes mellitus.

METHODS

Seventy nondiabetic adult kidney recipients were studied. Patients with continuous high plasma glucose levels, over 6.5 mg/dl of hemoglobin A1c, or requiring insulin and/or oral antidiabetic agents for more than 3 months after transplantation 6 months postoperatively were diagnosed as having PTDM. Twelve genomic polymorphisms were assessed.

RESULTS

Six months after transplantation, 10 recipients (14.3%) developed PTDM. Positive risk factors were age (P=0.019) and body mass index (P=0.038). There were no significant differences in acute rejection rate, total steroid doses, tacrolimus pharmacokinetics or its related to genetic polymorphisms between the two groups. The frequency of PTDM was significantly higher in patients with the vitamin D receptor (VDR) TaqI t allele than in those with the TT genotype (P=0.013). On multivariate analysis, age over 50 years (odds ratio 9.28, P=0.003) and the presence of the VDR TaqI t allele (odds ratio 7.05, P=0.048) were correlated with the development of PTDM.

CONCLUSION

The incidence of PTDM was 14.3% in our cohort. Age over 50 years was a risk factor. The presence of the VDR TaqI t allele may also be a risk factor for PTDM, suggesting that genotyping of diabetes-related polymorphisms is a possible method of predicting a patient's risk for developing PTDM and would be a valuable asset in selecting appropriate immunosuppressive regimens for individuals.

Predictive Factors for Development of Diabetes Mellitus Post-Heart Transplant

INTRODUCTION

It is known that there is a high incidence of diabetes mellitus (DM) among heart transplant (HT) patients, which may be up to 30% at 5 years. The presence of DM has been associated with increased morbidity (infections, renal dysfunction, or graft vascular disease), and its development has been related primarily to immunosuppressive therapy. The objective of this study was to determine, in our experience, the presence of predictive variables for the development of DM following HT.

METHODS

We studied 315 consecutive non-DM patients (88.6% men, mean age 51.5 years) who underwent HT in our hospital from November 1987 to May 2003, analyzing all variables that could be related to the development of DM during follow-up. Student t-test and chi(2) test were used for univariate statistical analysis and logistic regression for multivariate analysis.

RESULTS

Of the 315 patients, 64 developed DM (20.3%) during a mean follow-up of 3.3 years. The univariate analysis showed that patients developing DM are older (54.9 +/- 8.7 versus 50.7 +/- 11.8 years, P = .008), have a higher body mass index (BMI) (27.3 +/- 3.8 versus 25.7 +/- 3.7, P = .003), a higher prevalence of HT (37.5% versus 23.5%, P = .023), a lower frequency of urgent HT (9.4% versus 26.2%, P = .004), are more often treated with steroids (85.9% versus 70.1%, P = .011) and tacrolimus (12.5% versus 4.4%, P = .015), and have a higher frequency of rejection episodes (71.2% versus 44.6%, P = .001). Multivariate analysis identified the following as predictive factors for the development of DM: age (OR = 1.04, P = .013), urgent HT (OR = 0.36, P = .031), treatment with tacrolimus (OR = 3.89, P = .012), and number of rejections (OR = 2.34, P = .002).

CONCLUSION

In our population, age, urgent HT (which had a protective effect), treatment with tacrolimus, and number of rejections were independent predictive variables for the development of DM during follow-up.

Cardiovascular Risk Factors in Diabetic Patients With Renal Transplants

There is a progressive increase in cardiovascular events post-renal transplantation and diabetes mellitus (DM) is one of the major cardiovascular risk factors. The objective of this study was to analyze the prevalence of cardiovascular risk factors and nonfatal cardiovascular events among renal transplant recipients, according to the status of their carbohydrate metabolism. We studied 214 renal transplant recipients, among whom 18% diabetic and 82% were nondiabetic. The 16% prevalence of cardiovascular events were higher among the posttransplantation DM (PTDM) group (33%) compared with the other groups, 19% in pre-renal transplantation DM, 17% in altered baseline glycemia, and 13% in normal patients. Diabetic renal transplant recipients showed a greater prevalence of pretransplantation ischemic cardiopathy when they were older and had a higher pretransplantation body mass index (BMI) a heavier smoking habit, significantly increased microinflammation markers, and a greater need for antihypertensive and hypolipidemic treatment. Renal transplant recipients with altered baseline glycemia show greater BMI after transplantation, as well as higher Hb1Ac than patients with normoglycemia.

Post-transplant diabetes mellitus and HCV seropositive status after renal transplantation: meta-analysis of clinical studies

Hepatitis C virus (HCV) infection has a detrimental role on patient and graft survival after renal transplantation (RT). Some studies have also implicated HCV in the development of post-transplant diabetes mellitus (PTDM). We conducted a systematic review of the published medical literature of the relationship between anti-HCV seropositive status and DM after RT. The risk of DM occurrence in anti-HCV-positive and -negative patients after RT was regarded as the most reliable outcome end-point. We used the random effects model of DerSimonian and Laird to generate a summary estimate of the Odds Ratio (OD) of new onset DM in HCV-positive and -negative patients after kidney transplantation. Ten studies involving 2502 unique RT recipients were identified. The incidence of PTDM after RT ranged between 7.9% and 50%. The summary estimate for adjusted OR was 3.97 with a 95% confidence interval (CI) of 1.83-8.61 (p-value for homogeneity <0.0473). Thus, pooling of study results demonstrated the presence of a significant link between anti-HCV seropositive status and DM after RT. This relationship provides one potential explanation for the adverse effects of HCV on patient and graft survival after RT.

