Gender disparities in liver transplant candidates with nonalcoholic steatohepatitis

Sex-based Differences and Comparative Predictive Value of MELD 3.0 in Simultaneous Liver-Kidney Transplantation Waitlist Outcomes After Standardization of Listing Criteria in the United States

Background

Sex disparities in solid organ transplantation are well documented. Relative changes in sex-based outcome disparities after the 2017 standardization of simultaneous liver-kidney (SLK) listing criteria in the United States have not been reported. We hypothesized that this policy's objective measures of kidney dysfunction may differentially affect SLK patients by sex and that the use of MELD 3.0 in the SLK population might provide unique benefit to female transplant candidates.

Methods

Organ Procurement and Transplantation Network data were retrospectively analyzed comparing 2013-2016 with 2018-2021 SLK listings. Waitlist outcomes and Model for End-stage Liver Disease (MELD) 3.0 reclassifications were compared by sex and listing period.

Results

There were 2626 and 2609 male patients and 1670 and 1919 female patients pre- and post-policy changes, respectively. The proportion of female SLK listings post-policy change (42.4%) was higher than both female SLK listings pre-policy change (38.9%) and female single-organ liver listings post-policy change (36.8%; P < 0.01). A statistically significant interaction between sex and listing group (pre- versus post-policy change) was present in multivariable analysis (P = 0.02). Female patients were more likely to have a higher MELD 3.0 score than the listing MELD/MELD-Na score when the listing MELD score was <30 (P < 0.01). Among all patients who died on the waitlist, female patients were nearly twice as likely to be underrepresented by listing MELD compared with MELD 3.0 (23% female and 13% male patients; P < 0.01).

Conclusions

Waitlist outcomes were changed differentially between male and female patients after the 2017 SLK policy change. The application of MELD 3.0 to SLK patients is likely to benefit female patients.

Nonalcoholic steatohepatitis/metabolic dysfunction-associated steatohepatitis emerging market: Preparing managed care for early intervention, equitable access, and integrating the patient perspective

Nonalcoholic steatohepatitis (NASH)/metabolic dysfunction-associated steatohepatitis (MASH) is an advanced form of liver disease that can lead to significant morbidity and mortality primarily due to hepatic complications including fibrosis, cirrhosis, hepatocellular carcinoma, and liver failure, as well as cardiovascular disease. As the development of NASH/MASH is closely linked to cardiometabolic risk factors such as obesity and type 2 diabetes mellitus, its prevalence is increasing along with the prevalence of those conditions. Identifying at-risk patients or those early in the disease process is essential to optimizing care and may prevent future complications. Current treatment options include disease-modifying interventions, off-label use of US Food and Drug Administration (FDA)-approved medications for comorbid conditions, and resmetirom, the recently first-ever FDA-approved medication specifically for use in NASH/MASH. There is also considerable continued activity in related drug development research with several other potential emerging treatments. With the increasing prevalence of NASH/MASH and emerging treatments, it is important for managed care organizations (MCOs) to be prepared to assist in patient care and implement equitable treatment management. Understanding patient perspectives and their experience with NASH/MASH provides insights for MCOs such as the need for education of both health care providers and patients to encourage early diagnosis and for enhancing access to individualized care including resources and support. Additionally, MCOs can consider potential management strategies for new and emerging treatments.

Disparities in Liver Transplantation for Nonalcoholic Steatohepatitis in Women

BACKGROUND

Nonalcoholic steatohepatitis (NASH) is the fastest-growing indication for liver transplantation (LT). Sex disparities among patients with cirrhosis on the LT waitlist are well known. We wanted to understand these disparities further in women with end-stage liver disease patients listed for NASH cirrhosis in a contemporary cohort.

METHODS

We used data from the Scientific Registry of Transplant Recipients to assess sex racial, and ethnic differences in NASH patients listed for LT. Adults transplanted from August 1997 to June 2021 were included. Inferential statistics were used to evaluate differences with univariate and multivariate comparisons, including competitive risk analysis.

RESULTS

During the study time period, we evaluated 12 844 LT for NASH cirrhosis. Women were transplanted at a lower rate (46.5% versus 53.5%; P  < 0.001) and higher model for end-stage liver disease (MELD) (23.8 versus 22.6; P < 0.001) than men. Non-White women were transplanted at a higher MELD (26.1 versus 23.1; P  < 0.001) than White women and non-White male patients (26.1 versus 24.8; P  < 0.001). Graft and patient survivals were significantly different ( P  < 0.001) between non-White women and White women and men (White and non-White).

