Metabolic syndrome definitions and components in predicting major adverse cardiovascular events after kidney transplantation

Clinical implications of changes in metabolic syndrome status after kidney transplantation: a nationwide prospective cohort study

BACKGROUND

Metabolic syndrome (MetS) is prevalent in patients with end-stage kidney disease, and kidney transplantation is expected to modify the metabolic status. However, whether changes in metabolic status at the time of transplantation affect recipient outcomes remains unclear.

METHODS

We analyzed 4187 recipients registered in a nationwide prospective cohort from 2014 to 2020. MetS was defined as the presence of three or more components of the metabolic syndrome. Patients were classified based on the pre- and post-transplant MetS status: MetS-free, MetS-developed, MetS-recovered and MetS-persistent. Study outcomes were occurrence of death-censored graft loss and a composite of cardiovascular events and death.

RESULTS

Among recipients without pre-transplant MetS, 19.6% (419/2135) developed post-transplant MetS, and MetS disappeared in 38.7% (794/2052) of the recipients with pre-transplant MetS. Among the four groups, the MetS-developed group showed the worst graft survival rate, and the MetS-persistent group had a poorer composite event-free survival rate. Compared with the MetS-free group, the MetS-developed group was associated with an increased risk of graft loss [adjusted hazard ratio (aHR) 2.35; 95% confidence interval (CI) 1.17-4.98] and the risk of graft loss increased with increasing numbers of dysfunctional MetS components. MetS-persistent was associated with increased risks of cardiovascular events and death (aHR 2.46; 95% CI 1.12-5.63), but changes in the number of dysfunctional MetS components was not.

CONCLUSION

Kidney transplantation significantly alters the metabolic status. Newly developed MetS after transplantation was associated with an increased risk of graft loss, whereas persistent MetS exposure before and after transplantation was associated with increased risks cardiovascular events and patient survival.

Metabolic Syndrome and Dietary Intake are Associated With Quality of Life in Kidney Transplant Recipients

BACKGROUND

Although metabolic syndrome (MetS) is a significant risk factor, and dietary intake may affect the quality of life (QoL) of kidney transplant recipients (KTRs), the association between them are unclear. This study identified MetS and nutritional factors associated with the QoL of KTRs.

METHODS

This study reports baseline data from a longitudinal study that was conducted at a hospital in Vietnam. KTRs aged ≥18 years and >3 months post-transplantation were recruited. Assessments included sociodemographic and blood biomarkers. Dietary intake was estimated from 24-hour recalls. A Short Form-36 Health Survey, comprising physical (PCS) and mental component summaries (MCS), was administered to assess QoL. Multivariate linear regression models were performed.

RESULTS

The study included 106 patients (79 men) with a mean age of 43.2 years (± 11.9). Mean duration after kidney transplantation was 28.5 months (± 14.9). Patients with MetS had 6.43 lower PCS score (P < .05) and 3.20 lower MCS score (P < .05) than their counterparts without MetS. Calcium intake (β = -0.01; 95% CI, -0.03 to 0.00) and inadequate protein (β = -14.8; 95% CI, -23 to -6.65) were negatively associated with PCS score. MCS score was negatively associated with calcium intake (β = -0.02; 95% CI, -0.04 to -0.01) and inadequate protein intake (β = -15.1; 95% CI, -24.3 to -5.86), and positively associated with fat intake (β = 0.43, 95% CI, 0.02-0.85).

CONCLUSIONS

MetS and poor dietary intake are independently associated with the QoL of KTRs. Nutritional intervention plans developed specifically for the recipients will improve dietary intake, reduce the incidence of MetS, and help enhance QoL.