New-Onset Diabetes after Kidney Transplantation: An Application of 2003 International Guidelines

BACKGROUND

The 2003 International Consensus Guidelines defined new-onset diabetes after transplantation. This study determined the risk of new-onset diabetes following kidney transplantation using these criteria.

METHODS

Consecutive nondiabetic patients who received kidney transplantation between August 2001 and March 2003 (recent, n=61) and before August 2001 (earlier, n=61) were retrospectively evaluated.

RESULTS

In all, 74% in the recent group and 56% in the earlier group developed diabetes by 1 year posttransplant. Median time to diabetes development was 23 days in the recent vs. 134 days in the earlier group (P=0.0304). Most patients developed diabetes within 60 days after transplantation. Immunosuppression was the strongest correlate of diabetes development; tacrolimus and cyclosporine A treatments were associated with increased risk. The rate of development was also greater when rapamycin was added to tacrolimus, compared to when it was not. The risk was double in African-Americans compared to whites. Age, body mass index, family history of diabetes, and etiology of renal failure did not predict diabetes; however, the mean age of patients was greater than previously reported.

CONCLUSIONS

The majority of patients are at risk of developing new-onset diabetes within a short time after kidney transplantation. The risk may be due to preexisting risk factors, immunosuppressive agents, or older age. The significance of these findings is not clear, but demands appropriate follow-up studies related to glycemia, end-organ complications, and graft function. It remains to be determined whether the 2003 International Consensus Guidelines are adequate to appropriately diagnose diabetes in the posttransplant time period, with special emphasis on the first 3 months.

Factors influencing the onset of diabetes mellitus after kidney transplantation: a single French center experience

Posttransplantation diabetes mellitus (PTDM) is a complication arising mostly during the first 6 months after kidney transplantation. Considering the serious outcomes of chronic hyperglycemia in kidney transplant patients, the recognition of factors that contribute to the onset of PTDM is of particular relevance. A retrospective analysis was performed to document the incidence of and the risk factors for diabetes mellitus occurring in the first year after kidney transplantation among 177 adult patients, without previously known diabetes transplanted between January 1998 and December 2000. PTDM, defined as fasting plasma glucose > or = 126 mg/dL confirmed by repeat testing on a different day, occurred in 48 (27.12%) patients of whom 36 showed transient changes during the first year after transplantation. Univariate analysis identified variables to be associated with the onset of PTDM: older recipient age (P = .05), male gender (P = .03), family history of diabetes (P = .04), advanced donor age (P = .008), absence of induction immunosuppression (P = .04), use of tacrolimus (vs cyclosporine; P = .01), one or more than one (steroid-treated) acute rejection episode(s) (P = .000001), cytomegalovirus infection (P = .02), and use of beta-blockers or diuretics (P = .05). By multivariate analysis, five factors were independently associated with the onset of PTDM: two episodes of rejection (odds ratio = 42.69, P = .000025), one episode of rejection (5.01, P = .007), older recipient age (1.06, P = .017), family history of diabetes (7.24, P = .011), and weight at transplantation (1.03, P = .048). Tacrolimus treatment remained of borderline significance (2.77, P = .05). In addition to traditional risk factors predisposing to the development of type 2 diabetes in the general population, episodes of acute rejection significantly influence the incidence of PTDM.

Is HLA-DR6 a Protective Factor Against Posttransplantation Diabetes Mellitus?

BACKGROUND

Posttransplant diabetes mellitus (PTDM) has several pre- and posttransplant risk factors.

METHODS

The incidence and risk factors of PTDM were retrospectively evaluated in 2117 kidney allograft recipients from June 1984 to March 2004. Type and dosage of immunosuppressive agents, pretransplant weight and human leukocyte antigen (HLA) phenotypes in PTDM patients were compared with 61 matched controls.

RESULTS

Sixty-one cases (2.8%) developed PTDM requiring insulin or oral hypoglycemic therapy, out of which 47.5% were men and 52.5% were women, although only 35% of our overall recipients are women. Onset occurred at a mean of 489 days following transplantation. Patients receiving more than 15 mg/d prednisolone developed PTDM more often than those on less than 15 mg/d (P = .000). Similarly PTDM was more frequent among patients who received more than 300 mg/d cyclosporine compared with those on less than 300 mg/d (P = .015). Mean weight in PTDM cases and controls was 65 +/- 13.4 kg and 57 +/- 13.6 kg, respectively (P = .005). HLA-DR6 was observed in 12.2% of nonaffected subjects but in none of the PTDM group (P = .002). Conversely, HLA-DR8 was seen only in PTDM patients (P = .012). In addition HLA-A26 was more common among PTDM patients (P = .02) and HLA-DR52 more frequent in nonaffected subjects (P = .025).

CONCLUSION

Our findings suggest that female sex, dosages of prednisolone and cyclosporine, pretransplant weight, and genetic factors are associated with an increased risk of PTDM. The rate of PTDM appeared to be independent of weight gain in the first year posttransplant. Protection against PTDM may be afforded by HLA-DR6 and possibly HLA-DR52. Conversely and higher incidence of diabetes has been associated with HLA-DR8 and HLA-A26.

New-onset diabetes after transplantation

New-onset diabetes after transplantation (NODAT) is associated with significant morbidity and mortality. Given the availability of simple diagnostic methods and the known benefits of strict glycemic control, patients should be screened frequently after organ transplantation. The management of NODAT is multifaceted and aimed at both treatment and prevention of complications. Evaluation of patient risk for post-transplant diabetes mellitus and its complications is an important consideration in initial selection and subsequent modification of the immunosuppressive regimen.

