Risk for posttransplant Diabetes mellitus with current immunosuppressive medications

Chronic kidney disease post-liver transplantation

BACKGROUND

Renal disease is a recognized complication of orthotopic liver transplantation (OLT). We aimed to determine the incidence of all stages of chronic kidney disease (CKD), as defined in the Kidney Disease Outcomes Quality Initiative Guidelines. We also wanted to determine the risk factors for development of CKD and its impact on patient survival.

METHODS

All patients who underwent cadaveric OLT, from January 1993 until July 2004, were analysed. The glomerular filtration rate (GFR) was determined using the equation developed by the Modification of Diet in Renal Disease Study. Thirty potential risk factors were examined by univariate and multivariate ordinal logistic regression analysis. Kaplan-Meier survival analysis, the log-rank test and Cox regression analysis were performed to evaluate the survival data.

RESULTS

A total of 230 patients were included (107 males and 123 females) with a mean age of 47.7 years (4.5-70.35). Mean follow-up was 5.57 years (0.53-16.5). The following was the 10 year cumulative incidence for each stage of CKD: 0/1, 9.61%; 2, 53.71%; 3, 56.77%; 4, 6.11%; 5, 2.62%. Female gender, age, pre-OLT proteinuria, lower GFR from 1 year and higher creatinine from 6 months were associated with progression of CKD. The use of tacrolimus had a favourable impact. A GFR <30 ml/min, the need for re-transplantation and fulminant hepatic failure were all associated with reduced patient survival.

CONCLUSIONS

Moderate CKD was very prevalent. We identified the risk factors for progression of CKD and also that severe CKD was associated with reduced patient survival.

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.

Should we quantify insulin resistance in patients with renal disease?

Cardiovascular disease is a major cause of morbidity and mortality in dialysis patients. Vascular disease develops before the initiation of dialysis, and it is now recognized that chronic kidney disease (CKD) is an independent risk factor for cardiovascular disease. Death from cardiovascular disease is a more common endpoint of CKD than progression to dialysis. There are multiple mechanisms that contribute to the increased vascular risk of CKD, one of which is the presence of insulin resistance (IR). CKD is characterised by many features of the metabolic syndrome, and features of IR are also observed in dialysis and transplant patients. IR may be quantified by several different methods. One such method is homeostatic model assessment (HOMA) technique, which derives a measurement of IR from fasting plasma glucose and insulin concentrations. The HOMA index has been demonstrated to be an independent predictor of survival in dialysis patients. CKD is characterised by a chronic inflammatory response and abnormalities in the production and regulation of adipose tissue derived proteins, which may contribute to the development of IR. There are a range of interventions including diet and exercise programmes or medications that may influence IR; however, the impact of these interventions in the context of CKD has not been systematically evaluated.

Risk Factors for Development of Posttransplant Diabetes Mellitus in Renal Transplant Recipients

Diabetes mellitus appearing after kidney transplantation--posttransplant diabetes mellitus (PTDM)--is a common complication associated with poor graft and patient survival. The purpose of the current study was to determine the risk factors for developing PTDM in 204 renal transplant recipients who had been followed for at least 30 months. Posttransplant diabetes mellitus was diagnosed according to the American Diabetic Association/WHO criteria, or a requirement for insulin, an oral hypoglycemic agent, or both. Analyses of possible risk factors for PTDM included demographic features, dialysis and posttransplantation duration, smoking, body mass index, medications, co-morbid diseases, HLA mismatches, as well as laboratory metrics of serum creatinine, albumin, calcium, phosphorus, C-reactive protein, parathyroid hormone, and lipid profiles. Twenty-six patients displayed PTDM. Univariate analysis showed that older age, greater body mass index, presence of hepatitis C virus (HCV) infection, and smoking at the time of renal transplantation were associated with PTDM development. In a multivariate analysis, HCV infection, smoking, and patient age at the time of transplantation were independent risk factors for PTDM. In conclusion, the presence of HCV infection or a smoking habit in addition to older age at the time of transplantation were the main predictors for developing PTDM. Patients should be closely followed regarding their smoking habit and weight gain as modifiable risk factors for PTDM.

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.

Cardiovascular complications of immunosuppressive agents in renal transplant recipients

Fatal and nonfatal cardiovascular events are the most important cause of graft loss in patients with a functioning graft following transplantation. The available data indicate that transplant patients have a high prevalence of hypertension, hyperlipidaemia and new onset diabetes mellitus after transplantation. The aetiology and pathogenesis of post-transplant hypertension, hyperlipidaemia and diabetes are multifactorial. In addition, disease of the native kidney and recurrence of renal disease can contribute to the development of cardiovascular disease in transplant recipients. Most transplant patients are at risk of clinically important drug-drug interactions involving immunosuppressive agents. Adverse reactions and drug-drug interactions should not be neglected when selecting an agent for treatment of cardiovascular risk factors in transplant recipients.

