Relationship between obstructive lung disease and non-alcoholic fatty liver disease in the Korean population: Korea National Health and Nutrition Examination Survey, 2007-2010

Is type 2 diabetes a link between lung function and metabolic dysfunction-associated steatotic liver disease? Insights from population studies and Mendelian randomization

AIM

This study aimed to investigate the relationship between lung function and metabolic dysfunction-associated steatotic liver disease (MASLD), and the potential mediating role of type 2 diabetes.

METHODS

Data from the 2007 to 2012 National Health and Nutrition Examination Survey were used. Logistic regression analysis was employed to assess the association between lung function parameters [forced vital capacity (FVC), forced expiratory volume in 1 s (FEV 1 ), FEV 1 /FVC] and MASLD prevalence while exploring type 2 diabetes mediation. Further analyses included linkage disequilibrium score regression, Mendelian randomization, and meta-analysis to examine the causal relationship between lung function and MASLD, considering type 2 diabetes mediation.

RESULTS

The results showed that higher FVC and FEV 1 levels were associated with decreased MASLD risk, with type 2 diabetes partially mediating this relationship. Genetic analyses supported a causal link between lung function and MASLD, with type 2 diabetes acting as an intermediary. However, no significant association was found between FEV 1 /FVC and MASLD.

CONCLUSION

The study identified a causal relationship between lung function and MASLD, with type 2 diabetes playing a partial mediating role.

Inverse association between lung function and nonalcoholic fatty liver disease: An observational and mendelian randomization study

BACKGROUND AND AIM

The association between lung function with non-alcoholic fatty liver disease (NAFLD) in the general population remains unknown. We aimed to examine the association between lung function and NAFLD among the general population in an observational and Mendelian randomization (MR) study.

METHODS AND RESULTS

340, 253 participants without prior liver diseases were included from the UK Biobank. Of these, 30,397 participants had liver proton density fat fraction (PDFF) measurements by magnetic resonance image (MRI). Lung function parameters included forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC). The primary outcome was the presence of NAFLD, defined as a PDFF greater than 5.5%. The secondary outcome included incident severe NAFLD and severe liver diseases (including liver cirrhosis, liver failure, hepatocellular carcinoma and liver-related death), defined by the International Classification of Disease codes with different data sources. During a media follow-up duration of 9.3 years, 7335 (24.1%) the presence of NAFLD cases were documented. There was an inverse association of FEV1 (% predicted) (Per SD increment, adjusted OR = 0.91, 95%CI: 0.88-0.94) and FVC (% predicted) (Per SD increment, adjusted OR = 0.90, 95%CI: 0.87-0.92) with the presence of NAFLD. Similar results were found for incident severe NAFLD, severe liver disease, liver cirrhosis, liver failure and liver-related death. MR analyses showed that the genetically predicted FEV1 (adjusted OR = 0.63, 95%CI: 0.46-0.87) and FVC (adjusted OR = 0.69, 95%CI: 0.51-0.95) were both inversely associated with the presence of NAFLD.

CONCLUSIONS

There was an inverse causal relationship between lung function and NAFLD in the general population.

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.

Approach to the Patient With Nonalcoholic Fatty Liver Disease

CONTEXT

Nonalcoholic fatty liver disease (NAFLD) is associated with obesity and type 2 diabetes (T2D), causing substantial burden from hepatic and extrahepatic complications. However, endocrinologists often follow people who are at the highest risk of its more severe form with nonalcoholic steatohepatitis or NASH (i.e., T2D or obesity with cardiometabolic risk factors). Endocrinologists are in a unique position to prevent cirrhosis in this population with early diagnosis and treatment.

OBJECTIVE

This work aims to offer endocrinologists a practical approach for the management of patients with NAFLD, including diagnosis, fibrosis risk stratification, and referral to hepatologists.

PATIENTS

(1) An asymptomatic patient with obesity and cardiometabolic risk factors, found to have hepatic steatosis; (2) a patient with T2D and NASH with clinically significant liver fibrosis; and (3) a liver transplant recipient with a history of NASH cirrhosis, with significant weight regain and with recurrent NAFLD on the transplanted organ.

