**5.7 Non-alcoholic fatty liver disease (NAFLD)**

Non-alcoholic disease is a component of metabolic syndrome. It is being increasingly recognised since abdominal ultrasonography has become a common diagnostic tool. The overall prevalence of NAFLD in children is about 10%, which includes a prevalence of 17% in teenagers and 40–70% in obese children. Steatosis *per se* is benign and self-limiting but it can progress to non-alcoholic steatohepatitis (NASH) in 3–5% of patients [93]. In the US, about 12–24% of the children are obese and 10–25% of these have elevated serum transaminases. That means that 1–4% of children, in the US, are obese and have deranged transaminases and are at risk for NAFLD [94]. A more accurate estimation comes from an autopsy study done in San Diego. Steatosis was found in 9.6% of children between 2 and 19 years of age and in 38% of obese children autopsied between 1993 and 2003 [95]. Prevalence of NAFLD in obese children in China is estimated to be between 20 and 77% [96]. The latest theory on pathogenesis of NAFLD is a 'multi-hit' one where there is an interplay of numerous factors like hepatic fat accumulation, insulin resistance, oxidative stress due to genetic and epigenetic factors, unfavourable lifestyles, gut microbiota, gut-liver axis dysfunction, and trace element deficiency and fluctuations [97, 98]. The best predictors for NASH in obese individuals with no evidence of other liver disease are elevations of AST or ALT to >200 IU/L, or any elevation of AST (>46 IU/L) and ALT (>35 IU/L) for greater than 6 months. These criteria identified 100% cases of NASH in a small study [99]. If detected early, hepatic steatosis is reversible. Weight loss is the most effective treatment. A 10% reduction in weight can normalise AST, ALT values and decrease ultrasound evidence of fatty liver on 30 months follow-up [100]. Compliance to weight loss and lifestyle changes is poor, especially in children. A number of medical and surgical therapies are emerging. Medical approaches include micronutrient supplementation (Vit E, Vit D, PUFAs, choline), probiotics, anti-obesity medication, metformin, cysteamine, antioxidants, obeticholic acid, growth hormone, lipid-lowering agents and hormones like adiponectin, resistin and TNF alpha. Surgical approach is mainly bariatric surgery [93]. These therapeutic measures could serve as boosters for the weight loss and lifestyle programmes which are difficult to sustain on their own.