CONCLUSIONS

Evaluation of LT candidates in the United States demonstrates women with NASH cirrhosis have a higher MELD than men at LT. Additional disparities exist among non-White women with NASH as they have higher MELD and creatinine at LT compared with White women. After LT, non-White women have worse graft and patient survival compared with men or White women. These data indicate that non-White women with NASH are the most vulnerable on the LT waitlist.

Surging Liver Transplantation for Nonalcoholic Steatohepatitis from 2000-2022: A National Database Study

OBJECTIVES

Our aim was to provide an up-to-date, large-scale overview of the trends and clinicodemographics for NASH LTs performed in the United States compared with all other LT indications between 2000 and 2022. We also examined the demographic factors that will predict future demand for NASH LT.

METHODS

Our analysis of NASH LT from the Organ Procurement & Transplantation Network database spanning 2000-2022 consisted primarily of descriptive statistics and hypothesis testing with corrections for multiple testing when necessary. Trend lines and linear correlations were also explored.

RESULTS

NASH LTs have experienced a remarkable surge, escalating from 0.12% of all LTs in 2000 to a substantial 14.7% in 2022, marking a 100-fold increase. Examining demographic trends, a significant proportion of NASH LTs recipients fall within the 50- to 64-year-old age group. Moreover, 52% of these recipients concurrently exhibit type 2 diabetes mellitus, a notably higher percentage than the 19% observed in all LT recipients. Type 2 diabetes mellitus emerges as a prominent risk factor for NASH progressing to end-stage liver disease. The phenomenon of repeat transplantation is noteworthy; although 6% of all LTs necessitate repeat procedures, this figure dramatically drops to 0.6% for NASH LTs. Ethnic disparities are apparent, with African Americans representing a mere 2% of NASH LT recipients, significantly lower than their representation in the overall population. Regionally, the East Coast has a higher proportion of NASH LT recipients compared with waitlist additions. This trend holds true across demographics.

CONCLUSIONS

Our findings underscore the need for increased resources, particularly for minority, uninsured, or noncitizen individuals requiring LT for NASH. This analysis provides valuable insights into the dynamic landscape of LTs in the context of NASH, shaping the trajectory of medical interventions in the 21st century.

Non-alcoholic fatty liver disease in women - Current knowledge and emerging concepts

Non-alcoholic fatty liver disease (NAFLD) is a major cause of liver disease worldwide, affecting up to 30% of adults. Progression to non-alcoholic steatohepatitis (NASH) is a key risk factor for cirrhosis, hepatocellular carcinoma and cardiovascular events. Alterations in reproductive hormones are linked to the development and/or progression of NAFLD/NASH in women. Women with polycystic ovary syndrome and those with oestrogen deficiency are at increased risk of NAFLD/NASH, with higher mortality rates in older women compared to men of similar ages. NAFLD/NASH is currently the leading indication for liver transplantation in women without hepatocellular carcinoma. Therefore, a better understanding of NAFLD in women is needed to improve outcomes. In this review, we discuss the hormonal and non-hormonal factors that contribute to NAFLD development and progression in women. Furthermore, we highlight areas of focus for clinical practice and for future research.

The sex disparity in liver transplantation

PURPOSE OF THE REVIEW

This review describes the sex disparity in liver transplantation (LT) and explains its underlying causes.

RECENT FINDINGS

There is a small but persistent sex disparity in transplant rate and waitlist mortality that disappears once women are listed as Status 1. Allocation systems that could replace the Model for End Stage Liver Disease (MELD)-Na with scores less reliant on serum creatine and muscle mass have the potential to alleviate part of the sex disparity. Women perform worse on frailty assessments and are more likely to have nonalcoholic steatohepatitis (NASH). A diagnosis of NASH is compounding risk factor for frailty.

SUMMARY

Women remain disadvantaged in their access to LT despite multiple evolutions of the allocation system. An allocation system that relies less heavily on serum creatinine could partially alleviate the sex disparity. As NASH becomes more prevalent and frailty becomes more important in listing decisions, we may also need to carefully consider differences in the manifestations of frailty between the genders.

Changings and Challenges in Liver Transplantation for Nonalcoholic Fatty Liver Disease/Steatohepatitis

Liver transplantation for nonalcoholic fatty liver disease/steatohepatitis (NAFLD/NASH) is increasing rapidly worldwide. Compared with alcohol and viral-related liver disease, NAFLD/NASH is more frequently associated with a systemic metabolic syndrome, which significantly affects other organs, requiring multidisciplinary management, in all phases of liver transplant.

Addressing sex-based disparities in liver transplantation

PURPOSE OF REVIEW

Disparities in access to liver transplantation by sex have been well described, disadvantaging women. Understanding the multifactorial causes of these disparities as well as the variety of proposed solutions is critical to improving access to this life-saving intervention for women. This review aims to summarize the current body of evidence on observed sex disparities in liver transplantation and highlight actionable, evidence-based mechanisms by which these disparities can be addressed.

