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

FK506 prevented bone loss in streptozotocin-induced diabetic rats via enhancing osteogenesis and inhibiting adipogenesis

Background

Type 1 diabetes mellitus (DM) is associated with severe osteoporosis, which is still a great challenge in the clinic. This work aimed to investigate the skeletal effects of FK506 in a rat model of streptozocin induced type 1 DM.

Methods

Rats were divided into three groups: control (CTL), DM rats and DM rats treated with FK506. Dual energy X-ray absorption, micro-computed tomography, bone mechanics and bone histology were used for skeletal analysis. Bone marrow adipocytes infiltrations were detected by oil red O stain and H&E stain. In addition, the protein expression of adipocyte-specific makers (PPAR-γ, C/EBP-αβ), osteoblast-specific markers (Runx2, Osterix) and nuclear translocation of β-catenin in femurs were determined by western blot.

Results

In the study, bone mineral density of femurs and lumbar vertebras in diabetic rats were increased after FK506 administration. FK506 treatment resulted in higher cancellous bone volume but had no significant effect on cortical bones in diabetic rats. The ultimate force and work to failure were increased in DM+FK506 group, while they were reduced in the DM group. Compared with the CTL, the infiltration of bone marrow adipocytes was significantly increased in the DM group, which was reduced after the treatment of FK506. Besides, the expression levels of Runx2 and Osterix were up-regulated, and that of PPAR-γ and C/EBP-α were down-regulated in diabetic rats after FK506 treatment. In addition, the nuclear translocation of β-catenin protein levels were increased in diabetic rats after the treatment of FK506.

Conclusions

Our study indicated that FK506 could alleviate bone loss in diabetic rats. This effects could be due to the results of enhancing osteogenesis and inhibiting adipogenesis, which might be regulated by activation the nuclear translocation of β-catenin.

THE RATIONALE FOR USE OF INCRETINS IN THE MANAGEMENT OF NEW ONSET DIABETES AFTER TRANSPLANTATION (NODAT)

OBJECTIVE

Owing to advances in transplant science, increasing numbers of patients are receiving solid organ transplantation. New onset diabetes after transplantation (NODAT) frequently develops in transplant patients and requires acute and often ongoing management of hyperglycemia. The metabolic derangements of NODAT are similar to those of classic type 2 diabetes, and treatment has typically followed diabetes standards of care. Best practices for NODAT management remain to be developed.

METHODS

The mechanistic suitability of incretins to treat NODAT pathogenesis has been hitherto underappreciated. This review details the specific mechanistic value of incretins in patients with immunosuppression-associated hyperglycemia.

RESULTS

Corticosteroids have long been known to exert their effects on glucose metabolism by decreasing glucose utilization and enhancing hepatic gluconeogenesis. Corticosteroids also significantly and directly reduce insulin secretion, as do calcineurin inhibitors (CNIs), another commonly used group of immunosuppressive drugs that cause hyperglycemia and NODAT. The ability of incretins to counteract immunosuppressant-induced disruptions in insulin secretion suggest that the insulinotropic, glucagonostatic, and glucose-lowering actions of incretins are well suited to treat immunosuppressant-induced hyperglycemia in NODAT. Additional benefits of incretins include decreased glucagon levels and improved insulin resistance. In the case of glucagon-like peptide-1 (GLP-1) receptor agonists, weight loss is another benefit, countering the weight gain that is a common consequence of both hyperglycemia and transplantation. These benefits make incretins very attractive and deserving of more investigation.

CONCLUSION

Among diabetes treatment options, incretin therapies uniquely counteract immunosuppressant drugs' interference with insulin secretion. We propose an incretin-based treatment paradigm for NODAT management.

