Trends in nonalcoholic fatty liver disease-related hospitalizations in US children, adolescents, and young adults

Early life programming of nonalcoholic fatty liver disease in children

BACKGROUND

Research is beginning to implicate early life characteristics in the development of pediatric nonalcoholic fatty liver disease, however the relationship with perinatal characteristics is poorly understood.

AIMS

We evaluated the association between perinatal characteristics and nonalcoholic fatty liver disease in childhood.

STUDY DESIGN

Nested case-control study.

SUBJECTS

5104 children born in Quebec, Canada between 2006 and 2019. Exposures included maternal diabetes, obesity, prematurity, and other birth complications.

OUTCOME MEASURES

The outcome was nonalcoholic fatty liver disease diagnosed in hospital before 14 years of age. We calculated adjusted odds ratios (OR) and 95% confidence intervals (CI) for the association between birth characteristics and nonalcoholic fatty liver disease.

RESULTS

A total of 104 children with nonalcoholic fatty liver disease were included. Gestational diabetes (OR 2.17, 95% CI 1.15-4.10), preexisting diabetes (OR 5.75, 95% CI 2.67-12.4), and maternal obesity (OR 3.06, 95% CI 1.71-5.45) were associated with childhood nonalcoholic fatty liver disease. Prematurity (OR 1.93, 95% CI 1.06-3.54) and neonatal intensive care unit admission (OR 2.18, 95% CI 1.10-4.33) were also associated with nonalcoholic fatty liver disease. However, there was no association with low birthweight, small-for-gestational age birth, and macrosomia.

CONCLUSIONS

Maternal metabolic disorders and prematurity may initiate processes early in life that lead to the development of nonalcoholic fatty liver disease in childhood.

Trends and Disparities in Pediatric Nonalcoholic Fatty Liver Disease-Associated Hospitalizations in the United States

OBJECTIVE

Non-alcoholic fatty liver disease (NAFLD) represents a spectrum of disease characterized by accumulation of fat in the liver and is associated with co-morbidities linked to metabolic syndrome. The prevalence of NAFLD in children has increased in the United States over time and with marked racial differences observed in geographically limited studies. This study aims to provide a current, nation-wide analysis of temporal trends of pediatric NAFLD-related hospitalizations and associated co-morbidities as well as assess for racial/ethnic disparities.

METHODS

A cross-sectional study was conducted using the National Inpatient Sample (NIS) from 2004 to 2018 and included NAFLD-associated hospitalizations of children ages 0-17 years of age based on ICD-9/10 diagnosis codes. Rates and patient characteristics analyzed via descriptive statistics and associations via survey logistic regression. Temporal trends assessed via joinpoint regression.

RESULTS

There was an overall increase in pediatric NAFLD-associated hospitalizations with an average annual percent change (AAPC) of 6.6 with highest rates among Hispanic patients (AAPC = 11.1) compared to NH-White (AAPC = 4.1) and NH-Black (AAPC = 2.1). Analysis of race/ethnicity and NAFLD hospitalization showed an increased association in Hispanic patients (odds ratio [OR] = 1.64, 95% confidence interval [CI] = 1.51-1.77) and a decreased association in non-Hispanic (NH)-Black patients (OR = 0.49, 95% CI = 0.45-0.54) when compared to NH-White patients.

CONCLUSION

Utilizing a nation-wide database we demonstrated significant increases in NAFLD-associated hospitalizations with highest prevalence and rates seen in Hispanic patients. In addition, sex and comorbidities showed notable correlation to these hospitalization rates displaying the need for further studies on these relationships and highlights the potential for interventions aimed at high-risk groups.

Prevalence, trends, outcomes, and disparities in hospitalizations for nonalcoholic fatty liver disease in the United States

Background

As the frequency of nonalcoholic fatty liver disease (NAFLD) continues to rise in the United States (US) community, more patients are hospitalized with NAFLD. However, data on the prevalence and outcomes of hospitalizations with NAFLD are lacking. We investigated the prevalence, trends and outcomes of NAFLD hospitalizations in the US.

Methods

Hospitalizations with NAFLD were identified in the National Inpatient Sample (2007-2014) by their ICD-9-CM codes, and the prevalence and trends over an 8-year period were calculated among different demographic groups. After excluding other causes of liver disease among the NAFLD cohorts (n=210,660), the impact of sex, race and region on outcomes (mortality, discharge disposition, length of stay [LOS], and cost) were computed using generalized estimating equations (SAS 9.4).