Increased risk of post-transplant diabetes mellitus despite early steroid discontinuation in Hispanic kidney transplant recipients

Early steroid discontinuation (ESD) has been associated with a lower incidence of post-transplant diabetes mellitus (PTDM). We retrospectively reviewed the incidence of PTDM in relation to racial groups in kidney transplant recipients treated with ESD. Between January 2002 and September 2003, 125 consecutive primary adult kidney transplants were performed. Group A (n = 91) had steroids discontinued on postoperative day 6 and maintenance immunosuppression of Tacrolimus and mycophenolate mofetil. Group B (n = 34), received the same immunosuppression but was maintained on steroids indefinitely. Induction consisted of thymoglobulin in African-Americans; all others received Simulect. At 1 yr, patient/graft survival, serum creatinine and rate of acute rejection were similar in both groups. The incidence of PTDM was significantly lower in group A (7%) compared with group B (26%, p = 0.0209). The incidence of PTDM in group A was limited to Hispanic patients with a family history of diabetes mellitus. African-Americans and Caucasians in group A did not experience PTDM (p = 0.005 compared with African-American in group B). Our steroid free protocol nearly eliminated the incidence of PTDM in African-Americans and Caucasians, but was still associated with significant rate of PTDM in Hispanic recipients. Alternative immunosuppression may benefit this population.

Impact of Homocysteinemia on Long-Term Renal Transplant Survival

AIM

We prospectively followed a cohort of 202 renal transplant recipients for 5 years to examine the impact of fasting homocysteinemia on long-term patient and renal allograft survival.

METHODS

Cox proportional hazards regression analysis was used to identify independent predictors of all-cause mortality and graft loss.

RESULTS

Hyperhomocysteinemia (tHcy >15 micromol/L) was present in 48.7% of the 202 patients, predominantly among men (55.8%) as opposed to women (37.1%). At the end of the follow-up period, 13 (6.4%) patients had died including 10 from cardiovascular disease, and 23 had (11.4%) had lost their grafts. Patient death with a functioning allograft was the most prevalent cause of graft loss (13 recipients). Levels of tHcy were higher among patients who died than among survivors (median 23.9 vs 14.3 micromol/L; P = .005). Median tHcy concentration was also higher among the patients who had lost their allografts than those who did not (median 19.0 vs 14.1 micromol/L; P = .001). In a Cox regression model including gender, serum creatinine concentration, transplant duration, traditional cardiovascular risk factors, and associated conditions, such as past cardiovascular disease, only tHcy concentration (ln) (HR = 5.50; 95% CI, 1.56 to 19.36; P = .008) and age at transplantation (HR = 1.07; 95% CI, 1.02 to 1.13; P = .01) were independent predictors of patient survival. After censoring data for patient death, tHcy concentration was not a risk factor for graft loss.

CONCLUSIONS

This prospective study shows that tHcy concentration is a significant predictor of mortality, but not of graft loss, after censoring data for patient death.

Challenges in the diagnosis and management of new-onset diabetes after transplantation

With the availability of newer and more potent immunosuppressive agents, post-transplant survival has markedly improved. However, these agents, together with the rising age of transplant recipients, have been associated with a rise in the incidence of new-onset diabetes after transplantation (NODAT). Besides the traditional risk factors for diabetes mellitus, such as age, obesity, hypertension, and family history of diabetes, additional risk factors for NODAT are identified. These include immunosuppressive therapy, hepatitis C infection, acute rejection, and deceased donor kidney transplant. In this article, we discuss the epidemiology, risk factors, pathophysiology, clinical course, and therapeutic and diagnostic challenges of this emerging disease.

New-onset diabetes mellitus in transplant patients: pathogenesis, complications, and management

New-onset diabetes mellitus after transplantation is characterized by decreased insulin secretion and increased insulin resistance secondary to the effects of immunosuppression. Although impaired beta cell function appears to be the primary mechanism of calcineurin inhibitor-induced new-onset diabetes, impaired peripheral glucose utilization also appears to contribute to insulin resistance and abnormal glucose metabolism. Because transplant recipients who develop new-onset diabetes mellitus after transplantation are at increased risk for infections, cardiovascular disease, and poor patient and graft survival, all patients should undergo careful assessment of risk for diabetes prior to transplantation and regular screening for the development of hyperglycemia thereafter. For patients in high-risk groups, including certain ethnic backgrounds, older adults, and the very young, and patients with hepatitis C, consideration should be given to initiating immunosuppressive therapy with agents that are less diabetogenic. Recent guidelines include more stringent criteria for diagnosis and stress the importance of strict glycemic control. Diet, exercise, and weight management are core components of treatment with addition of oral hypoglycemic agents and/or insulin as needed to achieve control. Concomitant measures include aggressive control of lipids and blood pressure to reduce the risk of cardiovascular disease. New-onset diabetes after transplantation is a serious issue affecting patient and graft outcomes and warrants the attention of all health care professionals involved in assessing and managing the transplant recipient.

