Risk of infections in non-alcoholic fatty liver disease: A nationwide population-based cohort study

Association between triglyceride-glucose related indices and severe infection requiring hospital admission or resulting in mortality among individuals with metabolic dysfunction-associated steatotic liver disease

BACKGROUND AND AIMS

Despite increasing evidence linking triglyceride-glucose (TyG) related indices with metabolic and cardiovascular outcomes, the associations with severe infection in individuals with metabolic dysfunction-associated steatotic liver disease (MASLD) remain unclear.

METHODS

We analyzed data from a large population-based cohort, which included participants who were diagnosed with MASLD and enrolled in 2016 and 2017, with follow-up until December 2022. Severe infections were defined as those requiring hospital admission or resulting in mortality. Multivariate Cox and restricted cubic spline (RCS) regression models were used to evaluate the associations between TyG-related indices and severe infection among participants with MASLD. Additionally, we examined these associations within subgroups defined by age, sex, hypertension, diabetes, obesity, and hyperlipidemia.

RESULTS

Among the 11,782 eligible participants with MASLD (mean age 57.02 years; 34.36 % male), a total of 898 (7.62 %) severe infections occurred during the median follow-up of 5.71 years. The multivariate Cox regression analyses revealed that high levels of TyG (HR = 1.175, 95%CI = 1.049-1.315), TyG-BMI (HR = 1.004, 95%CI = 1.001-1.006), and TyG-WC (HR = 1.002, 95%CI = 1.001-1.003) indices were significantly associated with the severe infection in patients with MASLD. The RCS curves showed positive linear correlations between three TyG-related indices with severe infection in MASLD. Subgroup analyses showed these associations were more pronounced among MASLD patients without obesity. Additionally, incorporating TyG-related indices into the basic model considerably improved the predictive ability for severe infection.

CONCLUSIONS

Our study indicated that a high TyG-related indices are associated with an increased risk of severe infection in MASLD patients. TyG-related indices would be the surrogate biomarkers for the follow-up of the MASLD population.

Association between MASLD and increased risk of serious bacterial infections requiring hospital admission: A meta-analysis

BACKGROUND

Previous studies have reported an association between metabolic dysfunction-associated steatotic liver disease (MASLD) and the risk of serious bacterial infections. However, the magnitude of the risk and whether this risk varies with the severity of MASLD remains uncertain. We performed a meta-analysis of observational studies to quantify the association between MASLD and serious bacterial infections requiring hospital admission.

METHODS

We systematically searched PubMed, Scopus, Web of Science and Embase from database inception to 1 April 2024, using predefined keywords to identify studies examining the risk of serious bacterial infections among individuals with and without MASLD. MASLD was diagnosed using liver biopsy, imaging or International Classification of Diseases codes. Meta-analysis was performed using random-effects modelling.

RESULTS

We identified six cross-sectional and two prospective cohort studies with aggregate data on ~26.6 million individuals. MASLD was significantly associated with higher odds of serious bacterial infections (pooled random-effects odds ratio 1.93, 95% confidence interval [CI] 1.44-2.58; I2 = 93%). Meta-analysis of prospective cohort studies showed that MAFLD was associated with an increased risk of developing serious bacterial infections (pooled random-effects hazard ratio 1.80, 95% CI 1.62-2.0; I2 = 89%). This risk further increased across the severity of MASLD, especially the severity of fibrosis (pooled random-effects hazard ratio 2.42, 95% CI 1.89-2.29; I2 = 92%). These results remained significant after adjusting for age, sex, obesity, diabetes and other potential confounders. Sensitivity analyses did not modify these findings. The funnel plot did not reveal any significant publication bias.

CONCLUSIONS

This meta-analysis shows a significant association between MASLD and an increased risk of serious bacterial infections requiring hospital admission.