Results

Admissions with NAFLD tripled from 2007-2014 at an average rate of 79/100,000 hospitalizations/year (P<0.0001), with a larger rate of increase among males vs. females (83/100,000 vs. 75/100,000), Hispanics vs. Whites vs. Blacks (107/100,000 vs. 80/100,000 vs. 48/100,000), and government-insured or uninsured patients vs. privately-insured (94/100,000 vs. 74/100,000). Males had higher mortality, LOS, and cost than females. Blacks had longer LOS and poorer discharge destination than Whites; while Hispanics and Asians incurred higher cost than Whites. Uninsured patients had higher mortality, longer LOS, and poorer discharge disposition than the privately-insured.

Conclusions

Hospitalizations with NAFLD are rapidly increasing in the US, with a disproportionately higher burden among certain demographic groups. Measures are required to arrest this ominous trend and to eliminate the disparities in outcome among patients hospitalized with NAFLD.

Rising Inpatient Encounters and Economic Burden for Patients with Nonalcoholic Fatty Liver Disease in the USA

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the fastest-growing chronic liver disease. However, little is known about NAFLD inpatient resource utilization and clinical outcomes.

AIMS

The aim of this study was to quantify inpatient NAFLD encounters using patient-level data over time.

METHODS

This was a retrospective analysis of de-identified data for NAFLD patients from the California Patient Discharge Database from 2006 to 2013. NAFLD patients were identified by ICD9 codes 571.40, 571.41, 571.49, 571.8, and 571.9.

RESULTS

NAFLD patients (n = 91,558) were predominantly female (60%), 45-65 years old (44%), and white (53%). Inpatient encounters increased from 8153 in 2006 to 16,457 in 2013 and were associated with a 207% increase in charges ($686 million in 2006 to $1.42 billion in 2013) and average increase in charges of 9.8% per year adjusting for inflation. Comorbidities (obesity, diabetes, hyperlipidemia, cardiovascular disease, other cancer, and renal disease) increased significantly over time (all P < 0.05). From 2006 to 2011, there were 11,463 deaths (1849 for liver-related hospitalizations) (mean follow-up 4.00 ± 2.13 years). The most significant predictors of death were age > 75 (aHR 3.9, P < 0.0001), male gender (aHR 1.10, P < 0.0001), white race (aHR 1.2, P < 0.0001), decompensated cirrhosis (aHR 2.1, P < 0.0001), and cancer other than HCC (aHR 3.2, P < 0.0001). Within the liver-related hospitalization cohort, mortality predictors were similar, except for Hispanic race (aHR 0.92, P < 0.0096) and renal disease (aHR 1.50, P < 0.0001).

CONCLUSIONS

The number of NAFLD inpatient encounters increased significantly from 2006 to 2013, as did the inflation-adjusted inpatient charges. The most significant predictors of death were non-liver cancers (HR 3.11, P < 0.0001, CI 3.06-3.16) and age > 75 years (HR 3.94, P < 0.0001, HR 3.86-4.03).

Bariatric surgery improves nonalcoholic fatty liver disease: a contemporary systematic review and meta-analysis

High-level evidence of the impact of bariatric surgery on nonalcoholic fatty liver disease (NAFLD) is lacking. We conducted a systematic review and meta-analysis according to the Cochrane guidelines to assess the resolution of NAFLD after bariatric surgery. We searched PubMed, EMBASE, Web of Science, and CENTRAL for English language publications on bariatric surgery and NAFLD. We included randomized controlled trials and observational studies of patients with NAFLD who underwent bariatric surgery and were assessed by liver biopsy or liver function tests. Duodenal switch and biliopancreatic diversion were excluded. Our primary outcome was histologic or biochemical improvement of NAFLD. Twenty-one studies (12 Roux-en-Y gastric bypass [RYGB], 3 adjustable gastric banding, 2 sleeve gastrectomy, 1 vertical banded gastroplasty, 3 multiple procedures) enrolling 2374 patients were included. The pooled proportion of patients who had improvement of steatosis was 88% (95% confidence interval [CI]: .80, .94). Steatohepatitis improved in 59% (95% CI: .38, .78) and fibrosis improved or resolved in 30% of patients (95% CI: .21, .41). Similarly, aspartate aminotransferase (AST) improved in 32% of patients (95% CI: .22, .42) and alanine aminotransferase improved in 62% of patients (95% CI: .42, .82). After RYGB, the number of patients who had improvement in NAFLD was higher than the average of all the pooled studies. Bariatric surgery improves steatosis and steatohepatitis in the majority of patients and improves or resolves liver fibrosis in 30% of patients. RYGB has a greater impact on NAFLD histology compared with other procedures. This contemporary meta-analysis strongly suggests that bariatric surgery should be considered as a treatment of NAFLD.

