The prevalence of diabetes is growing rapidly all over the world and in India. According to a recent ICMR-INDIAB Study published by us in the Lancet Diabetes Endocrinology, the number of people with diabetes in India now stands at 101 million. In addition, there are 136 million people with prediabetes in India. It is well known that uncontrolled diabetes can lead to complications affecting the eye, kidney, heart, feet and nerves. However, the relationship between diabetes and the liver is not well appreciated and only recently has this link been emphasised.
So, what is the connection between diabetes and the liver?
The liver is a store house or a factory for various products and one of them is glucose. When there is excess glucose in the body, it gets deposited in the liver as glycogen. Moreover, the excess fat in the blood circulation (triglycerides and free fatty acids) also gets deposited in the liver and this is called ‘Fatty Liver’.
Epidemiological studies done us at the Madras Diabetes Research Foundation have shown that over 50% of people with type 2 diabetes have some degree of fatty liver. When there is excess fat in the liver, this leads to a condition called ‘Hepatic Insulin Resistance’. What this means is that the body’s insulin cannot function properly and that the action of insulin in the liver is considerably reduced. This leads to increased release of glucose from the liver, which is referred to as ‘Hepatic Glucose Production’. The early morning increase in glucose levels i.e. increase in the fasting plasma glucose is mainly attributed to this increased hepatic glucose production.
The relationship between fatty liver and type 2 diabetes is bidirectional. Thus, fatty liver can lead to type 2 diabetes and type 2 diabetes can promote fatty liver. Our studies have shown that if both obesity and diabetes are present, over 80% of such individuals will have fatty liver. While fatty liver by itself is not dangerous, very often it leads to inflammation of the liver, a condition known as Non-alcoholic ‘Steatohepatitis’ or NASH. Up to this stage it is probably reversible. However, at the next stage, it can progress to cirrhosis of the liver which is irreversible and can be a fatal condition. Some people with cirrhosis of the liver even go on to develop hepatocellular carcinoma (HCC). The link between diabetes, fatty liver, cirrhosis and HCC is being increasingly recognised.
Today non-alcoholic fatty liver (NAFLD) is recognised as a complication of diabetes and also as a cause of diabetes. Recently there is a shift occurring in the treatment of diabetes from a glucose centric approach, to a wider metabolic based care. Indeed, ‘diabetes care’ is slowly evolving into ‘metabolic care’ with the liver taking the centre stage in this, along with the heart and kidney. Thus, while choosing antidiabetic medications, those that are also beneficial to the liver, heart and kidneys are being preferred.
Recently the close association of metabolic syndrome (a term used to refer to a combination of diabetes, hypertension and central obesity) and NAFLD has been recognised and internationally, the term NALFD is being replaced with ‘Metabolic dysfunction-associated fatty liver disease’ (MAFLD).
How can we treat MAFLD?
The best way is by lifestyle modification. A healthy diet consisting of less calories, carbohydrate and fat but more vegetable protein and fibre is a powerful tool to lose weight and treat excess fat in the liver. Adequate exercise (e.g. walking, jogging, swimming etc.) along with yoga can also help to shed those extra kilograms. Indeed, it has been shown in research trials, that by profound calorie restriction (to about 800 calories /day), the excess fat in the liver can melt away even within a week! This can lead to reversal of diabetes and other metabolic abnormalities within a few days or weeks, even before significant weight loss is achieved.
Today, we also have specific medicines which can help reduce fatty liver and reverse liver changes even at the NASH stage. It is therefore important to identify early changes in the liver to prevent progression to its more advanced stages like cirrhosis or carcinoma. Apart from check ups for eyes, kidneys, heart, feet and nerves, the liver should also be included in the annual work up of all individuals with diabetes. This is my wish on the occasion of World Diabetes Day 2024.
(Dr. Mohan is Chairman, Dr. Mohan’s Diabetes Specialities Centre and Madras Diabetes Research Foundation, Chennai. drmohans@diabetes.ind.in)
