Nonalcoholic fatty liver disease is associated with decreased lung function

Assessing the consistency of FIB-4, APRI, and GPR in evaluating significant liver fibrosis and cirrhosis in COVID-19 patients with concurrent liver diseases

OBJECTIVE

This study investigated the consistency of the FIB-4, APRI, and GPR indices in assessing significant liver fibrosis and cirrhosis in patients with Coronavirus Disease 2019(COVID-19) who also suffer from various liver diseases, providing references for the clinical selection and application for non-invasive assessment methods.

METHODS

The study evaluated 744 COVID-19 patients with coexisting liver diseases: 508 cases with non-alcoholic fatty liver disease (NAFLD), 158 cases with chronic hepatitis B (CHB), and 78 cases with a combination of both ailments. FIB-4, APRI, and GPR were employed to assess significant liver fibrosis and cirrhosis. Concordance among the methods was determined using Kappa analysis, and receiver operating characteristic (ROC) curves helped identify the optimal cutoff values for each index.

RESULTS

For COVID-19 patients with NAFLD, Kappa values for significant liver fibrosis were 0.81, 0.90, 0.80, and 0.79, and for cirrhosis, they were 0.88, 0.97,0.88, and 0.88, respectively (all p < 0.05). Among those with CHB, Kappa values were 0.81, 0.81, 0.83, and 0.75 for fibrosis, and0.87, 0.91, 0.88, and 0.92 for cirrhosis (all p < 0.05). In patients with coexisting liver diseases, the values were 0.87, 0.86, 0.86, and 0.78 for fibrosis, and 0.67, 0.69, 0.54, and 0.81for cirrhosis (all p < 0.05). Linear trend analysis revealed significant relationships between FIB-4 values, APRI values, GPR values, and the severity of COVID-19 (χ2 trend: 15.205,35.114, and 13.973, respectively, all p < 0.001), between FIB-4 values and APRI values and the coronavirus negative conversion time (all p < 0.05) in COVID-19 with NAFLD, and between FIB-4 values and GPR values and the coronavirus negative conversion time in patients with COVID-19 with CHB(all p < 0.05).

CONCLUSION

Using the current cutoff values, the non-invasive assessments demonstrated almost perfect consistency in evaluating significant liver fibrosis and cirrhosis in COVID-19 patients with liver diseases, though FIB-4 and GPR showed moderate consistency in cirrhosis evaluation in patients with coexisting liver conditions. Moreover, it also indicated that increased liver fibrosis correlates with more severe COVID-19 and prolonged coronavirus negative conversion time.

Elevated neutrophil-to-lymphocyte ratio combined with decreased lymphocyte-to-monocyte ratio is associated with increased peripheral airway resistance in patients with hepatic steatosis

Although the link between hepatic steatosis and lung function has been confirmed, the focus has largely been on central airways. The association between hepatic steatosis and increased peripheral airway resistance has not yet been explored. Hepatic steatosis and increased peripheral resistance are connected with immunity dysregulation. High neutrophil-to-lymphocyte ratio (NLR) and low lymphocyte-to-monocyte ratio (LMR) have been recognized as indicators of immunity dysregulation. In this study, the association between hepatic steatosis and increased peripheral airway resistance was evaluated, and the effect of immunity dysregulation (high NLR/low LMR) on the increased peripheral airway resistance among patients with hepatic steatosis was explored. In this retrospective study, chest or abdomen CT scans and spirometry/impulse oscillometry (IOS) from 2018 to 2019 were used to identify hepatic steatosis and increased central/peripheral airway resistance in patients. Among 1391 enrolled patients, 169 (12.1%) had hepatic steatosis. After 1:1 age and abnormal ALT matching was conducted, clinical data were compared between patients with and without hepatic steatosis. A higher proportion of patients with hepatic steatosis had increased peripheral airway resistance than those without hepatic steatosis (52.7% vs 40.2%, P = .025). Old age, high body mass index, history of diabetes, and high NLR/low LMR were significantly correlated with increased peripheral airway resistance. The presence of hepatic steatosis is associated with increased peripheral airway. High NLR/low LMR is an independent associated factor of increased peripheral airway resistance in patients with hepatic steatosis. It is advisable for patients with hepatic steatosis to regularly monitor their complete blood count/differential count and undergo pulmonary function tests including IOS.

