Computed tomography-based intermuscular adipose tissue analysis and its predicting role in post-kidney transplantation diabetes mellitus

BACKGROUND

While body mass index (BMI) is the most widely used indicator as a measure of obesity factors in post-transplantation diabetes mellitus (PTDM), body composition is a more accurate measure of obesity. This study aims to investigate the effects of Computed tomography (CT)--based morphemic factors on PTDM and establish a prediction model for PTDM after kidney transplantation.

METHODS

The pre-transplant data and glycemic levels of kidney transplant recipients (June 2021 to July 2023) were retrospectively and prospectively collected. Univariate and multivariate analyses were conducted to analyze the relationship between morphemic factors and PTDM at one month, six months, and one year after hospital discharge. Subsequently, a one-year risk prediction model based on morphemic factors was developed.

RESULTS

The study consisted of 131 participants in the one-month group, where Hemoglobin A1c (HbA1c) (p = 0.02) was identified as the risk factor for PTDM. In the six-month group, 129 participants were included, and the intermuscular adipose tissue (IMAT) area (p = 0.02) was identified as the risk factor for PTDM. The one-year group had 128 participants, and the risk factors for PTDM were identified as body mass index (BMI) (p = 0.02), HbA1c (p = 0.01), and IMAT area (p = 0.007). HbA1c (%) and IMAT area were included in the risk prediction Model for PTDM in the one-year group with AUC = 0.716 (95 % CI 0.591-0.841, p = 0.001).

CONCLUSIONS

Compared to BMI and other morphemic factors, this study demonstrated that the IMAT area was the most potential predictor of PTDM.

CLINICAL TRIAL NOTATION

Chictr.org (ChiCTR2300078639).

The Emerging Role and Clinical Applications of Morphomics in Diagnostic Imaging

Analytic morphomics refers to the accurate measurement of specific biological markers of human body composition in diagnostic medical imaging. The increasing prevalence of disease processes that alter body composition including obesity, cachexia, and sarcopenia has generated interest in specific targeted measurement of these metrics to possibly prevent or reduce negative health outcomes. Typical morphomic measurements include the area and density of muscle, bone, vascular calcification, visceral fat, and subcutaneous fat on a specific validated axial level in the patient's cross-sectional diagnostic imaging. A distinct advantage of these measurements is that they can be made retrospectively and opportunistically with pre-existing datasets. We provide a narrative review of the current state of art in morphomics, but also consider some potential future directions for this exciting field. Imaging based quantitative assessment of body composition has enormous potential across the breadth and scope of modern clinical practice. From risk stratification to treatment planning, and outcome assessment, all can be enhanced with the use of analytic morphomics. Moreover, it is likely that many new opportunities for personalized medicine will emerge as the field evolves. As radiologists, embracing analytic morphomics will enable us to contribute added value in the care of every patient.

New-Onset Diabetes Mellitus after Kidney Transplantation

New-Onset Diabetes Mellitus after Transplantation (NODAT) emerges as a prevalent complication post-kidney transplantation, with its incidence influenced by variations in NODAT definitions and follow-up periods. The condition's pathophysiology is marked by impaired insulin sensitivity and β-cell dysfunction. Significant risk factors encompass age, gender, obesity, and genetics, among others, with the use of post-transplant immunosuppressants intensifying the condition. NODAT's significant impact on patient survival and graft durability underscores the need for its prevention, early detection, and treatment. This review addresses the complexities of managing NODAT, including the challenges posed by various immunosuppressive regimens crucial for transplant success yet harmful to glucose metabolism. It discusses management strategies involving adjustments in immunosuppressive protocols, lifestyle modifications, and pharmacological interventions to minimize diabetes risk while maintaining transplant longevity. The importance of early detection and proactive, personalized intervention strategies to modify NODAT's trajectory is also emphasized, advocating for a shift towards more anticipatory post-transplant care.

Changes in glucose metabolism among recipients with diabetes 1 year after kidney transplant: a multicenter 1-year prospective study

Background

Diabetes mellitus is a common and crucial metabolic complication in kidney transplantation. It is necessary to analyze the course of glucose metabolism in patients who already have diabetes after receiving a transplant. In this study, we investigated the changes in glucose metabolism after transplantation, and a detailed analysis was performed on some patients whose glycemic status improved.