Unexpectedly high prevalence of pretransplant abnormal glucose tolerance in pediatric kidney transplant recipients

Several studies suggested that the incidence of new-onset diabetes following pediatric kidney transplantation has increased markedly in recent years, with reported incidence of up to 20%. However, limited information is available regarding the incidence and features of pretransplant status of abnormal glucose tolerance in pediatric kidney transplant recipients. We assessed the risk of 55 non-diabetic pediatric transplant recipients developing PTDM by performing OGTT prior to transplantation. For post-transplant immunosuppression, each patient received either a CsA- or a TAC-based regimen. However, recipients who had abnormal glucose tolerance in the pretransplant OGTT were allocated to the CsA-based regimen. The mean age of the patients was 9.7 +/- 5.4 yr while mean BMI was 16.5 +/- 3.3 kg/m2. FPG level before transplantation was within the normal limit in all patients, while the mean HbA1C value was 4.5. However, 18 of the 55 patients (32.7%) had abnormal glucose tolerance in the pretransplant OGTT, 13 (23.6%) had impaired glucose tolerance, and 5 (9.4%) had DM. PTDM developed in two patients on the TAC-based regimen with these patients having normal glucose tolerance prior to the transplant. In contrast, the 18 patients with abnormal glucose tolerance did not develop PTDM under CsA-based immunosuppression. Our results demonstrated an unexpectedly high prevalence of abnormal glucose tolerance in pretransplant OGTT even in a pediatric population. We believe that modification of post-transplant immunosuppression by the identification of high-risk patients using the pretransplant OGTT may minimize the development of new onset of PTDM.

New-onset diabetes after liver transplantation

AIM

The impact of new-onset diabetes (NOD) posttransplantation has been underestimated in the past. The aim of this study was to evaluate the incidence of diabetes after liver transplantation.

METHODS

We retrospectively analyzed the incidence of NOD in 899 patients transplanted in our center. According to International Consensus 2003 Guidelines, criteria for diagnosis of diabetes were: fasting plasma glucose > or =126 mg/dL, symptoms of diabetes plus casual plasma glucose concentrations > or =200 mg/dL, and 2-hour plasma glucose levels > or =200 mg/dL during an oral glucose tolerance test. We considered only patients with follow-up over 10 months. We evaluated the risk factors correlated with NOD (age, hepatitis C virus [HCV] positivity, tacrolimus vs cyclosporine, steatosic graft), and the outcomes of diabetic patient and their grafts.

RESULTS

The incidence of NOD was 10.8% (90/830 patients). Sixty nine patients were diabetic before transplantation. Recipient age >45 years (14.7% vs 6.8%, P = .002, OR = 2.4) and HCV positivity (15.5% vs 7.8%, P = .001, OR = 2.2) significantly correlated with NOD. Multivariate analysis confirmed these variables to be independently associated with diabetic risk. Tacrolimus was associated with an increased risk of NOD (16.2% in HCV-negative patients, 25% in HCV-positive patients), but this difference was not statistically significant. Steatotic grafts (>10%) were associated with an increased risk of NOD (28.6% vs 10%, P = .001, OR = 3.6). The outcome of patients and grafts in the group of diabetic patients was not significantly different from all other patients.

CONCLUSIONS

The incidence of NOD was more relevant in patients older than 45 years and/or HCV-positive. A steatotic graft was an important risk factor, and the match with high-risk patients should be avoided.

Free fatty acids are associated with obesity, insulin resistance, and atherosclerosis in renal transplant recipients

BACKGROUND

Insulin resistance (IR) may be implicated in the pathogenesis of atherosclerosis in renal transplant recipients (RTRs) and be contributed to, in part, by free fatty acids (FFAs), produced in excess in centrally obese individuals. The aim of this study was to determine the prevalence of IR and the relationships between FFAs, central obesity, and atherosclerosis in a cohort of prevalent RTRs.

METHODS

Observational data were collected on 85 RTRs (mean age 54 years; 49% male, 87% Caucasian). Fasting serum was analyzed for FFAs, glucose, and insulin; IR was calculated using the homeostasis model assessment (HOMA-IR) score. Vascular structure was assessed by carotid intima-media thickness (IMT) measurement. Linear regression analyses were performed to determine the factors associated with IR and atherosclerosis.

RESULTS

IR occurred in 75% of RTRs, and FFA levels were independently associated with its occurrence (beta: -0.55, 95% CI: -1.02 to -0.07, P = 0.02). Other variables independently associated with IR were male sex, body mass index, central obesity, diabetes, systolic blood pressure and corticosteroid use. There was a significant correlation between FFA levels and IMT (r = 0.3, P=0.01). On multivariate analysis, IMT correlated with elevated FFA (beta: 0.07, 95% CI: 0.02-0.12, P = 0.007), diabetes mellitus (P = 0.05), older age (P < 0.002), and a body mass index >25 kg/m (P = 0.002).

CONCLUSIONS

FFAs are associated with the development of IR and may be involved in the pathogenesis of atherosclerosis in RTRs. Additional studies are required to explore these associations further before considering whether an interventional trial aimed at lowering FFA would be a worthwhile undertaking.

