Prediabetic States, Subclinical Atheromatosis, and Oxidative Stress in Renal Transplant Patients

Incidence and magnitude of post-transplant cardiovascular disease after pediatric kidney transplantation: Risk factor analysis of 1058 pediatric kidney transplants at the university of Minnesota

BACKGROUND

KT recipients have increased the risk of CVD. The incidence of post-transplant CVEs among pediatric recipients has not been well-characterized.

PATIENTS AND METHODS

Between 1963 and 2015, 884 pediatric (age: 0-17 years old) recipients received 1058 KTs at our institution. The cumulative incidence of CVEs was analyzed. Statistical models were used to estimate risk factors for developing post-transplant CVEs.

RESULTS

Overall median patient survival was 33 years (IQR: 18.7-47). A total of 362 CVEs occurred in 161 (18.3%) patients at a median age of 20.5 years. Arrhythmias (18%) were most common. Cumulative risk of post-transplant CVEs was 9% at 10 years, 17% at 20 years, 25% at 30 years, and 36% at 40 years. Development of post-transplant CVEs was associated with increased mortality (HR 2.25 [95% CI 1.61-3.14]); of those who developed a CVE and died, 22/51 (43.1%) died of CVD. Multivariable risk factors for post-transplant CVEs included a history of pretransplant CVD (aHR 1.92 [1.18-3.13] and graft failure (4.57 [3.13-6.67]).

DISCUSSION

A pretransplant history of CVD and a failed graft are significant risk factors for the development of post-transplant CVE. CVD increases the risk of post-transplant death or graft loss.

A Pilot Study Providing Evidence for a Relationship between a Composite Lifestyle Score and Risk of Higher Carotid Intima-Media Thickness: Is There a Link to Oxidative Stress?

Lifestyle behaviours have been closely linked to the progressive cell damage associated with oxidative stress (OS) and the development of cardiovascular disease (CVD). Early detection of lifestyle-linked OS may therefore be useful in the early identification of prodromal disease. To test this hypothesis, this study assessed the relationship between a comprehensive redox balance lifestyle score (RBLS) and carotid intima-media thickness (CIMT), a recognized marker for CVD, and plasma biomarkers of OS. In a cross-sectional study design, 100 apparently healthy middle-aged participants were asked to complete a comprehensive lifestyle questionnaire, followed by DXA scanning, CIMT ultrasonography, and blood collection. The RBLS was composed of lifestyle components with pro- and antioxidant properties with a higher score indicative of lower oxidative activity. Multiple linear regression and logistic regression analysis were performed for statistical analysis. The RBLS was significantly associated with the risk for increased CIMT that was independent of conventional CVD risk factors (χ²(9) = 35.60, P ≤ 0.001). The adjusted model explained 42.4% of the variance in CIMT. Participants with RBLS below the median were at significantly increased risk of higher CIMT compared to participants with RBLS above the median (OR = 3.60, 95% CI: 1.19–10.88, P = 0.023). Significant associations were also observed between the RBLS, plasma total antioxidant capacity (TAC) (r(99) = 0.28, P = 0.006), hydroperoxide (HPX) (r_s(99) = −0.28, P = 0.005), TAC/HPX ratio (r(98) = 0.41, P ≤ 0.001), γ-glutamyltransferase (r(97) = −0.23, P = 0.024), uric acid (r(98) = −0.20, P = 0.045), and inflammatory C-reactive protein (r_s(97) = −0.25, P = 0.012) and interleukin-1β (r(97) = −0.21, P = 0.040). These findings highlight the importance of identifying the collective influence of lifestyle behaviours on OS activity and its potential to remodel the vascular endothelium.

Effect of Prediabetes on Allograft Survival and Evolution of New-Onset Diabetes After Transplant in Deceased-Donor Kidney Transplant Recipients During Long-Term Follow-Up

OBJECTIVES

This study investigated the effect of prediabetes in long-term deceased-donor renal transplant recipients regarding graft survival, graft function, and evolution of new-onset diabetes after transplant compared with a control group of graft recipients with normal glucose tolerance test results.