Methods

The multicenter prospective cohort study was conducted between 1 April 2016 and 31 September 2018. Adult patients (aged 20 to 65 years) who received kidney allografts from living or deceased donors were included. Seventy-four subjects with pre-transplant diabetes were followed up for 1 year after kidney transplantation. Diabetes remission was defined as the results of the oral glucose tolerance test performed one year after transplantation and the presence or absence of diabetes medications. After 1-year post-transplant, 74 recipients were divided into the persistent diabetes group (n = 58) and the remission group (n = 16). Multivariable logistic regression was performed to identify clinical factors associated with diabetes remission.

Results

Of 74 recipients, 16 (21.6%) showed diabetes remission after 1-year post-transplant. The homeostatic model assessment for insulin resistance numerically increased in both groups throughout the first year after transplantation and significantly increased in the persistent diabetes group. The insulinogenic index (IGI₃₀) value significantly increased only in the remission group, and the IGI₃₀ value remained low in the persistent diabetes group. In univariate analysis, younger age, newly diagnosed diabetes before transplantation, low baseline hemoglobin A1c, and high baseline IGI₃₀ were significantly associated with remission of diabetes. After multivariate analysis, only newly diagnosed diabetes before transplantation and IGI₃₀ at baseline were associated with remission of diabetes (34.00 [1.192-969.84], P = 0.039, and 17.625 [1.412-220.001], P = 0.026, respectively).

Conclusion

In conclusion, some kidney recipients with pre-transplant diabetes have diabetes remission 1 year after transplantation. Our prospective study revealed that preserved insulin secretory function and newly diagnosed diabetes at the time of kidney transplantation were favorable factors for which glucose metabolism did not worsen or improve 1 year after kidney transplantation.

Metabolic-Related Index to Predict Post-Transplantation Diabetes Mellitus After Kidney Transplantation

Metabolic-related markers are novel tools for assessing insulin resistance. Early identification of post-transplantation diabetes mellitus (PTDM) before hyperglycemia can be helpful to attenuate the rapid development of diabetic complications. This article aims to explore the convenient and inexpensive values of metabolic-related markers, including TyG, TyG-BMI, TG/HDL-C, and non-HDL-C/HDL-C for predicting PTDM. The data of 191 kidney transplant recipients in our center were collected retrospectively. The association between TyG, TyG-BMI, TG/HDL-C, non-HDL-C/HDL-C and the risk of PTDM was examined by the area under the curve and logistic regression analyses. During 6 months follow-up, 12.04% of KT recipients developed PTDM, and significantly higher values of TyG-BMI, TyG, and non-HDL-C/HDL-C was found in patients with PTDM than in nondiabetic patients, especially among the recipients taking tacrolimus, regardless of gender. The incidence of PTDM increased along with the values of TyG or TyG-BMI. After adjusting for multiple potential factors, recipients with the highest trisector of TyG or TyG-BMI still had a higher risk of PTDM morbidity. In conclusion, TyG, TyG-BMI, TG/HDL-C and non-HDL-C/HDL-C can be used as cost-effective and promising monitors to identify individuals at high risk of PTDM, and TyG-BMI was the best alternative marker among the four markers.

Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitors Use for Atherogenic Dyslipidemia in Solid Organ Transplant Patients

Dyslipidemia is a widespread risk factor in solid organ transplant patients, due to many reasons, such as the use of immunosuppressive drugs, with a consequent increase in cardiovascular diseases in this population. PCSK9 is an enzyme mainly known for its role in altering LDL levels, consequently increasing cardiovascular risk. Monoclonal antibody PCSK9 inhibitors demonstrated remarkable efficacy in the general population in reducing LDL cholesterol levels and preventing cardiovascular disease. In transplant patients, these drugs are still poorly used, despite having comparable efficacy to the general population and giving fewer drug interactions with immunosuppressants. Furthermore, there is enough evidence that PCSK9 also plays a role in other pathways, such as inflammation, which is particularly dangerous for graft survival. In this review, the current evidence on the function of PCSK9 and the use of its inhibitors will be discussed, particularly in transplant patients, in which they may provide additional benefits.