One-Year Observation of Kidney Allograft Recipients Converted From Cyclosporine Microemulsion to Tacrolimus

The results from previous trials suggested that tacrolimus-based treatment in kidney transplantation was associated with a significantly lower incidence of acute rejection, and that cyclosporine microemulsion (CsA-Me)-treated patients converted to tacrolimus had numerically better 6-year graft survival than those remaining on CsA-Me. Death with a functioning graft and chronic graft nephropathy are the leading causes of late allograft loss. While standard cardiovascular risk factors are relevant, renal function itself becomes an important risk factor for cardiovascular morbidity and mortality in kidney transplantation patients. Expected benefits of the conversion from CsA-Me to tacrolimus with respect to renal function and cardiovascular status were the rationale for this observational study. Twenty one patients underwent conversion due to nephrotoxicity of cyclosporine (n = 18) or side effects (n = 3). Two out of 21 patients did not complete the study. The patient survival after 1 year was 100% in this group of patients; graft survival 94.7%. No cases of de novo diabetes mellitus were identified. Mean serum creatinine fell from 2.13 +/- 0.4 to 1.84 +/- 0.3 mg/dL (P < .02) and calculated glomerular filtration rate increased from 49.6 +/- 14.4 to 56.2 +/- 15.5 mL/min (P < .01). Total cholesterol decreased from 229.4 +/- 50.1 to 195.9 +/- 28.5 mg/dL (P < .005) and, low-density lipoprotein cholesterol from 125.7 +/- 37.3 to 104.4 +/- 22.6 mg/dL (P < .02). No significant changes in mean systolic or diastolic pressure or blood glucose levels were observed. The results of this observational study showed that in a group of patients with raised creatinine levels at entry, conversion to tacrolimus resulted in improved graft function and a more favorable cardiovascular risk profile.

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.

Chronic hepatitis C virus infection and post-liver transplantation diabetes mellitus

Patients with chronic hepatitis C virus (HCV) infection have a significantly increased prevalence of type 2 diabetes mellitus compared to controls or HBV-infected patients. Moreover, the incidence rate of post-liver transplantation diabetes mellitus (PTDM) also appears to be higher among patients with HCV infection. PTDM is often associated with direct viral infection, autoimmune disorders, and immunosuppressive regimen. Activation of tumor necrosis factor-α may be the link between HCV infection and diabetes. In this article, we reviewed the epidemiologic association between HCV infection and PTDM, highlighting the most recent pathophysiologic insights into the mechanisms underlying this association.

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.

[Risk factors for developing diabetes mellitus after renal transplantation]

We evaluated retrospectively 34 patients with post-kidney transplant diabetes (PTDM) (group 1) and 68 submitted to renal transplant without PTDM (group 0) to determine the prevalence and risk factors for developing PTDM in patients followed at the Hospital Universitário Pedro Ernesto. The prevalence of PTDM was 7.4%. Group 1 patients were older at data collection (p<0.005) and at transplantation (p<0.005). Among them there was a higher frequency of cadaver donors (p= 0.023) and hypercholesterolemia (p= 0.006), and a lower frequency of arterial hypertension (p<0.0001). We observed a trend to higher frequency of positive sorology for C hepatitis (p= 0.057) and use of tacrolimus (p= 0.069) in group 1 as compared to group 0. The most important risk factors for developing PTDM (by logistic regression) were the age at renal transplant [OR= 1.099, IC 95% (1.045-1.156), p= 0.0001] and positive sorology for C hepatitis [OR= 3.338, IC 95% (1.205-9.248), p= 0.020]. We conclude that the prevalence of PTDM in our hospital was similar to that found in the literature and that the patients who developed PTDM presented a higher prevalence of traditional risk factors for PTDM, like older age and positive C virus hepatitis sorology, comparing to controls.

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.

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.

New onset hyperglycemia and diabetes are associated with increased cardiovascular risk after kidney transplantation

BACKGROUND

Post-transplant diabetes (PTDM) is a common and serious complication of kidney transplantation. The implications of developing hyperglycemia of lesser severity are not well understood.

METHODS

In this study we used American Diabetes Association (ADA) criteria to assess the incidence of abnormal glycemia post-transplant, the variables that relate to this complication, and the relationship between hyperglycemia and cardiovascular (CV) disease. Included in the study were 490 kidney recipients, transplanted from 1998 to 2003, without a history of diabetes, and with a pretransplant fasting glucose <126 mg/dL.

RESULTS

Within one week post-transplant, 45% of recipients had impaired fasting glycemia (IFG, glucose 100-125 mg/dL), and 21% PTDM (glucose > or =126). One year post-transplant, 33% of patients had IFG, and 13% PTDM. Risk factors for hyperglycemia at one year included: older recipient, male gender, higher BMI, higher pretransplant glucose, and higher glucose one week post-transplant (all P < 0.002 by multivariable analyses). During a follow-up period of 40 +/- 14 months, 12% of recipients had CV events (cardiac, CVA, and/or peripheral). Increasing fasting glucose levels at one, four, and/or 12 months post-transplant were significantly related to CV events. Furthermore, these relationships were independent of other CV risk factors, including: older age, CV events pretransplant, male gender, dyslipidemia, and transplant year. Fasting glucose levels >100 mg/dL were associated with higher incidence of post-transplant cardiac (P= 0.001) and peripheral vascular disease events (P= 0.003).