Challenges and opportunities in drug and biomarker development for nonalcoholic steatohepatitis: findings and recommendations from an American Association for the Study of Liver Diseases-U.S. Food and Drug Administration Joint Workshop

Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease (CLD) in North America. It is a growing contributor to the burden of CDL requiring liver transplantation. Cirrhosis is also associated with an increased risk of hepatocellular cancer, which may occur even in the absence of cirrhosis in subjects with nonalcoholic steatohepatitis (NASH), the histological form of NAFLD associated with increased liver-related mortality. The diagnosis of NASH currently requires a liver biopsy. There are also no U.S. Food and Drug Administration (FDA)-approved therapies for NASH. Therefore, there is a need to develop better diagnostic and therapeutic strategies for patients with NASH, targeting both those with early-stage disease as well as those with advanced liver fibrosis. There are unique challenges in the design of studies for these target populations. The long relatively asymptomatic time interval in the progression of NAFLD and NASH to cirrhosis and ultimately liver failure, along with gaps in knowledge regarding disease modifiers, combine to present significant challenges in trial design. Therefore, there is an urgent need to develop methods to identify the populations at particular risk of disease progression and validate endpoints that reflect meaningful changes in health status in this population. This article summarizes the discussion at a joint workshop held September 5 and 6, 2013 in Silver Spring, Maryland, sponsored by the FDA and the American Association for the Study of Liver Diseases to develop guidance on diagnostic and therapeutic modalities for NASH.

Trends in outpatient resource utilizations and outcomes for Medicare beneficiaries with nonalcoholic fatty liver disease

BACKGROUND AND AIM

Nonalcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease. The objective of this study was to describe the recent trend of health care resource utilization and short-term mortality of Medicare beneficiaries with NAFLD.

METHODS

This study utilized data from a random sample of national outpatient claims of Medicare beneficiaries (2005 to 2010) who sought outpatient care for NAFLD.

RESULTS

This study included 29,528 patients who sought outpatient care for NAFLD from 2005 to 2010. The annual number of patients increased consistently from 3585 in 2005 to 6646 in 2010. The prevalence of studied comorbidities including cardiovascular disease, diabetes, hyperlipidemia, and hypertension also increased significantly. At the same time, the mean yearly charge and the mean yearly payment increased significantly from $2624±$3308 and $561±$835 in 2005 to $3608±$5132 and $629±$1157 (P<0.05), respectively. The observed mortality rate remained stable around 2.84% (P=0.64). After adjusting for the other covariates, the total number of outpatient visits and all the comorbidities considered were the most determinant factors for yearly charge and yearly payment (P<0.0001). Overall mortality was associated with age, gender, number of outpatient visits, diabetes, and hyperlipidemia.

CONCLUSIONS

The number of outpatient visits because of NAFLD rose between 2005 and 2010. Short-term mortality rates remained stable throughout the study period, whereas total annual charges and payments increased.

Fructose leads to hepatic steatosis in zebrafish that is reversed by mechanistic target of rapamycin (mTOR) inhibition