Risk of Serious Bacterial and Non-Bacterial Infections in People With MASLD

Metabolic dysfunction-associated steatotic liver disease (MASLD) has become the most common chronic liver disease globally. MASLD is a multisystem disease where metabolic dysfunction plays a key role in the development of MASLD and its most relevant liver-related morbidities and extrahepatic complications, such as cardiovascular disease, chronic kidney disease and certain types of extrahepatic cancers. Among the least examined MASLD-related extrahepatic complications, an ever-increasing number of observational studies have reported a positive association between MASLD and the risk of serious bacterial infections (SBI) requiring hospital admission. This risk remained significant in those studies where statistical analysis was adjusted for age, sex, ethnicity, obesity, type 2 diabetes and other common comorbidities. Notably, the incidence rates of SBI were further increased with more advanced MASLD, especially in patients with MASLD-related cirrhosis, and were also observed for some acute viral infections, including SARS-CoV-2 infection, leading to severe COVID-19. In this narrative review article, we provide an overview of the literature on (a) the recent epidemiological data linking MASLD to the risk of serious bacterial and non-bacterial infections requiring hospital admission, (b) the putative underlying mechanisms through which MASLD may increase the susceptibility to serious infections, both directly and through the immune dysfunction associated with cirrhosis and portal hypertension, and (c) the practical and clinical implications of the increased risk of serious bacterial and non-bacterial infections in the growing global population with MASLD.

Metabolic Dysfunction-Associated Steatotic Liver Disease Increases the Risk of Severe Infection: A Population-Based Cohort Study

BACKGROUND AND AIMS

Metabolic dysfunction-associated steatotic liver disease (MASLD) is linked to various intrahepatic and extrahepatic diseases, but its association with severe infectious disease remains to be investigated.

METHODS

We analysed data from the Shanghai Suburban Adult Cohort and Biobank, encompassing participants enrolled in 2016 and 2017 with available abdominal ultrasonography data, and followed them up until December 2022 (median follow-up = 5.71 years). We categorised the participants into the MASLD group and those without steatotic liver disease (non-SLD). Multivariable-adjusted Cox regression was used to estimate hazard ratios (HR) for severe infections in patients with MASLD compared to the non-SLD group. Cumulative incidences were calculated while accounting for competing risks (non-infection-related deaths). Mediation analyses were performed to explore the roles of cardiometabolic risk factors in the association between MASLD and severe infections.

RESULTS

Among the 33 072 eligible participants (mean age 56.37 years; 38.20% male), 11 908 (36.01%) were diagnosed with MASLD at baseline. Severe infections occurred in 912 (7.66%) MASLD patients and 1258 (5.94%) non-SLD. The rate of severe infections per 1000 person-years was higher in MASLD patients (13.58) than in comparators (10.48) (fully adjusted HR 1.18, 95% CI 1.07-1.30). The most frequent infections in MASLD were respiratory (7.25/1000 person-years) and urinary tract infections (2.61/1000 person-years). The 5-year cumulative incidence of severe infections was 6.79% (95% CI 6.36-7.26) in MASLD and 5.08% (95% CI 4.79-5.38) in comparators. Cardiometabolic risk factors, including waist circumference, triglycerides and HbA1C, partially mediate the association between MASLD and severe infections.

CONCLUSIONS

Patients with MASLD were at significantly higher risk of incident severe infections compared to the non-SLD group. Future studies are needed to elucidate the mechanisms linking MASLD to severe infections.

Prognostic factors for long-term mortality after surgery of left-sided infective endocarditis

BACKGROUND

Infective endocarditis has low prevalence but a high mortality rate. Left-sided infective endocarditis (LSIE) has a higher mortality rate than right-sided infective endocarditis. Surgical treatment is occasionally considered for LSIE; however, few data are available on the long-term prognostic factors for LSIE after surgical treatment. This study investigated the risk factors for long-term mortality in LSIE patients who underwent surgical treatment.

METHODS

This retrospective study enrolled adult patients with LSIE who were admitted to Severance Hospital in South Korea and underwent surgical treatment from November 2005 to August 2017. The primary outcome was risk factors for overall all-cause mortality. Multivariable Cox regression analysis was performed to identify risk factors for long-term mortality of patients with LSIE who received surgical treatment.

RESULTS

This study enrolled 239 with LSIE who underwent surgery. The median follow-up period was 75.9 months, and there were 34 deaths (14.2%) during the study period. Multivariable Cox analysis showed that central nervous system complications (hazard ratio [HR]: 3.55, 95% confidence interval [CI]: 1.76-7.17, P <  0.001), chronic liver disease (CLD) (HR: 4.33, 95% CI: 1.57-11.91, P =  0.005), and age ≥  65 years (HR: 2.65, 95% CI: 1.28-5.51, P =  0.009) were risk factors for overall mortality. Kaplan-Meier analysis indicated a significant difference in survival between patients with and without CNS complications (P <  0.001, log-rank).

CONCLUSION

Central nervous system complications, CLD, and older age were associated with long-term mortality in surgically treated patients with LSIE. Preventive strategies for CNS complications would improve the treatment of LSIE.