CONCLUSION

The incidence of post-transplant hyperglycemia and its CV impact have been underestimated. Pretransplant characteristics and, particularly, the glycemia during the first month post-transplant identified patients at risk of PTDM. Increasing glucose levels greater than 100 mg/dL, any time after the first month post-transplant, are associated with increasing CV risk. We postulate that aggressive detection and treatment of post-transplant hyperglycemia may significantly reduce CV morbidity and mortality after kidney transplantation.

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.

Strategies for minimizing immunosuppression in kidney transplantation

Immunosuppression remains the cause of most morbidity following organ transplantation. However, its use is also responsible for the outstanding graft and patient survival rates commonplace in modern transplantation. Thus, the predominant challenge for transplant clinicians is to provide a level of immunosuppression that prevents graft rejection while preserving immunocompetence against environmental pathogens. This review will outline several strategies for minimizing or tailoring the use of immunosuppressive drugs. The arguments for various strategies will be based on clinical trial data rather than animal studies. A distinction will be made between conventional immunosuppressive drug reduction based on over-immunosuppression, and newer induction methods specifically designed to lessen the need for chronic immunosuppression. Based on the available data we suggest that most patients can be transplanted with less immunosuppression than is currently standard.

Tacrolimus and Posttransplant Diabetes Mellitus in Renal Transplantation

The most prominent side effect of tacrolimus is the induction of posttransplant diabetes mellitus (PTDM). In this review, the authors discuss the incidence, mechanism, prevention, and treatment of tacrolimus-induced PTDM in renal patients.

Management of hyperglycaemia after pancreas transplantation: are new immunosuppressants the answer?

Pancreas transplantation is considered the optimal therapy for patients with diabetes mellitus who reach end-stage renal disease. Despite achievement of euglycaemia after this procedure, the progression to impaired pancreatic function and metabolic exhaustion still represents one of the major concerns that increase the risk of graft loss. This paper reviews the possible mechanisms that can induce post-transplant hyperglycaemia, including those related to immunosuppression and those non-related, and the new strategies available for minimising or preventing this complication. Different aetiologies can induce pancreatic dysfunction. Technical complications, acute pancreatitis and delayed graft function, mostly related to impaired insulin secretion, are considered the early causes for abnormal glucose control. In general, acute rejection does not affect the endocrine portion of the pancreas graft because islet destruction occurs later than the inflammation of the exocrine components. Hyperinsulinaemia and insulin resistance represent the main concern for the progression of blood glucose intolerance. The anastomotic techniques of the exocrine portion of the pancreas and the immunosuppressive regimens are of critical importance for the development of impaired glucose metabolism. Hyperinsulinaemia, as a result of the fact that systemic-enteric or systemic-bladder drainages reducing the hepatic clearance of insulin, has led to the introduction of more physiological techniques using portal drainage of the endocrine secretions. Experimental and clinical data have shown that many of the current immunosuppressants account, to a large degree, for the increased risk of the development of post-transplant hyperglycaemia. The most common maintenance regimen in pancreatic transplantation still consists of triple therapy with a combination of corticosteroids, calcineurin inhibitors (either ciclosporin [cyclosporine] or tacrolimus), and mycophenolate mofetil (MMF).The diabetogenic effects of corticosteroids and calcineurin inhibitors have resulted in the need for protocols able to minimise their use. Recent studies have shown the safety and efficacy of steroid-sparing or -free regimens. Sirolimus has shown powerful immunosuppressive potency in absence of nephrotoxicity and diabetogenicity. Multicentre and single-centre reports have demonstrated that both calcineurin inhibitor withdrawal and avoidance were possible when sirolimus was used in a concentration-controlled fashion, with low-dose corticosteroids and MMF. Although the experience with sirolimus in pancreatic transplantation is still limited, the results are promising. Patients affected by diabetic gastroparesis seem to better tolerate a regimen with sirolimus and low-dose tacrolimus than one with tacrolimus in combination with MMF.For successful, long-term results of pancreatic transplantation, it is crucial to combine donor selection, technical aspects, modified anastomotic techniques and new therapeutic approaches designed to minimise the metabolic and non-metabolic adverse effects of the immunosuppressive regimens.

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.

Challenges facing islet transplantation for the treatment of type 1 diabetes mellitus

Islet transplantation represents a most impressive recent advance in the search for a type 1 diabetes mellitus cure. While several hundred patients have achieved at least temporary insulin independence after receiving the islet "mini-organs" (containing insulin-producing beta cells), very few patients remain insulin independent beyond 4 years after transplantation. In this review, we describe historic as well as technical details about the procedure and provide insight into clinical and basic research efforts to overcome existing hurdles for this promising therapy.

Challenges facing islet transplantation for the treatment of type 1 diabetes mellitus

Islet transplantation represents a most impressive recent advance in the search for a type 1 diabetes mellitus cure. While several hundred patients have achieved at least temporary insulin independence after receiving the islet "mini-organs" (containing insulin-producing beta cells), very few patients remain insulin independent beyond 4 years after transplantation. In this review, we describe historic as well as technical details about the procedure and provide insight into clinical and basic research efforts to overcome existing hurdles for this promising therapy.

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.