Nonalcoholic fatty liver disease (NAFLD), the accumulation of lipid within hepatocytes, is increasing in prevalence. Increasing fructose consumption correlates with this increased prevalence, and rodent studies directly support fructose leading to NAFLD. The mechanisms of NAFLD and in particular fructose-induced lipid accumulation remain unclear, although there is evidence for a role for endoplasmic reticulum (ER) stress and oxidative stress. We have evidence that NAFLD models demonstrate activation of the target of rapamycin complex 1 (Torc1) pathway. We set out to assess the contribution of ER stress, oxidative stress, and Torc1 up-regulation in the development of steatohepatitis in fructose-treated larval zebrafish. Zebrafish were treated with fructose or glucose as a calorie-matched control. We also treated larvae with rapamycin, tunicamycin (ER stress), or valinomycin (oxidative stress). Fish were stained with oil red O to assess hepatic lipid accumulation, and we also performed quantitative polymerase chain reaction (qPCR)and western blot analysis. We performed immunostaining on samples from patients with NAFLD and nonalcoholic steatohepatitis (NASH). Treatment with fructose induced hepatic lipid accumulation, mitochondrial abnormalities, and ER defects. In addition, fructose-treated fish showed activation of inflammatory and lipogenic genes. Treatment with tunicamycin or valinomycin also induced hepatic lipid accumulation. Expression microarray studies of zebrafish NAFLD models showed an elevation of genes downstream of Torc1 signaling. Rapamycin treatment of fructose-treated fish prevented development of hepatic steatosis, as did treatment of tunicamycin- or valinomycin-treated fish. Examination of liver samples from patients with hepatic steatosis demonstrated activation of Torc1 signaling.

CONCLUSION

Fructose treatment of larval zebrafish induces hepatic lipid accumulation, inflammation, and oxidative stress. Our results indicate that Torc1 activation is required for hepatic lipid accumulation across models of NAFLD, and in patients.

Clinical outcomes and resource utilisation in Medicare patients with chronic liver disease: a historical cohort study

OBJECTIVE

The aim of this study is to assess recent trends in health resource utilisation and patient outcomes of Medicare beneficiaries with chronic liver disease (CLD).

SETTING

Liver-related mortality is the 10th leading cause of death in the USA, and hepatitis C virus (HCV) and obesity-related non-alcoholic fatty liver disease are the major causes of CLD. As the US population ages and becomes more obese, the impact of CLD is expected to become more prominent for the Medicare population.

PARTICIPANTS

This is a retrospective cohort study of Medicare beneficiaries with a diagnosis of CLD based on inpatient (N=21 576; 14 977 unique patients) and outpatient (N=515 990; 244 196 patients) claims from 2005 to 2010.

PRIMARY AND SECONDARY OUTCOME MEASURES

The study outcomes included hospital length of stay (LOS) and inpatient mortality as well as inpatient and outpatient inflation-adjusted payments.

RESULTS

Between 2005 and 2010, there was an annual decrease in LOS of 3.17% for CLD-related hospitalisations. Risk-adjusted in-hospital mortality decreased (OR 0.90, 95% CI 0.87 to 0.94), while short-term postdischarge mortality remained stable (1.00, 0.98 to 1.03). Inpatient per-claim payment increased from $11 769 in 2005 to $12 347 in 2010 (p=0.0006). Similarly, the average yearly payments for outpatient care increased from $366 to $404 (p<0.0001). This change in payment was observed together with a consistent decrease in the proportion of beneficiary-paid amount (25.4-20%, p<0.0001) as opposed to Medicare-paid amount (73.1-80%, p<0.0001). The major predictors of higher outpatient payments were younger age, Asian race or Hispanic ethnicity, living in California, and having more diagnoses and outpatient procedures per claim. The predictors of inpatient spending also included younger age, location and the number of inpatient procedures.

CONCLUSIONS

Length of inpatient stay and inpatient mortality among Medicare beneficiaries with CLD decreased, while inpatient and outpatient spending increased.

Assessment of atherosclerosis in obese adolescents: positive correlation of mean platelet volume and carotid intima media thickness

AIMS

This study aims to assess the correlation of mean platelet volume (MPV) and common carotid artery (CCA) thickness in a population of obese adolescents.

METHODS

Sixty-eight patients and 23 controls were enrolled. Anthropometric measurements, triglyceride, total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, alanine aminotransferase, aspartate aminotransferase, γ-glutamyl transpeptidase, hemoglobin, white blood cell count, platelet count, MPV and insulin resistance by homeostasis model of assessment of insulin resistance were investigated. Furthermore, CCA thickness was measured by high-resolution ultrasound.

RESULTS

MPV and the left CCA thickness were significantly higher in obese adolescents than the healthy controls. The association between MPV and left CCA was checked by linear regression analysis. MPV explained 19% of the variation in left CCA (P < 0.001). At multiple regression analysis, MPV maintained a positive association with the left CCA thickness (P = 0.002) independently of fatty liver grade, relative weight, total cholesterol and homeostasis model of assessment of insulin resistance.