Body fat percentage as a marker of new-onset diabetes mellitus after kidney transplantation

BACKGROUND

New-onset diabetes after transplantation (NODAT) is a serious metabolic complication that can follow kidney transplantation. Several risk factors, including obesity, have been related to NODAT development. Obesity is defined as an excessive accumulation of body fat, and body fat percentage (BF%) has been commonly measured by different techniques, including bioelectrical impedance analysis. However, the correlation between an increase in BF% and the development of NODAT during outpatient follow-up has not yet been explored. We aimed to elucidate the association between BF% changes and the development of NODAT.

METHODS

We performed a retrospective study involving 45 patients without diabetes who underwent kidney transplantation in our hospital between March 2008 and December 2010. We compared the BF% and demographic variables of patients who did and did not develop NODAT during follow-up.

RESULTS

Four patients (8.9%) developed NODAT during a mean follow-up period of 30.3 months. The post-transplantation increase in BF% was much higher in NODAT+ patients than the NODAT- patients. Univariate analysis indicated that the rate of increase in BF% was a risk factor for NODAT (hazard ratio [HR], 1.08 [1.02-1.18]; P < .005).

CONCLUSIONS

A large increase in BF% may be a risk factor for NODAT. These findings underline the importance of routine BF% measurements in medical practice.

Posttransplant increase of body mass index is associated with new-onset diabetes mellitus after kidney transplantation

New-onset diabetes after transplantation (NODAT) is a serious complication after kidney transplantation. Obesity was widely identified as a modifiable risk factor for NODAT. Body mass index (BMI) is the most frequently used diagnostic indication of obesity, and higher pretransplant BMI has been reported to be an independent risk factor of NODAT. However, the influence of posttransplant increase in BMI on the development of NODAT during outpatient follow-up has not been established. This is a single-centered retrospective study in Japan. We identified 158 consecutive patients who received living donor kidney transplantation in Sendai Shakaihoken Hospital from September 2000 to December 2009. Of these, 101 patients were included in this study. NODAT was defined based on the American Diabetes Association definitions. Fifteen patients developed NODAT with a median follow-up period of 27 (3-109) months. Of these 15 patients with NODAT, 13 patients were diagnosed after the first year of transplantation, with a median follow-up of 29 months, and 2 patients were diagnosed at 3 months after transplantation. Recipient age (HR: 1.06 [1.01-1.13]) and increase in BMI (HR: 1.12 [1.01-1.26]) proved to be independent risk factors of NODAT in multivariate logistic analysis after adjustments for pretransplant 2-hour OGTT level, pretransplant BMI, and use of tacrolimus. This is the first study showing the association between an increase in BMI and the development of NODAT. The increase in BMI might be a risk factor for NODAT. These findings underline the importance of routine BMI measurements in medical practice.

Conversion to sirolimus therapy in kidney transplant recipients with new onset diabetes mellitus after transplantation

New-onset diabetes mellitus after transplantation (NODAT) may complicate 2–50% of kidney transplantation, and it is associated with reduced graft and patient survivals. In this retrospective study, we applied a conversion protocol to sirolimus in a cohort of kidney transplant recipients with NODAT. Among 344 kidney transplant recipients, 29 patients developed a NODAT (6.6%) and continued with a reduced dose of calcineurin inhibitors (CNI) (8 patients, Group A) or were converted to sirolimus (SIR) (21 patients, Group B). NODAT resolved in 37.5% and in 80% patients in Group A and Group B, respectively. In Group A, patient and graft survivals were 100% and 75%, respectively, not significantly different from Group B (83.4% and 68%, resp., P = 0.847). Graft function improved after conversion to sirolimus therapy: serum creatinine was 1.8 ± 0.7 mg/dL at the time of conversion and 1.6 ± 0.4 mg/dL five years after conversion to sirolimus therapy (P < 0.05), while in the group of patients remaining with a reduced dose of CNI, serum creatinine was 1.7 ± 0.6 mg/dL at the time of conversion and 1.65 ± 0.6 mg/dL at five-year followup (P = 0.732). This study demonstrated that the conversion from CNI to SIR in patients could improve significantly the metabolic parameters of patients with NODAT, without increasing the risk of acute graft rejection.