Assessment and management of obesity and metabolic syndrome in children with CKD stages 2-5 on dialysis and after kidney transplantation-clinical practice recommendations from the Pediatric Renal Nutrition Taskforce

Obesity and metabolic syndrome (O&MS) due to the worldwide obesity epidemic affects children at all stages of chronic kidney disease (CKD) including dialysis and after kidney transplantation. The presence of O&MS in the pediatric CKD population may augment the already increased cardiovascular risk and contribute to the loss of kidney function. The Pediatric Renal Nutrition Taskforce (PRNT) is an international team of pediatric renal dietitians and pediatric nephrologists who develop clinical practice recommendations (CPRs) for the nutritional management of children with kidney diseases. We present CPRs for the assessment and management of O&MS in children with CKD stages 2-5, on dialysis and after kidney transplantation. We address the risk factors and diagnostic criteria for O&MS and discuss their management focusing on non-pharmacological treatment management, including diet, physical activity, and behavior modification in the context of age and CKD stage. The statements have been graded using the American Academy of Pediatrics grading matrix. Statements with a low grade or those that are opinion-based must be carefully considered and adapted to individual patient needs based on the clinical judgment of the treating physician and dietitian. Research recommendations are provided. The CPRs will be periodically audited and updated by the PRNT.

Malnutrition in Pediatric Chronic Cholestatic Disease: An Up-to-Date Overview

Despite recent advances, the causes of and effective therapies for pediatric chronic cholestatic diseases remain elusive, and many patients progress to liver failure and need liver transplantation. Malnutrition is a common complication in these patients and is a well-recognized, tremendous challenge for the clinician. We undertook a narrative review of both recent and relevant older literature, published during the last 20 years, for studies linking nutrition to pediatric chronic cholestasis. The collected data confirm that malnutrition and failure to thrive are associated with increased risks of morbidity and mortality, and they also affect the outcomes of liver transplantation, including long-term survival. Malnutrition in children with chronic liver disease is multifactorial and with multiple potential nutritional deficiencies. To improve life expectancy and the quality of life, patients require careful assessments and appropriate management of their nutritional statuses by multidisciplinary teams, which can identify and/or prevent specific deficiencies and initiate appropriate interventions. Solutions available for the clinical management of these children in general, as well as those directed to specific etiologies, are summarized. We particularly focus on fat-soluble vitamin deficiency and malnutrition due to fat malabsorption. Supplemental feeding, including medium-chain triglycerides, essential fatty acids, branched-chain amino acids, and the extra calories needed to overcome the consequences of anorexia and high energy requirements, is reviewed. Future studies should address the need for further improving commercially available and nutritionally complete infant milk formulae for the dietary management of this fragile category of patients. The aid of a specialist dietitian, educational training regarding nutritional guidelines for stakeholders, and improving family nutritional health literacy appear essential.

Managing cardiovascular disease risk in South Asian kidney transplant recipients

South Asians (SA) are at higher cardiovascular risk than other ethnic groups, and SA kidney transplant recipients (SA KTR) are no exception. SA KTR experience increased major adverse cardiovascular events both early and late post-transplantation. Cardiovascular risk management should therefore begin well before transplantation. SA candidates may require aggressive screening for pre-transplant cardiovascular disease (CVD) due to their ethnicity and comorbidities. Recording SA ethnicity during the pre-transplant evaluation may enable programs to better assess cardiovascular risk, thus allowing for earlier targeted peri- and post-transplant intervention to improve cardiovascular outcomes. Diabetes remains the most prominent post-transplant cardiovascular risk factor in SA KTR. Diabetes also clusters with other metabolic syndrome components including lower high-density lipoprotein cholesterol, higher triglycerides, hypertension, and central obesity in this population. Dyslipidemia, metabolic syndrome, and obesity are all significant CVD risk factors in SA KTR, and contribute to increased insulin resistance. Novel biomarkers such as adiponectin, apolipoprotein B, and lipoprotein (a) may be especially important to study in SA KTR. Focused interventions to improve health behaviors involving diet and exercise may especially benefit SA KTR. However, there are few interventional clinical trials specific to the SA population, and none are specific to SA KTR. In all cases, understanding the nuances of managing SA KTR as a distinct post-transplant group, while still screening for and managing each CVD risk factor individually in all patients may help improve the long-term success of all kidney transplant programs catering to multi-ethnic populations.