CONCLUSION

MPV is significantly correlated with CCA thickness in obese adolescents.

High rates of fructose malabsorption are associated with reduced liver fat in obese African Americans

OBJECTIVE

African Americans commonly have lower liver fat accumulation than Hispanics, despite a similar propensity for obesity. Both ethnicities exhibit high consumption of fructose-containing beverages, which has been associated with high liver fat owing to the lipogenic properties of fructose. Therefore, differences in fructose absorption may be an important factor in regulating liver fat deposition. We hypothesized that fructose malabsorption in African Americans may reduce hepatic delivery of fructose, thus contributing to lower liver fat deposition compared to Hispanics.

METHODS

Thirty-seven obese young adults aged 21.4 ± 2.1 years (16 African American, 21 Hispanic) underwent a 3-hour hydrogen (H2) breath test to assess fructose malabsorption. Magnetic resonance imaging was used to determine visceral and subcutaneous adipose tissue volume and liver fat. Fructose malabsorption was expressed as an area under the curve for H2 production (H2 AUC).

RESULTS

Compared to Hispanics, African Americans had lower liver fat (5.4% ± 5.0% vs 8.9% ± 2.3%, p = 0.02) and a higher prevalence of fructose malabsorption (75.0% vs 42.9%; p = 0.05). Liver fat was negatively related to the extent of fructose malabsorption in African Americans (r = -0.53, p = 0.03), and this relationship was independent of the volumes of total fat and subcutaneous and visceral adipose tissue. There were no significant relationships between liver fat and fructose malabsorption in Hispanics.

CONCLUSION

African Americans have both a higher prevalence and a greater magnitude of fructose malabsorption than Hispanics. In African Americans, fructose malabsorption was negatively correlated with liver fat, which may be protective against fatty liver disease.

Anthropometric and clinical factors associated with mortality in subjects with nonalcoholic fatty liver disease

AIM

Nonalcoholic fatty liver disease (NAFLD) is the hepatic manifestation of metabolic syndrome and may be associated with increased mortality. Our aim was to determine whether anthropometric measures are independently associated with mortality in NAFLD.

METHODS

The third National Health and Nutrition Examination Surveys (1988-1994) data was used. Extensive radiologic, serologic and clinical data were available. NAFLD was defined as moderate-to-severe hepatic steatosis on the hepatic ultrasound in the absence of any cause of chronic liver disease (e.g. hepatitis C virus RNA negative, hepatitis B-surface antigen negative, normal transferrin saturation and alcohol consumption <20 gram/day). Anthropometric measures [body mass index (kg/m(2)), waist, hip, arm, and thigh circumferences (cm), waist-to-hip ratio, percentage of body fat, and sum of skinfolds (mm)], laboratory measures and clinico-demographic data were analyzed. Statistical analyses were conducted with SUDAAN 10.0.

RESULTS

A total of 10,565 adult participants were included [2,510 (weighted 21 %) with NAFLD and 8,055 non-NAFLD controls]. In multivariate analysis, NAFLD was independently associated with being Mexican-American (including Hispanic or other ethnicity), larger waist circumference (cm), type-2 diabetes, insulin resistance and hypertension. After about 14 years (median) of follow up, liver-specific mortality was independently associated with NAFLD and being White.

CONCLUSIONS

Components of metabolic syndrome, and Mexican-American ethnicity are independently associated with NAFLD. Furthermore, NAFLD is an independent predictors of liver-specific mortality in men and Whites.

Pediatric obesity: a review for the child psychiatrist

Child and adolescent psychiatrists frequently encounter children who are obese in their practices and may be asked to work alongside primary care physicians and other specialists who treat youngsters with obesity. To offer expert consultation, they must understand all aspects of the pediatric obesity epidemic. By summarizing the relevant endocrinology, cardiology, nutrition, exercise science, and public health literature, this review of pediatric obesity assesses the epidemic's background, delineates the challenges of clinical care, and appraises the therapeutic recommendations for this population of patients and their families.