Diabetic ketoacidosis following development of de novo diabetes in renal transplant recipient associated with tacrolimus

Although drugs used in renal transplant recipients such as steroids, cyclosporine, and particularly, tacrolimus have diabetogenic potential, diabetic ketoacidosis is uncommon. There are few data concerning the long-term follow-up of these patients. Diabetic ketoacidosis occurred in a renal transplant recipient following de novo development associated with tacrolimus.

Conversion from cyclosporine to tacrolimus improves quality-of-life indices, renal graft function and cardiovascular risk profile

Long-term use of cyclosporine after renal transplantation results in nephrotoxicity and an increased cardiovascular risk profile. Tacrolimus may be more favorable in this respect. In this randomized controlled study in 124 renal transplant patients, the effects of conversion from cyclosporine to tacrolimus on renal function, cardiovascular risk factors, and perceived side-effects were investigated after a follow-up of 2 years. After conversion from cyclosporine to tacrolimus renal function remained stable, whereas continuation of cyclosporine was accompanied by a rise in serum creatinine from 142 +/- 48 micromol/L to 157 +/- 62 micromol/L (p < 0.05 comparing both groups). Conversion to tacrolimus resulted in a sustained reduction in systolic and diastolic blood pressure, and a sustained improvement in the serum lipid profile, leading to a reduction in the Framingham risk score from 5.7 +/- 4.3 to 4.8 +/- 5.3 (p < 0.05). Finally, conversion to tacrolimus resulted in decreased scores for occurrence of and distress due to side-effects. In conclusion, conversion from cyclosporine to tacrolimus in stable renal transplant patients is beneficial with respect to renal function, cardiovascular risk profile, and side-effects. Therefore, for most renal transplant patients tacrolimus will be the drug of choice when long-term treatment with a calcineurin inhibitor is indicated.

Post-liver transplant acute renal failure: factors predicting development of end-stage renal disease

BACKGROUND

Acute renal failure (ARF) occurs in 5-50% of patients undergoing orthotopic liver transplantation (OLT). The aim of this study was to determine factors that might predict the development of end stage renal disease (ESRD) in patients who had ARF after OLT.

METHODS

We studied all OLT recipients between 9/1/1988 through 12/31/2000.

RESULTS

A total of 1602 patients underwent OLT during the study period. About 350 patients (22%) developed ARF requiring dialysis post-operatively. One hundred and twenty-three (39.8%) died within a year after OLT. Median follow up was 5.8 yr (range 1-12 yr). Forty-three patients (23%) developed ESRD over median of 3.79 yr (range 1-8 yr). Multivariate logistic regression analysis revealed creatinine levels > 1.7 mg/dL at 1 yr (p < 0.001), cyclosporine as immunosuppression (p = 0.026), and the presence of diabetes pre-OLT (p < 0.001) to be associated with the development of ESRD. The development of ESRD did not decrease patient survival (p = 0.111). ESRD patients who received subsequent kidney transplantation had significantly improved survival rates (p = 0.005).

CONCLUSIONS

Serum creatinine levels at 1 yr, cyclosporine as immunosuppression, and the presence of diabetes pre-OLT are independent predictive factors for the development of ESRD. ESRD patients who received kidney transplantation had higher 10-yr survival rates when compared with patients maintained on dialysis.

Posttransplant diabetes mellitus in cyclosporine-treated renal allograft patients: a case-control study

The incidence and risk factors for the development of posttransplant diabetes mellitus (PTDM) was retrospectively evaluated in cyclosporine-treated renal transplant patients. An incidence of 9.4% was observed over a 10-year period. Weight and body mass index were risk factors identified in a case-controlled study. Age, race, family history of DM, and cyclosporine and prednisone doses were not associated with the development of PTDM. We concluded that the development of PTDM is mainly related to weight. All efforts must be taken to avoid this complication.

Posttransplant diabetes mellitus in renal transplant patients with hepatitis C virus

The aim of this study was to assess the possible association between posttransplant diabetes mellitus (DM) and hepatitis C virus (HCV) infection in renal transplant recipients. This study included 124 patients who underwent renal transplantation between 1997 and 2002. Inclusion criteria were patients who were not diabetic prior to transplantation and posttransplant follow-up longer than 6 months. DM was defined as fasting blood glucose levels higher than 126 mg/dL on at least two occasions. HCV infection was detected using second- or third-generation ELISA methods and/or polymerase chain reactions for HCV-RNA. Twenty-five HCV positive (HCV+) patients were compared with 25 consecutive HCV negative (HCV-) transplant patients. Demographic and clinical data of the groups were compared. Posttransplantation DM was observed in 24% of the HCV+ patients. There were no statistical differences in age, gender, race, family history of DM, follow-up, or body mass index between the two groups. There was a higher prevalence of posttransplantation DM in HCV+ patients, but the difference did not reach statistical significance (24% vs 12%, P = NS). Alternatively, comparing patients of the two groups (n = 50) who did versus not develop DM, the incidence of posttransplantation DM was higher among HCV+ patients, but the difference did not reach statistical significance (66.6% vs 46.3%, P = NS). In conclusion, there was no association between HCV infection and the development of posttransplantation DM in this cohort of renal transplant recipients. However, there was a trend that suggested an association.