Association between preoperative lipid profiles and new-onset diabetes after transplantation in Chinese kidney transplant recipients: A retrospective cohort study

Background

This study investigated the association between the preoperative lipid profiles and new‐onset diabetes after transplantation (NODAT) in Chinese kidney transplant recipients (KTRs).

Methods

In this study, of 1140 KTRs registered between January 1993 and March 2018 in Zhongshan Hospital, Fudan University, 449 were enrolled. Clinical data, obtained through a chart review of the patient records in the medical record system, were evaluated, and NODAT was diagnosed based on the American Diabetes Association guidelines. Multivariate Cox regression analysis was conducted to determine whether the preoperative lipid profiles in KTRs were independently associated with NODAT incidence. The preoperative lipid profiles were analyzed as continuous variables and grouped into tertiles. Smooth curve fitting was used to confirm the linear associations.

Results

During a median follow‐up of 28.03 (interquartile range 12.00–84.23) months, 104 of the 449 (23.16%) participants developed NODAT. The multivariate model analysis, adjusted for all potential covariates, showed that increased values of the following parameters were associated with NODAT (hazard ratio, 95% confidence interval): preoperative total cholesterol (TC; 1.25, 1.09–1.58, p = 0.0495), low‐density lipoprotein cholesterol (LDL‐C; 1.33, 1.02–1.75, p = 0.0352), non‐high‐density lipoprotein cholesterol (non‐HDL‐C; 1.41, 1.09–1.82, p = 0.0084), TC/HDL‐C (1.28, 1.06–1.54, p = 0.0109), and non‐HDL‐C/HDL‐C (1.26, 1.05–1.52, p = 0.0138). However, the association between the preoperative triglyceride, HDL‐C, or TG/HDL‐C and NODAT was not significant.

Conclusions

Preoperative TC, LDL‐C, non‐HDL‐C, TC/HDL‐C, and non‐HDL‐C/HDL‐C were independent risk factors for NODAT.

Serum Apolipoprotein B and A1 Concentrations Predict Late-Onset Posttransplant Diabetes Mellitus in Prevalent Adult Kidney Transplant Recipients

Background

Glucose metabolism links closely to cholesterol metabolism. Posttransplant diabetes mellitus (PTDM) adversely affects posttransplant outcomes, but its risk factors in relation to cholesterol metabolism have not been fully delineated. The apolipoprotein B/A1 (Apo B/A1) ratio, which is associated with insulin resistance, has not been evaluated in kidney transplant recipients as a risk factor for PTDM.

Objective

The objective of this study was to determine whether serum apolipoprotein profiles predict late PTDM, defined as a new onset diabetes occurring greater than 3 months posttransplant.

Design

Retrospective chart review of a prevalent population of kidney transplant recipients.

Setting

Large transplant center in Ontario, Canada.

Patients

We identified 1104 previously nondiabetic adults who received a kidney transplant between January 1, 1998, and December 1, 2015, and were followed at 1 transplant center.

Measurements

Recipients provided testing for serum apolipoprotein B (Apo B) and apolipoprotein A1 (Apo A1) concentrations from 2010, either at 3 months posttransplant for new transplant recipients or the next clinic visit for prevalent recipients. Late PTDM defined using Canadian Diabetes Association criteria as occurring ≥3 months posttransplant was recorded until May 1, 2016.

Methods

All analyses were conducted with R, version 3.4.0 (The R Foundation for Statistical Computing). Comparisons were made using Student t test, Fisher exact test or chi-square test, Kaplan-Meier methodology with the logrank test, or Cox proportional hazards analysis as appropriate. Covariates for the multivariate Cox proportional hazards models of PTDM as the outcome variable were selected based on significance of the univariate associations and biological plausibility.

