ACG Review (Zobair Younassi, MD): NAFLD and NASH

For PDF copy of slides: NAFLD and NASH

Dr. Zobair Younassi gave a recent virtual grand rounds –here are some of the slides:

Epidemiology:

Natural History:

  • Progression of disease is not linear
  • Fatty liver disease is a multisystem disorder.  Cardiovascular disease is leading cause of death in patients with fatty liver disease
  • Fatigue (~50%) is common with fatty liver disease

Main treatment:

  • Weight loss -Mediterranean diet may be helpful
  • Exercise
  • No FDA-approved treatments, though pioglitizone supported by AASLD for biopsy-proven NASH
  • Public health interventions are needed

Liver Shorts -February 2020

Caution with hemoglobin A1c interpretation: MM Kelsey et al. J Pediatr 2020; 216: 232-5. In the HEALTHY Study (n=8814), the authors note that a hemoglobin A1c was ≥5.7% in 2% of normal weight youth.  “This suggests need for cautious interpretation of prediabetes hemoglobin A1cs in youth”

Daily aspirin for NAFLD: TG Simon et al. Clin Gastroenterol Hepatol 2019; 17: 2776-84.  In this prospective cohort of 361 adults with biopsy-proven NAFLD, the use of daily aspirin (in 151) was associated with lower odds of NASH (aOR.68) and reduced risk of  fibrosis (aOR 0.54).  “The greatest benefit found with at least 4 years or more of aspirin use” (aHR =0.50).  The associated editorial (pages 2651-3) recommends controlled studies to determine if potential benefits outweigh the known risks (eg. bleeding).

Glecaprevir/pibrentasvir for HCV Treatment Failure:  AS Lok et al. Gastroenterol 2019; 157: 1506-17.  This randomized study with 177 patients showed that 16 weeks of glecaprevir and pibrentasvir was effective in retreatment of patients with genotype 1 hepatitis C viral infection (after prior failure with sofosbuvir plus an NS5A inhibitor).  The sustained virologic response 12 weeks after treatment was >90%.

Liver transplantation for Niemann-Pick Disease, type B:  YLY Luo et al. Liver Transplantation 2019; 25: 1233-40. This report analyzed 7 children receiving liver transplantation for Niemann-Pick disease, type B.  The authors report survival in the entire cohort and with normalized liver function within 3 weeks.  In addition, they noted improvement in psychomotor ability ( 10 months after transplantation) and resolution of insterstitial lung disease.  They state that developmental delay still existed in 4 patients during follow-up.  The editorial (1140-1) notes that these findings need to be confirmed but open a new window in improving the phenotype.  “A similar experience occurred with LT in maple syrup urine disease (MSUD), in which the liver is considered to host only 12-15% of the defective  enzyme responsible for the disease…in MSUD, liver replacement is able to counteract 85% of extrahepatic expression of the disease and to completely correct the phenotype.”

Increased Abdominal-Surgery Risk in Patients with Idiopathic Noncirrhotic Portal Hypertension: L Elkrief et al. Hepatology 2019; 70: 911-24. Among 44 patients (median age 44 years) with noncirrhoitic portal hypertension, 16 (33%) had one or more portal hypertension-related complication within 3 months after surgery.  4 (9%) died within 6 months.  “An unfavorable outcome (i.e. either liver or surgical complication or death) occurred in 22 (50%) patients” and was more likely in those with ascites, creatinine >100 micromol/L, or other extrahepatic complications related to portal hypertension.

One of my blog readers shared this image of “Liver Shorts” that can be purchased online

Bad Fatty Liver Disease Can Get Worse Quickly

A recent study (AJ Sanyal et al. Hepatology 2019; 70: 1913-27) used prospectively collected data from two large randomized, placebo-controlled phase 2b studies of simtuzumab in patients with either bridging fibrosis (n=217) or compensated cirrhosis (n=258) due to nonalcoholic fatty liver disease (NAFLD). The age range of participants were 48-61 years with median ages of 55 years and 57 years for the two cohorts.  All patients had liver biopsies at screening and at weeks 48 and 96.

Key findings:

  • Progression to cirrhosis occurred in 22% (48/217) of patients with bridging fibrosis (F3) over a median of 29 months
  • Liver-related adverse clinical events (eg. ascites, variceal bleeding, encephalopathy, MELD score ≥15, liver transplantation or death) occurred in 19% (50/258) with compensated cirrhosis over a median of 29 months. Only 1 patient in this cohort died.
  • Higher  baseline hepatic fibrosis or serum markers of fibrosis were associated with disease progression in patients with F3 disease

My take: Among those with advanced liver disease, this study indicates that disease progression/deterioration is rather rapid in about 20%.

