Impact of Non-alcoholic Fatty Liver Disease on long-term cardiovascular events and death in Chronic Obstructive Pulmonary Disease

Cardiovascular disease in patients with metabolic dysfunction-associated steatohepatitis compared with metabolic dysfunction-associated steatotic liver disease and other liver diseases: A systematic review

The burden of cardiovascular disease (CVD) in patients with metabolic dysfunction-associated steatohepatitis (MASH) is poorly characterized, particularly vs other liver diseases including metabolic dysfunction-associated steatotic liver disease (MASLD). To identify available evidence, Embase, MEDLINE, and Cochrane database searches (main search: 2011-September 6, 2021; additional ad hoc search [MEDLINE only]: September 7, 2021-February 15, 2023), plus manual searches (2019-September 2021), were performed. Studies reporting CVD outcomes (angina, coronary artery disease [CAD], heart failure, myocardial infarction, peripheral artery disease, stroke, venous thromboembolic disease, and CV mortality) in adults with histologically confirmed MASH and MASLD or other liver diseases were identified, with studies of MASLD without confirmed MASH excluded. Of 8732 studies, 21 were included. An increased incidence or prevalence of CVD in patients with MASH vs other conditions was reported in 12 studies; odds ratios (OR), where reported, ranged from 3.12 (95 % CI: 1.33-5.32) to 4.12 (95 % CI: 1.91-8.90). The risk of CAD was increased in people with MASH in 6 of 7 studies, while the risk of stroke was increased in 6 of 6 studies, and heart failure in 2 of 4 studies. Three of 6 studies provided evidence of increased CVD-related mortality in patients with MASH vs those without. In conclusion, this literature review suggests that CVD is prevalent in patients with MASH and may contribute to increased mortality. Accordingly, cardiovascular risk factors should be aggressively managed in this population. Whether the CVD burden in patients with MASH is a direct consequence of MASH itself requires further study.

Longitudinal Outcomes Associated With Metabolic Dysfunction-Associated Steatotic Liver Disease: A Meta-analysis of 129 Studies

BACKGROUND & AIMS

The progression of metabolic dysfunction-associated steatotic liver disease (MASLD) has been found to manifest in a series of hepatic and extrahepatic complications. A comprehensive meta-analysis of the longitudinal outcomes associated with MASLD has yet to be conducted.

METHODS

To investigate the longitudinal outcomes associated with MASLD, Medline and Embase databases were searched to identify original studies that evaluated the longitudinal risks of incident clinical outcomes among MASLD patients compared with non-MASLD individuals. DerSimonian Laird random-effects meta-analysis was performed. Pooled effect estimates were calculated, and heterogeneity among studies was evaluated.

RESULTS

One hundred twenty-nine studies were included in the meta-analysis. Meta-analysis revealed a significant increase in the risk of cardiovascular outcomes (hazard ratio [HR], 1.43; 95% confidence interval [CI], 1.27-1.60; P < .01), various metabolic outcomes such as incident hypertension (HR, 1.75; 95% CI, 1.46-2.08; P < .01), diabetes (HR, 2.56; 95% CI, 2.10-3.13; P < .01), pre-diabetes (HR, 1.69; 95% CI, 1.22-2.35; P < .01), metabolic syndrome (HR, 2.57; 95% CI, 1.13-5.85; P = .02), chronic kidney disease (HR, 1.38; 95% CI, 1.27-1.50; P < .01), as well as all cancers (HR, 1.54; 95% CI, 1.35-1.76; P < .01) among MASLD patients compared with non-MASLD individuals. By subgroup analysis, MASLD patients with advanced liver disease (HR, 3.60; 95% CI, 2.10-6.18; P < .01) were also found to be associated with a significantly greater risk (P = .02) of incident diabetes than those with less severe MASLD (HR, 1.63; 95% CI, 1.0-2.45; P = .02) when compared with non-MASLD.

CONCLUSIONS

The present study emphasizes the association between MASLD and its clinical outcomes including cardiovascular, metabolic, oncologic, and other outcomes. The multisystemic nature of MASLD found in this analysis requires treatment targets to reduce systemic events and end organ complications.