The impact of calcineurin inhibitors on insulin sensitivity and insulin secretion: a randomized crossover trial in uraemic patients

AIMS

The calcineurin inhibitors cyclosporine and tacrolimus are implicated in post-transplant complications such as new-onset diabetes after transplantation. The relative contribution of each calcineurin inhibitor to new-onset diabetes after transplantation remains unclear. We sought to compare the impact of cyclosporine and tacrolimus on glucose metabolism in humans.

METHODS

Eight haemodialysis patients received 8-10 days of oral treatment followed by 5-h infusions with cyclosporine, tacrolimus and saline in a randomized, investigator-blind, crossover study. Glucose metabolism and β-cell function was investigated through: a hyperinsulinaemic-euglycaemic clamp, an intravenous glucose tolerance test and insulin concentration time series.

RESULTS

Cyclosporine and tacrolimus decreased insulin sensitivity by 22% (P = 0.02) and 13% (P = 0.048), respectively. The acute insulin response and pulsatile insulin secretion were not significantly affected by the drugs.

CONCLUSION

In conclusion, 8-10 days of treatment with cyclosporine and tacrolimus impairs insulin sensitivity to a similar degree in haemodialysis patients, while acute insulin responses and pulsatile insulin secretion remain unaffected.

Metabolic abnormalities associated with initiation of systemic treatment for psoriasis: evidence from the Italian Psocare Registry

OBJECTIVE

To evaluate variations in laboratory parameters and diagnoses of selected clinical conditions up to 16 weeks after starting a new systemic psoriasis treatment for Psocare Registry enrollees.

DESIGN

Prospective cohort study.

SETTING

Italian public referral centres for psoriasis treatment.

PATIENTS

First-time recipients (n = 10,539) of continuous systemic psoriasis treatment for at least 16 weeks.

MAIN OUTCOME MEASURE

Mean variations in (weeks 8 and 16) and proportions of patients reaching a clinically meaningful increase in serum levels (week 16) of total and low-density lipoprotein cholesterol, triglycerides, aspartate amino transferase, alanine amino transferase and creatinine, as well as week-16 cumulative incidences of new diagnoses of diabetes mellitus and arterial hypertension.

RESULTS

Mean cholesterol and triglyceride levels significantly increased in patients treated with acitretin or cyclosporine. Mean triglyceride levels also increased in efalizumab- and etanercept-treated patients. Mean transaminase values increased in methotrexate-treated patients, and mean aspartate amino transferase levels increased in infliximab-treated patients. The average serum creatinine value increased in cyclosporine-treated patients. Acitretin and cyclosporine were associated with risk of hypercholesterolaemia (odds ratios 1.51 and 1.34) and acitretin with risk of hypertriglyceridaemia (odds ratio 1.43). Methotrexate and infliximab were associated with risk of more than doubling the upper normal aspartate amino transferase (odds ratios 2.06 and 1.87) and alanine amino transferase (odds ratios 2.38 and 1.74) values. The relative risk of developing arterial hypertension and diabetes was increased for patients receiving cyclosporine (odds ratios 3.31 and 2.88).

CONCLUSION

Systemic treatments for psoriasis resulted in heterogeneous effects on the parameters analysed.

Effect of different immunosuppressive regimens on the evolution of distinct metabolic parameters: evidence from the Symphony study

BACKGROUND

The metabolic syndrome (MS) is an important risk factor for graft dysfunction and patient death after renal transplantation. The aim of this sub-analysis of the Symphony study was to assess the progression of the laboratory parameters associated with MS in the first year after transplantation.

METHODS

Data collected from the Symphony study were used; 1645 patients were randomized to receive standard-dose cyclosporine (Stand-CsA), low-dose cyclosporine (Low-CsA), tacrolimus (Low-Tac) or sirolimus (Low-SRL), in addition to mycophenolate mofetil (MMF) and corticosteroids. Data were collected for levels and progression over the first year post-transplantation of systolic and diastolic blood pressure, uric acid, triglycerides, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol and fasting glucose levels by treatment arm.