Advanced glycation end products in kidney transplant patients: a putative role in the development of chronic renal transplant dysfunction

Chronic renal transplant dysfunction is one of the leading causes of graft failure in kidney transplantation. A complex interplay of both alloantigen-related and alloantigen-unrelated risk factors is believed to underlie its development. We propose that advanced glycation end products (AGEs) are involved in the development of chronic renal transplant dysfunction. AGE formation is associated with different alloantigen-unrelated risk factors for chronic renal transplant dysfunction, such as recipient age, diabetes, proteinuria, hypertension, and hyperlipidemia. In vitro studies have shown that AGEs induce the expression of various mediators associated with chronic renal transplant dysfunction. Furthermore, AGE-induced renal damage has been found in multiple experimental studies. This renal damage shows similarity to the damage found in chronic renal transplant dysfunction. Together, several lines of evidence support a role of AGEs in the development of chronic renal transplant dysfunction and suggest that preventive therapy with AGE inhibitors may be helpful in preserving renal function in transplant recipients.

Post-transplant diabetes mellitus: a case-control analysis of the risk factors

Aim of the present study was to assess, in a pair-matched analysis design, risk factors for post-transplant diabetes mellitus (PTDM) in renal transplant recipients (KTx). The incidence of PTDM was evaluated in 538 consecutive KTx in relation to their baseline immunosuppression. PTDM was defined according to the 2003 American Diabetes Association and World Health Organization experts committee definition. As risk factors for PTDM development were considered: age, family history of diabetes, body mass index (BMI), baseline immunosuppression, doses and blood levels of the immunosuppressive agents used. Baseline immunosuppression consisted of CSA, TAC and SRL + CNI. Thirty-two pair-matched controls were identified among the 538 KTx and included in the risk analysis. Significant risk factors for the development of PTDM were identified in the family history of diabetes (P < 0.02) and BMI (P < 0.05). Higher BMI and positive family history for diabetes mellitus were significant risk factors for the development of PTDM, regardless of the immunosuppressive agent used.

Post-Transplantation Diabetes Mellitus

Post-transplantation diabetes mellitus (PTDM) is defined as sustained hyperglycemia developing in any patient without history of diabetes before transplantation, that meets the current diagnostic criteria by the American Diabetes Association or the World Health Organization. Several risk factors have been identified: age, nonwhite ethnicity, and glucocorticoid therapy for rejection and chronic immunosuppression with cyclosporine and especially tacrolimus. The pathophysiology of this condition resembles that of type 2 diabetes mellitus: pretransplantation end-stage liver/renal and heart disease are insulin-resistant states, and after transplantation, glucocorticoids induce further peripheral insulin insensitivity. The "second hit" appears to be an acquired (yet reversible) insulin secretion defect resulting from the calcineurin inhibitors cyclosporine and tacrolimus. An international panel of experts has recently published the proceeding of a Consensus Conference proposing strategies for the screening, prevention and management of PTDM. Future directions include pre- and post-transplantation glucose load testing for high-risk individuals and pharmacological agents to decrease insulin resistance and to preserve beta-cell function.

Pioglitazone in the management of diabetes mellitus after transplantation

Type 2 diabetes mellitus is a common problem in patients after solid organ transplantation. We studied the safety and efficacy of pioglitazone therapy in this setting. Ten patients with diabetes mellitus treated with insulin or glyburide after transplantation were studied after the addition of the thiazolidinedione pioglitazone. Serum creatinine, HBA1C, total daily insulin dose, tacrolimus dose, tacrolimus level and prednisone dose were followed for a mean of 242 days and compared to the corresponding values measured before the initiation of pioglitazone. The addition of pioglitazone caused no significant changes in serum creatinine or mean tacrolimus dose, and caused decreases in HBA1C (8.36%+/- 1.5% pre-pioglitazone, 7.08%+/- 1.5% post-pioglitazone, p = 0.018) and total daily insulin dose (125.1 +/- 28.1 units pre-pioglitazone, 80.6 +/- 22.8 units post-pioglitazone, p = 0.002). Our preliminary study suggests that pioglitazone is a safe and effective oral agent for the management of diabetes mellitus after transplantation.

Combined 'en bloc' liver and pancreas transplantation in patients with liver disease and type 1 diabetes mellitus

Liver disease alters the glucose metabolism and may cause diabetes, but this condition is potentially reversible with liver transplantation (LTx). Type 1 diabetes mellitus may be coincidentally present in a LTx candidate and immunosuppressive drugs will aggravate diabetes and make its management more difficult for posttransplant. In addition, diabetes negatively influences outcome after LTx. Therefore, the question arises as to why not transplanting the pancreas in addition to the liver in selected patients suffering from both liver disease and Type 1 diabetes. We report two cases of en bloc combined liver and pancreatic transplantation, a technique originally described a decade ago in the treatment of upper abdominal malignancies but rarely used for the treatment of combined liver disease and Type 1 diabetes. Both recipients are currently liver disease-free and insulin-free more than 2 and 4 years posttransplant, respectively. Surgical, medical and immunological aspects of combined liver-pancreas transplantation are discussed in the light of the existing relevant literature.

Development of diabetes mellitus following kidney transplantation: a Canadian experience

The onset of diabetes mellitus following kidney transplantation or post-transplant diabetes mellitus (PTDM) is now recognized as being an increasingly common complication that is associated with poor graft and patient survival. The incidence and clinical correlates of PTDM in a Canadian kidney transplant population has not been examined and may vary based on differences in demographics (i.e. race). Furthermore, little information exists on the association of variables such as cumulative dose of corticosteroids and trough calcineurin inhibitor levels and PTDM. We examined all recipients of a kidney transplant in our center between 1995 and 2001 and found an overall PTDM rate of 9.8%. Five clinical factors were independently associated with PTDM: older recipient age, deceased donor, hepatitis C antibody status, rejection episode and use of tacrolimus (vs. cyclosporine). Furthermore, cumulative corticosteroid dose and calcineurin inhibitor trough level were not associated with PTDM. This study demonstrates that in a Canadian kidney transplant population that there is a significant risk of PTDM following kidney transplantation, and it is therefore advisable to minimize this risk.