Impact of metabolic dysfunction-associated steatotic liver disease on COVID-19 hospitalizations: A propensity-matched analysis of the United States

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD), formally known as nonalcoholic fatty liver disease, is the most common chronic liver disease in the United States. Patients with MASLD have been reported to be at a higher risk of developing severe coronavirus disease 2019 (COVID-19) and death. However, most studies are single-center studies, and nationwide data in the United States is lacking.

AIM

To study the influence of MASLD on COVID-19 hospitalizations during the initial phase of the pandemic.

METHODS

We retrospectively analyzed the 2020 National Inpatient Sample (NIS) database to identify primary COVID-19 hospitalizations based on an underlying diagnosis of MASLD. A matched comparison cohort of COVID-19 hospitalizations without MASLD was identified from NIS after 1: N propensity score matching based on gender, race, and comorbidities, including hypertension, heart failure, diabetes, and cirrhosis. The primary outcomes included inpatient mortality, length of stay, and hospitalization costs. Secondary outcomes included the prevalence of systemic complications.

RESULTS

A total of 2210 hospitalizations with MASLD were matched to 2210 hospitalizations without MASLD, with a good comorbidity balance. Overall, there was a higher prevalence of severe disease with more intensive care unit admissions (9.5% vs 7.2%, P = 0.007), mechanical ventilation (7.2% vs 5.7%, P = 0.03), and septic shock (5.2% vs 2.7%, P <0.001) in the MASLD cohort than in the non-MASLD cohort. However, there was no difference in mortality (8.6% vs 10%, P = 0.49), length of stay (5 d vs 5 d, P = 0.25), and hospitalization costs (42081.5 $ vs 38614$, P = 0.15) between the MASLD and non-MASLD cohorts.

CONCLUSION

The presence of MAFLD with or without liver cirrhosis was not associated with increased mortality in COVID-19 hospitalizations; however, there was an increased incidence of severe COVID-19 infection. This data (2020) predates the availability of COVID-19 vaccines, and many MASLD patients have since been vaccinated. It will be interesting to see if these trends are present in the subsequent years of the pandemic.

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.

Chronic viral hepatitis accelerates lung function decline in smokers

Although hepatitis B virus (HBV) and hepatitis C virus (HCV) are hepatotrophic viruses, they may affect pulmonary diseases. The purpose of this study was to assess whether chronic viral hepatitis (CVH) infection was associated with a rapid decline in lung function. Repeated measurements of lung function were obtained from a well-curated health check-up database. A case was defined as an individual positive for HBsAg or anti-HCV antibody. A control was randomly selected (from the same dataset) after 1:1 matching in terms of age, sex, height, the body mass index, and smoking status. Separate analyses of non-smokers and smokers were performed. A total of 701 cases were enrolled (586 with HBV and 115 with HCV). In cross-sectional analysis, both forced expiratory volume in 1 s (FEV1) and forced vital capacity (FVC) decreased significantly only in smokers (smoking cases vs. smoking controls) (adjusted p = 6.6 × 10-5 and adjusted p = 2.2 × 10-3, respectively). In longitudinal analysis, smoking cases showed significantly greater FEV1 and FVC decline rates than did smoking controls (adjusted p = 8.5 × 10-3 and adjusted p = 1.2 × 10-5, respectively). Such associations were particularly high in smoking cases at intermediate-to-high risk of hepatic fibrosis, as evaluated by the non-invasive Fibrosis-4 index. In summary, CVH was associated with both decreased lung function and accelerated lung function decline in smokers. A non-invasive measurement of hepatic fibrosis may be useful in predicting rapid lung function decline in smokers with CVH.

Impact of Evolutionary Changes in Nonalcoholic Fatty Liver Disease on Lung Function Decline

Background/Aims

A relationship between fatty liver and lung function impairment has been identified, and both are independently associated with metabolic dysfunction. However, the temporal relationship between changes in fatty liver status and lung function and their genome-wide association remain unclear.