CONCLUSION

NASH can be reversed with proper management of obesity and of T2D. While no agents are currently approved for the treatment of NASH, treatment should include lifestyle changes and a broader use of structured weight-loss programs, obesity pharmacotherapy, and bariatric surgery. Diabetes medications such as pioglitazone and some glucagon-like peptide 1 receptor agonists may also improve liver histology and cardiometabolic health. Sodium-glucose cotransporter-2 inhibitors and insulin may ameliorate steatosis, but their effect on steatohepatitis remains unclear. Awareness by endocrinologists about, establishing an early diagnosis of fibrosis (ie, FIB-4, liver elastography) in patients at high-risk of cirrhosis, long-term monitoring, and timely referral to the hepatologist are all critical to curve the looming epidemic of cirrhosis from NAFLD.

Exercise training attenuates pulmonary inflammation and mitochondrial dysfunction in a mouse model of high-fat high-carbohydrate-induced NAFLD

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) can lead to pulmonary dysfunction that is associated with pulmonary inflammation. Moreover, little is known regarding the therapeutic role of exercise training on pulmonary pathophysiology in NAFLD. The present study aimed to investigate the effect of exercise training on high-fat high-carbohydrate (HFHC)-induced pulmonary dysfunction in C57BL/6 mice.

METHODS

Male C57BL/6 mice (N = 40) were fed a standard Chow (n = 20) or an HFHC (n = 20) diet for 15 weeks. After 8 weeks of dietary treatment, they were further assigned to 4 subgroups for the remaining 7 weeks: Chow (n = 10), Chow plus exercise (Chow+EX, n = 10), HFHC (n = 10), or HFHC plus exercise (HFHC+EX, n = 10). Both Chow+EX and HFHC+EX mice were subjected to treadmill running.

RESULTS

Chronic exposure to the HFHC diet resulted in obesity with hepatic steatosis, impaired glucose tolerance, and elevated liver enzymes. The HFHC significantly increased fibrotic area (p < 0.001), increased the mRNA expression of TNF-α (4.1-fold, p < 0.001), IL-1β (5.0-fold, p < 0.001), col1a1 (8.1-fold, p < 0.001), and Timp1 (6.0-fold, p < 0.001) in the lung tissue. In addition, the HFHC significantly altered mitochondrial function (p < 0.05) along with decreased Mfn1 protein levels (1.8-fold, p < 0.01) and increased Fis1 protein levels (1.9-fold, p < 0.001). However, aerobic exercise training significantly attenuated these pathophysiologies in the lungs in terms of ameliorating inflammatory and fibrogenic effects by enhancing mitochondrial function in lung tissue (p < 0.001).

CONCLUSIONS

The current findings suggest that exercise training has a beneficial effect against pulmonary abnormalities in HFHC-induced NAFLD through improved mitochondrial function.

The Emerging Clinical Significance of the Red Cell Distribution Width as a Biomarker in Chronic Obstructive Pulmonary Disease: A Systematic Review

There is an intense focus on the identification of novel biomarkers of chronic obstructive pulmonary disease (COPD) to enhance clinical decisions in patients with stable disease and acute exacerbations (AECOPD). Though several local (airway) and circulatory inflammatory biomarkers have been proposed, emerging evidence also suggests a potential role for routine haematological parameters, e.g., the red cell distribution width (RDW). We conducted a systematic literature search in PubMed, Web of Science, and Scopus, from inception to April 2022, for articles investigating the diagnostic and prognostic role of the RDW in stable COPD and AECOPD. The risk of bias was assessed using the Joanna Briggs Institute Critical Appraisal Checklist. Significant associations between the RDW and the presence and severity of disease, outcomes (mortality, hospital readmission), and other relevant clinical parameters (right heart failure, pulmonary arterial hypertension) were reported in 13 out of 16 studies in stable COPD (low risk of bias in 11 studies), and 17 out of 21 studies of AECOPD (low risk of bias in 11 studies). Pending further research, our systematic review suggests that the RDW might be useful, singly or in combination with other parameters, for the diagnosis and risk stratification of patients with stable COPD and AECOPD (PROSPERO registration number: CRD42022348304).