Mean platelet volume in obese adolescents with nonalcoholic fatty liver disease

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is the accumulation of excess fat in the liver in the absence of alcohol consumption, which commonly coexists with obesity. NAFLD is associated with increased risk of atherosclerosis and insulin resistance. Mean platelet volume (MPV) is a marker of platelet activation, which is a determinant of atherosclerosis.

AIMS

The first aim of the present study was to investigate the MPV levels in obese adolescents and compare the MPV levels in patients with and without NAFLD and also with healthy controls. The second aim of this study was to evaluate the relationship between IR and MPV.

PATIENTS AND METHODS

Case records of 128 exogenous obese adolescents were retrospectively evaluated. Laboratory parameters were collected by using a computerized patient database. Insulin resistance was calculated by a homeostasis model assessment (HOMA-IR) index. Patients were divided into two groups: patients with NAFLD (Group 1) and patients without NAFLD (Group 2). Forty-seven healthy children constituted the control group.

RESULTS

MPV was significantly higher in obese adolescents than their healthy peers. Group 1 had significantly higher MPV than group 2. HOMA-IR was significantly higher in group 1 than group 2. MPV was significantly higher in patients with IR than patients without IR. There was a positive correlation between MPV and HOMA-IR. MPV was inversely correlated with HDL cholesterol and platelet count.

CONCLUSION

MPV may be used as a follow-up marker in patients with NAFLD at the point of atherosclerosis.

Pediatric obesity: a review for the child psychiatrist

Child and adolescent psychiatrists frequently encounter children who are obese in their practices and may be asked to work alongside primary care physicians and other specialists who treat youngsters with obesity. To offer expert consultation, they must understand all aspects of the pediatric obesity epidemic. By summarizing the relevant endocrinology, cardiology, nutrition, exercise science, and public health literature, this review of pediatric obesity assesses the epidemic's background, delineates the challenges of clinical care, and appraises the therapeutic recommendations for this population of patients and their families.

Nonalcoholic fatty liver disease after liver transplantation for cryptogenic cirrhosis or nonalcoholic fatty liver disease

Nonalcoholic steatohepatitis (NASH) may account for many cases of cryptogenic cirrhosis. If so, then steatosis might recur after liver transplantation. Two thousand fifty-two patients underwent primary liver transplantation for chronic liver disease between 1986 and 2004. Serial liver biopsy samples were assessed for steatosis and fibrosis. Two hundred fifty-seven patients (12%) had a pretransplant diagnosis of cryptogenic cirrhosis (239) or NASH (18). Fatty liver developed in 31% and was more common when the pretransplant diagnosis was NASH (45% at 5 years versus 23% for cryptogenic cirrhosis, P = 0.007). NASH developed in only 4% and occurred exclusively when steatosis had already occurred. Steatosis after liver transplantation was associated with the baseline body weight and body mass index by univariate analyses, but no pretransplant or posttransplant characteristic independently predicted steatosis after liver transplantation because obesity was so common in all groups. Five percent and 10% developed bridging fibrosis or cirrhosis after 5 and 10 years, respectively, and this was more common after NASH (31%) than in those who developed steatosis alone (6%) or had no fat (3%, P = 0.002). One-, 5-, and 10-year survival was the same in patients who underwent transplantation for cryptogenic cirrhosis or NASH (86%, 71%, and 56%) and in patients who underwent transplantation for other indications (86%, 71%, and 53%; not significant), but death was more often due to cardiovascular disease and less likely from recurrent liver disease. In conclusion, fatty liver is common after liver transplantation for cryptogenic cirrhosis or NASH but is twice as common in the latter group; this suggests that some cryptogenic cirrhosis, but perhaps not all, is caused by NASH. Posttransplant NASH is unusual, and steatosis appears to be a prerequisite. Advanced fibrosis is uncommon, and survival is the same as that of patients who undergo transplantation for other causes.

The healthcare burden imposed by liver disease in aging Baby Boomers

The Baby Boomer generation is composed of 78 million Americans who are just beginning to reach their retirement years. Most Boomers have at least one chronic health problem, and these significantly increase the expense of providing medical care. Liver disease is the 12th most common cause of death in the United States, representing a relatively small portion of overall healthcare costs compared with cardiovascular disease and malignancy. Nonetheless, hepatitis C and fatty liver disease are more common in the Boomers and may play a more dominant role as they age. As a consequence, primary liver cancer is likely to become more prevalent. As with most chronic illnesses, prevention rather than disease management is likely to have the greatest impact. For those already afflicted by chronic liver disease, recognition and treatment can reduce the incidence of late complications, as was clearly demonstrated with chronic hepatitis B and C. Perhaps obesity is the greatest threat to our future health, and fatty liver disease, although likely preventable, will probably become the disease that fills the waiting rooms of future hepatologists.

