Omega-3 for nonalcoholic fatty liver disease in children

[摘要] Question An overweight 12-year-old male patient with nonalcoholic fatty liver disease has had little improvement in liver steatosis or triglyceride levels over the past 2 years. Is omega-3 supplementation useful in managing his condition? Answer Nonalcoholic fatty liver disease in children is prevalent in the Canadian population and can lead to liver fibrosis, cirrhosis, transplant, and reduced life expectancy. There is no recommended pharmacologic treatment of nonalcoholic fatty liver disease. Omega-3 fatty acids are associated with small improvements in liver steatosis and triglyceride concentrations. There are conflicting results with regard to liver function test results and insulin resistance, and while there might be histologic improvement revealed on biopsy, there is little evidence that fibrosis is improved. In children who have struggled to be consistent with the changes needed in their diet, particularly those with elevated triglyceride levels, there might be a role for omega-3 supplementation while continuing to focus on the mainstays of treatment (diet and physical activity); however, further research is still needed. Nonalcoholic fatty liver disease (NAFLD) has become a leading cause of liver disease in children and is related to the overweight and obesity epidemic. ¹ Defined as hepatic fat seen in excess of 5% of hepatocytes in the absence of alcohol use and viral-, autoimmune-, and drug-induced liver disease, ² it ranges in severity from fat infiltration and accumulation in the liver (steatosis), to nonalcoholic steatohepatitis, characterized by inflammation and risk of progression to fibrosis, cirrhosis, or hepatocellular carcinoma. ^{1 , 2} The pathogenesis of NAFLD is multifactorial, but hepatic steatosis ultimately develops from an imbalance between processes that increase intrahepatic fat content (eg, hepatic uptake of lipids from the diet or peripheral adipose tissue in the context of insulin resistance; de novo lipogenesis) and those that reduce it (eg, oxidation of fatty acids; synthesis and export of very low–density lipoproteins). Nonalcoholic fatty liver disease is considered by some to be the hepatic manifestation of metabolic syndrome (a cluster of obesity, hypertension, hyperglycemia, hypertriglyceridemia, and dyslipidemia), as it often coexists with these comorbidities. ^{1 , 3} Pediatric NAFLD histologic features differ compared with adults and has milder lobular inflammation, ballooning, and perisinusoidal fibrosis but more severe steatosis, portal inflammation, ⁴ and possibly portal fibrosis. ⁵ While adult NAFLD has been thought to have little effect on mortality, ⁶ children might face faster progression, ⁷ as a retrospective study reported a standardized mortality ratio of 13.6 over a mean follow-up of 6.4 years. ⁸ Children with NAFLD are commonly asymptomatic even while dealing with associated comorbidities such as liver damage, insulin resistance, and type 2 diabetes mellitus. ⁹ Patients with NAFLD might complain of nonspecific symptoms such as fatigue, malaise, or abdominal pain, and examination might reveal acanthosis nigricans and increased waist circumference. ^{1 , 10} While serum testing, ultrasound, and magnetic resonance imaging have been used to identify the presence of NAFLD, they are characterized by poor sensitivity (serum testing and ultrasound) ^{10 , 11} or require further research in pediatric NAFLD. ¹² Liver biopsy remains the criterion standard for diagnosis. ¹⁰

[学科分类] 卫生学