MAFLD associated with COPD via systemic inflammation independent of aging and smoking in men

BACKGROUND AND AIM

Metabolic dysfunction and associated systemic inflammation are risk factors for chronic obstructive pulmonary disease (COPD) and COPD is highly prevalent in men. We investigated the impact of metabolic-associated fatty liver disease (MAFLD) and MAFLD-related systemic inflammation on COPD in men.

METHODS

We enrolled 2,041 men with fatty liver. Patients were classified into the COPD (n = 420/2041) and non-COPD (n = 1621/2041) groups. COPD and its high-risk group were diagnosed using the Japanese Respiratory Society Disease statement. Systemic inflammation was evaluated using the C-reactive protein (CRP)/albumin ratio. Independent factors for COPD were investigated by multivariate analysis and decision-tree analysis.

RESULTS

The prevalence of MAFLD was significantly higher in the COPD group than in the non-COPD group. In multivariable analysis, in addition to heavy smoking and aging, MAFLD was identified as an independent factor for COPD (OR 1.46, 95% CI 1.020-2.101, P = 0.0385). Decision-tree analysis showed that MAFLD, rather than heavy smoking, was the most influential classifier for COPD in non-elderly men (14% in MAFLD vs 6% in non-MAFLD groups). MAFLD was also the second most influential factor in elderly men who were not heavy smokers. In both groups, the CRP/albumin ratio was the first classifier for COPD (16% in the high CRP/albumin ratio group vs 3% in the low CRP/albumin ratio group of non-elderly men).

CONCLUSIONS

MAFLD is an independent predictor of COPD in men. MAFLD had a significant impact on COPD through systemic inflammation in men of all ages who were not heavy smokers. MAFLD may be useful to broadly identify COPD in men.

Metabolic Dysfunction-associated Fatty Liver Disease is Associated with Greater Impairment of Lung Function than Nonalcoholic Fatty Liver Disease

BACKGROUND AND AIMS

We compared lung function parameters in nonalcoholic fatty liver disease (NAFLD) and metabolic dysfunction-associated fatty liver disease (MAFLD), and examined the association between lung function parameters and fibrosis severity in MAFLD.

METHODS

In this cross-sectional study, we randomly recruited 2,543 middle-aged individuals from 25 communities across four cities in China during 2016 and 2020. All participants received a health check-up including measurement of anthropometric parameters, biochemical variables, liver ultrasonography, and spirometry. The severity of liver disease was assessed by the fibrosis (FIB)-4 score.

RESULTS

The prevalence of MAFLD was 20.4% (n=519) and that of NAFLD was 18.4% (n=469). After adjusting for age, sex, adiposity measures, smoking status, and significant alcohol intake, subjects with MAFLD had a significantly lower predicted forced vital capacity (FVC, 88.27±17.60% vs. 90.82±16.85%, p<0.05) and lower 1 s forced expiratory volume (FEV1, 79.89±17.34 vs. 83.02±16.66%, p<0.05) than those with NAFLD. MAFLD with an increased FIB-4 score was significantly associated with decreased lung function. For each 1-point increase in FIB-4, FVC was diminished by 0.507 (95% CI: -0.840, -0.173, p=0.003), and FEV1 was diminished by 0.439 (95% CI: -0.739, -0.140, p=0.004). The results remained unchanged when the statistical analyses was performed separately for men and women.

CONCLUSIONS

MAFLD was significantly associated with a greater impairment of lung function parameters than NAFLD.

Increased Oxygen Desaturation Time During Sleep Is a Risk Factor for NASH in Patients With Obstructive Sleep Apnea: A Prospective Cohort Study

Introduction

Given that obstructive sleep apnea (OSA) is commonly associated with metabolic disorders, in this prospective study, we sought to determine the prevalence and risk factors for hepatosteatosis, non-alcoholic steatohepatitis (NASH), and advanced liver fibrosis in patients with clinical and polygraphic criteria of OSA (n = 153) and in subjects with normal lung function parameters (NLP, n = 43).

Methods

Hepatosteatosis, NASH, and advanced liver fibrosis were determined by blood-based non-invasive tools, such as the fatty liver index and the hepatic steatosis index, a serum lipidomic (OWLiver™) test, and three distinct fibrosis algorithms, respectively. Logistic regression models adjusted by potential confounders were performed to evaluate risk factors.