Body Fat Distribution, Adipocytokines Levels and Variability in Associated Genes and Kidney Transplant Outcomes

Introduction: Body fat distribution is known to contribute to a variety of pathologies. Research Questions: We aimed to assess whether this distribution is associated with clinical outcomes in renal transplant recipients (RTR) and to examine its relationship with leptin and adiponectin gene variants and plasma concentrations. Design: Bioelectrical impedance analyses were performed in 236 RTR. Leptin/adiponectin levels were measured by immunoassay and relevant polymorphisms in the leptin receptor (LEPR) and adiponectin (ADIPOQ) genes were identified. Associations were assessed by logistic regression modeling. Results: The waist-to-height ratio (WHr) displayed a significant association with delayed graft function, acute rejection and post-transplant diabetes mellitus, with OR values of 2.04 (1.02-4.08) p = 0.045; 3.08 (1.22-7.79) p = 0.017 and 2.79 (1.16-6.74) p = 0.022, respectively. Waist circumference was linked to delayed graft function [OR = 1.03 (1.01-1.05), p = 0.025] and AR [OR = 1.041 (1.01-1.07), p = 0.009]. Leptin levels were significantly higher in patients who experienced rejection [19.91 ± 23.72 versus 11.22 ± 16.42 ng/ml; OR = 1.021 (1.01-1.04), p = 0.017]. The ADIPOQ rs1501299TT genotype showed a significant association with higher WHr (0.63 ± 0.11 vs 0.59 ± 0.87 for GG/GT genotypes; p = 0.015) and WC values (102.3 ± 14.12 vs 96.38 ± 14.65 for GG/GT genotypes; p = 0.021). Conclusion: WC, and especially WHr, are associated with adverse outcomes in renal transplantation and are affected by variability in the ADIPOQ gene.

Is Intestinal Dysbiosis-Associated With Immunosuppressive Therapy a Key Factor in the Pathophysiology of Post-Transplant Diabetes Mellitus?

Post-transplant diabetes mellitus (PTDM) is one of the most common and deleterious comorbidities after solid organ transplantation (SOT). Its incidence varies depending on the organs transplanted and can affect up to 40% of patients. Current research indicates that PTDM shares several common features with type 2 diabetes mellitus (T2DM) in non-transplant populations. However, the pathophysiology of PTDM is still poorly characterized. Therefore, ways should be sought to improve its diagnosis and therapeutic management. A clear correlation has been made between PTDM and the use of immunosuppressants. Moreover, immunosuppressants are known to induce gut microbiota alterations, also called intestinal dysbiosis. Whereas the role of intestinal dysbiosis in the development of T2DM has been well documented, little is known about its impacts on PTDM. Functional alterations associated with intestinal dysbiosis, especially defects in pathways generating physiologically active bacterial metabolites (e.g., short-chain fatty acids, trimethylamine N-oxide, indole and kynurenine) are known to favour several metabolic disorders. This publication aims at discussing the potential role of intestinal dysbiosis and dysregulation of bacterial metabolites associated with immunosuppressive therapy in the occurrence of PTDM.

Novel management of diabetes in kidney transplantation

PURPOSE OF REVIEW

Posttransplant diabetes mellitus (PTDM) is a prevalent complication in kidney transplant recipients, and has been associated with worse short-term and long-term outcomes.

RECENT FINDINGS

While hyperglycemia is frequently seen in the early posttransplant period because of surgical stress, infection, and use of high-dose steroids, the diagnosis of PTDM should be established after patients are clinically stable and on stable maintenance immunosuppression. In the early posttransplant period, hyperglycemia is typically treated with insulin, and pilot data have suggested potential benefit of lower vs. higher glycemic targets in this setting. Growing data indicate lifestyle modifications, including dietary interventions, physical activity, and mitigation of obesity, are associated with improved posttransplant outcomes. While there are limited data to support a first-line antidiabetic medication for PTDM, more established pharmacotherapies such as sulfonylureas, meglitinides, and dipetidyl peptidase IV inhibitors are commonly used. Given recent trials showing the benefits of sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide 1 receptor agonists upon kidney outcomes in nontransplant patients, further study of these agents specifically in kidney transplant recipients are urgently needed.