Results

There were 53 incident late PTDM cases, or 1.71 cases per 100 patient-years. Incident late PTDM differed between the highest and lowest quartiles for Apo B/A1 ratio, 2.47 per 100 patient-years vs 0.88 per 100 patient-years (P = .005 for difference). In multiple Cox regression analysis, first measured serum Apo B/A1 concentration better predicted subsequent PTDM than low-density lipoprotein cholesterol (LDL-C; hazard ratio [HR] = 7.80 per unit increase, P = .039 vs HR = 1.05 per unit increase, P = .774). Non-high-density lipoprotein cholesterol (HDL-C) concentrations also did not predict PTDM (P = .136). By contrast to Apo B, Apo A1 was protective against PTDM in statin users (HR = 0.17 per unit increase, P = .016).

Limitations

Posttransplant diabetes mellitus cases occurring before apolipoprotein testing was implemented were not included in the analysis.

Conclusions

Apolipoproteins B and A1 better predict late PTDM than conventional markers of cholesterol metabolism.

Center variation in screening for and management of metabolic syndrome in pediatric liver transplant recipients: A survey of SPLIT centers

INTRODUCTION

PTMS-a clustering of hypertension, dyslipidemia, glucose intolerance/diabetes, and obesity-is increasingly recognized as a contributor to long-term morbidity after transplant. We sought to describe pediatric liver transplant center protocols and provider practices in screening for and managing these conditions.

METHODS

Cross-sectional survey of pediatric liver transplant providers from centers that participate in Studies of Liver Transplantation (SPLIT).

RESULTS

Of 49 survey respondents from 39 centers, 64% were hepatologists or surgeons, 18% nurses/NPs/PAs, 12% coordinators, and 4% other. All providers felt that pediatric liver transplant recipients should be routinely screened for PTMS components. For each condition, at least 70% felt that the liver transplant team should be primarily responsible for routine screening. For each condition, at least 30% of providers reported that their center had no standardized protocol for screening. For diagnostic evaluation and initial management, >60% of providers reported that their center had no standardized protocol for glucose intolerance/diabetes, dyslipidemia, or obesity. Almost 40% had no standardized workup or initial management protocol for hypertension or chronic kidney disease. Of centers that did have screening or workup protocols, most were based on existing center practice, provider consensus, or informal review of published evidence. Screening tools, treatment steps, and thresholds for referral to another specialist varied widely.

CONCLUSIONS

Transplant providers intend to screen for and initiate management of PTMS components in these children, but protocols and practices vary substantially. This highlights opportunities for multi-center collaboration on protocols or interventions to improve screening and management.

Interleukin-2 receptor antagonists: Protective factors against new-onset diabetes after renal transplantation

BACKGROUND

The aim of the present study was to examine the association between interleukin-2 receptor antagonists (IL-2Ra) and new-onset diabetes after transplantation (NODAT) among renal transplant recipients (RTRs).

METHODS

Between January 1993 and March 2014, 915 patients underwent renal transplantation at Zhongshan Hospital. In all, 557 RTRs were included in the present retrospective cohort study. The incidence of NODAT in this cohort was determined and multivariate Cox regression analysis was used to evaluate the risk factors for NODAT and to show the association between IL-2Ra use and NODAT development among RTRs. The cumulative incidence of NODAT was compared between groups treated with or without IL-2Ra.

RESULTS

The mean ±SD postoperative follow-up was 5.08 ±3.17 years. The incidence of NODAT at the end of follow-up was 20.3%. After adjusting for potential confounders in the multivariate logistic regression (i.e. age, sex, body mass index, history of smoking, family history of diabetes, duration of dialysis, type of dialysis, donor type, recovery of graft function, acute rejection, hepatitis B or C or cytomegalovirus infection, fasting plasma glucose levels before and 1 week after transplantation, preoperative total cholesterol and triglyceride levels, daily dose of glucocorticoid, immunosuppressive regimen type, and immunosuppressant concentration after transplantation), IL-2Ra use was found to be related to a reduced incidence of NODAT.