Results

Insulin resistance and dyslipidemia were more frequent in patients with OSA than in subjects with NLP. The prevalence of hepatosteatosis was significantly higher in patients with OSA than in subjects with NLP. NASH was also found more frequently in patients with OSA than in subjects with NLP. In contrast, advanced liver fibrosis was rarely detected in the entire study population, and no significant differences were observed between patients with OSA and subjects with NLP. Besides male gender, increased body mass index (BMI), and presence of type 2 diabetes, percentage of sleep time with oxygen saturation <90% (Tc90%) was the only polygraphic variable significantly associated with NASH in patients with OSA.

Conclusions

This study shows that hepatosteatosis and NASH are highly prevalent in patients with OSA and indicates that those with a Tc90% higher than 10% are at increased risk for NASH.

Whole-Body MRI-Derived Adipose Tissue Characterization and Relationship to Pulmonary Function Impairment

Background: Specification of adipose tissues by whole-body magnetic resonance imaging (MRI) was performed and related to pulmonary function parameters in a population-based cohort. Methods: 203 study participants underwent whole-body MRI and pulmonary function tests as part of the KORA (Cooperative Health Research in the Augsburg Region) MRI study. Both visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT) were derived from the T1-Dixon sequence, and hepatic adipose tissue from the proton density fat fraction (PDFFhepatic). Associations between adipose tissue parameters and spirometric indices such as forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1) and Tiffeneau-index (FEV1/FVC) were examined using multivariate linear regression analysis excluding cofounding effects of other clinical parameters. Results: VAT (β = −0.13, p = 0.03) and SAT (β = −0.26, p < 0.001), but not PDFFhepatic were inversely associated with FEV1, while VAT (β = −0.27, p < 0.001), SAT (β = −0.41, p < 0.001), and PDFFhepatic (β = −0.17, p = 0.002) were inversely associated with FVC. PDFFhepatic was directly associated with the Tiffeneau index (β = 2.46, p < 0.001). Conclusions: In the adjusted linear regression model, VAT was inversely associated with all measured spirometric parameters, while PDFFhepatic revealed the strongest association with the Tiffeneau index. Non-invasive adipose tissue quantification measurements might serve as novel biomarkers for respiratory impairment.

Chest CT-assessed comorbidities and all-cause mortality risk in COPD patients in the BODE cohort

BACKGROUND AND OBJECTIVE

The availability of chest computed tomography (CT) imaging can help diagnose comorbidities associated with chronic obstructive pulmonary disease (COPD). Their systematic identification and relationship with all-cause mortality have not been explored. Furthermore, whether their CT-detected prevalence differs from clinical diagnosis is unknown.

METHODS

The prevalence of 10 CT-assessed comorbidities was retrospectively determined at baseline in 379 patients (71% men) with mild to severe COPD attending pulmonary clinics. Anthropometrics, smoking history, dyspnoea, lung function, exercise capacity, BODE (BMI, Obstruction, Dyspnoea and Exercise capacity) index and exacerbations rate were recorded. The prevalence of CT-determined comorbidities was compared with that recorded clinically. Over a median of 78 months of observation, the independent association with all-cause mortality was analysed. A 'CT-comorbidome' graphically expressed the strength of their association with mortality risk.

RESULTS

Coronary artery calcification, emphysema and bronchiectasis were the most prevalent comorbidities (79.8%, 62.7% and 33.9%, respectively). All were underdiagnosed before CT. Coronary artery calcium (hazard ratio [HR] 2.09; 95% CI 1.03-4.26, p = 0.042), bronchiectasis (HR 2.12; 95% CI 1.05-4.26, p = 0.036) and low psoas muscle density (HR 2.61; 95% CI 1.23-5.57, p = 0.010) were independently associated with all-cause mortality and helped define the 'CT-comorbidome'.

CONCLUSION

This study of COPD patients shows that systematic detection of 10 CT-diagnosed comorbidities, most of which were not detected clinically, provides information of potential use to patients and clinicians caring for them.