NAFLD and AATD Are Two Diseases with Unbalanced Lipid Metabolism: Similarities and Differences

Non-alcoholic fatty liver disease (NAFLD) is a type of steatosis commonly associated with obesity, dyslipidemia, hypertension, and diabetes. Other diseases such as inherited alpha-1 antitrypsin deficiency (AATD) have also been related to the development of liver steatosis. The primary reasons leading to hepatic lipid deposits can be genetic and epigenetic, and the outcomes range from benign steatosis to liver failure, as well as to extrahepatic diseases. Progressive hepatocellular damage and dysregulated systemic immune responses can affect extrahepatic organs, specifically the heart and lungs. In this review, we discuss the similarities and differences between the molecular pathways of NAFLD and AATD, and the putative value of hepatic organoids as novel models to investigate the physio pathological mechanisms of liver steatosis.

Lipid Metabolism Disorders in the Comorbid Course of Nonalcoholic Fatty Liver Disease and Chronic Obstructive Pulmonary Disease

Non-alcoholic fatty liver disease (NAFLD) is currently among the most common liver diseases. Unfavorable data on the epidemiology of metabolic syndrome and obesity have increased the attention of clinicians and researchers to the problem of NAFLD. The research results allow us to emphasize the systemicity and multifactoriality of the pathogenesis of liver parenchyma lesion. At the same time, many aspects of its classification, etiology, and pathogenesis remain controversial. Local and systemic metabolic disorders are also a part of the pathogenesis of chronic obstructive pulmonary disease and can influence its course. The present article analyzes the metabolic pathways mediating the links of impaired lipid metabolism in NAFLD and chronic obstructive pulmonary disease (COPD). Free fatty acids, cholesterol, and ceramides are involved in key metabolic and inflammatory pathways underlying the pathogenesis of both diseases. Moreover, inflammation and lipid metabolism demonstrate close links in the comorbid course of NAFLD and COPD.

A review of liver dysfunction in the lung transplant patient

Liver dysfunction is an increasingly common finding in patients evaluated for lung transplantation. New or worsening dysfunction in the perioperative period, defined by presence of clinical ascites/encephalopathy, high model for end-stage liver disease (MELD) score, and/or independent diagnostic criteria, is associated with high short- and long-term mortality. Therefore, a thorough liver function assessment is necessary prior to listing for lung transplant. Unfortunately, identification and intraoperative monitoring remain the only options for prevention of disease progression with isolated lung transplantation. Combined lung and liver transplantation may provide an option for definitive long-term management in selecting patients with known liver disease at high risk for postoperative progression. However, experience with the combined operation is extremely limited and indications for combined lung and liver transplant remain unclear. Herein, we present a comprehensive literature review of patients with liver dysfunction undergoing lung transplantation with and without concurrent liver transplant in an effort to illuminate the risks, benefits, and clinical judgement surrounding decision to pursue combined lung-liver transplantation (CLLT). We also argue description of liver function is currently a weakness of the current lung allocation scoring system. Additional algorithms incorporating liver function may aid in risk stratification and decision to pursue combined transplantation.

Distinct Cause of Death Profiles of Hospitalized Non-alcoholic Fatty Liver Disease: A 10 Years' Cross-Sectional Multicenter Study in China

Background: The clinical burden and natural history of non-alcoholic fatty liver disease (NAFLD) vary globally. We aimed to investigate NAFLD-related mortality profiles in hospitalized patients in southern China.

Methods: A multicenter retrospective investigation with a 10-year study period (2009–2018) analyzed 10,071 deaths during hospitalization (NAFLD: 2,015; other liver diseases: 1,140; without liver diseases: 6,916) was performed using a multiple cause of death analysis. Medical histories and biochemistry and imaging findings were extracted from the electronic medical record system. The underlying causes of death were classified by 10th Revision of the International Classification of Diseases (ICD-10) codes.