RESULTS

The low-SRL group had significantly higher levels of triglycerides and LDL. The two CsA arms were associated with the highest uric acid levels at each time point. There were no significant differences in overall levels or changes in glucose or HDL. Patients in the standard-CsA arm had significantly higher diastolic blood pressure than those in the Low-SRL and Low-Tac arms. Systolic blood pressure was higher in the Low-CsA arm than in the Low-Tac arm. The use of antihypertensive and antidiabetic agents was similar between the treatment arms. In the Low-SRL arm, more patients were treated with lipid-lowering therapy. Mean daily steroid doses were the highest in the Low-SRL arm.

CONCLUSIONS

This sub-analysis demonstrates that there is a difference in metabolic parameters between immunosuppressive groups. CsA therapy was associated with the highest values of uric acid and systolic and diastolic blood pressure. Patients on SRL therapy had the worst lipaemic control. A possible effect of Tac on new-onset diabetes could not be excluded.

Cyclosporin and tacrolimus impair insulin secretion and transcriptional regulation in INS-1E beta-cells

BACKGROUND AND PURPOSE

Introducing the calcineurin inhibitors cyclosporin (CsA) and tacrolimus (Tac) has improved the outcome of organ transplants, but complications such as new onset diabetes mellitus after transplantation (NODAT) decrease survival rates.

EXPERIMENTAL APPROACH

We sought, in a beta-cell culture model, to elucidate the pathogenic mechanisms behind NODAT and the relative contribution of the calcineurin inhibitors. INS-1E cells were incubated at basal and stimulatory glucose concentrations, while exposed to pharmacologically relevant doses of CsA, Tac and vehicle for 6 or 24 h.

RESULTS

Tac inhibited basal (P < 0.05), but not glucose-stimulated insulin secretion (GSIS) after 6 h of exposure. After 24 h, both agents inhibited basal and GSIS (P < 0.05). Calcineurin phosphatase activity was decreased by both drugs during all conditions. Apoptosis was only seen with CsA treatment, which also induced a slight suppression of calcineurin and insulin mRNA, as well as increased levels of the sterol receptor element binding protein (SREBP)-1c, a transcription factor thought to suppress genes essential for beta-cell function and induce insulin resistance. Expression levels of nuclear factor of activated T-cells (NFAT)-c1, -c2, -c3 and -c4 were not decreased notably by either drug.

CONCLUSIONS AND IMPLICATIONS

Tac had acute inhibitory effects on basal insulin secretion, but prolonged exposure (24 h) to Tac or CsA revealed similar suppression of insulin secretion. These prolonged effects were mirrored by a total inhibition of calcineurin activity in beta-cells. CsA showed greater inhibition of beta-cell survival and transcriptional markers, essential for beta-cell function.

KCNQ1 gene variants and risk of new-onset diabetes in tacrolimus-treated renal-transplanted patients

Recent genome-wide association studies identified single-nucleotide polymorphisms (SNPs) in the gene encoding the pore-forming subunit of the voltage-gated K+ channel (KCNQ1) as a risk factor for type 2 diabetes. Tacrolimus (Tac) increased the risk of new-onset diabetes after transplantation (NODAT). The aim of this study was to analyze the association between KCNQ1 variants and the risk for NODAT in kidney-transplanted patients who received Tac as primary immunosuppressor. We genotyped three common KCNQ1 SNPs in 145 Spanish patients who received a cadaveric kidney graft and developed NODAT in the first-year post-transplant (the NODAT group), and 260 patients who remained non-diabetics (non-NODAT). In addition, we searched for DNA variants in the whole KCNQ1 coding exons in these patients. SNP rs2237895 (genotype CC) was associated with an increased risk for NODAT in our population (p = 0.008; OR = 1.83, 95% CI = 1.14-2.93), independently of other risk factors as body mass index, recipient age, or tacrolimus dosage. Other KCNQ1 variants were not associated with NODAT in our patients. Our work supported a role for KCNQ1 gene variants as determinants of the risk of developing NODAT among Tac-treated patients.