Fatty Liver in Hormone Receptor-Positive Breast Cancer and Its Impact on Patient's Survival

Purpose

Long-term estrogen inhibition may cause fatty liver disease (non-alcoholic fatty liver disease; NAFLD) among other adverse conditions such as osteoporosis, climacteric symptoms, thromboembolism, dyslipidemia, and metabolic syndrome. The prevalence of NAFLD among breast cancer patients ranges from 2.3%–45.2%. This study aimed to determine the risk factors for newly developed NAFLD among breast cancer patients after hormonal treatment and whether it influences survival outcomes.

Methods

This retrospective study investigated hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative (HR+/HER2−), nonmetastatic breast cancer patients diagnosed between January 2010 and December 2018. All patients received adjuvant hormonal treatment for at least 6 months. Clinical data on metabolic profile indicators such as body mass index (BMI), waist circumference, serum cholesterol, triglycerides, low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), diabetes, and presence of metabolic syndrome (MetS) were collected. In total, 160 eligible patients with complete covariate data and survival follow-up were included.

Results

NAFLD was diagnosed in 35% of patients. There were significant associations of being overweight (BMI ≥ 25 kg/m²), waist circumference > 80 cm, triglycerides ≥ 150 mg/dL, HDL-C ≤ 50 mg/dL, LDL-C < 150 mg/dL, and presence of MetS with the development of NAFLD. However, unlike other factors, MetS and HDL-C were not independently associated with NAFLD. Patients with breast cancer who developed NAFLD had longer disease-free survival (DFS). The median DFS was not reached in the NAFLD group, whereas it was 59.3 (45.6–73.0) months in the non-NAFLD group. No worsening of overall survival was observed in patients with breast cancer and NAFLD.

Conclusion

The development of NAFLD during treatment in patients with HR+/HER2− breast cancer was associated with several independent risk factors: being overweight, waist circumference, triglycerides, and LDL-C. Interestingly, breast cancer patients with NAFLD during treatment had longer DFS than those without NAFLD.

Prevalence of asymptomatic bronchiectasis and associations among the health screening population in South Korea

Despite the burden of bronchiectasis, there is little data from South Korea regarding asymptomatic bronchiectasis. We aimed to investigate the prevalence of bronchiectasis based on computed tomography (CT) findings, with emphasis on asymptomatic bronchiectasis (CT-proven) and its related factors. We analysed data of individuals who underwent chest CT at a South Korean health screening centre from 2016 to 2017. The prevalence of bronchiectasis was evaluated and adjusted by sex, age, and corresponding year for the Korean general population. Logistic regression analysis was performed to identify factors related to asymptomatic bronchiectasis by comparison between a group without bronchiectasis and a group with symptomatic bronchiectasis. Among the 27 617 subjects screened, 1005 were diagnosed with bronchiectasis based on CT findings, representing an adjusted prevalence of 2329 out of 100 000. The adjusted prevalence of asymptomatic bronchiectasis was 1235 out of 100 000, and that of symptomatic bronchiectasis was 1094 out of 100 000. Compared with the non-bronchiectasis group, the factors related to asymptomatic bronchiectasis were female sex (OR 1.41; 95% CI 1.18-1.70), older age (OR 1.06; 95% CI 1.05-1.07), comorbid liver disease (OR 1.32; 95% CI 1.07-1.63) or COPD (OR 4.99; 95% CI 2.88-8.64), history of tuberculosis (OR 1.98; 95% CI 1.46-2.68) and low forced expiratory volume in 1 s (FEV₁; OR 0.99; 95% CI 0.98-0.998). In South Korea, the prevalence of asymptomatic bronchiectasis appeared higher than that of symptomatic bronchiectasis. Female sex, older age, liver disease, COPD, history of tuberculosis and low FEV₁ may be the factors related to asymptomatic bronchiectasis.

