Tag Archives: NAFLD

NAFLD –Analogous to a Dog Chasing A Bus?

Posted on by

I am not sure of the origin of the expression “what is a dog going to do if it catches a bus?”  However, I am reminded of this expression after reading a recent article about nonalcoholic fatty liver disease (J Pediatr 2014; 164: 707-13).

This retrospective study, “Histologic Abnormalities in Children with Nonalcoholic Fatty Liver Disease with Normal or Mildly Elevated Alanine Aminotransferase Levels,” analyzed 91 children (5-18 years) with suspected NAFLD who had normal or mildly elevated ALT values from 12 U.S. medical centers.  They obtained liver biopsy specimens within 180 days of the ALT measurement and compared them from 392 children with elevated ALT.

When reading this title, one has to wonder, how did they select these children for this study?  First of all the authors used two NASH CRN databases with 483 children.  The reasons for NAFLD evaluation at entry in the current study included symptoms of liver disease in 22%, identification during evaluation of another illness in 38%, routine physical exam (41%), and other causes in 6%. At one point, elevated ALT was evident in 74% and radiographic evidence of steatosis in 55%.

The authors conclude that “liver biopsy specimens from children with NAFLD with normal or mildly elevated ALT levels show significant histological abnormalities, including advanced fibrosis…measurement of ALT may underestimate liver injury in NAFLD.” Yet, while it is true that ALT values may not have adequate sensitivity for liver injury, the authors deploy some circular logic; when one understands the selection of these patients, it comes as no surprise that some had advanced liver findings on biopsy.  If one identifies an abnormal liver on ultrasound and confirms this on liver biopsy, this is targeting a population whose findings are not generalizable.

Outside of a research study, how does one decide which patients will benefit from a liver biopsy? This study does not offer any clarity.

And, if one identifies more cases of NAFLD, what is one to do?  Besides weight loss (which should be recommended already in the majority), there are no other proven treatments.  The associated editorial (pgs 684-86) reminds the reader to use appropriate normative values for ALT (<25.8 U/L for boys and <22.1 U/L for girls).  In the study’s discussion, the lack of consensus among expert recommendations is acknowledged.  Furthermore, in those who have recommended frequent screening with ALT values in obese children, the authors note that “evidence of the utility and cost-effectiveness of this approach is still lacking.”

Another study in the same issue (J Pediatr 2014; 164: 699-706) suggests a possible link between obstructive sleep apnea (OSA) and more advanced liver histology in NAFLD.  This was a cross-sectional study with only 25 patients (88% Hispanic, mean age 12.8 years).  The authors speculate that nighttime hypoxemia triggers oxidative stress and may induce further liver injury.  53% of those with OSA had stage 2 or higher fibrosis compared with only 10% of those without OSA.

Bottomline: NAFLD occurs in a lot of children and a normal or mildly elevated ALT does not exclude more severe disease.  OSA may be either an epiphenomenon or a causative factor for more severe NAFLD findings.

Related blog posts:

The Liver –Front and Center

Posted on by

Before proceeding with today’s post, those who read yesterday’s post may be interested in Atul Gawande’s take on the NEJM checklist publication -here’s the link (from Atul Gawande’s twitter feed): bit.ly/1d6v31z. 

A recent review “Extrahepatic Complications of Nonalcoholic Fatty Liver Disease” (NAFLD)(Hepatology 2014; 59: 1174-97) seems to position the liver as the center of a multitude of problems rather than one of many associated problems.

It is known that NAFLD increases the risk of end-stage liver disease and hepatocellular carcinoma.  However, the majority of deaths among individuals with NAFLD are attributed to cardiovascular disease and malignancy.  This lengthy review describes in great detail the associations between NAFLD and the risk of developing cardiovascular disease (CVD), type 2 diabetes mellitus (T2DM), chronic kidney disease (CKD), and colorectal neoplasm.  The presence of NAFLD appears to convey an independent increase in risk for these conditions.

Key points:

  • “The aggregated evidence provides strong evidence that individuals with NAFLD are at increased “independent” risk of developing CVD.  The risk of CVD mortality may be greater in subgroups of subjects with NASH and advanced fibrosis, compared to those with simple steatosis.”
  • “USS-defined NAFLD is associated with a 2- to 5-fold risk of developing T2DM after adjustment of several lifestyle and metabolic confounders.”
  • “NAFLD (in particular, biopsy-proven NASH) is associated with a greater prevalence of CKD (20% to 50% of patients). USS-defined NAFLD carries a 1.5- to 2-fold adjusted risk of incident CKD.”
  • “A true causal relationship between and NASH and colorectal cancer cannot be confirmed.”
  • Other potential extrahepatic manifestations: hypothyroidism, polycystic ovarian syndrome, obstructive sleep apnea syndrome, and osteoporosis.