SUMMARY

Increasing evidence supports a multidisciplinary approach, including lifestyle modification, obesity treatment, judicious immunosuppression selection, and careful utilization of novel antidiabetic therapies in PTDM patients.

Diabetes in Kidney Transplantation

Diabetes mellitus (DM) is one of the most common complications after kidney transplantation and is associated with unfavorable outcomes including death. DM can be present before transplant but post-transplant DM (PTDM) refers to diabetes that is diagnosed after solid organ transplantation. Despite its high prevalence, optimal treatment to prevent complications of PTDM is unknown. Medical therapy of pre-existent DM or PTDM after transplant is challenging because of frequent interactions between antidiabetic and immunosuppressive agents. There is also frequent need for medication dose adjustments due to residual kidney disease and a higher risk of medication side effects in patients treated with immunosuppressive agents. Sodium-glucose cotransporter 2 inhibitors have demonstrated a favorable cardio-renal profile in patients with DM without a transplant and hence hold great promise in this patient population although there is concern about the higher risk of urinary tract infections. The significant gaps in our understanding of the pathophysiology, diagnosis, and management of DM after kidney transplantation need to be urgently addressed.

Glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter 2 inhibitors for diabetes after solid organ transplantation

Post-transplant diabetes mellitus (PTDM) is a common complication of solid organ transplantation and a major cause of increased morbidity and mortality. Additionally, solid organ transplant patients may have pre-existent type 2 diabetes mellitus (T2DM). While insulin is the treatment of choice for hyperglycemia in the first weeks after transplantation, there is no preferred first line agent for long-term management of PTDM or pre-existent T2DM. Glucagon-like peptide-1 receptor agonists (GLP-1RA) and sodium-glucose cotransporter 2 (SGLT2) inhibitors improve glycemic control, lower body weight, and blood pressure, are recommended after lifestyle and metformin as initial therapy for diabetic patients with cardiovascular or kidney comorbidities regarding their cardiorenal benefits. Furthermore, the mechanisms of action of GLP-1RA may counteract some of the driving forces for PTDM, as calcineurin-induced β cell toxicity as per preclinical data, and improve obesity. However, their use in the treatment of PTDM is currently limited by a paucity of data. Retrospective observational and small exploratory studies suggest that GLP-1RA effectively improve glycemic control and induce weight loss in patients with PTDM without interacting with commonly used immunosuppressive agents, although randomized-controlled clinical trials are required to confirm their safety and efficacy. In this narrative review, we evaluate the risk factors and pathogenesis of PTDM and compare the potential roles of GLP-1RA and SGLT2 inhibitors in PTDM prevention and management as well as in pre-existent T2DM, and providing a roadmap for evidence generation on newer antidiabetic drugs for solid organ transplantation.

Deep Learning-Based Quantification of Visceral Fat Volumes Predicts Posttransplant Diabetes Mellitus in Kidney Transplant Recipients

Background: Because obesity is associated with the risk of posttransplant diabetes mellitus (PTDM), the precise estimation of visceral fat mass before transplantation may be helpful. Herein, we addressed whether a deep-learning based volumetric fat quantification on pretransplant computed tomographic images predicted the risk of PTDM more precisely than body mass index (BMI).

Methods: We retrospectively included a total of 718 nondiabetic kidney recipients who underwent pretransplant abdominal computed tomography. The 2D (waist) and 3D (waist or abdominal) volumes of visceral, subcutaneous, and total fat masses were automatically quantified using the deep neural network. The predictability of the PTDM risk was estimated using a multivariate Cox model and compared among the fat parameters using the areas under the receiver operating characteristic curves (AUROCs).

