Non-alcoholic liver disease

Non-alcoholic fatty liver disease (NAFLD) is metabolic condition which is strongly associated with insulin resistance.  It is a build-up of fat, specifically triglycerides, within the cells of the liver which isn’t caused by drinking alcohol.  Normally the liver cells only have very little fat within them, <5%, but this is raised in NAFLD. 

The exact cause for NAFLD is unknown.  It has been shown to be more prevalent in women with PCOS, affecting around 40% which is over double the rate in women without PCOS. particularly in women with raised androgens[1].  It is also more prevalent in women with a raised BMI, who have type II DM, raised lipids, raised blood pressure or who are on tamoxifen.

What does the liver do?

The liver is in the upper right part of the tummy (abdomen). Its functions include:

· Storing fuel for the body. Much of the food we eat is broken down by the body into a type of sugar called glucose. This is what our bodies use for energy. Glucose can't be stored so it is turned into a storage version called glycogen. This is kept in the liver and, when we need energy, it releases it in the form of glucose. The liver also stores iron and vitamins.

· Making proteins that are essential for blood to clot (clotting factors).

· Helping to remove or process alcohol, medicines and poisons from the body.

· Making a type of fat called cholesterol. This is needed in the body, although too much of it causes harm.

· Making a juice called bile, which digests fat. This passes from the liver to the gut down the bile duct. Bile breaks down the fats in food so that they can be absorbed from the bowel.

What are the stages of NAFLD?

[2]

What symptoms does it cause?

It usually doesn’t cause any symptoms, but in some people, it can cause tiredness, abdominal discomfort or malaise (general feeling of lack of well-being).

Only 5-6% of people with NAFLD will have progression of their disease.

Who should be tested for NAFLD?

·         Central obesity – 90% of people with a BMI above 30 kg/m2 or a waist circumference above 80cm in women have NAFLD

·         Known diagnosis of PCOS – 40% of women with PCOS have NAFLD

·         Known type II diabetes mellitus = 55% of people with type II diabetes have NAFLD

·         Hypertension

·         Raised lipids

·         Taking tamoxifen – 30-40% of women taking tamoxifen for breast cancer will develop NAFLD

·         Obstructive sleep apnoea

How can you find out if you have NAFLD?

The NHS does not offer screening for the condition as it isn’t cost effective for them.  Diagnois of NAFLD is strictly only possible with a biopsy of the liver but this is an invasive procedure and is therefore not recommended due to the risks in involved.  At Sirona Health we can you refer you for an ultrasound scan if you have risk factors for developing NAFLD, to measure the amount of fat within the liver.  This will diagnose 80-90% cases of NAFLD.  If you would like the most sensitive test, one that has is as accurate as liver biopsy, then we can organise a MRI scan for you. We can also do blood tests to check your liver function, blood sugar and platelet count to assess your NAFLD score.  If NAFLD is diagnosed, then you should have an Enhanced Liver Fibrosis (ELF) test at least every 3 years to check for disease progression.

How is NAFLD treated?

There are no prescription only medications for the treatment of NAFLD and lifestyle approaches are vital in its management.

Treatment includes weight loss, if relevant, with an emphasis on a Mediterranean diet[3] (including the use of olive oil as the fat of choice[4]).

There is evidence that sugary drinks can be particularly harmful to the liver and should be avoided[5].

Supplementation with vitamin E has been proven to be effective[6].  There is also some evidence of omega 3 fatty acids[7], and for the use of milk thistle[8].  A metanalysis published in 2023 has suggested that ginger supplementation may also be helpful[9].

References

[1] Non-Alcoholic Fatty Liver Disease in Patients with Polycystic Ovary Syndrome: A Systematic Review, Meta-Analysis, and Meta-Regression J Clin Med 2023 Jan 20;12(3):856. doi: 10.3390/jcm12030856

[2] Glen J, Floros L, Day C, Pryke R. Non-alcoholic fatty liver disease (NAFLD): summary of NICE guidance BMJ 2016; 354 :i4428 doi:10.1136/bmj.i4428

[3] George ES, Reddy A, Nicoll AJ, Ryan MC, Itsiopoulos C, Abbott G, Johnson NA, Sood S, Roberts SK, Tierney AC. Impact of a Mediterranean diet on hepatic and metabolic outcomes in non-alcoholic fatty liver disease: The MEDINA randomised controlled trial. Liver Int. 2022 Jun;42(6):1308-1322. doi: 10.1111/liv.15264. Epub 2022 Apr 26. PMID: 35357066; PMCID: PMC9544144.

[4] Bjermo H, Iggman D, Kullberg J, Dahlman I, Johansson L, Persson L, Berglund J, Pulkki K, Basu S, Uusitupa M, Rudling M, Arner P, Cederholm T, Ahlström H, Risérus U. Effects of n-6 PUFAs compared with SFAs on liver fat, lipoproteins, and inflammation in abdominal obesity: a randomized controlled trial. Am J Clin Nutr. 2012 May;95(5):1003-12. doi: 10.3945/ajcn.111.030114. Epub 2012 Apr 4. PMID: 22492369.

[5] Sigala DM, Hieronimus B, Medici V, Lee V, Nunez MV, Bremer AA, Cox CL, Price CA, Benyam Y, Chaudhari AJ, Abdelhafez Y, McGahan JP, Goran MI, Sirlin CB, Pacini G, Tura A, Keim NL, Havel PJ, Stanhope KL. Consuming Sucrose- or HFCS-sweetened Beverages Increases Hepatic Lipid and Decreases Insulin Sensitivity in Adults. J Clin Endocrinol Metab. 2021 Oct 21;106(11):3248-3264. doi: 10.1210/clinem/dgab508. PMID: 34265055; PMCID: PMC8530743.

[6] Vadarlis A, Antza C, Bakaloudi DR, Doundoulakis I, Kalopitas G, Samara M, Dardavessis T, Maris T, Chourdakis M. Systematic review with meta-analysis: The effect of vitamin E supplementation in adult patients with non-alcoholic fatty liver disease. J Gastroenterol Hepatol. 2021 Feb;36(2):311-319. doi: 10.1111/jgh.15221. Epub 2020 Sep 10. PMID: 32810309.

[7] Prikhodko VA, Bezborodkina NN, Okovityi SV. Pharmacotherapy for Non-Alcoholic Fatty Liver Disease: Emerging Targets and Drug Candidates. Biomedicines. 2022 Jan 26;10(2):274. doi: 10.3390/biomedicines10020274. PMID: 35203484; PMCID: PMC8869100.

[8] Zhong S, Fan Y, Yan Q, Fan X, Wu B, Han Y, Zhang Y, Chen Y, Zhang H, Niu J. The therapeutic effect of silymarin in the treatment of nonalcoholic fatty disease: A meta-analysis (PRISMA) of randomized control trials. Medicine (Baltimore). 2017 Dec;96(49):e9061. doi: 10.1097/MD.0000000000009061. PMID: 29245314; PMCID: PMC5728929.

[9] Zhou Q, Peng Y, Chen F, Dai J. Ginger supplementation for the treatment of non-alcoholic fatty liver disease: a meta-analysis of randomized controlled trials. Afr Health Sci. 2023 Mar;23(1):614-621. doi: 10.4314/ahs.v23i1.65. PMID: 37545930; PMCID: PMC10398503.