One quarter of the global population is estimated to have nonalcoholic fatty liver disease (NAFLD). The incidence of nonalcoholic steatohepatitis (NASH) is projected to increase by up to 56% in the ...next 10 years. NAFLD is already the fastest growing cause of hepatocellular carcinoma (HCC) in the USA, France and the UK. Globally, the prevalence of NAFLD-related HCC is likely to increase concomitantly with the growing obesity epidemic. The estimated annual incidence of HCC ranges from 0.5% to 2.6% among patients with NASH cirrhosis. The incidence of HCC among patients with non-cirrhotic NAFLD is lower, approximately 0.1 to 1.3 per 1,000 patient-years. Although the incidence of NAFLD-related HCC is lower than that of HCC of other aetiologies such as hepatitis C, more people have NAFLD than other liver diseases. Urgent measures that increase global awareness and tackle the metabolic risk factors are necessary to reduce the impending burden of NAFLD-related HCC. Emerging evidence indicates that reduced immune surveillance, increased gut inflammation and gut dysbiosis are potential key steps in tumorigenesis. In this Review, we discuss the global epidemiology, projections and risk factors for NAFLD-related HCC, and propose preventive strategies to tackle this growing problem.
Chronic hepatitis B virus (HBV) infection affects about 296 million people worldwide and is the leading aetiology of cirrhosis and liver cancer globally. Major medical complications also include ...acute flares and extrahepatic manifestations. In addition, people living with HBV infection also experience stigma. HBV-related cirrhosis resulted in an estimated 331,000 deaths in 2019, and it is estimated that the number of deaths from HBV-related liver cancer in 2019 was 192,000, an increase from 156,000 in 2010. Meanwhile, HBV remains severely underdiagnosed and effective measures that can prevent infection and disease progression are underutilized. Birth dose coverage for HBV vaccines remains low, particularly in low-income countries or regions where HBV burden is high. Patients with HBV infection are inadequately evaluated and linked to care and are undertreated worldwide, even in high-income countries or regions. Despite the goal of the World Health Organization to eliminate viral hepatitis as a public health problem by 2030, the annual global deaths from HBV are projected to increase by 39% from 2015 to 2030 if the status quo remains. In this Review, we discuss the current status and future projections of the global burden of HBV infection. We also discuss gaps in the current care cascade and propose future directions.
Heavy alcohol consumption is a major cause of morbidity and mortality. Globally, alcohol per-capita consumption rose from 5.5 litres in 2005 to 6.4 litres in 2016 and is projected to increase further ...to 7.6 litres in 2030. In 2019, an estimated 25% of global cirrhosis deaths were associated with alcohol. The global estimated age-standardized death rate (ASDR) of alcohol-associated cirrhosis was 4.5 per 100,000 population, with the highest and lowest ASDR in Africa and the Western Pacific, respectively. The annual incidence of hepatocellular carcinoma (HCC) among patients with alcohol-associated cirrhosis ranged from 0.9% to 5.6%. Alcohol was associated with approximately one-fifth of global HCC-related deaths in 2019. Between 2012 and 2017, the global estimated ASDR for alcohol-associated cirrhosis declined, but the ASDR for alcohol-associated liver cancer increased. Measures are required to curb heavy alcohol consumption to reduce the burden of alcohol-associated cirrhosis and HCC. Degree of alcohol intake, sex, older age, obesity, type 2 diabetes mellitus, gut microbial dysbiosis and genetic variants are key factors in the development of alcohol-associated cirrhosis and HCC. In this Review, we discuss the global epidemiology, projections and risk factors for alcohol-associated cirrhosis and HCC.
Summary
Background
Non‐alcoholic fatty liver disease (NAFLD) occurs in around a quarter of the global population and is one of the leading causes of chronic liver disease. The phenotypic ...manifestation and the severity of NAFLD are influenced by an interplay of environmental and genetic factors. Recently, several inactivating variants in the novel 17‐Beta hydroxysteroid dehydrogenase 13 (HSD17B13) gene have been found to be associated with a reduced risk of chronic liver diseases, including NAFLD.
Aims
To review the existing literature on the epidemiology of HSD17B13 and discuss its role in the natural history, disease pathogenesis and treatment of NAFLD.
Methods
We extensively searched relevant literature in PubMed, Google Scholar, clinicaltrials.gov and the reference list of articles included in the review.
Results
HSD17B13 is a liver‐specific, lipid droplet (LD)‐associated protein that has enzymatic pathways involving steroids, pro‐inflammatory lipid mediators and retinol. The estimated prevalence of the best characterised HSD17B13 variant (rs72613567) ranges from 5% in Africa to 34% in East Asia. Loss‐of‐function variants in HSD17B13 are protective against the progression of NAFLD from simple steatosis to non‐alcoholic steatohepatitis (NASH), liver fibrosis, cirrhosis and hepatocellular carcinoma. Emerging data from mechanistic and preclinical studies with RNA interference (RNAi) and small molecule agents indicate that inhibiting HSD17B13 activity may prevent NAFLD progression.
