Liver fibrosis is the technical term for scarring of the liver which may occur, for example, in response to fatty infiltration of the liver, alcohol abuse or Hepatitis C, and can progress to end-stage liver disease.
A study just released (1) estimates that there are 52 million Americans with Non-Alcoholic Fatty Liver Disease (NAFLD), that is 22 % of the population! While the majority of NAFLD patients do not progress to advanced fibrosis (scarring of the liver), which is a precursor to end-stage liver disease and liver cancer, 30.1 % of women and 14.1 % of men in the NAFLD group currently have advanced fibrosis. This means that any adult woman in the US has a 6.6 % chance of having advanced liver fibrosis. Women beyond the age of 60 with diabetes are at even higher risk. Most don’t know that they have fibrosis.
How did the researchers arrive at these numbers?
The researchers used data from the updated 2011-2014 National Health and Nutrition Examination Survey (NHANES) which combines interviews, physical examinations and laboratory tests. To estimate the number of patients with fibrosis (scarring of the liver), they used scores that are calculated from the results of the simple blood tests obtained during NHANES: platelet count, ALT and AST and age. These results should already be in your personal medical record and can be easily calculated during a visit to your liver doctor or gastroenterologist, no expensive scans or liver biopsy needed.
How do I know whether I have fibrosis?
While the calculation of liver fibrosis scores is easy, the interpretation is often far from easy. The scores are generally most helpful when they are very low or very high. When they are very low there is normally nothing to worry about, when they are very high several different tests, more expensive or more invasive, may not need to be done. The complex decisions are best made by a gastroenterologist with an interest in liver disease.
- Wong RJ, Liu B, Bhuket T. Significant burden of nonalcoholic fatty liver disease with advanced fibrosis in the US: a cross-sectional analysis of 2011-2014 National Health and Nutrition Examination Survey. Aliment Pharmacol Ther. 2017;00:1–7. https://doi.org/10.1111/apt.14327