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China Is Catching and Passing U.S. with NAFLD Plus Updates

F Zhou et al. Hepatology 2019; 70: 1119-33. The authors performed a systematic review (n=392 studies, more than 2 million subjects) and found that NAFLD in China increased from 25.4% in 2008-2010 to 32.3% in 2015-2018. The pooled prevalence across all studies was 29.2%. The associated editorial speculates that some of this increase is related to diet changes as well as PNPLA3 gene.  This allele “is more common among East Asians than Caucasians”  It is lower in African Americans in the U.S. which helps explain why this population is at reduced risk.

JB Schwimmer, JS Johnson et al Gastroenterol 2019; 157: 1109-22.  In this prospective study with 87 children (89% Hispanic), the authors associated fecal microbiomes with NAFLD and NASH.  Both NAFLD and NASH were associated with intestinal dysbiosis with lower diversity and high abundance of Prevotella copri. Full text link: Microbiome Signatures Associated With Steatohepatitis and Moderate to Severe Fibrosis in Children With Nonalcoholic Fatty Liver Disease

S Pelusi et al. Clin Gastroenterol Hepatol 2019; 17: 2310-9.  This study analyzed data from 1738 subjects (45% with severe obesity) who had undergone liver biopsy.  132 of 389 (33.9%) with significant fibrosis did NOT have nonalcoholic steatohepatitis (NASH) and 39 patients (10%) had no inflammation. NASH diagnosis required steatosis (≥5% of hepatocytes), hepatocellular ballooning, and lobular inflammation. Factors associated with significant fibrosis in the absence of NASH, included fasting hyperglycemia, severe steatosis, mild inflammation or ballooning, and PNPLA3 1148M variant.  My take: this study shows that the finding of NASH on liver biopsy is NOT required for the development of severe liver disease related to NAFLD.

D Linden et al. Molecular Metabolism 2019; 22: 49-61. This study, summarized in Gastroenterol 2019; 157: 1156-9) showed that PNPLA3 silencing with antisense oligonucleotides ameliorates NASH in PNPLA3 1148M knock-in mice.  The summary notes that the mutated 1148 M PNPLA3 protein variant accumulates on lipid droplets altering clearance and affecting triglycerides and phospholipid turnover.

Liver Briefs -September 2019

P Rosenthal et al. Hepatology 2019; 69: 2326-37.  This study examined the efficacy and safety of combined entecavir and Peginterferon for immune-tolerant chronic hepatitis B-infected children (n=60). 48 weeks after completing treatment (week 96), 2 children (3%) achieved the primary outcome of undetectable HBeAg with HBV DNA levels <1000 IU/mL.  These two children were also HBsAg negative/anti-HBs positive. In the other children (55 completed study), the ALT and HBV DNA levels were similar to baseline.  37 children experienced adverse events.  My take: Entecavir/peginterferon is not very effective in immune-tolerant children infected with chronic HBV.

DL Thomas. NEJM 2019; 380: 2041-50. This article reviews the pathway to the global elimination of chronic hepatitis.  Currently, it is estimated that hepatitis C virus (HCV) and hepatitis B virus (HBV) kill more than 1 million persons each year. “In fact, by 2040, deaths from chronic hepatitis are projected to exceed the combined mortality associated with HIV infection, tuberculosis, and malaria.”

JR Dillman et al. J Pediatr 2019; 212: 60-5. This study with 41 patients and 13 patients with biliary atresia prospectively assessed ultrasound shear wave elastography (SWE). The authors found that SWE with a cut-off value of >1.84 m/s had 92% sensitivity and 79% specificity.  Also, in their cohort, GGT >320 had a sensitivity of 100% and specificity of 78%.

Z Younossi et al. Hepatology 2019; 69: 2672-82.  This review provides a global perspective of NAFLD.  25% of the world’s population is currently thought to have NAFLD with highest prevalence in South America at 30.45% and lowest in Africa at 13.5%. This article usggest North America to have 24.1% prevalence rate.

NAFLD Outcomes After Bariatric Surgery

A recent systematic review and meta-analysis (Y Lee, et al. Clin Gastroenterol Hepatol 2019; 17: 1040-60) included 32 cohort studies with 3093 liver biopsy specimens from patients with nonalcoholic fatty liver disease (NAFLD).

