Fatty liver disease is the common form of Non-alcoholic fatty liver disease (NAFLD), whereas very extreme form of NAFLD is termed as Non-alcoholic Steatohepatitis (NASH). NASH is characterized by deposition of fat with 5%-10% of liver weight in liver of people who drink very little or no drinking leading to inflammation and scarring of liver, with obesity and diabetes regarded as main causes of NAFLD.
The progress of fatty liver to NASH is estimated to be only 1.7 per 1000 person, so not all NAFLD results into NASH. The DIONYSOS study revealed that the frequency of NAFLD remission was 55 per 1000 person per year. In US and Japan the incidences of hepatocellular carcinoma have increased due to NAFLD, NASH and NASH related cirrhosis. Incidences of NAFLD and NASH are increasing rapidly in US and seem to be the second largest cause for liver transplantation. The adult proportion with NASH has increased by 170% from 2004-2013.
PubMed/Medline searches from 1989 to 2015 showed that global incidences of occurrence of NAFLD are 25.24%. The data included was only of selected groups and nothing related to alcohol consumption or any other liver disease was included. The highest prevalence was seen in Middle East and South America and lowest in Africa. Incidences of NAFLD were 0.44 per 1000 person while liver specific mortality and overall mortality for NASH and NAFLD were 0.77 per 1000. The incidence risk ratios for liver specific mortality for NAFLD were 1.94 and 1.05.
|Classification||Group||NAFDL group Prevalence||Remarks|
|Europe||4%-49%||Incidence estimate: 29 per 100 000 person-years|
|Asia||15%-44%||Incidence estimate: 31-86 per 1000 person-years|
|Risk factors||Obesity||Up to 90%||51% with NAFLD have obesity|
|Diabetes mellitus||69%||30%-50% with diabetes have NAFLD|
|Hypertension||35%-40%||39.4% with hypertension have NAFLD|
|Dyslipidemia||50%||Up to 90% with dyslipidemia have NAFLD|
A case study conducted in Chinese population was aimed to identify risk factors for NAFLD through a span of 8 years. The study found 691 patients out of the ones enrolled were diagnosed with NAFLD. In the 8 year follow up, it was seen that 337 subjects developed NAFLD and there was increased body mass index (BMI), serum uric acid, fasting plasma glucose, decreased low density lipoprotein cholesterol as well as in high density lipoprotein cholesterol. On the other hand, 123 participants showed decrease in BMI, fasting plasma glucose, triglycerides, total cholesterol, low-density lipoprotein cholesterol, alanine aminotransferase, aspartate aminotransferase, and γ-glutamyl transpeptidase and were seen as NAFLD free. From the study, it was very clear that if the risk factors are reduced, then NAFLD can be reversed.