Results: PTDM occurred in 179 patients (24.9%) during the median follow-up period of 5 years (interquartile range, 2.5–8.6 years). All the fat parameters predicted the risk of PTDM, but the visceral and total fat volumes from 2D and 3D evaluations had higher AUROC values than BMI did, and the best predictor of PTDM was the 3D abdominal visceral fat volumes [AUROC, 0.688 (0.636–0.741)]. The addition of the 3D abdominal VF volume to the model with clinical risk factors increased the predictability of PTDM, but BMI did not.

Conclusions: A deep-learning based quantification of visceral fat volumes on computed tomographic images better predicts the risk of PTDM after kidney transplantation than BMI.

Antimicrobial Dosing in Specific Populations and Novel Clinical Methodologies: Obesity

Obesity and its related comorbidities can negatively influence the outcomes of certain infectious diseases. Specific dosing recommendations are often lacking in the product label for patients with obesity that leads to unclear guidance in practice. Higher rates of therapeutic failure have been reported with some fixed dose antibiotics and pragmatic approaches to dose modification are limited for orally administered agents. For i.v. antimicrobials dosed on weight, alternate body size descriptors (ABSDs) have been used to reduce the risk of overdosing. These ABSDs are mathematical transformations of height and weight that represent fat-free weight and follow the same principles as body surface area (BSA)-based dosing of cancer chemotherapy. However, ABSDs are rarely studied in pivotal phase III studies and so can risk the underdosing of antimicrobials in patients with obesity when incorrectly applied in the real-world setting. Specific case examples are presented to highlight these risks. Although general principles may be considered by clinicians, a universal approach to dose modification in obesity is unlikely. Studies that can better distinguish human body phenotypes may help reduce our reliance on height and weight to define dosing. Simple and complex technologies exist to quantify individual body composition that could improve upon our current approach. Early evidence suggests that body composition parameters repurposed from medical imaging data may improve upon height and weight as covariates of drug clearance and distribution. Clinical trials that can integrate human body phenotyping may help us identify new approaches to optimal dose selection of antimicrobials in patients with obesity.

Metabolic Consequences of Solid Organ Transplantation

Metabolic complications affect over 50% of solid organ transplant recipients. These include posttransplant diabetes, nonalcoholic fatty liver disease, dyslipidemia, and obesity. Preexisting metabolic disease is further exacerbated with immunosuppression and posttransplant weight gain. Patients transition from a state of cachexia induced by end-organ disease to a pro-anabolic state after transplant due to weight gain, sedentary lifestyle, and suboptimal dietary habits in the setting of immunosuppression. Specific immunosuppressants have different metabolic effects, although all the foundation/maintenance immunosuppressants (calcineurin inhibitors, mTOR inhibitors) increase the risk of metabolic disease. In this comprehensive review, we summarize the emerging knowledge of the molecular pathogenesis of these different metabolic complications, and the potential genetic contribution (recipient +/- donor) to these conditions. These metabolic complications impact both graft and patient survival, particularly increasing the risk of cardiovascular and cancer-associated mortality. The current evidence for prevention and therapeutic management of posttransplant metabolic conditions is provided while highlighting gaps for future avenues in translational research.

Automated Measurements of Muscle Mass Using Deep Learning Can Predict Clinical Outcomes in Patients With Liver Disease

INTRODUCTION

There is increasing recognition of the central role of muscle mass in predicting clinical outcomes in patients with liver disease. Muscle size can be extracted from computed tomography (CT) scans, but clinical implementation will require increased automation. We hypothesize that we can achieve this by using artificial intelligence.

METHODS

Using deep convolutional neural networks, we trained an algorithm on the Reference Analytic Morphomics Population (n = 5,268) and validated the automated methodology in an external cohort of adult kidney donors with a noncontrast CT scan (n = 1,655). To test the clinical usefulness, we examined its ability to predict clinical outcomes in a prospectively followed cohort of patients with clinically diagnosed cirrhosis (n = 254).

RESULTS

Between the manual and automated methodologies, we found excellent inter-rater agreement with an intraclass correlation coefficient of 0.957 (confidence interval 0.953-0.961, P < 0.0001) in the adult kidney donor cohort. The calculated dice similarity coefficient was 0.932 ± 0.042, suggesting excellent spatial overlap between manual and automated methodologies. To assess the clinical usefulness, we examined its ability to predict clinical outcomes in a cirrhosis cohort and found that automated psoas muscle index was independently associated with mortality after adjusting for age, gender, and child's classification (P < 0.001).