Methods

This longitudinal cohort consisted of subjects who received serial health check-ups, including liver ultrasonography and spirometry, for ≥3 years between 2003 and 2015. Lung function decline rates were classified as "slow" and "accelerated" and compared among four different sonographic changes in steatosis status: "normal," "improved," "worsened," and "persistent." A genome-wide association study was conducted between the two groups: normal/improved steatosis with a slow decline in lung function versus worsened/persistent steatosis with an accelerated decline in lung function.

Results

Among 6,149 individuals, the annual rates of decline in forced vital capacity (FVC) and forced expiratory volume measured in the first second of exhalation (FEV₁) were higher in the worsened/persistent steatosis group than in the normal/improved steatosis group. In multivariable analysis, persistent or worsened status of fatty liver was significantly associated with accelerated declines in FVC (persistent status, odds ratio [OR]=1.22, 95% confidence interval [CI]=1.04-1.44; worsened status, OR=1.30, 95% CI=1.12-1.50), while improved status of fatty liver was significantly associated with slow declines in FEV₁ (OR=0.77, 95% CI=0.64-0.92). The PNPLA3 risk gene was most strongly associated with steatosis status change and accelerated declines in FVC (rs12483959, p=2.61×10^-7) and FEV₁ (rs2294433, p=3.69×10^-8).

Conclusions

Regression of fatty liver is related to lung function decline. Continuing efforts to improve fatty liver may preserve lung function, especially for subjects with a high genetic risk.

Greater Muscular Strength Is Associated with a Lower Risk of Pulmonary Dysfunction in Individuals with Non-Alcoholic Fatty Liver Disease

This study investigated the combined effect of handgrip strength (HGS) and non-alcoholic fatty liver disease (NAFLD) on pulmonary function using the Korea National Health and Nutrition Examination Survey (KNHANES) from 2016 to 2018. For the present study, forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), the FEV1/FVC ratio, handgrip strength (HGS) and the hepatic steatosis index (HSI) to estimate NAFLD were obtained from nationwide cross-sectional surveys. For HGS, subjects were divided into higher HGS (upper 50%) and lower HGS (lower 50%). For NAFLD, subjects were divided into the NAFLD cohort (HSI > 36) and the normal cohort (HSI ≤ 36). Of 1651 subjects (men, n = 601), 25.5% of subjects (n = 421) met the HSI > 36. Based on the normal cohort with high HGS, the normal cohort with low HGS showed an increased risk of reduced FVC (OR = 3.062, 95% CI = 2.46−4.83, p < 0.001) and the NAFLD cohort with low HGS showed a further increased risk of reduced FVC (OR = 4.489, 95% CI = 3.43−7.09, p < 0.001). However, the risk of reduced FVC was not significantly increased in NAFLD with high HGS (OR = 1.297, 95% CI = 0.67−2.50, p = 0.436). After adjusted for covariates such as age, sex, smoking, FBG, HDL-C, TG, SBP, DBP, CRP and alcohol consumption, the results remained similar. More importantly, these results were consistent in the obesity-stratified analysis. The current findings of the study suggest that higher muscle strength is associated with a lower risk of reduced pulmonary function in individuals with NAFLD.

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.

Development of a risk-stratification scoring system for predicting risk of breast cancer based on non-alcoholic fatty liver disease, non-alcoholic fatty pancreas disease, and uric acid

Many breast cancer patients have both non-alcoholic fatty liver disease (NAFLD) and non-alcoholic fatty pancreas disease (NAFPD). Consequently, we hypothesized that NAFPD and NAFLD were associated with breast cancer, and aimed to build a novel risk-stratification scoring system based on it. In this study, a total of 961 patients with breast cancer and 1,006 non-cancer patients were recruited. The clinical characteristics were collected and analyzed using logistic analysis. Risk factors were assessed by a risk rating system. Univariate analysis showed that body mass index, triglyceride, total cholesterol, NAFLD, NAFPD, low-density lipoprotein, and uric acid (UA) were significantly related to breast cancer. Among them, NAFLD, NAFPD, and UA were independent risk factors related to breast cancer identified by multivariate analysis. The risk assessment model was established based on these factors and demonstrated that the odds ratio sharply increased with the rising scores. Compared with the low-risk group, the odds ratio in the intermediate- and high-risk groups were 1.662 (1.380–2.001) and 3.185 (2.145–4.728), respectively. In conclusion, the risk-stratification scoring system combining NAFLD, NAFPD, and UA can accurately predict the occurrence of breast cancer.