Conclusions
The loss‐of‐function polymorphisms of the newly identified HSD17B13 gene mitigate the progression of NAFLD. It is important to understand the exact mechanism by which these variants exert a protective effect and implement the gathered knowledge in the treatment of NAFLD.
Genetic variants in HSD17B13 are protective against the progression of NAFLD. The worldwide prevalence of the most well‐characterized HSD17B13 variant (rs72613567) is 18%. Wild type HSD17B13 catalyzes the conversion of retinol to retinaldehyde in hepatocytes. Therapeutic studies targeting HSD17B13 gene expression via siRNA‐based approaches have shown promising results.
Coronavirus disease 2019 (COVID‐19) has become a pandemic, but its reported characteristics and outcomes vary greatly amongst studies. We determined pooled estimates for clinical characteristics and ...outcomes in COVID‐19 patients including subgroups by disease severity (based on World Health Organization Interim Guidance Report or Infectious Disease Society of America/American Thoracic Society criteria) and by country/region. We searched Pubmed, Embase, Scopus, Cochrane, Chinese Medical Journal, and preprint databases from 1 January 2020 to 6 April 2020. Studies of laboratory‐confirmed COVID‐19 patients with relevant data were included. Two reviewers independently performed study selection and data extraction. From 6007 articles, 212 studies from 11 countries/regions involving 281 461 individuals were analyzed. Overall, mean age was 46.7 years, 51.8% were male, 22.9% had severe disease, and mortality was 5.6%. Underlying immunosuppression, diabetes, and malignancy were most strongly associated with severe COVID‐19 (coefficient = 53.9, 23.4, 23.4, respectively, all P < .0007), while older age, male gender, diabetes, and hypertension were also associated with higher mortality (coefficient = 0.05 per year, 5.1, 8.2, 6.99, respectively; P = .006‐.0002). Gastrointestinal (nausea, vomiting, abdominal pain) and respiratory symptoms (shortness of breath, chest pain) were associated with severe COVID‐19, while pneumonia and end‐organ failure were associated with mortality. COVID‐19 is associated with a severe disease course in about 23% and mortality in about 6% of infected persons. Individuals with comorbidities and clinical features associated with severity should be monitored closely, and preventive efforts should especially target those with diabetes, malignancy, and immunosuppression.
Highlights
1.
In this systematic review and meta‐analysis of 212 studies involving 281,461 individuals with COVID‐19 from 11 countries/regions, the overall mortality was 5.6%, and 22.9% had severe disease. Immunosuppression, diabetes, malignancy and abdominal pain were strongly associated with severe disease.
2.
Close to one‐quarter of individuals with COVID‐19 develop a severe disease course, and individuals with clinical features associated with severity should be monitored closely.
Liver fibrosis is the most important prognostic factor in patients with nonalcoholic fatty liver disease (NAFLD). Several noninvasive markers for fibrosis, including blood‐based markers and imaging ...based‐markers have been developed. Indirect fibrosis markers (e.g., fibrosis‐4 index and NAFLD fibrosis score) consist of standard laboratory data and clinical parameters. Given its availability and high negative predictive value for advanced fibrosis, these markers are suitable for screening at primary care. Blood‐based fibrogenesis markers (enhanced liver fibrosis and N‐terminal propeptide of type 3 collagen), ultrasound‐based modalities (vibration‐controlled transient elastography, point shear wave elastography SWE, and two‐dimensional SWE), and magnetic resonance elastography have high diagnostic accuracy for liver fibrosis and are suitable for diagnosing liver fibrosis at secondary care centers. Sequential use of these markers can increase diagnostic accuracy and reduce health care costs. Furthermore, combining noninvasive makers may assist in identifying candidates for pharmacological trials and reducing screening failure. Emerging data suggest that these noninvasive markers are associated with liver‐related events (hepatocellular carcinoma and decompensation) and mortality. Furthermore, delta change in noninvasive markers over time is also associated with time‐course change in fibrosis, liver‐related event risk, and mortality risk. However, the association between liver fibrosis and cardiovascular disease (CVD) risk is still controversial. CVD risk may decrease in patients with decompensated liver disease and noninvasive markers may be useful for assessing CVD risk in these patients. Therefore, noninvasive markers may be utilized as measures of fibrosis as well as real‐time prognostic tools, in place of liver biopsy.
The clinical presentation and outcomes of non-alcoholic fatty liver disease (NAFLD)-related hepatocellular carcinoma are unclear when compared with hepatocellular carcinoma due to other causes. We ...aimed to establish the prevalence, clinical features, surveillance rates, treatment allocation, and outcomes of NAFLD-related hepatocellular carcinoma.