Tacrolimus causes a blockage of protein secretion which reinforces its immunosuppressive activity and also explains some of its toxic side-effects

BACKGROUND

Tacrolimus (FK506) is a macrolide immunosuppressant drug from the calcineurin inhibitor family, widely used in solid organ and islet cell transplantation, but produces significant side-effects.

OBJECTIVE

This study examined the effect of FK506 on interleukin-2 (IL-2) and insulin secretion, establishing a novel characteristic of this drug that could explain its diverse adverse effects, and developed an experimental model for the simultaneous analysis of mRNA expression and protein secretion affected by this drug.

METHODS

The IL-2 levels when tacrolimus was administered were analysed by Western blot, immunocytochemistry and RT-PCR in a T lymphocyte cellular line (Jurkat) 24 h post-stimulation. The insulin levels when tacrolimus was administered were analysed 4 h after stimulation of glucose-induced insulin secretion in a pancreatic cellular line (MIN6).

RESULTS

The previously published information describes tacrolimus as only capable of partially blocking IL-2 mRNA expression. In our hands, the cellular content of IL-2 is almost undetectable in stimulated Jurkat cells and can be detected in cellular extracts only when the secretory pathway is blocked by brefeldin A (BFA). BFA added 2 h after the beginning of stimulation was able to inhibit IL-2 secretion, without affecting IL-2 mRNA expression. Therefore BFA utilization allowed us to establish a model to analyze the effect on IL-2 secretion, separately from its expression. Tacrolimus added before stimulation inhibits only IL-2 synthesis, but blocks IL-2 protein secretion when added 2 h after stimulation. Similarly, tacrolimus is also capable of blocking the glucose-stimulated secretion of insulin by MIN6 cells. An increase of the intracellular content can be detected concomitantly with a decrease of the hormone measured in the culture medium.

CONCLUSIONS

Results of this study indicate that tacrolimus possesses another important effect in addition to the inhibition of IL-2 gene transcription, namely the ability to act as a general inhibitor of the protein secretory pathway. These results strongly suggest that the diabetogenic effect of the immune suppressant FK506 could be caused by the blockade of insulin secretion. This novel effect also provides an explanation for other side-effects observed in immunosuppressive treatment.

Early pulse pressure and low-grade proteinuria as independent long-term risk factors for new-onset diabetes mellitus after kidney transplantation

Risk factors for new-onset diabetes after transplantation (NODAT) need to be assessed in large cohorts. We retrospectively evaluated the impact of early (3 and 6 months after transplantation) proteinuria, urinary albumin excretion (UAE) and arterial pressure on NODAT in 828 Caucasian renal transplant recipients (median follow-up: 5.3 years; 5832 patient-years). The 10- and 20-year incidence of NODAT was 15.0% and 22.0%, respectively. Low-grade (<1 g/day) (HR: 2.04 [1.25-3.33], p = 0.0042) and very low-grade (<0.3 g/day) (HR: 2.21 [1.32-3.70], p = 0.0025) proteinuria were independent risk factors for NODAT. There was a dose-dependent relationship across UAE categories (increasing risk from normoalbuminuria to macroalbuminuria) with NODAT. Tacrolimus, sirolimus and beta-blockers (HR: 1.86 [1.07-3.22], p = 0.0277) were significantly associated with NODAT even after multiple adjustments, but not diuretics, angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers. Systolic arterial pressure (HR per 10 mmHg: 1.16 [1.03-1.29], p = 0.0126) and pulse pressure (HR: 1.26 [1.12-1.43], p = 0.0002) were associated with NODAT. Only pulse pressure remained significant after adjustments. Patients at highest risks had early proteinuria and pulse pressure >60 mmHg. Early low-grade proteinuria and pulse pressure (in addition to beta-blockers) constitute independent risk factors for NODAT; they may be markers of the metabolic syndrome and/or vascular damage in renal transplant recipients.