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.

Stratifying individuals into non-alcoholic fatty liver disease risk levels using time series machine learning models

Non-alcoholic fatty liver disease (NAFLD) affects 25% of the population worldwide, and its prevalence is anticipated to increase globally. While most NAFLD patients are asymptomatic, NAFLD may progress to fibrosis, cirrhosis, cardiovascular disease, and diabetes. Research reports, with daunting results, show the challenge that NAFLD's burden causes to global population health. The current process for identifying fibrosis risk levels is inefficient, expensive, does not cover all potential populations, and does not identify the risk in time. Instead of invasive liver biopsies, we implemented a non-invasive fibrosis assessment process calculated from clinical data (accessed via EMRs/EHRs). We stratified patients' risks for fibrosis from 2007 to 2017 by modeling the risk in 5579 individuals. The process involved time-series machine learning models (Hidden Markov Models and Group-Based Trajectory Models) profiled fibrosis risk by modeling patients' latent medical status resulted in three groups. The high-risk group had abnormal lab test values and a higher prevalence of chronic conditions. This study can help overcome the inefficient, traditional process of detecting fibrosis via biopsies (that are also medically unfeasible due to their invasive nature, the medical resources involved, and costs) at early stages. Thus longitudinal risk assessment may be used to make population-specific medical recommendations targeting early detection of high risk patients, to avoid the development of fibrosis disease and its complications as well as decrease healthcare costs.

Nonalcoholic fatty liver disease is associated with COVID-19 severity independently of metabolic syndrome: a retrospective case-control study

AIM

Coronavirus disease 2019 (COVID-19) is a recently encountered disease that was declared a pandemic by WHO in 2020. Obesity and other components of the metabolic syndrome may aggravate the severity of COVID-19. Nonalcoholic fatty liver disease (NAFLD) represents the hepatic manifestation of metabolic syndrome. The aim of this study was to investigate a possible association between MAFLD and COVID-19 severity.

METHODS

We performed a retrospective, case-control study, enrolling 71 consecutive COVID-19 patients who were divided into two groups according to the presence or absence of fatty liver by computed tomography scan. All medical records of eligible patients were reviewed including demographic, clinical, laboratory parameters and data regarding the presence of NAFLD and COVID-19 severity.

RESULTS

NAFLD was identified in 22/71 (31%) of the study group. Out of 71, thirteen suffered from severe COVID-19. NAFLD patients had more severe COVID-19 compared with non-NAFLD subjects, 8/22 (36.3%) vs. 5/49(10.2%), (P < 0.005), respectively. Multiple logistic regression analysis showed that NAFLD subjects were more likely to have severe COVID-19 disease (odds ratio 3.57, 95% confidence interval: 1.22, 14.48, P = 0.0031).

CONCLUSION

NAFLD represents a high risk for severe COVID-19 irrespective to gender, and independent of metabolic syndrome specifically in male gender. Moreover, obesity, hypertension and metabolic syndrome were also significantly associated with severe COVID-19.

Hepatic fibrosis is associated with an increased rate of decline in bone mineral density in men with nonalcoholic fatty liver disease

BACKGROUND

There is still controversy about the association between nonalcoholic fatty liver disease (NAFLD) and bone mineral density (BMD). The aim of this study was to clarify the association between NAFLD and the decline in BMD in healthcare examinees.

METHODS

Participants who underwent regular health check-ups with BMD and hepatic ultrasonography from 2006 to 2015 with more than one follow-up until 2020 were included. Propensity score matching was performed between the NAFLD group and the control group, and mixed linear regression models were used for the longitudinal analysis.

RESULTS

Of 2623 eligible participants (mean age 58.7 ± 7.3 years; males 31.3%), 888 (33.9%) had NAFLD. At baseline, the NAFLD group had a higher total hip BMD than the non-NAFLD group in men (0.988 vs. 1.015 g/cm², p = 0.007); however, there was no difference in baseline BMD in women (p = 0.253). In longitudinal analysis during a follow-up period of 7.1 years, there was no significant difference in the BMD decline rate between the two groups in the PS-matched cohort (p = 0.816 in men and p = 0.827 in women). However, among men with NAFLD, those with a high and intermediate probability of advanced fibrosis by the FIB-4 showed a significantly increased rate of decline in total hip BMD compared to those with low scores (0.01 vs. - 0.19% change/year, p = 0.011).

