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.

Related blog posts:

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:

Related blog posts on bariatric surgery:

 

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.”

Related blog posts:

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.

 

Related blog posts:

 

 

My Favorite Posts from the Past Year

Recently, I listed the posts that had the most views in the past year –some dating back to 2012.  The following list includes less viewed but some of my favorite posts from 2018:

GI:

Nutrition:

LIVER:

Miscellaneous:

Flowers in Calgary

Most Popular Posts 2011-2018

Since this blog’s inception, there are now more than 2500 posts; these are the most popular (most views):

Most of these posts are referenced in more recent posts on the same or similar subjects.

Near Banff

 

Which Diet is Best For a Fatty Liver?

A recent randomized controlled trial (C Properzi et al. Hepatology 2018; 68: 1741-54) compare the Mediterranean diet (MD) and a low-fat (LF) diet for non-alcoholic fatty liver disease.

A total of 48 patients completed the 12-week study and were analyzed; subjects had a mean BMI of 31.  Both groups consumed a 2400-2600 kcal diet.

Key findings:

  • Despite minimal weight loss, both groups had significant reduction in hepatic steatosis as determined by magnetic resonance spectroscopy (MRS): 25.0% in LF and 32.4% in MD.  Both had wide confidence intervals due to the small number of subjects.
  • Liver enzyme improved in both groups.
  • Weight loss was minimal, 1.6 kg and 2.1 kg in LF and MD respectively
  • Framingham Risk Score (FRS), cholesterol, triglycerides, and hemoglobin A1c were improved with MD but not with LF (all P<0.05)

The associated editorial (pg 1668-71) notes the following:

  • “Considering the current evidence, recommending the MD for patients with NAFLD might be an appropriate therapeutic option, not least because …[of the} increased risk of CVD.”
  • Longer-term RCTs are needed
  • “It has to be stressed that, in most cases, any form of healthy diet (eg. LF or MD), which leads to caloric reduction…should be encourage for patients with NAFLD…The importance of weight loss has been highlighted in patients with biopsy-proven NASH.”

My take: If you have to make a dietary recommendation, this study indicates that MD is probably a better diet than LF in patients with NAFLD.

Related blog posts:

Town of Banff