Non-alcoholic fatty liver disease and type 2 diabetes mellitus: diagnostic and therapeutic aspects. Review

Abstract

The increase in the prevalence of non‑alcoholic fatty liver disease (NAFLD) occurs in parallel with the global epidemic of obesity and type 2 diabetes mellitus (T2DM) in the world. T2DM is an independent risk factor for the development of NAFLD. At the same time, researchers found that patients diagnosed with NAFLD have a two‑fold increased risk of developing T2DM. NAFLD is encompasses a spectrum of liver manifestations ranging from simple steatosis to nonalcoholic steatohepatitis (NASH), fibrosis and cirrhosis, which may ultimately progress to hepatocellular carcinoma. NASH is an aggressive form of NAFLD, associated with an increased risk of liver and non‑liver‑related mortality. Liver‑biopsy remains the gold standard for diagnosis, but the majority of patients liver damage can be diagnosed accurately by noninvasive methods.
 The presence of NAFLD in a patient with T2DM makes it difficult to achieve adequate glycemic control, deepens the manifestations of insulin resistance and atherogenic dyslipidemia, increases the risk of serious cardiovascular events and chronic kidney disease. Lifestyle modification and treatment of concomitant T2DM should be undertaken in all patients with NAFLD. To reduce the severity of liver steatosis, weight reduction by 3—5% is necessary, to reduce the inflammatory‑necrotic process, a more significant reduction may be required — up to 10% within 6—12 months. Physical activity increases the sensitivity of insulin receptors, and in combination with diet leads to a significantly significant improvement in biochemical and histological indicators in patients with NAFLD. Early identification and management of patients with intensive dietary and lifestyle modification are essential to prevent the development of advanced liver disease and its complications. Pharmacological therapy should be administered to patients with NASH purposed on the fibrosis inhibition, especially in case of the established predictors of high risk of disease progression (age >50 years, metabolic syndrome, T2DM, or increase in the activity of alanine aminotransferase), as well as to the patients with active NASH with high inflammatory activity.
 At the congress of the European Association for the Study of the Liver (EASL), which took place in Vienna on June 21—24, 2023, a new classification and nomenclature of NAFLD was adopted. It was proposed to replace the term «non‑alcoholic fatty liver disease» to the term «metabolic dysfunction‑associated steatotic liver disease» (MASLD). This diagnosis is established in patients with confirmed steatosis of the liver and one of five cardiometabolic risk factors: obesity, T2DM, insulin resistance, hyperlipidemia, atherosclerosis. The concept of «non‑alcoholic steatohepatitis» (NASH) has been changed to the concept of «metabolic dysfunction‑ associated steatohepatitis» (MASH). Coordination of the views of international and domestic experts in the field of studying this pathology will be important for clinical practice and scientific research.