Cause-specific mortality in 13,099 patients with metabolic dysfunction-associated steatotic liver disease in Sweden

BACKGROUND & AIMS

Data on cause-specific mortality in metabolic dysfunction-associated steatotic liver disease (MASLD) are limited. We aimed to determine the rate and risk of death from different causes in patients with MASLD compared to the general population in Sweden.

METHODS

In this population-based cohort study, we identified individuals with an ICD-10 code for MASLD in inpatient or specialized outpatient care using Swedish healthcare registers from 2002-2020 (n = 13,099) and matched them with up to 10 controls (median 9) from the general population for age, sex, municipality, and calendar year (n = 118,884). We used Cox regression to estimate adjusted hazard ratios (HRs) and 95% CIs for 11 different primary causes of death. 15-year cumulative incidences of death were calculated while accounting for competing risks.

RESULTS

In total, 1,628 (12.4%) deaths occurred in patients with MASLD and 9,119 (7.7%) in controls during a median follow-up of 4.7 (IQR 2.0-9.2) and 5.8 years (IQR 2.7-10.5), respectively. MASLD was associated with higher all-cause mortality (HR 1.85, 95% CI 1.74-1.96) and higher rates of all specific causes of death except mental health disorder. The strongest associations were observed for non-hepatocellular carcinoma (HCC) liver-related (HR 26.9, 95% CI 19.4-37.3) and HCC-related (HR 35.0, 95% CI 17.0-72.1) mortality. However, the highest estimated 15-year cumulative incidences of death in patients with MASLD were for non-HCC cancer (7.3%) and cardiovascular disease (7.2%).

CONCLUSIONS

MASLD was strongly associated with liver- and HCC-related mortality, but the absolute risks of death were highest for non-HCC cancer and cardiovascular disease. Mortality was increased for nearly all causes in patients with MASLD, suggesting that earlier multidisciplinary care is needed to reduce excess mortality.

IMPACT AND IMPLICATIONS

Previous studies on mortality in patients with metabolic dysfunction-associated steatotic liver disease (MASLD) were either small, restricted to liver-related mortality, relied on liver biopsy to identify patients (thus inducing selection bias), or mainly used data from old cohorts. In a nationwide cohort study of all patients diagnosed with MASLD in inpatient or specialized outpatient care in Sweden between 2002 and 2020, we found a nearly doubled all-cause mortality rate and higher mortality than the general population from a wide range of causes, indicating that earlier multidisciplinary care may be needed to reduce premature mortality in patients with MASLD. The absolute risk estimates of death in our study may be useful for clinicians and policymakers to inform patients about their prognosis and potentially implement clinical or public health strategies to reduce premature mortality.

Metabolic dysfunction-associated steatotic liver disease and urinary system cancers: Mere coincidence or reason for concern?

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a systemic disease characterized by insulin resistance and lipotoxicity. Its association with type 2 diabetes, cardiovascular disease, liver cirrhosis, and hepatocellular carcinoma are well described. However, the association of MASLD and extra-hepatic cancers has received significantly less attention. This narrative review will summarize the conflicting evidence regarding the association between MASLD and cancers of the urinary system, including renal cell carcinoma, urothelial carcinoma, and prostate adenocarcinoma. It will explore potential mechanisms that could be responsible for a higher risk of urinary system cancers in patients with MASLD. We hope that our comprehensive assessment of the literature will help the readers to better interpret the available evidence.

Impact of Non-Alcoholic Fatty Liver Disease on Sepsis Inpatient Outcomes: A Nationwide Sample Analysis (2000-2019)