Key findings:

  • Bariatric surgery resulted in a biopsy-confirmed resolution of steatosis in 66%, inflammation in 50%, ballooning degeneration in 76%, and fibrosis in 40%.
  • Bariatric surgery resulted in worsening features of NAFLD in 12%.
  • The authors note that Roux-en-Y Gastric Bypass (RYGB) “showed greater reduction of liver side effects and higher: resolution of NAFLD.”
  • Jejejnoileal bypass (JIB) and biliopancreatic diversion (BPD) “both have been associated with higher liver function morbidity.”
  • The overall GRADE quality of evidence was considered very low.

My take: Though better studies are needed, the majority of patients’ livers appear to benefit from bariatric surgery.

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How Often Do Children with Obesity Have a Fatty Liver?

According to a recent study (EL Yu et al. J Pediatr 2019; 207: 64-70), about one-third of boys and one-fourth of girls with obesity have nonalcoholic fatty liver disease (NAFLD).

This study from San Diego with 408 children aged 9-17 years (mean 13.2 years) with obesity evaluated for NAFLD with laboratories (to exclude other etiologies) and with liver MRI proton density fat fraction (PDFF), with ≥5% considered the threshold for NAFLD.

Key findings:

  • Prevalence of NAFLD was 26% in this population, with 29.4% in males and 22.6% in females
  • The optimal cut offs of ALT for detecting NAFLD in this study were ≥30 U/L for females and ≥42 U/L for males. These are much lower than NASPGHAN guidelines which proposed ≥80 U/L or twice the ULN as thresholds for further investigation.  (The NASPGHAN recommendations are likely to have higher specificity in identifying children at greater risk for nonalcoholic steatohepatitis (NASH).)

Limitations:

  • 77% of this cohort were hispanic, thus prevalence may vary significantly in other populations.
  • MRI-PDFF -the exact cut off is unclear.  The authors note that if 3.5% were chosen, the NAFLD prevalence jumped to 49.3% (according to Table II –though the discussion stated 53.2%)

My take: Understanding the likelihood of NAFLD in children at risk is a helpful first step.  This study points to the growing use of non-invasive diagnosis with MRI.

On a related topic, briefly noted: “Obesity in Adolescents and Youth: The Case for and against Bariatric Surgery” (A Khattab, MA Sperling. J Pediatr 2019; 207: 18-22). In this review, the authors refer frequently to endocrine society guidelines (J Clin Endocrinol Metab 2017; 102: 709-57).    These guidelines generally recommend bariatric surgery only under specific conditions (eg. completion of Tanner 4 or 5 along with a BMI of 40 kg/m-squared or BMI of 35 with significant extreme comorbidities after failure of lifestyle modifications & without untreated psychiatric illness).  This review predicts increasing use of bariatric surgery in adolescents “as more data on long-term outcomes in larger cohorts become known.”

Related blog posts on fatty liver disease:

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Liver Shorts Feb 2019

ZM Younossi et al. Hepatology 2019; 69: 564-72. This study, using Markov models for nonalcoholic steatohepatitis (NASH), estimated that there are 6.65 million adults with NASH in the U.S. and that lifetime costs will be $.222.6 billion.

Y Chang et al. Hepatology 2019; 69: 64-75.  This study with 58,927 Koreans with non-alcoholic fatty liver disease (NAFLD), found that nonheavy alcohol consumption was “significantly and independently associated with worsening of noninvasive markers of fibrosis, indicating that even moderate alcohol consumption might be harmful.”

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KA Forde et al. Hepatology 2019; 69: 270-81.  This study examined screening for hepatopulmonary syndrome (HPS) in patients (n=363) evaluated for liver transplantation (LT). It found that pulse oximetry had low sensitivity for detecting HPS. Overall, 21% of the cohort had HPS. “We found that pulse oximetry essentially performed no better than chance (i.e.. a ‘coin flip’) in the discrimination of patients with HPS from all-comers.” 18% of patients with an SpO2 of 96% or higher had HPS. Based on their findings, the authors recommend that routine screening of LT candidates include ABG and contrast-enhanced echocardiograpy.

