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.
- 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).)
- 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:
- Pediatric NAFLD: You Don’t Have to Be Obese/Overweight to Have Fatty Liver Disease (But It Helps)
- NAFLD Guidance from AASLD
- Pediatric NAFLD Guidelines 2017
- Concise Review: Fatty Liver in Pediatrics
- Ultrasound Unreliable to Exclude Fatty Liver
- A liver disease tsunami | gutsandgrowth
- Increasing prevalence of pediatric NAFLD | gutsandgrowth
Related blog posts on bariatric surgery:
- Should teenagers with severe NAFLD undergo bariatric surgery?
- Reaching Consensus on Bariatric Intervention in Children …
- 12 Year Data on Bariatric Surgery: Pros and Cons
- Is a Three Year-Old Too Young for Bariatric Surgery …
- Treating diabetes with surgery | gutsandgrowth