DISCUSSION

We demonstrated that deep learning techniques can allow for automation of muscle measurements on clinical CT scans in a diseased cohort. These automated psoas size measurements were predictive of mortality in patients with cirrhosis showing proof of principal that this methodology may allow for wider implementation in the clinical arena.

Obesity, transplantation, and bariatric surgery: An evolving solution for a growing epidemic

The increasing obesity epidemic has major implications in the realm of transplantation. Patients with obesity face barriers in access to transplant and unique challenges in perioperative and postoperative outcomes. Because of comorbidities associated with obesity, along with the underlying end-stage organ disease leading to transplant candidacy, these patients may not even be referred for transplant evaluation, much less be waitlisted or actually undergo transplant. However, the use of bariatric surgery in this population can help optimize the transplant candidacy of patients with obesity and end-stage organ disease and improve perioperative and postoperative outcomes. We review the impact of obesity on kidney, liver, and cardiothoracic transplant candidates and recipients and explore potential interventions to address obesity in these populations.

Evaluation of Tacrolimus Trough Level in Patients Who Developed Post-transplant Diabetes Mellitus After Kidney Transplantation: A Retrospective Single-Center Study in Saudi Arabia

BACKGROUND

Post-transplant diabetes mellitus (PTDM) is a complication after kidney transplantation. Studies showed an association between high trough levels of tacrolimus FK506 and PTDM. This study aims to investigate the association between FK506 trough levels during the first year after kidney transplant and the incidence of PTDM.

METHODS

This retrospective study included adult kidney transplant patients who were not diabetic before transplantation from 2011 to 2014. The analysis evaluated FK506 trough levels at different time points post-transplant, as well as other variables to determine whether they were associated with PTDM.

RESULTS

The cumulative incidence of PTDM was 22.5% with a median time to PTDM diagnosis of 10 months. PTDM patients had higher first FK506 (ng/mL) levels (P = .001), and more patients in the PTDM group had FK506 level >10 ng/mL during the first 3 months (P = .004). After 12 months of transplant, PTDM patients had higher body mass index (BMI) 28.3 ± 6.9 kg/m² compared to non-PTDM patients 26.4 ± 6.7 kg/m² (P = .015). Binary logistic regression analysis showed that age ≥40 years (odds ratio [OR] = 2.75, P = .004), BMI ≥25 kg/m² (OR = 2.04, P = .040), and FK506 level ≥10 ng/mL during the first 3 months (OR = 2.65, P = .009) were significantly related to PTDM development.

CONCLUSION

Patients with FK506 trough level >10 ng/mL during the first 3 months after transplantation are at higher risk of PTDM, especially in patients >40 years of age and/or who are overweight. These results may strengthen the notion that there is a connection between high FK506 trough levels and PTDM development.

Morphomic Signatures Derived from Computed Tomography Predict Hepatocellular Carcinoma Occurrence in Cirrhotic Patients

BACKGROUND AND AIMS

Computed tomography (CT) provides scans of the human body from which digitized features can be extracted. The aim of this study was to examine the role of these digital biomarkers for predicting subsequent occurrence of hepatocellular carcinoma (HCC) in cirrhotic patients.

METHODS

A cohort of 269 patients with cirrhosis were recruited and prospectively followed for the occurrence of HCC in Taiwan. CT scans were retrospectively retrieved and computationally processed using analytic morphomics. A predictive score was constructed using Cox regression and the generalized iterative modeling method, maximizing the log likelihood of the time to HCC development. An independent cohort of 274 patients from University of Michigan was utilized to examine the predictive validity of this score in a Western population.

RESULTS

Of the 27 digitized features at the 12th thoracic vertebral level, six features were significantly associated with HCC occurrence. Two digitized features (fascia eccentricity and the bone mineral density) were able to stratify patients into high- and low-risk groups with distinct cumulative incidence of HCC in both the training and validation cohorts (P = 0.015 and 0.044, respectively). When the two digitized features were tested in the Michigan cohort, only bone mineral density remained an effective predictor.