Risk factors for the development of posttransplantation diabetes mellitus in simultaneous pancreas and kidney recipients

We sought to determine the risk factors involved in the development of posttransplantation diabetes mellitus (PTDM) following simultaneous pancreas and kidney transplantation. Correlations were sought between tacrolimus (FK-506) levels/dose 2-hour capillary glucose (CG) and glycosylated hemoglobin (HbA(1c)), cyclosporine (CSA) levels/dose with HbA1c, 2-hour CG with prednisone dose and body mass index (BMI) and PTDM. Four patients (9.3%) developed PTDM. Three treated with FK-506 had altered 2-hour CG at 3 months after transplantation; 1 prescribed CSA displayed diabetes diagnosed after 1 year. There was no statistically significant difference among HbA(1c) values and FK-506 (P =.18) or CSA (P =.81) doses or FK-506 (P =.53) and CSA (P =.54) levels. In contrast, there was a statistically significant relationship between elevated 2-hour CG (> or =200 mg/dL) and daily prednisone dose (9.7 mg vs. 16.2 mg; P =.003). There was no correlation between 2-hour CG and FK-506 dose (P =.084) or FK-506 levels (P =.075). The greater BMI correlated with an increased risk of PTDM (21.25 +/- 3.13 kg/m(2) vs 24.67 +/- 2.38 kg/m(2); P =.034). Two-hour CG may be a useful tool to screen the diabetogenic effects of corticosteroids. A BMI increase should be discouraged due to the risk of PTDM.

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.

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.

Exercise augments the acute anabolic effects of intradialytic parenteral nutrition in chronic hemodialysis patients

Decreased dietary protein intake and hemodialysis (HD)-associated protein catabolism are among several factors that predispose chronic hemodialysis (CHD) patients to uremic malnutrition and associated muscle wasting. Intradialytic parenteral nutrition (IDPN) acutely reverses the net negative whole body and forearm muscle protein balances observed during the HD procedure. Exercise has been shown to improve muscle protein homeostasis, especially if performed with adequately available intramuscular amino acids. We hypothesized that exercise performance would provide additive anabolic effects to the beneficial effects of IDPN. We studied six CHD patients at two separate HD sessions: 1) IDPN administration only and 2) IDPN + exercise. Patients were studied 2 h before, during, and 2 h after an HD session by use of a primed constant infusion of l-[1-(13)C]leucine and l-[ring-(2)H(5)] phenylalanine. Exercise combined with IDPN promoted additive twofold increases in forearm muscle essential amino acid uptake (455 +/- 105 vs. 229 +/- 38 nmol.100 ml(-1).min(-1), P < 0.05) and net muscle protein accretion (125 +/- 37 vs. 56 +/- 30 microg.100 ml(-1).min(-1), P < 0.05) during HD compared with IDPN alone. Measurements of whole body protein homeostasis and energy expenditure were not altered by exercise treatment. In conclusion, exercise in the presence of adequate nutritional supplementation has potential as a therapeutic intervention to blunt the loss of muscle mass in CHD patients.

The pharmacogenetics of immunosuppression for organ transplantation: a route to individualization of drug administration

Transplantation has transformed the treatment of patients with organ failure in a number of clinical settings, and immunosuppressive drug therapy is fundamental to its success. However, all the drugs in current use have a narrow therapeutic index. Under-dosing can lead to rejection, while over-dosing increases the risks of infection, malignant disease, and serious drug-specific adverse effects, including diabetes mellitus, nephrotoxicity, hypertension, and hyperlipidemia. Heterogeneity in the pharmacokinetics of these drugs makes initial dose determination difficult, as there is a poor correlation between dose and blood concentration. This results in difficulties in achieving target blood concentrations early after transplantation, which are important for reducing the rate of immunological rejection. This problem is compounded by the observation that neither drug dose nor drug blood concentration accurately predict clinical efficacy or toxicity. The main determinant of heterogeneity in dose requirements is intestinal absorption of the active drug. The oxidative enzymes, cytochrome P450 (CYP) 3A4 and CYP3A5, and the drug efflux pump P-glycoprotein (P-gp) in enterocytes regulate this process. Most substrates for the P-gp pump are also substrates for the CYP3A enzymes. An efficient barrier to xenobiotic absorption is formed by the CYP enzymes and P-gp, and by the two systems working synergistically. Genetic polymorphisms have been reported for the genes associated with the expression of the CYP3A enzymes and P-gp. Genotyping patients for CYP3A genes has the potential to aid the establishment of optimal dosage regimens for transplant patients. Genetic polymorphism of the multiple drug resistance gene-1 (MDR1, also known as ABCB1) [3435C/T] and the CYP3A5 genes (CYP3A5*1, CYP3AP1*1) have the greatest potential to influence the pharmacokinetics of immunosuppressants. Homozygosity of the T allele of the MDR1 3435C/T polymorphism has been associated with reduced enterocyte expression of P-gp resulting in increased drug absorption. The presence of the CYP3A5*1 allele is necessary for the production of a fully catalytic CYP3A5 protein, and also influences the ratio of CYP3A4 : CYP3A5 as well as the overall CYP3A catalytic activity. The CYP3A4 : CYP3A5 ratio may, in turn, influence the pattern of drug metabolites formed. Heterogeneity in the production of active and inactive metabolites has implications for both the pharmacokinetics and pharmacodynamics of these drugs.Gene frequencies and drug dose requirements differ between ethnic groups. Ethnic differences in dose requirements for immunosuppressants have been discussed widely. However, ethnicity is a rather crude marker for genotype. Pharmacogenetic typing offers the possibility of significant improvement in the individualization of immunosuppressive drug prescribing with reduced rates of rejection and toxicity.