In this systematic review and meta-analysis, we searched MEDLINE and Embase from inception until Jan 17, 2022, for articles in English that compared clinical features, and outcomes of NAFLD-related hepatocellular carcinoma versus hepatocellular carcinoma due to other causes. We included cross-sectional and longitudinal observational studies and excluded paediatric studies. Study-level data were extracted from the published reports. The primary outcomes were (1) the proportion of hepatocellular carcinoma secondary to NAFLD, (2) comparison of patient and tumour characteristics of NAFLD-related hepatocellular carcinoma versus other causes, and (3) comparison of surveillance, treatment allocation, and overall and disease-free survival outcomes of NAFLD-related versus non-NAFLD-related hepatocellular carcinoma. We analysed proportional data using a generalised linear mixed model. Pairwise meta-analysis was done to obtain odds ratio (OR) or mean difference, comparing NAFLD-related with non-NAFLD-related hepatocellular carcinoma. We evaluated survival outcomes using pooled analysis of hazard ratios.
Of 3631 records identified, 61 studies (done between January, 1980, and May, 2021; 94 636 patients) met inclusion criteria. Overall, the proportion of hepatocellular carcinoma cases secondary to NAFLD was 15·1% (95% CI 11·9–18·9). Patients with NAFLD-related hepatocellular carcinoma were older (p<0·0001), had higher BMI (p<0·0001), and were more likely to present with metabolic comorbidities (diabetes p<0·0001, hypertension p<0·0001, and hyperlipidaemia p<0·0001) or cardiovascular disease at presentation (p=0·0055) than patients with hepatocellular carcinoma due to other causes. They were also more likely to be non-cirrhotic (38·5%, 27·9–50·2 vs 14·6%, 8·7–23·4 for hepatocellular carcinoma due to other causes; p<0·0001). Patients with NAFLD-related hepatocellular carcinoma had larger tumour diameters (p=0·0087), were more likely to have uninodular lesions (p=0·0003), and had similar odds of Barcelona Clinic Liver Cancer stages, TNM stages, alpha fetoprotein concentration, and Eastern Cooperative Oncology Group (ECOG) performance status to patients with non-NAFLD-related hepatocellular carcinoma. A lower proportion of patients with NAFLD-related hepatocellular carcinoma underwent surveillance (32·8%, 12·0–63·7) than did patients with hepatocellular carcinoma due to other causes (55·7%, 24·0–83·3; p<0·0001). There were no significant differences in treatment allocation (curative therapy, palliative therapy, and best supportive care) between patients with NAFLD-related hepatocellular carcinoma and those with hepatocellular carcinoma due to other causes. Overall survival did not differ between the two groups (hazard ratio 1·05, 95% CI 0·92–1·20, p=0·43), but disease-free survival was longer for patients with NAFLD-related hepatocellular carcinoma (0·79, 0·63–0·99; p=0·044). There was substantial heterogeneity in most analyses (I2>75%), and all articles had low-to-moderate risk of bias.
NAFLD-related hepatocellular carcinoma is associated with a higher proportion of patients without cirrhosis and lower surveillance rates than hepatocellular carcinoma due to other causes. Surveillance strategies should be developed for patients with NAFLD without cirrhosis who are at high risk of developing hepatocellular carcinoma.
None.
Cirrhosis is an important cause of morbidity and mortality in people with chronic liver disease worldwide. In 2019, cirrhosis was associated with 2.4% of global deaths. Owing to the rising prevalence ...of obesity and increased alcohol consumption on the one hand, and improvements in the management of hepatitis B virus and hepatitis C virus infections on the other, the epidemiology and burden of cirrhosis are changing. In this Review, we highlight global trends in the epidemiology of cirrhosis, discuss the contributions of various aetiologies of liver disease, examine projections for the burden of cirrhosis, and suggest future directions to tackle this condition. Although viral hepatitis remains the leading cause of cirrhosis worldwide, the prevalence of non-alcoholic fatty liver disease (NAFLD) and alcohol-associated cirrhosis are rising in several regions of the world. The global number of deaths from cirrhosis increased between 2012 and 2017, but age-standardized death rates (ASDRs) declined. However, the ASDR for NAFLD-associated cirrhosis increased over this period, whereas ASDRs for other aetiologies of cirrhosis declined. The number of deaths from cirrhosis is projected to increase in the next decade. For these reasons, greater efforts are required to facilitate primary prevention, early detection and treatment of liver disease, and to improve access to care.
Liver cancer epidemiology is changing due to increasing alcohol consumption, rising prevalence of obesity, and advances in hepatitis B virus (HBV) and hepatitis C virus (HCV) treatment. However, the ...impact of these changes on global liver cancer burden remains unclear. We estimated global and regional temporal trends in the burden of liver cancer and the contributions of various liver disease etiologies using the methodology framework of the Global Burden of Disease study. Between 2010 and 2019, there was a 25% increase in liver cancer deaths. Age-standardized death rates (ASDRs) increased only in the Americas and remained stable or fell in all other regions. Between 2010 and 2019, non-alcoholic steatohepatitis (NASH) and alcohol had the fastest growing ASDRs, while HCV and HBV declined. Urgent measures are required at a global level to tackle underlying metabolic risk factors and slow the growing burden of NASH-associated liver cancer, especially in the Americas.
LINKED CONTENT
This article is linked to Kim et al papers. To view these articles, visit https://doi.org/10.1111/apt.17564 and https://doi.org/10.1111/apt.17606
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