Take-Home Message: NAFLD has independent associations for greater risk of CVD, hyperglycemia, and malignancy.  Whether these associations are simply an epiphenomenon  of more aggressive metabolic syndrome or whether the liver injury primarily causes these additional risks remains unclear.

Related blog posts:

Probiotics For Fatty Liver Disease

Posted on by

Probiotics and alterations in the microbiome are being examined for a range of ailments.  However, as noted in previous blog posts, the current evidence shows only a limited number of disorders where probiotics have been proven effective.  There is more evidence, now, that probiotics may be beneficial for nonalcoholic fatty liver disease (NAFLD).

  • Am J Clin Nutr 2014; 99: 425-6. editorial
  • Am J Clin Nutr 2014; 99: 535-42.

The referenced article examined 52 nondiabetic patients with fatty liver disease in a double-blind, randomized, placebo-controlled trial. Patients were considered to have NAFLD on the basis of an ultrasonography and an alanine aminotransferase value >60 U/L.  Those who received a probiotic were compared with a placebo group and followed for 28 weeks.

In this study, rather than a probiotic, technically, the treatment group received a synbiotic because it contained fructooligosaccharides (FOS) which are non digestible oligosaccharides in addition to a probiotic mixture.  FOS can stimulate the growth of intestinal bacteria.  The probiotic mixture included Lactobacillus case, Lactobacillus rhamnosus, Streptococcus thermopiles, Bificobacterium breve, Lactobacillus, acidophilus, B. longum, and Lactobacillus bulgaricus.

Key findings:

  • There were improvements in ALT values and in baseline mild fibrosis (estimated by Fibroscan).
  • There were decreased levels of circulating TNF-α and decreased nuclear transcription factor κβ in circulating mononuclear leukocytes –both consistent with decreased systemic inflammation

Limitations: 

  1. Study did not include liver histology (biopsy).  In addition, in nearly all subjects, the fibroscans were near normal, both before and after the intervention.  Thus, the reduction in liver stiffness is not clear cut.
  2. Small number of participants.
  3. Short study period.

Bottomline: This study along with several others points towards a potential role for modulating the microbiome to improve NAFLD along with metabolic syndrome more broadly.

Related blog posts:

 

 

 

Magnetic Resonance Elastography for Hepatic Fibrosis Assessment

Posted on by

This large case series of 35 children indicates that Magnetic Resonance Elastography (MRE) may be quite useful to assess hepatic fibrosis as well as steatosis (J Pediatr 2014; 164: 186-8).

The study (2011-2012) included 27 patients with nonalcoholic fatty liver disease (NAFLD); 22 of this group had probable or definite nonalcoholic steatohepatitis (NASH).  Other diseases included progressive familial intrahepatic cholestasis (type 2), autoimmune sclerosing hepatitis, Wilson disease, glycogenic hepatopathy (due to type 1 diabetes), and other liver conditions.  All of the patients in the study had undergone liver biopsy as well.

The authors showed that MRE had a high accuracy to detect significant fibrosis and may be better suited for severely obese patients.  At the cutoff they identified, the sensitivity was 88% and the specificity 85% for detecting significant fibrosis.

In severely obese patients, alternative imaging techniques, namely transient elastography and acoustic radiation force imaging have higher technical failure rates.  The authors note that at their institution, more than 100 MRE studies have been completed (including many without liver biopsies); thus far, only two morbidly obese patients failed completion.  In addition, the authors state that this limited study costs about twice that of an ultrasound.

Related posts:

Liver Update: Headlines and Links Only

Posted on by
  1. From AGA: Hepatic failure flagged as unexpected boceprevir safety signal in adverse event review. GI & Hep News: http://ow.ly/rSCEF 
  2. From NY Times: Spike in Harm to Liver Is Tied to Dietary Aids nyti.ms/JPN9fK 
  3. From Jeff Schwimmer (The Liver Post): First case report of Liver Cancer in a child with Nonalcoholic Fatty Liver Disease. He is only 7 years-old. http://goo.gl/6dJbzs 
  4. “Recurrence of Hepatopulmonary Syndrome Post-Orthotopic Liver Transplantation in a Patient with Noncirrhotic Portal Hypertension” Hepatology 2013; 58: 2205-06.
  5. “Management of Hepatitis B: Our Practice and How It Relates to the Guidelines” Clin Gastroenterol Hepatol 2014; 12: 16-26.  Terrific review and insights.
  6. “Acute Liver Failure” NEJM 2013; 369: 2525-34.
  7. “Cesarean Section Reduces Perinatal Transmission of Hepatitis B Virus Infection from Hepatitis B Surface Antigen-Positive Women to Their Infants” Clin Gastroenterol Hepatol 2013; 11: 1349-55. Retrospective, nonrandomized study -“performing elective cesarean section only in highly viremic mothers with pre-delivery HBV DNA levels ≥1,000,000 copies/mL may be advisable.”