RECENT FINDINGS

Strategies for addressing sex disparities in liver transplantation include increasing organ utilization, changing allocation policy, and leveraging public policies to reduce the incidence of end-stage liver disease. Several other promising interventions are currently being explored.

SUMMARY

In the United States, women face additional barriers to liver transplantation on the basis of sex. Immediate action is necessary to systematically address these inequities.

Health disparities in chronic liver disease

The syndemic of hazardous alcohol consumption, opioid use, and obesity has led to important changes in liver disease epidemiology that have exacerbated health disparities. Health disparities occur when plausibly avoidable health differences are experienced by socially disadvantaged populations. Highlighting health disparities, their sources, and consequences in chronic liver disease is fundamental to improving liver health outcomes. There have been large increases in alcohol use disorder in women, racial and ethnic minorities, and those experiencing poverty in the context of poor access to alcohol treatment, leading to increasing rates of alcohol-associated liver diseases. Rising rates of NAFLD and associated fibrosis have been observed in Hispanic persons, women aged > 50, and individuals experiencing food insecurity. Access to viral hepatitis screening and linkage to treatment are suboptimal for racial and ethnic minorities and individuals who are uninsured or underinsured, resulting in greater liver-related mortality and later-stage diagnoses of HCC. Data from more diverse cohorts on autoimmune and cholestatic liver diseases are lacking, supporting the need to study the contemporary epidemiology of these disorders in greater detail. Herein, we review the existing literature on racial and ethnic, gender, and socioeconomic disparities in chronic liver diseases using a social determinants of health framework to better understand how social and structural factors cause health disparities and affect chronic liver disease outcomes. We also propose potential solutions to eliminate disparities, outlining health-policy, health-system, community, and individual solutions to promote equity and improve health outcomes.

Current status of disparity in liver disease

Disparities have emerged as an important issue in many aspects of healthcare in developed countries and may be based on race, ethnicity, sex, geographical location, and socioeconomic status. For liver disease specifically, these potential disparities can affect access to care and outcome in viral hepatitis, chronic liver disease, and hepatocellular carcinoma. Shortages in hepatologists and medical providers versed in liver disease may amplify these disparities by compromising early detection of liver disease, surveillance for hepatocellular carcinoma, and prompt referral to subspecialists and transplant centers. In the United States, continued efforts have been made to address some of these disparities with better education of healthcare providers, use of telehealth to enhance access to specialists, reminders in electronic medical records, and modifying organ allocation systems for liver transplantation. This review will detail the current status of disparities in liver disease and describe current efforts to minimize these disparities.

The fundamentals of sex-based disparity in liver transplantation: Understanding can lead to change

Liver transplantation (LT) is the definitive treatment for end-stage liver disease. Unfortunately, women are disadvantaged at every stage of the LT process. We conducted a literature review to increase the understanding of this disparity. Hormonal differences, psychological factors, and Model for End-Stage Liver Disease (MELD) score inequalities are some pretransplantation factors that contribute to this disparity. In the posttransplantation setting, women have differing risk than men in most major outcomes (perioperative complications, rejection, long-term renal dysfunction, and malignancy) and assessing the two groups together is disadvantageous. Herein, we propose interventions including standardized criteria for LT referral, using an alternate MELD, education for support of women, and motivating women to seek living donors. Understanding sex-based differences will allow us to improve access, tailor management, and improve overall outcomes for all patients, particularly women.

An Analysis by the European Committee on Organ Transplantation of the Council of Europe Outlining the International Landscape of Donors and Recipients Sex in Solid Organ Transplantation

Discrepancies in donation and transplantation by sex and gender have previously been reported. However, whether such differences are invariably the inevitable, unintended outcome of a legitimate process has yet to be determined. The European Committee on Organ Transplantation of the Council of Europe (CD-P-TO) is the committee that actively promotes the development of ethical, quality and safety standards in the field of transplantation in Europe. Whilst the ultimate objective is to shed light on the processes underlying potential gender inequities in transplantation, our initial goal was to represent the distribution by sex among organ donors and recipients in the CD-P-TO Member States and observer countries. Our survey confirms previous evidence that, in most countries, men represent the prevalent source of deceased donors (63.3% in 64 countries: 60.7% and 71.9% for donation after brain and circulatory death, respectively). In contrast, women represent the leading source of organs recovered from living kidney and liver donors (61.1% and 51.2% in 55 and 32 countries, respectively). Across countries, most recovered organs are transplanted into men (65% in 57 countries). These observations may be explained, at least in part, by the higher burden of certain diseases in men, childbearing related immune sensitization in women, and donor-recipient size mismatch. Future research should establish whether gender-related socially-constructed roles and socioeconomic status may play a detrimental role reducing the access of women to transplantation.