CONCLUSIONS

NAFLD was not associated with the total hip BMD decline rate. However, hepatic fibrosis was significantly associated with an increased rate of decline in total hip BMD in men with NAFLD.

CLINICAL TRIAL REGISTRATION

This study is a retrospective observational study and is not a drug trial. There was no need for clinical trial registration.

The association of impaired lung function and nonalcoholic fatty liver disease: a systematic review

BACKGROUND AND AIMS

Nonalcoholic fatty liver disease (NAFLD) and impaired lung function share similar risk factors and phenotypes, such as obesity and type 2 diabetes. The study is an updated meta-analysis to evaluate the association between NAFLD and impaired lung function.

METHODS

A total of 696 articles were identified with mention of NAFLD and lung function (or pulmonary function testing) in MEDLINE, EMBASE, and Scopus. After de-duplication, 455 articles were screened, 18 underwent full-text review. Five studies met our review and inclusion criteria with an interrater reliability kappa score of 1.

RESULTS

Five studies with a total of 118 118 subjects (28.4% with NAFLD) were included. The cross-sectional studies supported a statistically significant relationship between decreased pulmonary function tests and NAFLD. There was no association observed with obstructive lung pattern. One of the longitudinal studies revealed an association with increased rate of decline in forced vital capacity in patients with NAFLD and FIB4 score ≥1.30 (-21.7 vs. -27.4 mL/year, P = 0.001 in males, -22.4 vs. -27.9 mL/year, P = 0.016 in females). The second longitudinal study revealed that patients with impaired pulmonary function had an increased hazard ratio of developing NAFLD dependent on the severity of pulmonary impairment.

CONCLUSIONS

This is the first systematic review that supports an association of NAFLD with decreased (restrictive) lung function. The estimated severity of liver fibrosis correlates with the rate of progression of restrictive lung function. There are also data showing that patients with impaired lung function have a higher risk of developing NAFLD.

Obesity, malnutrition, and trace element deficiency in the coronavirus disease (COVID-19) pandemic: An overview

The world is currently facing the coronavirus disease (COVID-19) pandemic which places great pressure on health care systems and workers, often presents with severe clinical features, and sometimes requires admission into intensive care units. Derangements in nutritional status, both for obesity and malnutrition, are relevant for the clinical outcome in acute illness. Systemic inflammation, immune system impairment, sarcopenia, and preexisting associated conditions, such as respiratory, cardiovascular, and metabolic diseases related to obesity, could act as crucial factors linking nutritional status and the course and outcome of COVID-19. Nevertheless, vitamins and trace elements play an essential role in modulating immune response and inflammatory status. Overall, evaluation of the patient's nutritional status is not negligible for its implications on susceptibility, course, severity, and responsiveness to therapies, in order to perform a tailored nutritional intervention as an integral part of the treatment of patients with COVID-19. The aim of this study was to review the current data on the relevance of nutritional status, including trace elements and vitamin status, in influencing the course and outcome of the disease 3 mo after the World Health Organization's declaration of COVID-19 as a pandemic.

Pulmonary function is associated with fibrosis severity in patients with biopsy-proven nonalcoholic fatty liver disease

BACKGROUND & AIMS

The association between nonalcoholic fatty liver disease (NAFLD) and pulmonary function remains elusive because of the heterogeneous spectrum and inaccurate diagnostic methods of NAFLD, and insufficient pulmonary function data. We conducted this study to identify the association between histological severity of NAFLD and pulmonary function.

METHODS

This study included patients ≥18 years old with baseline pulmonary function data between August 2014 and July 2019 within a biopsy-evaluated prospective NAFLD cohort. Cross-sectionally, pre-/post-bronchodilator spirometric data with diffusing capacity (DL_CO ) were compared according to histological severity of NAFLD in the various demographic and metabolic subgroups. Multivariable-adjusted analysis revealed specific histological features associated with reduced pulmonary function.