MATERIALS AND METHODS

This was a follow-up trial of 187 deceased-donor renal transplant recipients. Based on oral glucose tolerance test results, the cohort was divided into groups A and B, comprising individuals with normal glucose metabolism (n = 130, 69.9%) and individuals with prediabetes (n = 56, 30.1%). Data are shown as means ± standard errors.

RESULTS

Both groups showed similar total transplant survival (116.8 ± 5.4 vs 114.5 ± 7.4 mo; P = .742) and transplant survival measured since oral glucose tolerance test (58.5 ± 1.4 vs 59.5 ± 1.9 mo; P = .990, Mantel-Cox P = .943). Univariate and multivariate Cox regression analyses showed no association of prediabetes with graft loss. Transplant function changes were similar between cohorts (-3 ± 1 vs -5 ± 2 mL/min/1.73 m2 body surface area, using the Chronic Kidney Disease Epidemiology Collaboration formula; P = .538). At 5-year follow-up, recipients with prediabetes had higher hemoglobin A1c than controls (5.99% ± 0.10% vs 5.67% ± 0.04%; P = .002). Prediabetes was associated with a 4.5-fold increased hazard of new-onset diabetes after transplant (P = .021).

CONCLUSIONS

Prediabetes was associated with a 4.5-fold higher hazard ratio for new-onset diabetes after transplant but not with reduced graft function or survival.

Causes of changes in carotid intima-media thickness: a literature review

Atherosclerosis causes significant morbidity and mortality. Carotid intima-media thickness (CIMT) predicts future cardiovascular and ischaemic stroke incidence. CIMT, a measure of atherosclerotic disease, can be reliably determined in vivo by carotid ultrasound. In this review, we determined that CIMT is associated with traditional cardiovascular risk factors such as age, sex, race, smoking, alcohol consumption, habitual endurance exercise, blood pressure, dyslipidemia, dietary patterns, risk-lowering drug therapy, glycemia, hyperuricemia, obesity-related anthropometric parameters, obesity and obesity-related diseases. We also found that CIMT is associated with novel risk factors, including heredity, certain genotypic indices, anthropometric cardiovascular parameters, rheumatoid arthritis, immunological diseases, inflammatory cytokines, lipid peroxidation, anthropometric hemocyte parameters, infectious diseases, vitamin D, matrix metalloproteinases, and other novel factors and diseases. However, the conclusions are inconsonant; the underlying causes of these associations remain to be further explored.

Artery Wall Assessment Helps Predict Kidney Transplant Outcome

Background

Kidney transplant recipients have high cardiovascular risk, and vascular inflammation may play an important role. We explored whether the inflammatory state in the vessel wall was related to carotid intima-media thickness (c-IMT) and patient survival following kidney transplantation.

Methods

In this prospective observational cohort study we measured c-IMT and expression of proinflammatory cytokines and adhesion molecules in the inferior epigastric artery in 115 kidney transplant candidates. Another c-IMT measurement was done 1-year post-transplantation in 107. By stepwise multiple regression analysis we explored factors associated with baseline c-IMT and their changes over time. Multivariate Cox regression analysis was constructed to identify risk factors for mortality.

Results

A worse cardiovascular profile (older age, smoker, diabetic, carotid plaque, systolic blood pressure and vascular calcification) and higher VCAM-1 levels were found in patients in the highest baseline c-IMT tertile, who also had a worse survival. Factors independently related to baseline c-IMT were age (β=0.369, P<0.0001), fasting glucose (β=0.168, P=0.045), smoking (β=0.228, P=0.003) and VCAM-1 levels (β=0.244, P=0.002). Independent factors associated with c-IMT measurement 1-year post-transplantation were baseline c-IMT (β=-0.677, P<0.0001), post-transplant diabetes (β=0.225, P=0.003) and triglycerides (β=0.302, P=0.023). Vascular VCAM-1 levels were associated with increased risk of mortality in bivariate and multivariate Cox regression. Notably, nearly 50% of patients showed an increase or maintenance of high c-IMT 1 year post-transplantation and these patients experienced a higher mortality (13 versus 3.5%; P=0.021).