Results: The distribution of death causes in patients with NAFLD has stabilized over time, with cardio- and cerebral vascular disease (CVD) ranked first (35.6%), followed by extrahepatic malignancies (22.6%), infection (11.0%), kidney disease (7.5%), liver-related diseases (5.2%), respiratory diseases (3.9%), digestive diseases (3.5%), endocrine diseases (3.5%), and other diseases (7.2%). NAFLD patients had more deaths attributable to CVD, extrahepatic malignancies, liver-related diseases (all P < 0.001) and multiorgan failure than the deceased controls. The severity of steatosis was independently associated with these relationships (liver-related diseases: OR = 1.37, 95% CI: 1.20–1.59, cardio- and cerebrovascular diseases: OR = 1.23, 95% CI: 1.19–1.31, infectious diseases: OR = 1.14, 95% CI: 1.04–1.26, and renal diseases: OR = 1.21, 95% CI: 1.02–1.47, all P < 0.05) after adjustment for sex, body mass index (BMI), fasting blood glucose, low-density lipoprotein cholesterol, uric acid, metabolic syndromes and fibrosis index based on the 4 factors.

Conclusion : NAFLD patients had higher proportions of death due to underlying CVD and liver-related diseases than the general population in China; these proportions positively correlated with steatosis degree.

The Association Between Nonalcoholic Fatty Liver Disease and Risk of Cardiovascular Disease, Stroke, and Extrahepatic Cancers

BACKGROUND & AIMS

Although primarily a disease with liver-specific complications, nonalcoholic fatty liver disease (NAFLD) is a systemic disease with extrahepatic complications. We aim to evaluate the association between NAFLD and cardiovascular disease (CVD), stroke and cerebrovascular disease, and extrahepatic cancers.

METHODS

We searched MEDLINE, EMBASE, and Cochrane Systematic Review Database from January 1, 2000 to July 1, 2019 to identify peer-reviewed English language literature using predefined keywords for NAFLD, CVD, stroke and cerebrovascular disease, and extrahepatic cancers among adults. Two reviewers independently selected studies for inclusion. Measures of association between NAFLD and CVD, stroke and cerebrovascular disease, and extrahepatic cancers were extracted. Quality assessed using Newcastle-Ottawa scale and Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

Thirty studies were included evaluating CVD, 16 studies evaluating stroke or cerebrovascular disease, and 13 studies evaluating extrahepatic cancers. On pooled meta-analysis assessment, NAFLD was associated with increased risk of CVD (risk ratio [RR]: 1.78; 95% confidence interval [CI]: 1.52-2.08) and stroke or cerebrovascular disease (RR: 2.08, 95% CI: 1.72-2.51). Significant heterogeneity in assessing extrahepatic cancers prevented applying meta-analysis methods, but NAFLD seemed to be associated with increased risk of breast and colorectal cancers. Overall level of quality of studies were very low by GRADE.

CONCLUSIONS

NAFLD is associated with increased risks of CVD and stroke or cerebrovascular disease among adults. There appears to be increased risk of breast and colorectal cancers. Given low quality of evidence, it is premature to make any strong conclusions to modify CVD, stroke, or cancer screening policies in patients with NAFLD.

Extra-hepatic manifestations and complications of nonalcoholic fatty liver disease

This review article aims to synthesize the evidence regarding nonalcoholic fatty liver disease (NAFLD) as a systemic disorder. We critically discuss the metabolic syndrome and its components; the cardiovascular and the endocrine system; chronic respiratory disorders; the musculoskeletal system; the skin; and extra-hepatic tumors. We conclude that, while some of these extra-hepatic conditions clearly predispose to the development of secondary forms of NAFLD (typically hypothyroidism-induced NAFLD), others result from pre-existent NAFLD (e.g., certain extra-hepatic tumors) and others (such as Type 2 Diabetes) have, with NAFLD, mutual and bidirectional associations. Analyzed data imply that NAFLD is not merely a hepatic disease. It is also and possibly more importantly, a systemic disorder requiring a special awareness, a multidisciplinary approach and a multidimensional vision.