Kupffer cell activation by ambient air particulate matter exposure may exacerbate non-alcoholic fatty liver disease

Owing to increased obesity, non-alcoholic fatty liver disease (NAFLD) is now the most prevalent liver disease in the United States. NAFLD is considered a component of metabolic syndrome, a cluster of disorders that also includes diabetes mellitus, dyslipidemia, arteriosclerosis, and hypertension. Exposure to ambient air particulate matter with aerodynamic diameters < 2.5 microm (PM(2.5)) is a risk factor for arteriosclerosis and lung disease, but its effect on NAFLD is unknown. PM(2.5) induces pulmonary dysfunction via Toll-like receptor (TLR) activation on alveolar macrophages. TLR activation of Kupffer cells, resident hepatic macrophages, and subsequent pro-inflammatory cytokine production have been shown to play a key role in NAFLD progression. We hypothesized that PM(2.5) exposure is a significant risk factor for the progression of NAFLD. Thus, following exposure of male C57BL/6 mice fed high fat chow (HFC) to concentrated air particulate matter (CAPs) or filtered air for 6 weeks, progression of NAFLD was evaluated by standardized histological assessment of hepatic inflammation and fibrosis. In mice fed HFC, the hepatic inflammatory grade (3.00 +/- 0.00 vs. 1.50 +/- 0.71, P < 0.001) and fibrosis stage (1.00 +/- 0.00 vs. 0.60 +/- 0.52, P = 0.023) were both significantly higher in mice exposed to CAPs versus filtered air, respectively. Increased numbers of Kupffer cells contained PM in CAPs-exposed mice scores of (2.00 +/- 0.94 vs. 0.20 +/- 0.42, respectively, P < 0.001). PM exposure increased IL-6 secretion up to seven-fold in a dose-dependent manner by isolated wild-type but not TLR4(-/-) Kupffer cells (P < 0.050). In conclusion, ambient PM(2.5) exposure may be a significant risk factor for NAFLD progression.

Kupffer cell activation by ambient air particulate matter exposure may exacerbate non-alcoholic fatty liver disease

Owing to increased obesity, non-alcoholic fatty liver disease (NAFLD) is now the most prevalent liver disease in the United States. NAFLD is considered a component of metabolic syndrome, a cluster of disorders that also includes diabetes mellitus, dyslipidemia, arteriosclerosis, and hypertension. Exposure to ambient air particulate matter with aerodynamic diameters < 2.5 microm (PM(2.5)) is a risk factor for arteriosclerosis and lung disease, but its effect on NAFLD is unknown. PM(2.5) induces pulmonary dysfunction via Toll-like receptor (TLR) activation on alveolar macrophages. TLR activation of Kupffer cells, resident hepatic macrophages, and subsequent pro-inflammatory cytokine production have been shown to play a key role in NAFLD progression. We hypothesized that PM(2.5) exposure is a significant risk factor for the progression of NAFLD. Thus, following exposure of male C57BL/6 mice fed high fat chow (HFC) to concentrated air particulate matter (CAPs) or filtered air for 6 weeks, progression of NAFLD was evaluated by standardized histological assessment of hepatic inflammation and fibrosis. In mice fed HFC, the hepatic inflammatory grade (3.00 +/- 0.00 vs. 1.50 +/- 0.71, P < 0.001) and fibrosis stage (1.00 +/- 0.00 vs. 0.60 +/- 0.52, P = 0.023) were both significantly higher in mice exposed to CAPs versus filtered air, respectively. Increased numbers of Kupffer cells contained PM in CAPs-exposed mice scores of (2.00 +/- 0.94 vs. 0.20 +/- 0.42, respectively, P < 0.001). PM exposure increased IL-6 secretion up to seven-fold in a dose-dependent manner by isolated wild-type but not TLR4(-/-) Kupffer cells (P < 0.050). In conclusion, ambient PM(2.5) exposure may be a significant risk factor for NAFLD progression.