Related Blog Posts:

Most Popular Posts

Posted on by

Most popular posts: In the past year, the most popular posts from this blog were the following:

I want to thank all of you who provide feedback and wish you all a good year ahead.  As always, feel free to comment on posts or to send an email with suggestions.

Screening for NAFLD

Posted on by

As noted in previous blogs (see below), there is not a consensus with regard to screening for NAFLD in overweight and obese patients.  While some have argued for aggressive screening leading to an expensive tiered evaluation, other experts have been reluctant to endorse this approach, in part due to the magnitude of the problem and due to the perceived lack of therapeutic options.  Weighing in on this controversy is a new study (Aliment Pharm Ther 2013; DOI: 10.1111/apt.12518, link -from Jeff Schwimmer’s twitter feed: http://t.co/q1CUKBJtVo).

In the study’s introduction, the prevalence of NAFLD, estimated to be 9.6% of all children aged 2-19 years, along with society guidelines are reviewed.

The authors examined information from the clinical evaluation of 347 children (>10 years) [overweight (7%)/obese (93%)] who were referred by their primary care physician due to either an elevated ALT or suspected NAFLD.  Referral was at the discretion of the primary care attending and not based on a specific ALT value.  Median age was 13.5 years and 64% were boys.

1st tier: Subsequently, all patients underwent hepatic panel, GGT, CBC/diff, and coagulation studies.  2nd tier: If abnormal, the next set of labs may have included any or all of the following: studies for hepatitis infection (HAV, HBV, HCV), HIV, alpha-1-antitrypsin, ANA, anti-smooth muscle antibody, anti-liver kidney microsomal antibody, quantitative IgG, ceruloplasmin,  24-h urinary copper, tissue transglutaminase antibody, serum IgA, serum amino acids, urine organic acids, serum acylcarnitine, creatine kinase, ESR, CRP, and thyroid studies. (The authors did not evaluate iron status.) 3rd tier: Then, if evidence of chronic liver disease, patients were offered a liver biopsy under general anesthesia.

Results:

  • 21% did not have significant liver disease (after 1st tier).  Also, 3 liver biopsies were normal.
  • 94% of 273 with evidence of chronic liver disease underwent liver biopsy; no significant complications were noted, though a small percentage had some discomfort.
  • Ultimately, 55% were determined to have NAFLD (75% of those who underwent liver biopsy.
  • The authors report that 61 patients who had a liver biopsy had another liver disease, including autoimmune hepatitis in 11, celiac disease in 4, sclerosing cholangitis in 1, and drug-induced in 6.
  • Advanced fibrosis was noted overall in 11% (38 of 347) and in 17% of those with NAFLD.  Those with advanced fibrosis were more likely to have higher aminotransferases (eg. ALT 120 U/L compared with 82 U/L), higher GGT, and higher ceruloplasmin; however, there was significant overlap.
  • Approximately half of NAFLD patients had steatohepatitis.

Take-home message: while this article does not resolve the issue of whether screening overweight/obese children is the best strategy, it does provide useful information in those with elevated liver tests.  Careful investigation for treatable causes (and possibly nontreatable) of liver disease is worthwhile in those with sustained abnormalities in transaminases.  At a minimum, tests for autoimmune hepatitis, celiac disease, viral hepatitis, and Wilson’s disease should be at the top of the list.

Related blog entries:

Breakthrough for Fatty Liver Disease?

Posted on by

Could bile acids play a role in reducing metabolic syndrome and in particular fatty liver disease?  This question is now being studied (Gastroenterology 2013; 145: 574-82).

This recent study examined whether obeticholic acid (OCA) which is a semisynthetic derivative of the human bile acid chenodeoxycholic acid could aid with insulin resistance and ultimately nonalcoholic fatty liver disease (NAFLD).  OCA is an agonist of the farnesoid X receptor which is a nuclear hormone receptor that regulates glucose and lipid metabolism.