CONCLUSIONS

Use of IL-2Ra is associated with protection against the development of NODAT in RTRs.

The Role of Bariatric Surgery in Abdominal Organ Transplantation-the Next Big Challenge?

Obesity is linked to inferior transplant outcome. Bariatric surgery (BS) is an established treatment of morbid obesity. We provide an overview on BS in the field of kidney (KT) and liver transplantation (LT). In end-stage renal disease (ESRD) and KT patients, BS seems safe and feasible. Complication rates were slightly higher compared to the non-transplant population, whereas weight loss and improvement of comorbidities were comparable. Sleeve gastrectomy (SG) was the preferred procedure before KT and superior to gastric bypass (GB) in regard to mortality and morbidity. If conducted after KT, both procedures showed comparable results. BS before LT was associated with high complication rates, in particular after GB. Albeit distinct complications, SG conducted after LT showed the best results. Immunosuppression (IS) changes after BS were rare.

Statin therapy for preventing cardiovascular diseases in patients treated with tacrolimus after kidney transplantation

Background

Lipid abnormalities are prevalent in tacrolimus-treated patients. The aim of the study was to evaluate the preventive effects of statin therapy on major adverse cardiovascular events (MACE) in patients treated with tacrolimus-based immunosuppression after kidney transplantation (KT), and to identify the risk factors.

Methods

This observational cohort study included adult patients who underwent KT and were treated with tacrolimus. Patients who received any lipid-lowering agents except statins, or had a history of immunosuppressant use before transplantation were excluded. The primary outcome was the adjusted risk of the first occurrence of MACE. The secondary outcomes included the risk of individual cardiovascular disease (CVD) and changes in cholesterol level. Subgroup analyses were performed in the statin-user group according to the dosage and/or type of statin.

Results

Compared with the control group (n=73), the statin-users (n=92) had a significantly reduced risk of MACE (adjusted HR, 0.31; 95% CI, 0.13–0.74). In the Cox regression analysis, old age, history of CVD, and comorbid hypertension were identified as independent factors associated with increased MACE. The total cholesterol levels were not significantly different between the two groups. Subjects with higher cumulative defined daily dose of statins had significantly lower risks of MACE.

Conclusion

Statin therapy in patients treated with tacrolimus after KT significantly lowered the risk of MACE. Long-term statin therapy is clearly indicated in older kidney transplant recipients for secondary prevention.

Five myths about variable selection

Multivariable regression models are often used in transplantation research to identify or to confirm baseline variables which have an independent association, causally or only evidenced by statistical correlation, with transplantation outcome. Although sound theory is lacking, variable selection is a popular statistical method which seemingly reduces the complexity of such models. However, in fact, variable selection often complicates analysis as it invalidates common tools of statistical inference such as P-values and confidence intervals. This is a particular problem in transplantation research where sample sizes are often only small to moderate. Furthermore, variable selection requires computer-intensive stability investigations and a particularly cautious interpretation of results. We discuss how five common misconceptions often lead to inappropriate application of variable selection. We emphasize that variable selection and all problems related with it can often be avoided by the use of expert knowledge.

Diabetes mellitus, hypertension and frailty: A population-based, cross-sectional study of Mexican older adults

AIM

Chronic diseases are frequent in older adults, particularly hypertension and diabetes. The relationship between frailty and these two conditions is still unclear. The aim of the present analyses was to explore the association between frailty with diabetes and hypertension in Mexican older adults.