Perspectives of nonalcoholic fatty liver disease research: a personal point of view

Rational government of patient fluxes from primary care to hepatology clinic is a priority of nonalcoholic fatty liver disease (NAFLD) research. Estimating pre-test probability of disease, risk of fibrosis progression, and exclusion of competing causes of liver disease must be addressed. Here we propose a novel taxonomic classification of NAFLD based on hepatic, pathogenic and systemic features of disease in the individual patient. The variable course of disease in any given patient remains a clinical enigma. Therefore, future studies will have to better characterize the role of genetic polymorphisms, family and personal history, diet, alcohol, physical activity and drugs as modifiers of the course of disease and clues to the early diagnosis of hepatocellular carcinoma. A better understanding of these, together with a taxonomic diagnosis, may prompt a more accurate personalization of care. For example, understanding the putative role of psycho-depression in NAFLD promises to revolutionize disease management in a proportion of cases. Similarly, sex differences in outcome and response to treatment are insufficiently characterized. More studies are awaited regarding those forms of NAFLD which occur secondary to endocrine derangements. The intersections between NAFLD and the lung must better be defined. These include the bi-directional associations of NAFLD and chronic obstructive pulmonary disease and sleep apnoea syndrome, as well as the totally unexplored chapter of NAFLD and coronavirus disease 2019 (COVID-19). Finally, the therapeutic roles of intermittent fasting and anticoagulation must be assessed. In conclusion, over the last 20 years, NAFLD has taught us a lot regarding the pathogenic importance of insulin resistance, the limitations of correcting this in the treatment of NAFLD, the root causes of diabetes and the metabolic syndrome, sex differences in disease and the role of nuclear receptors. However, the overwhelming COVID-19 pandemic is now expected to reset the priorities of public health.

Perspectives of nonalcoholic fatty liver disease research: a personal point of view

Rational government of patient fluxes from primary care to hepatology clinic is a priority of nonalcoholic fatty liver disease (NAFLD) research. Estimating pre-test probability of disease, risk of fibrosis progression, and exclusion of competing causes of liver disease must be addressed. Here we propose a novel taxonomic classification of NAFLD based on hepatic, pathogenic and systemic features of disease in the individual patient. The variable course of disease in any given patient remains a clinical enigma. Therefore, future studies will have to better characterize the role of genetic polymorphisms, family and personal history, diet, alcohol, physical activity and drugs as modifiers of the course of disease and clues to the early diagnosis of hepatocellular carcinoma. A better understanding of these, together with a taxonomic diagnosis, may prompt a more accurate personalization of care. For example, understanding the putative role of psycho-depression in NAFLD promises to revolutionize disease management in a proportion of cases. Similarly, sex differences in outcome and response to treatment are insufficiently characterized. More studies are awaited regarding those forms of NAFLD which occur secondary to endocrine derangements. The intersections between NAFLD and the lung must better be defined. These include the bi-directional associations of NAFLD and chronic obstructive pulmonary disease and sleep apnoea syndrome, as well as the totally unexplored chapter of NAFLD and coronavirus disease 2019 (COVID-19). Finally, the therapeutic roles of intermittent fasting and anticoagulation must be assessed. In conclusion, over the last 20 years, NAFLD has taught us a lot regarding the pathogenic importance of insulin resistance, the limitations of correcting this in the treatment of NAFLD, the root causes of diabetes and the metabolic syndrome, sex differences in disease and the role of nuclear receptors. However, the overwhelming COVID-19 pandemic is now expected to reset the priorities of public health.

Sarcopenia Is an Independent Risk Factor for NAFLD in COPD: A Nationwide Survey (KNHANES 2008-2011)

Background

Nonalcoholic fatty liver disease (NAFLD) is highly prevalent in patients with chronic obstructive pulmonary disease (COPD) and is independently associated with cardiometabolic comorbidities and systemic inflammation. Although several factors are associated with NAFLD, the influence of sarcopenia on NAFLD has not been fully determined in patients with COPD. We explored whether sarcopenia is associated with NAFLD in a COPD population.