Background/Objectives: Patients with Non-Alcoholic Fatty Liver Disease (NAFLD) are reported to have an increased risk of developing severe infections, leading to hospitalizations with sepsis. However, data regarding the impact of comorbid NAFLD on in-hospital outcomes of patients with sepsis is scarce. Methods: This nationwide retrospective observational study using discharge data from the National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), and Agency for Healthcare Research and Quality included 21,057,911 adult patients who were admitted to hospitals in the United States between 2000 and 2019 with a primary discharge diagnosis of sepsis. These patients were categorized according to the presence or absence of comorbid NAFLD. The twenty-year trend of nationwide NAFLD prevalence among sepsis inpatients was elucidated. Multivariable logistic regression analysis was used to analyze NAFLD's impact on sepsis outcomes. Results: In the twenty-year study period, the prevalence of NALFD among sepsis inpatients trended up from 1.2% in 2000 to 4.2% in 2019. Similar trends were observed in regional analysis. While overall sepsis mortality decreased, comorbid NAFLD in sepsis patients was consistently associated with a higher adjusted in-hospital all-cause mortality rate (adjusted odds ratio (OR), 1.19; 95% confidence interval (CI), 1.07-1.32), higher odds of developing septic shock, and higher likelihood of development of multi-organ dysfunction. Conclusions: Comorbid NAFLD in the stage of NASH or cirrhosis is associated with higher in-hospital all-cause mortality and worse clinical outcomes in sepsis inpatients. Addressing this rising epidemic will be of paramount importance to improve sepsis in-hospital outcomes.

Inflammatory liver diseases and susceptibility to sepsis

Patients with inflammatory liver diseases, particularly alcohol-associated liver disease and metabolic dysfunction-associated fatty liver disease (MAFLD), have higher incidence of infections and mortality rate due to sepsis. The current focus in the development of drugs for MAFLD is the resolution of non-alcoholic steatohepatitis and prevention of progression to cirrhosis. In patients with cirrhosis or alcoholic hepatitis, sepsis is a major cause of death. As the metabolic center and a key immune tissue, liver is the guardian, modifier, and target of sepsis. Septic patients with liver dysfunction have the highest mortality rate compared with other organ dysfunctions. In addition to maintaining metabolic homeostasis, the liver produces and secretes hepatokines and acute phase proteins (APPs) essential in tissue protection, immunomodulation, and coagulation. Inflammatory liver diseases cause profound metabolic disorder and impairment of energy metabolism, liver regeneration, and production/secretion of APPs and hepatokines. Herein, the author reviews the roles of (1) disorders in the metabolism of glucose, fatty acids, ketone bodies, and amino acids as well as the clearance of ammonia and lactate in the pathogenesis of inflammatory liver diseases and sepsis; (2) cytokines/chemokines in inflammatory liver diseases and sepsis; (3) APPs and hepatokines in the protection against tissue injury and infections; and (4) major nuclear receptors/signaling pathways underlying the metabolic disorders and tissue injuries as well as the major drug targets for inflammatory liver diseases and sepsis. Approaches that focus on the liver dysfunction and regeneration will not only treat inflammatory liver diseases but also prevent the development of severe infections and sepsis.

NAFLD and NASH are obesity-independent risk factors in COVID-19: Matched real-world results from the large PINC AI™ Healthcare Database

BACKGROUND & AIMS

Non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatohepatitis (NASH) are potential risk factors for severe pneumonia and other infections. Available data on the role of NAFLD/NASH in worsening outcomes for COVID-19 are controversial and might be confounded by comorbidities.

METHODS

We used the PINC AI™ Healthcare Data Special Release (PHD-SR) to identify patients with COVID-19 (ICD-10) at approximately 900 hospitals in the United States. We performed exact matching (age, gender, and ethnicity) for patients with or without NAFLD/NASH, adjusting for demographics (admission type, region) and comorbidities (e.g., obesity, diabetes) through inverse probability of treatment weighting and then analysed hospitalisation-related outcomes.

RESULTS

Among 513 623 patients with SARS-CoV-2 (COVID-19), we identified 14 667 with NAFLD/NASH who could be matched to 14 667 controls. Mean age was 57.6 (±14.9) years, 50.8% were females and 43.7% were non-Hispanic whites. After matching, baseline characteristics (e.g., age, ethnicity, and gender) and comorbidities (e.g., hypertension, obesity, diabetes, and cardiovascular disease) were well balanced (standard difference (SD) <.10), except for cirrhosis and malignancies. Patients with COVID-19 and NAFLD/NASH had higher FIB-4 scores, a significantly longer hospital length of stay (LOS) and intensive care LOS than controls (9.4 vs. 8.3 days, and 10.4 vs. 9.3, respectively), even after adjusting for cirrhosis and malignancies. Patients with COVID-19 and NAFLD/NASH also had significantly higher risk of needing invasive mandatory ventilation (IMV) (odds ratio 1.0727; 95% CI 1.0095-1.1400). Other outcomes were similar in both groups.

CONCLUSIONS

In this large real-world cohort of patients hospitalised for COVID-19 in the United States, NAFLD/NASH were obesity-independent risk factors for complicated disease courses.