Reduced incidence of new-onset diabetes mellitus after renal transplantation with 3-hydroxy-3-methylglutaryl-coenzyme a reductase inhibitors (statins)

Statins have anti-inflammatory effects, modify endothelial function and improve peripheral insulin resistance. We hypothesized that statins influence the development of new-onset diabetes mellitus in renal transplant recipients. The records of all previously non-diabetic adults who received an allograft in Toronto between January 1, 1999 and December 31, 2001 were reviewed with follow-up through December 31, 2002. All patients receiving cyclosporine or tacrolimus, mycophenolate mofetil and prednisone were included. New-onset diabetes was diagnosed by the Canadian Diabetic Association criteria: fasting plasma glucose > or =7.0 mmol/L or 2-h postprandial glucose > or =11.1 mmol/L on more than two occasions. Statin use prior to diabetes development was recorded along with other variables. Cox proportional hazards models analyzing statin use as a time-dependent covariate were performed. Three hundred fourteen recipients met study criteria, of whom 129 received statins. New-onset diabetes incidence was 16% (n = 49). Statins (p = 0.0004, HR 0.238[0.109-0.524]) and ACE inhibitors/ARB (p = 0.01, HR 0.309[0.127-0.750]) were associated with decreased risk. Prednisone dose (p = 0.0001, HR 1.007[1.003-1.010] per 1 mg/d at 3 months), weight at transplant (p = 0.02, HR 1.022[1.003-1.042] per 1 kg), black ethnicity (p = 0.02, HR 1.230[1.023-1.480]) and age > or =45 years (p = 0.01, HR 2.226[1.162-4.261]) were associated with increased diabetes. Statin use is associated with reduced new-onset diabetes development after renal transplantation.

Time-related clinical determinants of long-term tacrolimus pharmacokinetics in combination therapy with mycophenolic acid and corticosteroids: a prospective study in one hundred de novo renal transplant recipients

BACKGROUND

Tacrolimus is an efficient primary immunosuppressive drug in renal transplantation but its long-term use is associated with calcineurin-inhibitor-related toxicity. The specific characteristics of the inter-relationship between dose, concentration and clinical (side-)effects for tacrolimus have not yet been identified and extensive long-term pharmacokinetic studies are presently lacking.

OBJECTIVE

To establish the characteristics of the long-term pharmacokinetics of tacrolimus, to determine the time-dependent factors that influence the pharmacokinetics within the first critical post-transplant year and to identify a more appropriate way of monitoring drug exposure in clinical practice.

STUDY DESIGN

A prospective pharmacokinetic study of tacrolimus was conducted in 100 de novo renal allograft recipients during the first year post-transplantation.

METHODS

Area under the concentration-time curve (AUC) blood samplings for tacrolimus were performed on days 7, 42, 90, 180 and 360 for all patients. Model-independent pharmacokinetic parameters for tacrolimus were calculated and dose-corrected when appropriate: AUC12, peak plasma concentration (Cmax), pre-dose trough concentration (C0), time to Cmax, average steady-state blood concentration, steady-state total body clearance, terminal half-life, volume of distribution and an estimate for tacrolimus bioavailability was derived from additional steady-state intravenous clearance data. The association between tacrolimus pharmacokinetic parameters and different clinical variables was evaluated on days 7, 42, 90, 180 and 360. The clinical variables were either donor-related (e.g. donor age), transplantation-related (e.g. delayed graft function), recipient-related (e.g. bodyweight), biochemical (e.g. serum albumin), therapeutic variables (e.g. corticosteroid dose) or disease variables (e.g. liver dysfunction).

RESULTS

Long-term tacrolimus dose-corrected exposure (AUC12, C0) is characterised by a late significant increase towards the end of the first year post-transplantation as the result of a significant increase in tacrolimus bioavailability (p < 0.05) and a slow decrease in tacrolimus steady-state clearance. Consequently, tacrolimus dose-requirements corrected for bodyweight decrease significantly in the first postoperative year (p < 0.05), in part because of the simultaneous tapering of the corticosteroid dose which significantly affects tacrolimus bioavailability (p < 0.05). Other clinical variables that significantly influenced tacrolimus administration, exposure and bioavailability in a time-related fashion were identified in this study (renal allograft function [p < 0.05], liver dysfunction [p < 0.05], diarrhoea [p < 0.05]), while the clinical relevance of other variables was considerably moderated by our findings (serum albumin, haematocrit). Time-unrelated variables proved to be of significant continuing clinical importance for tacrolimus dose-exposure pharmacokinetics throughout the first post-transplant year (recipient age [p < 0.05], gender [p < 0.01] and donor-receptor gender mismatch [p < 0.05]), while donor hypotension (p < 0.05) and cold ischaemia time (p < 0.05) also proved significant although at present the reasons for this are unknown. Finally, using multiple stepwise regression analysis we demonstrated that classical assessment of tacrolimus exposure by monitoring pre-dose trough blood concentration (or any other single concentration sampling timepoint) is not the most reliable method and that abbreviated AUC measurements may constitute a more accurate clinical tool for (therapeutic) monitoring of drug exposure.