Low alanine aminotransferase as a risk factor for chronic obstructive pulmonary disease in males

Alanine aminotransferase (ALT) levels reflect skeletal muscle volume and general performance, which are associated with chronic obstructive pulmonary disease (COPD) development and prognosis. This study aimed to investigate ALT levels as a risk factor for COPD development. This 13-year population-based retrospective observational cohort study included 422,452 participants for analysis. We classified groups according to the baseline ALT levels (groups 1-5: ALT (IU/L) < 10; 10-19; 20-29; 30-39; and ≥ 40, respectively). The incidence of COPD was the highest in group 1, decreasing as the group number increased in males, but not in females. The Cox regression analysis in males revealed that a lower ALT level, as a continuous variable, was a significant risk factor for COPD development [univariable, hazard ratio (HR): 0.992, 95% confidence interval (CI): 0.991-0.994; multivariable, HR: 0.998, 95% CI: 0.996-0.999]. In addition, COPD was more likely to develop in the lower ALT level groups (groups 1-4; < 40 IU/L), than in the highest ALT level group (group 5; ≥ 40 IU/L) (univariable, HR: 1.341, 95% CI: 1.263-1.424; multivariable, HR: 1.097, 95% CI: 1.030-1.168). Our findings suggest that males with low ALT levels should be carefully monitored for COPD development.

Carotid Intima-Media Thickness and Markers of Brain Health in a Biracial Middle-Aged Cohort: CARDIA Brain MRI Sub-study

BACKGROUND

We investigated whether carotid intima-media thickness is associated with measures of cerebral blood flow (CBF), white matter hyperintensities, and brain volume in a biracial cohort of middle-aged individuals.

METHODS

We performed a cross-sectional cohort study based on data from a multicenter, population-based study Coronary Artery Risk Development in Young Adults. Using linear and logistic regression, we estimated the association of the composite intima-media thickness measured in three segments of carotid arteries (common carotid artery, carotid artery bulb, and internal carotid artery) with volume (cm3) and CBF (mL/100 g/min) in the total brain and gray matter as well as volume of white matter hyperintensities (cm3).

RESULTS

In the analysis, 461 participants (54% women, 34% African Americans) were included. Greater intima-media thickness was associated with lower CBF in gray matter (β=-1.36; p = .04) and total brain (β=-1.26; p = .04), adjusting for age, sex, race, education, and total brain volume. The associations became statistically nonsignificant after further controlling for cardiovascular risk factors. Intima-media thickness was not associated with volumes of total brain, gray matter, and white matter hyperintensities.

CONCLUSIONS

This study suggests that lower CBF in middle age is associated with markers of atherosclerosis in the carotid arteries. This association may reflect early long-term exposure to traditional cardiovascular risk factors. Early intervention on atherosclerotic risk factors may modulate the trajectory of CBF as people age and develop brain pathology.

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.

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

Recent observational studies assessed the association between non-alcoholic fatty liver disease (NAFLD) and lung function in adults, but the magnitude of this association remains uncertain. We estimated the magnitude of the association between NAFLD and lung function on spirometry (predicted forced expiratory volume in 1 s [FEV1] 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

Six observational studies (5 cross-sectional and 1 longitudinal) with aggregate data on 133,707 individuals (27.8% with NAFLD) of predominantly Asian ethnicity (74.6%) were included in the final analysis. There were significant differences in predicted FEV1 (n = 5 studies; pooled weighted mean difference [WMD]: -2.43%, 95% CI: -3.28 to -1.58; I2 = 69.7%) and predicted FVC (pooled WMD: -2.96%, 95% CI: -4.75 to -1.17; I2 = 91.7%) between individuals with and without NAFLD. Decreased FEV1 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

NAFLD is associated with significant reductions of both FEV1 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.

Mortality Related to Nonalcoholic Fatty Liver Disease Is Increasing in the United States