Immunosuppressive medications, clinical and metabolic parameters in new-onset diabetes mellitus after kidney transplantation

New-onset diabetes after transplantation (NODAT) is a growing concern in transplantation. All modifiable risk factors are not yet identified. We assessed the relationship between baseline clinical and biochemical parameters and NODAT. Eight-hundred and fifty-seven in-Caucasian renal transplant recipients were included. Charts were individually reviewed. The follow-up was 5.3 years (ranges: 0.25-20.8; 5613 patient-years). The incidence of NODAT was 15.0%, 18.4% and 22.0% at 10, 15 and 20 years following transplantation. Age, body mass index (BMI), glucose (all P < 0.0001) and triglycerides [hazard ratio (HR) per 1 mmol/l: 1.44 [1.17-1.77], P = 0.0006] were potent risk factors whereas steroid withdrawal (HR: 0.69 [0.47-1.01], P = 0.0601) reduced the risk. As compared to cyclosporine, sirolimus (HR: 3.26 [1.63-6.49], P = 0.0008) and tacrolimus (HR: 3.04 [2.02-4.59], P < 0.0001) were risk factors for NODAT. The risk of NODAT was comparable for sirolimus (HR: 2.35 [1.06-5.19], P = 0.0350) and tacrolimus (HR: 2.34 [1.46-3.75], P = 0.0004) after adjustments on age, BMI, glucose and steroid withdrawal; however, unlike sirolimus, tacrolimus remained significant after adjustment on triglycerides. The risk of NODAT appeared similar, but its pathophysiology seemed different in sirolimus- and tacrolimus-treated patients; this observation needs confirmation. However, main independent risk factors were age, BMI, initial glucose and triglycerides.

Immunosuppressive drug-induced diabetes

Post-transplant diabetes mellitus (PTDM) has emerged as a major adverse effect of immunosuppressive drugs (ISD). As recipients of organ transplants survive longer, the complications of diabetes mellitus have assumed greater importance. The predominant factor for causing PTDM by corticosteroids seems to be the aggravation of insulin resistance, however several studies have displayed deleterious effects on insulin secretion and beta-cells. Calcineurin inhibitors induce PTDM by a number of mechanisms, including decreased insulin secretion and a direct toxic effect on the pancreatic beta-cells. Recent in vitro studies stress on the increased apoptosis of beta-cells when exposed to these drugs. Studies involving other immunosuppressive agents (mycophenolate mofetil [MMF], sirolimus) are scarcer and lead to conflicting results, while daclizumab seems to have a neutral effect. Clinical studies have consistently shown a greater potential of tacrolimus to induce PTDM compared with cyclosporine. Reducing PTDM incidence is a feasible goal while using corticosteroid-sparing regimens and/or lower tacrolimus trough levels. In patients developing PTDM, conversion from tacrolimus to cyclosporine could improve or reverse glucose tolerance abnormalities. In the absence of well-designed studies in this specific indication, treatment of PTDM is based on the same principles as type 2 diabetes mellitus. Thiazolidinediones do not display any pharmacological interaction with calcineurin inhibitors, but their safety and efficacy in PTDM need to be confirmed in large-scale randomized trials. Use of sulfonylureas has to be cautious regarding the suspected interaction of some of them with calcineurin inhibitors. If needed, insulin regimens have to be adapted in patients who display the particular glycaemic profile of corticosteroid-induced diabetes. Incretin-based therapies, due to their specific action on beta-cell apoptosis and proliferation, raise promises that have to be confirmed in clinical studies. Until methods for inducing specific graft tolerance become available, immunosuppressive regimens should be tailored to the individual patient on the basis of predictive criteria for the development of PTDM.