CONCLUSION

Tacrolimus pharmacokinetics in the first year after renal transplantation are characterised by a specific time-dependent evolution. The identification of clinical variables that determine tacrolimus pharmacokinetics is an important aid in the development of reliable drug monitoring strategies using abbreviated AUC measurements.

New-onset diabetes after transplantation

For many years new-onset diabetes after transplantation has been recognized as a complication of solid-organ transplantation, although its importance has been greatly underestimated. Studies have shown that the cumulative incidence of this condition in heart transplant recipients may reach 32% at 5 years, similar to that reported in kidney and liver transplant patients. Several factors predispose to increased risk for developing new-onset diabetes after transplantation, including age, ethnicity, family history of diabetes, obesity and immunosuppressive therapy. Corticosteroids are associated with the greatest risk of developing the condition. Tacrolimus is more diabetogenic than cyclosporine in kidney and liver transplant patients, but there are few data reporting the effects of these agents in heart transplant patients. In kidney transplant patients, diabetes is known to be a significant risk factor for cardiovascular disease post-transplant. Although this has yet to be demonstrated clearly in heart transplant patients, evidence suggests that new-onset diabetes after transplantation may play a role in the development of cardiac allograft vasculopathy (CAV). Because CAV is the major limitation to long-term survival in this population, it is clear that efforts should be made to reduce the risk of diabetes and treat this condition appropriately. Management of transplant recipients with new-onset diabetes after transplantation has been assisted by the recent publication of International Consensus Guidelines. The guidelines were developed to establish a standard definition and describe risk factors for new-onset diabetes after transplantation. Use of these guidelines will help to prospectively identify those at risk of developing new-onset diabetes after transplantation so that therapeutic strategies can be individualized early in the treatment regimen. These management approaches should help to lower the risk of new-onset diabetes after heart transplantation and reduce the possible long-term consequences of the condition.

De novo diabetic nephropathy on renal allografts

BACKGROUND

Posttransplant diabetes mellitus (PTDM) is a well-recognized clinical problem following renal transplantation. Long-term risks of PTDM are similar to those of diabetes mellitus in general population. The aim of our study was to identify de novo diabetic nephropathy (DN) in our group of patients with PTDM.

METHODS

Thirty-four patients with PTDM were reviewed retrospectively. Light microscopy, immunofluorescence, and electron microscopy techniques were performed in 10 of 21 patients with graft biopsy.

RESULTS

Five patients (four women, one man), aged 47.4 years (range, 29 to 58), four of whom received cadaveric grafts, were found to have de novo DN. Their serum creatinine was 211.4 micromol/L (range, 140 to 294). Three patients were slightly proteinuric (0.3 to 0.5 g/L). PTDM was diagnosed 2.4 months after transplantation (range, 1 to 6). Histologic diagnosis of de novo DN was made, on average, 52.6 months after transplantation (range, 8 to 115), and 50.2 months (range, 2 to 114) after PTDM. De novo DN presented as diffuse diabetic glomerulosclerosis in four patients and nodular diabetic sclerosis in one patient, and combined with transplant glomerulopathy in all five patients. The mean graft survival time for this group of patients was equivalent with a control group. Although the difference in slopes of serum creatinine between the studied groups was clinically relevant, it was not statistically significant.

CONCLUSION

In view of our findings, when histologic de novo DN was found in 5 out of 10 patients, one could conclude that de novo DN could be a frequent complication of PTDM.

Posttransplantation diabetus mellitus under calcineurin inhibitor

BACKGROUND

The development of postransplantation diabetes mellitus (PTDM) is a serious complication of kidney transplantation. PTDM has a major impact on quality of life decreasing rates of patient and graft survival. It is well known that some currently used immunosuppressants are diabetogenic. Greater diabetogenicity of FK-506 has been reported in multicenter trials. We initiated a study of conversion from tacrolimus (FK-506) to cyclosporine (CsA) among kidney allograft recipients presenting with PTDM to evaluate whether this maneuver would ameliorate a diabetic state.

METHODS

This analysis of 20 adult, renal allograft recipients presenting with PTDM assumed the need for insulin therapy or oral hypoglycemics before and after conversion of the immunosuppressive regimen. The criteria for evaluating the outcome were as follows: dose reduction of insulin or oral hypoglycemic agents, adequacy of glucose control, C-peptide levels, and insulin concentration.

RESULTS

During the follow-up, we observed an improvement in the control of blood glucose in the converted group. In 13 patients, satisfactory glucose control was obtained without insulin or any other agent. In 3 patients a significant dose reduction of required insulin was possible. In another 2 patients who were insulin-dependent, the switch to oral hypoglycemic treatment was clinically possible after conversion. After conversion we observed significantly lowered fasting blood glucose levels and increased C-peptide levels.

CONCLUSIONS

The conversion from a tacrolimus to a CsA-based immunosuppressive regimen resulted in better glucose metabolism. We demonstrated a positive effect of conversion on the diabetic state of patients with PTDM.

ROSIGLITAZONE TREATMENT OF DIABETES MELLITUS AFTER SOLID ORGAN TRANSPLANTATION

BACKGROUND

Diabetes mellitus is a common clinical problem after solid organ transplantation. Whether patients have preexisting diabetes or develop posttransplant diabetes, insulin therapy is usually required. Achieving excellent diabetic control is an important target in reducing the incidence of cardiovascular disease after transplantation.

METHODS

The authors treated 18 patients with type 2 diabetes after transplantation with rosiglitazone. Eleven patients had preexisting type 2 diabetes and seven patients developed posttransplant diabetes. Rosiglitazone was added to insulin or glyburide to improve elevated hemoglobin Hb A1C levels in patients with preexisting diabetes or was used to try to avoid insulin therapy in posttransplant diabetics. Blood levels of cyclosporine, tacrolimus, creatinine, and HbA1C were followed for a mean of 381 days (range, 133-718 days).