RESULTS

In a total of 420 patients with biopsy-proven NAFLD, pre-/post-bronchodilator forced vital capacities (FVCs; a percentage of the predictive value) were inversely correlated with histological severity of NAFLD. Conversely, pre-bronchodilator forced expiratory volume in 1 second (FEV₁ )/FVC was positively correlated with NAFLD severity. Post-bronchodilator FVC (%) decreased and DL_CO /alveolar volume (V_A ) increased linearly with worsening histological severity of NAFLD in multivariable analysis. In particular, fibrosis stage remained a significant independent predictor of decreased post-bronchodilator FVC (%) (β-coefficient, 4.41; 95% confidence interval [-8.39, -0.43]; P = .031) even after adjusted for clinical variables, exclusively in age <65 years, female, never-smoker and nonchronic obstructive pulmonary disease subgroups.

CONCLUSIONS

Pulmonary function deteriorates with worsening histological severity of NAFLD, especially at the fibrosis stage. The common pathogenesis of reduced pulmonary function and NAFLD fibrosis progression should be further explored.

Metabolic Syndrome and Abnormal Peri-Organ or Intra-Organ Fat (APIFat) Deposition in Chronic Obstructive Pulmonary Disease: An Overview

Chronic obstructive pulmonary disease (COPD) is a common disorder with an increasing prevalence, characterised by persistent respiratory symptoms and airflow limitation. Systemic inflammation is involved in the pathogenesis of COPD and can also predispose to metabolic disorders (e.g., metabolic syndrome (MetS) and non-alcoholic fatty liver disease (NAFLD)). Such comorbidities can negatively affect COPD outcomes, cardiovascular risk, and quality of life. Apart from NAFLD, abnormal peri-organ or intra-organ fat (APIFat) could be considered as markers for cardiometabolic diseases and even for COPD. The present narrative review considers the associations of COPD with MetS, NAFLD, and other APIFat, including epicardial, perirenal, peripancreatic, and intramuscular adipose tissue. Further research is needed to define these relationships and identify any potential clinical implications.

NRF-2 and nonalcoholic fatty liver disease

Currently, chronic liver diseases have conditioned morbidity and mortality, many of these with a metabolic, toxicologic, immunologic, viral, or other etiology. Thus, a transcription factor that has been of huge importance for biomedical research is NRF-2. The latter is considered a principal component of the antioxidant mechanism, and it has been acknowledged that it impairs the function of NRF-2 in many liver diseases and that it forms an essential part of the pathologic changes that occur in the liver to contain inflammation and damage. Within the investigations and experiments carried out, there are isolated drugs, many of them related to plants and natural extracts that possess antioxidant properties through the NRF-2 signaling pathway, or even involving the stimulation of the transcription target proteins of NRF-2. Notwithstanding all of these experimental findings, to date there is not sufficient clinical evidence to justify the use of NRF-2 in medical practice.

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.

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.

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.

Nonalcoholic fatty liver disease is associated with breast cancer in nonobese women

BACKGROUND

Growing evidence supports that nonalcoholic fatty liver disease (NAFLD) is associated with extrahepatic cancers. Nonalcoholic fatty liver disease (NAFLD) and breast cancer share similar risk factors, including obesity.

AIM

The aim of this case-control study was to investigate the association between NAFLD and breast cancer.

METHODS

Subjects who received health screening, including mammography and breast and hepatic ultrasonography simultaneously, were included. Subjects diagnosed with breast cancer were matched with controls. Conditional logistic regression analyses were performed.

RESULTS

Among 270 breast cancer patients and 270 controls, 81 cancer patients (30.0%) and 54 controls (20.0%) had NAFLD (P = 0.008). NAFLD was significantly associated with breast cancer in multivariate analysis (P = 0.046). When the interaction between obesity (BMI < 25 kg/m2 vs. ≥25 kg/m2) and NAFLD in breast cancer patients was examined, a significant effect modification between obesity and NAFLD in breast cancer was noted (P = 0.021). The subgroup analysis showed that NAFLD was significantly associated with breast cancer in the nonobese subgroup (odds ratio 3.04, 95% confidence interval 1.37-4.32, P = 0.002) but not in the obese group (P = 0.163).

CONCLUSIONS

NAFLD was significantly associated with breast cancer independent of traditional risk factors, and this association existed in the nonobese subgroup but not in the obese subgroup.

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.