The authors performed a phase 2, double-blind, placebo-controlled study to assess the effects of OCA on insulin sensitivity in patients with NAFLD and type 2 diabetes mellitus.  Patients received either placebo (n=23), 25 mg OCA (n=20), or 50 mg OCA (n=21) once daily for 6 weeks.  Using an insulin clamp, insulin sensitivity was measured before and after the study period.  Numerous blood tests were obtained as well.

Results:

  • Insulin sensitivity improved 28% in the 25mg OCA group and 20.1% in the 50 mg OCA group whereas it decreased 5.5% in the placebo group.
  • The OCA groups also had significant reductions in gamma-glutamyltransferase, alanine aminotransferase, and dose-related weight loss.
  • Markers of liver fibrosis decreased in the 25 mg OCA group.
  • Side effects of OCA were minimal.  Constipation was reported in the 50 mg OCA group.

Take-home message: OCA may help patients with NAFLD and a bigger, longer study is in the works (FLINT study: 25 mg OCA for 72 weeks compared with placebo, http://www.clinicaltrials.gov; NCT01265498)

Related blog posts:

.

Pediatric Fatty Liver Disease -in the news

Posted on by

An excerpt from The Wall Street Journal, Fatty Liver Disease: More Prevalent in Children (also covered by this blog previously: Increasing prevalence of pediatric NAFLD | gutsandgrowth):

A type of liver disease once thought to afflict primarily adult alcoholics appears to be rampant in children.

image

Some 1 in 10 children in the U.S., or more than 7 million, are thought to have the disease, according to recent studies.

The condition, in which the normally rust-colored organ becomes bloated and discolored by yellowish fat cells, has become so common in non-drinkers that it has been dubbed nonalcoholic fatty liver disease.

The disease’s prevalence is alarming doctors who worry about its progression to nonalcoholic steatohepatitis, or NASH, when the fatty liver becomes inflamed and cells are damaged. That leads to the end stage of cirrhosis, when the liver forms scar tissue and ultimately stops working.

Organ Damage

Some facts about nonalcoholic fatty liver disease:

  • About 10% of children in the U.S. are thought to have the condition.
  • Several factors likely contribute, including genetics, obesity, diet and insulin resistance.
  • It has no detectable symptoms.
  • Weight loss is the standard treatment for earlier stages of liver disease.

The condition’s rise is tied to the obesity epidemic—about 40% of obese children have it—but isn’t caused solely by being overweight. The disease appears to be growing among normal-weight children too, experts say.

And even though obesity rates are starting to level off, the prevalence of fatty liver disease continues to rise, they say.

It also has no symptoms, which means a person could have it for decades without knowing. 

Full link:

Fatty Liver Disease: More Prevalent in Children

Related blog entries:

Does NAFLD cause hepatocellular cancer?

Posted on by

Probably (Clin Gastroenterol Hepatol 2012; 10: 1342-59).

The authors of this study reviewed original reports between 1992-2011 and narrowed them to those with pertinent information regarding evidence of whether non-alcoholic fatty liver disease (NAFLD) or non-alcoholic steatohepatitis (NASH) contributed to a higher risk of hepatocellular carcinoma (HCC).

17 cohort studies, 18 case-control and cross-sectional studies, and 26 case series were identified.

Results:

  • Cohorts with NASH and cirrhosis had a consistently higher risk of HCC; cumulative risk ranged from 2.4% over seven years to 12.8% over 3 years.
  • Cohorts with few or no cases of cirrhosis had a minimal risk of HCC; cumulative risk of HCC mortality was 0-3% for study periods up to 20 years.

The results of patients with NASH and cirrhosis are in agreement with a recent presentation at AASLD meeting; however, there may be a small risk even in the absence of cirrhosis (Fatty Liver Disease Cited for Rise in Hepatocellular Carcinoma November 2012):

“Of 17,895 HCC cases in the linked Surveillance, Epidemiology and End Results (SEER)-Medicare database, 2,863 (16%) had only NAFLD without any other risk factors or etiologies for HCC. The linked database covers 30% of the U.S. Medicare population. SEER itself contains data from 18 cancer registries covering 28% of the U.S. population.” In addition, “Cirrhosis was not present in 36% of the NAFLD-related HCC cases.” In the SEER database, the odds ratio for developing HCC with cirrhotic NAFLD was 16.5 compared with those with noncirrhotic NAFLD.

Related blog entry:

NAFLD Guidelines 2012 | gutsandgrowth