RESULTS

The addition of rosiglitazone did not cause any significant changes in serum creatinine, cyclosporine, or tacrolimus. There were no significant changes in cyclosporine or tacrolimus doses. Mean HbA1C improved from 8.1+/-1.5% to 6.9+/-1.3% (P =0.01) in the 18 patients and from 8.6+/-1.5% to 6.7+/-0.5% (P =0.035) in the 7 patients with posttransplant diabetes. All patients with posttransplant diabetes were well controlled without insulin therapy.

CONCLUSIONS

Rosiglitazone is a safe and effective oral agent for the treatment of diabetes mellitus after solid organ transplantation. It is the first agent to allow successful oral therapy for patients with posttransplant diabetes, and is a well-tolerated alternative to insulin for these patients.

New onset diabetes mellitus in patients receiving calcineurin inhibitors: a systematic review and meta-analysis

New onset diabetes mellitus (NODM) is a serious complication of transplantation. This meta-analysis evaluates the reported incidence of NODM after solid organ transplantation in patients receiving CNI treatment. Databases from January 1992 to April 2002 were searched. Fifty-six publications providing NODM incidence data were reviewed. Sixteen prospective, randomized comparative studies providing information on incidence of insulin-dependent diabetes mellitus (IDDM) were subjected to meta-analysis. New onset diabetes mellitus was reported in 13.4% of patients after solid organ transplantation, with a higher incidence in patients receiving tacrolimus than cyclosporine (16.6% vs. 9.8%). This trend was observed across renal, liver, heart and lung transplant groups. Meta-analysis of 16 studies included patients receiving either tacrolimus (n=1636) or cyclosporine (n=1407). The incidence of IDDM was significantly higher among tacrolimus-treated patients (10.4% vs. 4.5%, p<0.00001), an effect observed in renal (9.8% vs. 2.7% p<0.00001) and nonrenal (11.1% vs. 6.2%; p<0.003) groups, and among patients receiving equal doses of concomitant medication in both treatment arms (12.0% vs. 3.0%; p<0.00001). The reported incidence of NODM during the past decade was significantly higher among patients receiving tacrolimus than cyclosporine. These data provide a quantitative foundation for studies designed to reduce the rates of NODM following solid organ transplantation.

Cyclosporine: advantages versus disadvantages vis-à-vis tacrolimus

Despite a different molecular structure and biochemical properties, cyclosporine and tacrolimus--by inhibiting calcineurin activity--have been shown in the previous two decades of solid organ transplantation to be well tolerated and effective immunosuppressants. Initial randomized clinical trials showed a lower incidence of acute rejection in tacrolimus than in cyclosporine-treated patients, in combination with steroids and azathioprine. But in conjunction with mycophenolate mofetil, the difference in the incidence of acute rejection episodes is less clear. In general, short- and medium-term outcome variables (1-year serum creatinine, graft and patient survival) with cyclosporine and tacrolimus are excellent, and (almost) identical, with both substances having the same intrinsic nephrotoxic potential. On the other hand, cyclosporine and tacrolimus have a different impact on cardiovascular risk factors with tacrolimus having a better profile on arterial tension and lipid metabolism and cyclosporine on glucose metabolism. However, at present no data are available to discern that these differences in risk profile alter patient or graft survival or long-term cardiovascular morbidity/mortality. Therefore, prospective long-term trials are needed to study the quantitative impact of different immunosuppressive agents and concomitant cardiovascular risk factors on long-term patient and graft survival, before evidence-based (patient, graft, or cardiovascular) risk reduction can be firmly claimed by tailoring calcineurin inhibitors.

Tacrolimus conversion in kidney transplant recipients: analysis of 107 patients

Early results of an alteration in immunosuppressive protocol of tacrolimus conversion at a mean follow-up of 16 (range 1 to 36) months are presented with a mean time after transplantation of 34 +/- 1.4 months (range 1 to 158 months). Chronic allograft nephropathy in 16 (17%) patients, nephrotoxicity related to cyclosporine in 27(23%) patients and steroids resistant acute rejection in 64 (58%) represented the indications for tacrolimus conversion. Before starting tacrolimus there were 1 acute rejection episode in 37 patients, 2 in 17 patients, and 3 in 10 patients. After the drug conversion, 1 acute rejection occurred in 18 and 2 acute rejection in 4 patients. Graft loss was seen in 16 (16%) patients after drug conversion. Tacrolimus was withdrawn due to diabetes mellitus (n = 9), epilepsy (n = 4), and severe Nocardia sepsis, lymphoma and Kaposi sarcoma (each in one patient). Decreases in serum creatinine and increases in blood glucose levels were significantly associated with the tacrolimus doses (P = 0.0004 and P = 0.0400, respectively). The increase in creatinine clearance values were closely related to higher tacrolimus levels. The target range with maximum efficacy and minimum toxicity seemed to be 10 to 15 ng/mL. Tacrolimus conversion can be successful in cases of rejection and nephrotoxicity, but dose-dependent blood glucose elevations require close observation in these patients.

Obesity as an independent predictor of posttransplant diabetes mellitus

BACKGROUND

In the general population, there is a clear association between obesity and type 2 diabetes mellitus. However, the evidence of relationship between body mass index (BMI: weight/height(2)) and the risk of posttransplant diabetes mellitus (PTDM) is inconsistent when studied at a level of single center. The aim of our study was to determine if pretransplant BMI is an independent risk factor for PTDM at our center and to demonstrate the pattern of weight gain in patients who develop PTDM.