Methods

Data from the Korean National Health and Nutrition Examination Surveys 2008–2011 were analyzed. The subjects were defined as having NAFLD when they had a hepatic steatosis index (HSI) score >36, which is a previously validated NAFLD prediction score. Sarcopenia_BMI (=total appendicular skeletal muscle mass [kg]/body mass index [kg/m²]), sarcopenia_BW (=total appendicular skeletal muscle mass [kg]/body weight [kg] × 100), and sarcopenia_height (= total appendicular skeletal muscle mass (kg)/height² (m)) measured using dual-energy X-ray absorptiometry was used to diagnose sarcopenia.

Results

NAFLD was identified in 124 (14.6%) of 850 COPD subjects using the HSI. Multivariable logistic analyses adjusted for age, sex, hypertension, diabetes mellitus (DM), forced vital capacity (FVC), and metabolic syndrome demonstrated that sarcopenia (sarcopenia_BMI, odds ratio [OR] = 1.95; 95% confidence interval [CI], 1.11–3.46, p = 0.022; sarcopenia_BW, OR = 2.25; 95% CI, 1.30–3.92, p = 0.004) was associated with NAFLD in patients with COPD. The proportion of sarcopenia_BMI was higher in patients with a high fibrotic burden from NAFLD (Q3, Q4) than in subjects with a low fibrotic burden from NALFD (Q1, Q2) (54.8% vs 24.2%, p = 0.024). The proportion of sarcopenia_BW was also higher in patients with a high fibrotic burden from NAFLD than in patients with a low fibrotic burden from NAFLD (51.6% vs 30.6%, p = 0.029).

Conclusion

Sarcopenia was associated with an increased risk for NAFLD in patients with COPD, independent of age, sex, lung function, and metabolic factors. Sarcopenic COPD was also associated with a high fibrotic burden in NAFLD patients. Pulmonologists should be aware of possible liver comorbidities in the sarcopenic COPD phenotype.

Hepatic Fibrosis Assessed Using Fibrosis-4 Index Is Predictive of All-Cause Mortality in Patients with Chronic Obstructive Pulmonary Disease

Background

Various comorbidities influence the prognosis of patients with chronic obstructive pulmonary disease (COPD). We investigated if liver fibrosis assessed using fibrosis-4 index (FIB-4) is associated with all-cause mortality in patients with COPD.

Methods

We included 756 patients diagnosed with COPD between 2006 and 2010. Medical records were retrospectively reviewed until 2018. FIB-4 was calculated using the following equation: [age (years) × aspartate aminotransferase (IU/L)/(platelet count (10⁹/L) × √alanine aminotransferase (IU/L))].

Results

From a total of 756 patients, 582 (76.9%) patients were categorized into survivor and 174 (23.1%) into non-survivor groups. The non-survivor group was significantly older with a higher proportion of male, smoker and lower FEV₁/FVC ratio than the survivor group (all P<0.05). Various comorbidities were more frequently observed in the non-survivor group (P<0.05). In addition, the non-survivor group had significantly higher FIB-4 than the survivor group (1.8 vs 1.4, P<0.001). In multivariate analysis, older age (hazard ratio [HR]=1.05), underlying malignancy (HR=2.94), coronary artery occlusive disease (HR=1.58), higher FIB-4 (HR=1.15), and higher GOLD stage (HR=1.26) were significantly associated with the increased risk of all-cause mortality (P<0.05), whereas body mass index (HR=0.95) was independently protective for all-cause mortality (all P<0.05). The high FIB-4 (>1.57) group showed a significantly lower cumulative survival rate than the low FIB-4 (≤1.05) group (P=0.031, Log-rank test). In multivariate regression analysis, higher FIB-4 independently predicted the risk of acute exacerbation (odds ratio=1.08, P=0.034).

Conclusion

Higher fibrotic burden assessed using FIB-4 was independently predictive of the increased risk of all-cause mortality and acute exacerbation in patients with COPD.

Obstructive sleep apnea, chronic obstructive pulmonary disease and NAFLD: an individual participant data meta-analysis

RATIONALE

Chronic intermittent hypoxia occurring in obstructive sleep apnea (OSA) is independently associated with nonalcoholic fatty liver disease (NAFLD). Chronic obstructive pulmonary disease (COPD) has also been suggested to be linked with liver disease.