METHODS

Analyses of the Mexican Health and Nutrition Survey, a cross-sectional survey, are presented. Data on diabetes and hypertension were acquired along with associated conditions (time since diagnosis, pharmacological treatment, among others). A 36-item frailty index was constructed and rescaled to z-values (individual scores minus population mean divided by one standard deviation). Multiple linear regression models were carried out, adjusted for age and sex.

RESULTS

From 7164 older adults, 54.8% were women, and their mean age was 70.6 years with a mean frailty index score of 0.175. The prevalence of diabetes was of 22.2%, and 37.3% for hypertension. An independent association between diabetes, hypertension or both conditions (coefficients 0.28, 0.4 and 0.63, respectively, P < 0.001) with frailty was found. Having any diabetic complication was significantly associated with frailty with a coefficient of 0.55 (95% CI 0.45-0.65, P < 0.001) in the adjusted model. The number of years since diagnosis was also associated with frailty for both conditions.

CONCLUSIONS

Diabetes and hypertension are associated with frailty. In addition, an incremental association was found when both conditions were present or with worse associated features (any complication, more time since diagnosis). Frailty should be of particular concern in populations with a high prevalence of these conditions. Geriatr Gerontol Int 2017; 17: 925-930.

Post-transplant dyslipidemia: Mechanisms, diagnosis and management

Post-transplant dyslipidemia is highly prevalent and presents unique management challenges to the clinician. The two major outcomes to consider with post-transplant therapies for dyslipidemia are preserving or improving allograft function, and reducing cardiovascular risk. Although there are other cardiovascular risk factors such as graft dysfunction, hypertension, and diabetes, attention to dyslipidemia is warranted because interventions for dyslipidemia have an impact on reducing cardiac events in clinical trials specific to the transplant population. Dyslipidemia is not synonymous with hyperlipidemia. Numerous mechanisms exist for the occurrence of post-transplant dyslipidemia, including those mediated by immunosuppressive drug therapy. Statin therapy has received the most attention in all solid organ transplant recipient populations, although the effect of proper dietary advice and adjuvant pharmacological and non-pharmacological agents should not be dismissed. At all stages of treatment appropriate monitoring strategies for side effects should be implemented so that the benefits from these therapies can be achieved. Clinicians have a choice when there is a conflict between various transplant society and lipid society guidelines for therapy and targets.

Relationships Between Metabolic Syndrome, Microalbuminuria, and C-Reactive Protein in Turkish Kidney Transplant Recipients

AIM

The aims of this study were to report the prevalence of metabolic syndrome (MS) in a cohort of Turkish kidney transplant recipients and to define the relationships between MS, microalbuminuria and C-reactive protein (CRP), which are cardiovascular risk factors, in kidney transplant setting.

METHODS

This cross sectional study included 170 adult renal transplantation recipients with a mean follow-up of 53.1 ± 49.9 months. The diagnosis of MS was made according to the National Cholesterol Education Program-Adult Treatment Panel III (NCEP-ATP III) criteria. Microalbuminuria was defined as a urinary albumin/creatinine ratio of 30-300 mg/g. CRP levels ≥6.0 were classified as high CRP.

RESULTS

Mean age was 39.3 ± 11 years. The prevalence of MS was 45.8% (n = 78). The prevalence of microalbuminuria was not different in patients with MS compared to those without MS (39.7% vs 37%, P = .428). In multivariate logistic regression analyses, systolic blood pressure (SBP) (odds ratio 1.68; 95% confidence interval [CI] 1.12-2.52; P = .011) and high fasting glucose (odds ratio 2.82; 95% confidence interval [CI] 1.16-6.86; P = .022) were significantly associated with microalbuminuria. When patients with MS and high CRP were compared with patients with normal CRP and without MS, microalbuminuria did not differ between the groups (P = .213).

CONCLUSION

The prevalence of MS in our kidney recipient cohort was found to be increased compared to general population. MS was not related to increased prevalence of microalbuminuria, even when combined with high CRP. Microalbuminuria was associated with elevated SBP and hyperglycemic status.