METHODS

This is a retrospective analysis of renal allograft recipients at University of Colorado Hospital. The medical records of patients who received a kidney transplant from January 1998 to March 2001 were screened to identify the cases of PTDM. Controls were matched for immunosuppressive regimen, gender, and type of donor. A total of 18 cases and 36 controls were identified.

RESULTS

The incidence of PTDM in our transplant population was 10%. Of these cases, 72% developed PTDM in the first 2 months after transplant, and 38% of them required insulin. On multivariate analysis, BMI was significantly associated with PTDM (adjusted odds ratio 1.22, 95% confidence interval 1.04-1.42) while controlling for number of rejections, age, and other factors. We also noticed that weight gain was significantly lower in patients who developed PTDM after transplantation.

CONCLUSIONS

We conclude that obesity is an independent predictor of PTDM. The weight gain was significantly poor among patients who developed PTDM. Among all the risk factors for PTDM, obesity is the only modifiable risk factor before transplantation. Obese patients should be treated with a less diabetogenic immunosuppressive regimen and be counseled to lose weight before transplant.

Development of diabetes mellitus post–renal transplantation is associated with poor short-term clinical outcomes

BACKGROUND

Although posttransplant diabetes mellitus (PTDM) is associated with poor long-term outcomes short-term outcomes are not well studied in renal transplant recipients (RTRs).

METHODS

RTRs between January 1999 and December 2000 (n = 181) stratified according to the occurrence of diabetes mellitus (DM), namely, non-DM (n = 72), previous DM (n = 88), and PTDM (n = 21) were compared for infections, hospital readmissions, and graft rejections during the first 6 months posttransplantation.

RESULTS

PTDM showed patients affected by a significantly higher rate of infections (57.1% vs 29.2%) and recurrent infections (28.5% vs 11.1%) compared to non-DM and a trend toward an increase compared to previous DM. PTDM patients had a significantly higher incidence of multiple readmissions compared to both previous DM (52.4% vs 20.5%) and non-DM (52.4% vs 23.6%). Subjects with PTDM showed a significantly higher occurrence of rejection (28.6% vs 9.1%) and recurrent rejection (14.3% vs 2.3%) than previous DM and a greater trend compared to non-DM.

CONCLUSION

PTDM is associated with poorer short-term outcomes than either non-DM or previous DM.

Pediatric post-transplant diabetes: data from a large cohort of pediatric heart-transplant recipients

A retrospective analysis of 381 pediatric heart-transplant recipients was performed to determine the frequency, characteristics, and risk factors for post-transplant diabetes. The rate of post-transplant diabetes was 1.8% with antithymocyte globulin, cyclosporine and azathioprine as primary immunosuppressive therapy. Time from transplant to diabetes was 0.25-13 years. Diabetes was characterized by reversibility, and lack of insulinopenia and autoimmunity. The post-transplant diabetes rate in tacrolimus-converted children (n = 45) was 8.8%. In tacrolimus-converted children, age at transplant, mean and maximum tacrolimus blood levels, and first-year rejection episodes were higher in the post-transplant diabetes group, which also consistently had DR-mismatched transplants and HLA DR3/DR4 haplotypes. Body mass index was not different between diabetic and control tacrolimus-converted children. In conclusion, pediatric post-transplant diabetes may be related to reversible insulin resistance. Tacrolimus levels, HLA DR mismatch, and older age at transplant may predispose to post-transplant diabetes.

Improved cardiovascular risk profile and renal function in renal transplant patients after randomized conversion from cyclosporine to tacrolimus

Cyclosporine is considered to contribute to the high cardiovascular morbidity and mortality in patients after renal transplantation. Tacrolimus may be more favorable in this respect, but controlled data are scarce. In this prospective randomized study in 124 stable renal transplant patients, the effects of conversion from cyclosporine to tacrolimus on cardiovascular risk factors and renal function were investigated. Follow-up was 6 mo. Statistical analysis was performed by ANOVA for repeated measurements. The serum creatinine level decreased from 137 +/- 30 micromol/L to 131 +/- 29 micromol/L (P < 0.01). Three months after conversion from cyclosporine to tacrolimus, mean BP significantly decreased from 104 +/- 13 to 99 +/- 12 mmHg (P < 0.001). Serum LDL cholesterol decreased from 3.48 +/- 0.80 to 3.11 +/- 0.74 mmol/L (P < 0.001,) and serum apolipoprotein B decreased from 1018 +/- 189 to 935 +/- 174 mg/L (P < 0.001). Serum triglycerides decreased from 2.11 +/- 1.12 to 1.72 +/- 0.94 mmol/L (P < 0.001). In addition, both rate and extent of LDL oxidation were reduced. The fibrinogen level decreased from 3638 +/- 857 to 3417 +/- 751 mg/L (P < 0.05). Plasma homocysteine concentration did not change. Three months after conversion, plasma fasting glucose level temporarily increased from 5.4 +/- 1.3 mmol/L to 5.8 +/- 1.9 mmol/L (P < 0.05). Conversion to tacrolimus resulted in a significant reduction of the Framingham risk score. In conclusion, conversion from cyclosporine to tacrolimus in stable renal transplant patients has a beneficial effect on renal function, BP, serum concentration and atherogenic properties of serum lipids, and fibrinogen.