Conclusion

A worse cardiovascular profile and a higher vascular VCAM-1 protein levels at time of KT are related to subclinical atheromatosis. This could lead to a higher post-transplant mortality. Pre-transplant c IMT, post-transplant diabetes and triglycerides at 1-year post-transplantation may condition a high c-IMT measurement post-transplantation, which may decrease patient survival.

Glutathione S-transferase M1 gene polymorphism is associated with susceptibility to impaired long-term allograft outcomes in renal transplant recipients

BACKGROUND

Despite improved post-transplantation care, progress in long-term kidney allograft survival of diabetic renal transplant recipients (pre-DM RTR) is worse than that of non-diabetic recipients (non-DM). We hypothesized that there are other potential risk factors, that predispose RTR to adverse renal allograft outcomes.

METHODS

A total of 323 transplant recipients who underwent renal transplantation between March 2000 and January 2008 were recruited. The composite end-point consisted of serum creatinine (SCr) doubling, graft failure, and death. Baseline clinical data were recorded, and polymerase chain reaction-restriction fragment length polymorphism measurements of interleukin (IL)-4, IL-10, IL-23, glutathione S-transferase (GST)A1, GSTM1, and GSTP1 polymorphisms were determined. The risk factors for developing the primary outcome were analyzed among these clinical and genetic factors.

RESULTS

Within a mean follow-up of 71.1 ± 24 months, there were 43 (13.3 %) patients with the primary outcome. Stepwise multivariate Cox regression analysis was used to determine the risk factors for the primary outcome of RTR. Renal transplant recipients who possessed the GSTM1 null genotype had a 2.2-fold risk (95 % CI: 1.10-4.40; P = 0.026) of developing the primary outcome. Additionally, RTR that had DM before transplantation (aHR: 3.31; 95 % CI: 1.77-6.20; P = 0.0002) or changes in SCr 6 to 12 months after transplantation (aHR: 2.83; 95 % CI: 1.29-6.19; P = 0.0095) had an increased risk of developing the primary outcome.

CONCLUSIONS

In addition to the adverse role played by DM, the GSTM1 null genotype also has an unfavorable influence on the long-term allograft outcome of RTR.

New-onset diabetes after renal transplantation: diagnosis, incidence, risk factors, impact on outcomes, and novel implications

OBJECTIVE

New-onset diabetes after transplantation (NODAT) is a multifactorial, complex metabolic disorder associated with impaired long-term graft function, reduced recipient survival, and increased risks of cardiovascular disease and infectious complications. The impact of NODAT is generally underestimated partly due to the inconsistent criteria that have been previously used for its diagnosis and to the generally short observation periods. The aim of this article was to review the recent literature on NODAT and to highlight the novel implications.

FINDINGS

The 2010 American Diabetes Association guidelines provide useful, simplified criteria to unify the diagnosis including application of hemoglobin A1C levels. We sought to establish the impact of various modifiable and nonmodifiable risk factors. A vast number of papers have examined the effects of immunosuppressive medications on the development of NODAT: Neither calcineurin inhibitor nor sirolimus (SRL) or steroids seems to be innocent of contributing to it. Immunosuppressants account for 74% of the occurrence of NODAT. Among modifiable risk factors, obesity is independent and significant, with great prevalence in the population. In additional to lifestyle modifications, the role of bariatric surgery (BS) either before or after transplantation is highlighted herein as a strategy to reduce disease in the view of the results among overweight, nontransplanted patients.

SUMMARY

Because of the strong association between high glucose values in the early posttransplant period and the development of NODAT, the condition must be recognized early after (or even before) transplantation by intensive screening. Patients at risk for NODAT must modify appropriate risk factors and particularly undergo pretransplant planning and/or posttransplant adjustment individualizing immunosuppressive therapy to mitigate the risk of this serious complication.