Gender Differences in Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) has currently emerged as the most common liver disorder in both developed and developing countries. It has been observed that NAFLD exhibits sexual dimorphism, and there is limited understanding on the sex differences in adults with NAFLD. Nonalcoholic fatty liver disease shows marked differences in prevalence and severity with regards to gender. There are considerable biological disparities between males and females attributed to differences in the chromosomal makeup and sex hormone levels, distinct from the gender differences resulting from the sociocultural influences that lead to differences in lifestyle, which have a significant impact on the pathogenesis of this complex disorder. A multitude of factors contributes to the gender disparities seen and need to be researched in-depth to better understand the mechanisms behind them and the therapeutic measures that can be taken. In this article, we will review the gender disparities seen in NAFLD, as well as recent studies highlighting certain gender-specific factors contributing to its varying prevalence and severity.

HOW TO CITE THIS ARTICLE

Nagral A, Bangar M, Menezes S, et al. Gender Differences in Nonalcoholic Fatty Liver Disease. Euroasian J Hepato-Gastroenterol 2022;12(Suppl 1):S19-S25.

What Do We Know about Inequalities in NAFLD Distribution and Outcomes? A Scoping Review

With prevalence high and rising given the close relationship with obesity and diabetes mellitus, non-alcoholic fatty liver disease (NAFLD) is progressively becoming the most common chronic liver condition worldwide. However, little is known about the health inequalities in NAFLD distribution and outcomes. This review aims to analyze health inequalities in NAFLD distribution globally and to assess the health disparities in NAFLD-related outcomes. We conducted a scoping review of global health inequalities in NAFLD distribution and outcomes according to gender/sex, ethnicity/race, and socioeconomic position from PubMed's inception to May 2021. Ultimately, 20 articles were included in the review, most (75%) of them carried out in the United States. Males were found to have a higher NAFLD prevalence (three articles), while available evidence suggests that women have an overall higher burden of advanced liver disease and complications (four articles), whereas they are less likely to be liver-transplanted once cirrhosis develops (one article). In the US, the Hispanic population had the highest NAFLD prevalence and poorer outcomes (seven articles), whereas Whites had fewer complications than other ethnicities (two articles). Patients with low socioeconomic status had higher NAFLD prevalence (four articles) and a higher likelihood of progression and complications (five articles). In conclusion, globally there is a lack of studies analyzing NAFLD prevalence and outcomes according to various axes of inequality through joint intersectional appraisals, and most studies included in our review were based on the US population. Available evidence suggests that NAFLD distribution and outcomes show large inequalities by social group. Further research on this issue is warranted.

Gender disparities in transplantation

PURPOSE OF REVIEW

Transplantation is the life-saving therapy for patients suffering from end-organ failure, and as such, equitable access to transplantation (ATT) is of paramount importance. Unfortunately, gender/sex-based disparities exist, and despite the transplant community's awareness of this injustice, gender/sex-based disparities have persisted for more than two decades. Importantly, no legislation or allocation policy has addressed inequity in ATT that women disproportionately face. In fact, introduction of the model for end-stage liver disease-based liver allocation system in 2002 widened the gender disparity gap and it continues to be in effect today. Moreover, women suffering from kidney disease are consistently less likely to be referred for transplant evaluation and subsequently less likely to achieve a kidney transplant, yet they comprise the majority of living kidney donors.

RECENT FINDINGS

Acknowledging gender/sex-based disparities in ATT is the first step toward interventions aimed at mitigating this long-standing injustice in healthcare.

SUMMARY

This article provides a background of end-stage liver and kidney disease in women, summarizes the existing literature describing the issue of gender disparity in ATT, and identifies potential areas of intervention and future investigation.

Clinical impact of sexual dimorphism in non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH)

NAFLD/NASH is a sex-dimorphic disease, with a general higher prevalence in men. Women are at reduced risk of NAFLD compared to men in fertile age, whereas after menopause women have a comparable prevalence of NAFLD as men. Indeed, sexual category, sex hormones and gender habits interact with numerous NAFLD factors including cytokines, stress and environmental factors and alter the risk profiles and phenotypes of NAFLD. In the present review, we summarized the last findings about the influence of sex on epidemiology, pathogenesis, progression in cirrhosis, indication for liver transplantation and alternative therapies, including lifestyle modification and pharmacological strategies. We are confident that an appropriate consideration of sex, age, hormonal status and sociocultural gender differences will lead to a better understanding of sex differences in NAFLD risk, therapeutic targets and treatment responses and will aid in achieving sex-specific personalized therapies.