OBJECTIVE

In this individual participant data meta-analysis, we investigated the association between liver damage and OSA and COPD severity.

METHODS AND MEASUREMENTS

Patients suspected of OSA underwent polysomnography (PSG) or home sleep apnea testing (HSAT). Non-invasive tests were used to evaluate liver steatosis (Hepatic Steatosis Index) and fibrosis (Fibrotest or FibroMeter). An individual participant data meta-analysis approach was used to determine if the severity of OSA/COPD affects the type and severity of liver disease. Results were confirmed by multivariate and causal mediation analysis. Sub-group analyses were performed to investigate specific populations.

MAIN RESULTS

Among 2120 patients, 1584 had steatosis (75%). In multivariable analysis, risk factors for steatosis were an apnea-hypopnea index (AHI) > 5/h, body mass index (BMI) > 26 kg/m², age, type 2 diabetes (all p-values <0.01) and male gender (p = 0.02). Concerning fibrosis, among 2218 patients 397 had fibrosis (18%). Risk factors associated with fibrosis were BMI>26 kg/m², age, male gender, and type 2 diabetes (all p-values <0.01). AHI severity was not associated with fibrosis. A combination of AHI >30/h and COPD stage 1 was associated with an increased risk of steatosis.

CONCLUSION

This meta-analysis confirms the strong association between steatosis and the severity of OSA. The relation between OSA and fibrosis is mainly due to BMI as shown by causal mediation analysis.

Low Liver Density Is Linked to Cardiovascular Comorbidity in COPD: An ECLIPSE Cohort Analysis

Purpose

Fatty liver disease is associated with cardiometabolic disorders and represents a potential key comorbidity in Chronic Obstructive Pulmonary Disease (COPD). Some intermediary mechanisms of fatty liver disease (including its histological component steatosis) include tissue hypoxia, low-grade inflammation and oxidative stress that are key features of COPD. Despite these shared physiological pathways, the effect of COPD on the prevalence of hepatic steatosis, and the association between hepatic steatosis and comorbidities in this population remain unclear. Liver density measured by computed tomography (CT)-scan is a non-invasive surrogate of fat infiltration, with lower liver densities reflecting more fat infiltration and a liver density of 40 Hounsfield Units (HU) corresponding to a severe 30% fat infiltration.

Patients and Methods

We took advantage of the international cohort ECLIPSE in which non-enhanced chest CT-scans were obtained in 1554 patients with COPD and 387 healthy controls to analyse the liver density at T12-L1.

Results

The distribution of liver density was similar and the prevalence of severe steatosis (density<40 HU) was not different (4.7% vs 5.2%, p=0.7) between COPD and controls. In patients with COPD, the lowest liver density quartile was associated, after age and sex adjustment, with coronary artery disease (OR_a=1.59, 95% CI 1.12 to 2.24) and stroke (OR_a=2.20, 95% CI 1.07 to 4.50), in comparison with the highest liver density quartile.

Conclusion

The present data indicate that a low liver density emerged as a predictor of cardiovascular comorbidities in the COPD population. However, the distribution of liver density and the prevalence of severe steatosis were similar in patients with COPD and control subjects.

Association between non-alcoholic fatty liver disease and decreased lung function in adults: A systematic review and meta-analysis

AIM

] and forced vital capacity [FVC]).

METHODS

We searched publication databases using predefined keywords to identify studies (published up to October 4, 2018), in which NAFLD was diagnosed by imaging or biochemistry (no studies with biopsy-proven NAFLD were available). Data from selected studies were extracted, and meta-analysis was performed using random-effects modelling.

RESULTS

and FVC at baseline were also independently associated with a ∼ 15% increased risk of incident NAFLD (n = 1 study in Korean individuals). Subgroup analyses did not materially modify these findings.

CONCLUSIONS

and FVC in Asian and United States adults, and such small, but significant, reductions of lung volumes at baseline may be also associated with increased NAFLD incidence in Asian individuals. Further research is needed to better elucidate the link between NAFLD and impaired lung volumes.