CONCLUSION

Digitized features derived from the CT were effective in predicting subsequent occurrence of HCC in cirrhosis patients. The bone mineral density measured on CT was an effective predictor for patients in both Taiwan and USA.

Comparisons of Manual Tape Measurement and Morphomics Measurement of Patients with Upper Extremity Lymphedema

Lymphedema is a debilitating condition characterized by swelling from lymph fluid exceeding transport capacity. A gold standard for arm measurement is not established, and measurement methods vary. This study evaluates the comparability of the tape measure and Analytic Morphomics in deriving limb circumference measurements in patients with upper extremity lymphedema.

Sarcopenia of the Psoas Muscles Is Associated With Poor Outcomes Following Lung Transplantation

BACKGROUND

Sarcopenia, a known component of frailty, defined by diminished cross-sectional area of the psoas muscles, is associated with poor outcomes after a range of surgical procedures. However, little is known of the relationship between sarcopenia of the psoas muscles (SPM) and long-term survival, decline in pulmonary function, and graft failure after lung transplantation.

METHODS

We reviewed patients who underwent primary lung transplantation at our institution from 2011 to 2014. Cross-sectional areas of the psoas muscles at the L4 vertebral level were measured using preoperative computed tomography. Gender-based cutoff values for sarcopenia were generated and validated. The primary outcomes were 1-, 2-, and 3-year all-cause mortality, forced expiratory volume in 1 second values, and graft function. Adjusted logistic regression and survival analysis was used to analyze outcomes.

RESULTS

Ninety-five patients were included in this study; 39 (41.1%) patients were considered sarcopenic. SPM was significantly associated with short-term and midterm mortality on multivariate analysis (1 year: odds ratio [OR], 8.7, p = 0.017; 2 years: OR, 12.7, p < 0.01; 3 years: OR, 13.4, p < 0.01). Survival analysis showed significantly decreased survival in sarcopenic patients at 3 years (35.9% versus 76.8%; p < 0.01). SPM is also associated with decreased forced expiratory volume in 1 second (coefficient, -17.3; p = 0.03). Adjusted Cox analysis showed an increased hazard for all-cause mortality (hazard ratio, 5.8, p < 0.01) and graft failure (hazard ratio, 14.7, p < 0.01) in sarcopenic patients.

CONCLUSIONS

This study demonstrates a significant association between SPM and death, pulmonary function, and graft failure in patients receiving a lung transplant. Determining SPM preoperatively may be a useful component of frailty assessment and a predictor of survival in this patient population.

Post-transplantation diabetes in kidney transplant recipients: an update on management and prevention

Post-transplantation diabetes mellitus (PTDM) may severely impact both short- and long-term outcomes of kidney transplant recipients in terms of graft and patient survival. However, PTDM often goes undiagnosed is underestimated or poorly managed. A diagnosis of PTDM should be delayed until the patient is on stable maintenance doses of immunosuppressive drugs, with stable kidney graft function and in the absence of acute infections. Risk factors for PTDM should be assessed during the pre-transplant evaluation period, in order to reduce the likelihood of developing diabetes. The oral glucose tolerance test is considered as the gold standard for diagnosing PTDM, whereas HbA1c is not reliable during the first months after transplantation. Glycaemic targets should be individualised, and comorbidities such as dyslipidaemia and hypertension should be treated with drugs that have the least possible impact on glucose metabolism, at doses that do not interact with immunosuppressants. While insulin is the preferred agent for treating inpatient hyperglycaemia in the immediate post-transplantation period, little evidence is available to guide therapeutic choices in the management of PTDM. Metformin and incretins may offer some advantage over other glucose-lowering agents, particularly with respect to risk of hypoglycaemia and weight gain. Tailoring immunosuppressive regimens may be of help, although maintenance of good kidney function should be prioritised over prevention/treatment of PTDM. The aim of this narrative review is to provide an overview of the available evidence on management and prevention of PTDM, with a focus on the available therapeutic options.