Calcineurin inhibitors in renal transplantation: what is the best option?

Recently, new calcineurin inhibitors, such as tacrolimus (FK-506) and microemulsion cyclosporin, have been approved for maintenance immunosuppression in renal transplant recipients and short-term outcomes have been accumulating. In the majority of patients, these calcineurin inhibitors have been used in combination with new immunosuppressive drugs, such as mycophenolate mofetil (MMF) or sirolimus. Under these circumstances, a comparison of cyclosporin and tacrolimus provides the answer to a very important controversial issue. Which drug should we choose in individual patients? In an attempt to answer this question, this review compared the use of tacrolimus and cyclosporin in modern immunosuppressive regimens, which have already been published in well designed clinical studies, and discusses how immunosuppression should be individualised in renal transplant patients.Overall, short-term patient and graft survival with cyclosporin microemulsion and tacrolimus is almost identical. The incidence of acute rejection is generally lower in tacrolimus/azathioprine- than in cyclosporin/azathioprine-treated patients. However, in conjunction with MMF, the difference in the incidence of acute rejection between tacrolimus- and cyclosporin-treated patients became smaller. Adverse events, such as hypertension, hyperlipidaemia and cosmetic changes (gum hypertrophy, hirsutism) seem to be less frequent in tacrolimus-treated than in cyclosporin-treated patients. Recent randomised studies showed that the incidence of post-transplant diabetes mellitus was almost identical between low-dose tacrolimus- and cyclosporin-treated patients. According to the data discussed in this review, the recommendation on the choice of calcineurin inhibitors at this moment is that either cyclosporin or tacrolimus can be used safely and effectively for patients without any risk factors. However, at our centre, we prefer tacrolimus to cyclosporin in patients with a high risk for rejection, such as those with ABO-incompatibility, delayed graft function, sensitisation, and African American race and some other risk factors, such as hypertension and hyperlipidaemia. Moreover, tacrolimus may be preferable to cyclosporin for women because of hirsutism and for children because of the steroid-sparing effect. We consider that cyclosporin should be chosen when patients experience tacrolimus-related adverse events, such as severe chest pain, tremor, gastrointestinal symptoms and encephalopathy. In conclusion, well tolerated and effective immunosuppression is feasible with both cyclosporin and tacrolimus. In the current immunosuppressive regimens, a calcineurin inhibitor, either tacrolimus or cyclosporin, is the essential basic standard immunosuppressant. Clinicians need to decide the best means of optimising therapy for individual patients, based on various risk factors, such as risk of rejection, i.e. sensitisation, delayed graft function and ABO-incompatibility, and some adverse events, such as hypertension, hyperlipidaemia and cosmetic changes.

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.

Impact of renal insufficiency in patients undergoing primary angioplasty for acute myocardial infarction

BACKGROUND

The prognostic importance of renal insufficiency (RI) in patients undergoing primary percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) has not been well characterized.

METHODS AND RESULTS

PCI was performed in 2082 AMI patients without shock presenting within 12 hours of symptom onset in a prospective, multicenter randomized trial. RI was defined as a calculated (Cockroft-Gault) creatinine clearance (CrCl) < or =60 mL/min. RI at baseline was present in 18% of patients. Compared with patients without RI, patients with RI were older and were more likely to be female; to have hypertension, peripheral vascular disease, or cerebrovascular disease; and to present in heart failure. Mortality was markedly increased in patients with versus without baseline RI both at 30 days (7.5% versus 0.8%, P<0.0001) and at 1 year (12.7% versus 2.4%, P<0.0001). Mortality rates increased incrementally for every 10-mL/min decrease in baseline CrCl. By multivariate analysis, reduced baseline CrCl was a powerful independent predictor of 30-day mortality (hazard ratio, 5.77; P<0.0001) and remained associated with reduced survival at 1 year (hazard ratio, 1.98; P=0.08). Hemorrhagic complications and transfusion requirements were also increased more than 2-fold in patients with RI, as were severe restenosis (diameter stenosis > or =70%; 20.6% versus 11.8%, P=0.024) and infarct artery reocclusion (14.7% versus 7.3%, P=0.02).

CONCLUSIONS

Baseline RI in patients with AMI undergoing primary PCI is associated with a markedly increased risk of mortality, as well as bleeding and restenosis. Novel approaches are needed to improve the otherwise poor prognosis of patients with RI and AMI.

Diabetes mellitus after transplant: relationship to pretransplant glucose metabolism and tacrolimus or cyclosporine A-based therapy

OBJECTIVE

The purpose of this study was to identify pretransplantation and posttransplantation indicators for the development of diabetes mellitus in the first 2 months after renal transplantation and to examine the influence of a cyclosporine A (CsA)-based versus a tacrolimus-based immunosuppressive regimen on these risk factors.