From Joshua Tree National Park..Gorgeous views from Ryan Mountain

Low Free Sugar Diet for Nonalcoholic Fatty Liver Disease in Adolescent Boys

A recent randomized study (Jeffrey B. Schwimmer, MD1,2Patricia Ugalde-Nicalo, MD1Jean A. Welsh, PhD, MPH, RN3,4,5et al JAMA. 2019;321(3):256-265. doi:10.1001/jama.2018.20579) examined the beneficial effects of a low free sugar diet for Nonalcoholic Fatty Liver Disease (NAFLD) in adolescent boys.  Congratulations to the authors, particularly to Miriam Vos (my Emory colleague & corresponding author) and Jeffrey Schwimmer (whose training overlapped with mine in Cincinnati).

Key finding:

“In this randomized clinical trial that included 40 adolescent boys aged 11 to 16 years with nonalcoholic fatty liver disease followed up for 8 weeks, provision of a diet low in free sugars compared with usual diet resulted in a greater reduction in hepatic steatosis [based on MRI] from 25% to 17% in the low free sugar diet group and from 21% to 20% in the usual diet group, a statistically significant difference of −6.23% when adjusted for baseline.”

Summary of this study in NY Times: To Fight Fatty Liver, Avoid Sugary Foods and Drinks

An excerpt from NY Times:

To make the diet easier and more practical for the children in the limited-sugar group to follow, the researchers asked their families to follow it as well. They tailored the diet to the needs of each household by examining the foods they consumed in a typical week and then swapping in lower sugar alternatives. If a family routinely ate yogurts, sauces, salad dressings and breads that contained added sugar, for example, then the researchers provided them with versions of those foods that did not have sugar added to them.

Fruit juices, soft drinks and other sweet drinks were forbidden. They were replaced with unsweetened iced teas, milk, water and other nonsugary beverages. Dietitians prepared and delivered meals to the families twice a week, which helped them stick to their programs.

Full abstract:

Importance  Pediatric guidelines for the management of nonalcoholic fatty liver disease (NAFLD) recommend a healthy diet as treatment. Reduction of sugary foods and beverages is a plausible but unproven treatment.

Objective  To determine the effects of a diet low in free sugars (those sugars added to foods and beverages and occurring naturally in fruit juices) in adolescent boys with NAFLD.

Design, Setting, and Participants  An open-label, 8-week randomized clinical trial of adolescent boys aged 11 to 16 years with histologically diagnosed NAFLD and evidence of active disease (hepatic steatosis >10% and alanine aminotransferase level ≥45 U/L) randomized 1:1 to an intervention diet group or usual diet group at 2 US academic clinical research centers from August 2015 to July 2017; final date of follow-up was September 2017.

Interventions  The intervention diet consisted of individualized menu planning and provision of study meals for the entire household to restrict free sugar intake to less than 3% of daily calories for 8 weeks. Twice-weekly telephone calls assessed diet adherence. Usual diet participants consumed their regular diet.

Main Outcomes and Measures  The primary outcome was change in hepatic steatosis estimated by magnetic resonance imaging proton density fat fraction measurement between baseline and 8 weeks. The minimal clinically important difference was assumed to be 4%. There were 12 secondary outcomes, including change in alanine aminotransferase level and diet adherence.

Results  Forty adolescent boys were randomly assigned to either the intervention diet group or the usual diet group (20 per group; mean [SD] age, 13.0 [1.9] years; most were Hispanic [95%]) and all completed the trial. The mean decrease in hepatic steatosis from baseline to week 8 was significantly greater for the intervention diet group (25% to 17%) vs the usual diet group (21% to 20%) and the adjusted week 8 mean difference was −6.23% (95% CI, −9.45% to −3.02%; P < .001). Of the 12 prespecified secondary outcomes, 7 were null and 5 were statistically significant including alanine aminotransferase level and diet adherence. The geometric mean decrease in alanine aminotransferase level from baseline to 8 weeks was significantly greater for the intervention diet group (103 U/L to 61 U/L) vs the usual diet group (82 U/L to 75 U/L) and the adjusted ratio of the geometric means at week 8 was 0.65 U/L (95% CI, 0.53 to 0.81 U/L; P < .001). Adherence to the diet was high in the intervention diet group (18 of 20 reported intake of <3% of calories from free sugar during the intervention). There were no adverse events related to participation in the study.

Conclusions and Relevance  In this study of adolescent boys with NAFLD, 8 weeks of provision of a diet low in free sugar content compared with usual diet resulted in significant improvement in hepatic steatosis. However, these findings should be considered preliminary and further research is required to assess long-term and clinical outcomes.

 

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