Population‐level nonalcoholic fatty liver disease (NAFLD) death rate data are sparse. We described death rates for adults with NAFLD in the United States using mortality data from the National Vital Statistics System multiple‐cause mortality data (2007‐2016). Decedents who had NAFLD were identified by International Classification of Diseases (ICD) codes K75.81, K76.0, K74.0, K74.6, and K76.9. Among NAFLD decedents, cause‐specific deaths (e.g., cardiovascular disease [CVD], cirrhosis, hepatocellular carcinoma [HCC], non‐liver cancer, diabetes mellitus [DM]) were identified by underlying cause of death ICD‐10 codes. Trends were evaluated by average annual percentage change (AAPC) in age‐standardized death rate (ASDR) per 100,000 persons. Among the 25,129,960 decedents aged ≥20 years, 353,234 (1.4%) decedents had NAFLD (212,322 men; 260,765 non‐Hispanic whites, 32,868 non‐Hispanic blacks, 46,530 Hispanics, 5,025 non‐Hispanic American Indian or Alaska Natives [AIANs], 7,023 non‐Hispanic Asian or Pacific Islanders [APIs]), with a mean age at death of 64.47 ± 13.17 years. During the study period, the ASDR for NAFLD increased by 15% (12.94 to 14.90; AAPC, 1.98%; P < 0.001]), while women (AAPC, 2.99% vs. 1.16% men; P = 0.003), non‐Hispanic whites (AAPC, 2.48%), non‐Hispanic AIANs (AAPC, 2.31%), and Hispanics (AAPC, 0.74%) experienced the highest annual increases. Stable trends were noted for non‐Hispanic blacks and non‐Hispanic APIs. Among subgroups, Mexican (AAPC, 1.75%) and Asian Indians (AAPC, 6.94%) experienced annual increases. The top six underlying causes of death (155,894 cirrhosis, 38,444 CVD, 19,466 non‐liver cancer, 10,867 HCC, 8,113 DM, and 5,683 lung disease) accounted for 67.5% of NAFLD‐related deaths. For cause‐specific deaths, ASDR increased for HCC (AAPC, 3.82%), DM (AAPC, 2.23%), non‐liver cancer (AAPC, 2.14%), CVD (AAPC, 1.59%), and cirrhosis (AAPC, 0.96%). Conclusion: NAFLD‐related deaths in U.S. adults are increasing. Cirrhosis is the top cause‐specific death, followed by CVD. Women, non‐Hispanic whites, and non‐Hispanic AIANs (subgroups Mexicans and Asian Indians) experienced the highest increases in deaths. Policies addressing the societal burden of NAFLD are needed.

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.

Decreased lung function is associated with risk of developing non-alcoholic fatty liver disease: A longitudinal cohort study

BACKGROUND

Decreased lung function is associated with non-alcoholic fatty liver disease (NAFLD), based on linking mechanisms such as insulin resistance and systemic inflammation However, its association with the risk of developing NAFLD is unclear. Our aim was to investigate whether baseline lung function is associated with incident NAFLD in middle-aged healthy Koreans.

METHODS

A cohort study of 96,104 subjects (mean age: 35.7 years) without NAFLD were followed up from 2002 to 2015. NAFLD was diagnosed by ultrasound after the exclusion of other possible causes of liver diseases. Baseline percent predicted forced expiratory volume in one second (FEV1%) and forced vital capacity (FVC%) were categorized in quartiles. Adjusted hazard ratios (aHR) and 95% confidence intervals (CIs) (using the highest quartile as reference) were calculated for incident NAFLD at follow-up, controlling for covariates and potential confounders.

RESULTS

During 579,714.5 person-years of follow-up, 24,450 participants developed NAFLD (incidence rate, 42.2 per 1,000 person-years). The mean follow-up period was 5.9±3.4 years. Regardless of smoking history, the risk for incident NAFLD increased with decreasing quartiles of FEV1 (%) and FVC (%) in a dose-response manner (p for trend<0.001). In never smokers, the aHRs (95% CIs) for incident NAFLD were 1.15 (1.08-1.21), 1.11 (1.05-1.18), and 1.08 (1.02-1.14) in quartiles 1-3 for FEV1 (%) and 1.12 (1.06-1.18), 1.11 (1.05-1.18), and 1.09 (1.03-1.15) in quartiles 1-3 for FVC (%), compared with the highest quartile reference. Similar inverse association was present in smoke-exposed subjects (aHR for incident NAFLD were 1.14, 1.21, 1.13 and 1.17, 1.11, 1.09 across FEV1(%) and FVC(%) quartile in increasing order, respectively).

CONCLUSIONS

Reduced lung function was a risk factor for incident NAFLD in a large middle-aged Korean cohort with over half a million person-years of follow-up.