METHODS

Key variables associated with the development of posttransplant diabetes mellitus (PTDM) in the first 2 months after transplantation were assessed in 48 patients who underwent living-related renal transplantation and who were treated with a CsA-based or a tacrolimus-based immunosuppressive regimen. The insulinogenic index (I Index) and glucose infusion rate (GIR) were measures of insulin secretion and insulin sensitivity, respectively.

RESULTS

Eight patients developed PTDM. I Index (odds ratio, 0.000384) and GIR (odds ratio, 0.349) were significant risk factors for PTDM development. The cumulative steroid dose had a borderline association. PTDM developed in 4 of 28 CsA-treated patients and in 4 of 20 tacrolimus-treated patients. CsA therapy increased the mean I Index from 0.713+/-0.071 preoperatively to 1.130+/-0.140 postoperatively (P<0.01), whereas in tacrolimus-treated patients, I Index remained unchanged (1.09+/-0.264 preoperatively and 0.949+/-0.296 postoperatively; P=not significant). Age, duration of pretransplant dialysis, and body mass index did not predict PTDM development. All eight patients with PTDM had hypertension.

CONCLUSIONS

Pre- and posttransplant abnormalities of insulin secretion and sensitivity are significant predictors of PTDM. Corticosteroid cumulative dose may affect the incidence of PTDM during the first 2 months after transplantation. CsA treatment increases insulin secretion in patients with a high pretransplant risk of PTDM.

The immunosuppressant FK506 uncovers a positive regulatory cross-talk between the Hog1p and Gcn2p pathways

The immunosuppressant Tacrolimus (FK506) has increased the survival rates of organ transplantation. FK506 exerts its immunosuppressive effect by inhibition of the protein phosphatase calcineurin in activated T-cells. Unfortunately, FK506 therapy is associated with undesired non-therapeutic effects involving targets other than calcineurin. To identify these targets we have addressed FK506 cellular toxicity in budding yeast. We show that FK506 increased cell sensitivity upon osmotic challenge independently of calcineurin and the FK506-binding proteins Fpr1p, -2p, -3p, and -4p. FK506 also induced strong amino acid starvation and activation of the general control (GCN) pathway. Tryptophan prototrophy or excess tryptophan overcame FK506 toxicity, showing that tryptophan deprivation mediated this effect. Mutation of the GCN3 and -4 genes partially alleviated FK506 toxicity, suggesting that activation of the GCN pathway by FK506 was also involved in osmotic tolerance. FK506 enhanced osmotic stress-dependent Hog1p kinase phosphorylation that was not accompanied by induction of a Hog1p-dependent reporter. Interestingly, deletion of the GCN2 gene suppressed FK506-dependent Hog1p hyperphosphorylation and restored Hog1p-dependent reporter activity. Conversely, deletion of the HOG1 gene impaired FK506-dependent activation of Gcn2p kinase and translation of a GCN4-LacZ reporter, highlighting functional cross-talk between the Gcn2p and Hog1p protein kinases. Taken together, these data demonstrate that both FK506-induced amino acid starvation and activation of the GCN pathway contribute to cell sensitivity to osmotic stress and reveal a positive regulatory loop between the Hog1p and Gcn2p pathways. Given the conserved nature of Gcn2p and Hog1p pathways, this mechanism of FK506 toxicity could be relevant to the non-therapeutic effects of FK506 therapy.

Risk factors for cardiovascular disease after renal transplantation

Cardiovascular diseases (CVD) have become the leading cause of mortality in renal transplant recipients. Well-known cardiovascular (CV) risk factors and graft dysfunction both play an important role in the development of the posttransplantation CV events. We studied 233 stable kidney transplant patients to establish the prevalence of CVD and to assess CV risk factors that can be evaluated (and modified) in daily clinical practice. While 6.2% of the patients had coronary heart disease (CHD) before the transplantation, 16% displayed at least 1 CV event posttransplantation. The most significant factors associated with CV events were as follows: gender, length of smoking, diabetes mellitus, hepatitis C virus antibodies (HCV), dyslipidemia, proteinuria, and serum creatinine levels.

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.

Diabetes mellitus in transplantation: 2002 consensus guidelines

Diabetes mellitus is a serious complication following organ transplantation that is underdiagnosed, possibly due to the inadequate definitions used in published literature and the lack of standardized screening. Diabetes in transplantation amplifies the already increased risk of cardiovascular disease among transplant patients, and increases the risk of graft loss and death. Patients at risk of developing diabetes in transplantation should therefore be prospectively identified and given individualized immunosuppressive therapy to minimize the risk of developing this disease. These guidelines are intended to: (1) help identify patients at risk for diabetes after transplantation; (2) set down a standard definition of posttransplant diabetes mellitus (PTDM); (3) create a standard monitoring protocol for the diagnosis of PTDM; and (4) optimize the management of patients at risk of developing or who develop diabetes after transplantation. With improved diagnosis, individualization of therapy, and proper early management, the incidence of diabetes in transplantation, and the accompanying additional burden of illness the disease carries, may be diminished. In turn, this will help achieve the therapeutic goals of reducing the risk of graft complications, improving quality of life, and reducing postoperative morbidity and mortality in transplant patients.