The Efficacy of Pedometer-motivated Physical Activity for the Management of Patients With Metabolic-associated Steatotic Liver Disease: a Randomized-controlled Trial

The results of the health survey of the Thai population through physical examinations in the year 2022 found that among Thai people aged 18 and older, the prevalence of obesity (BMI ≥25 kg/m2) was 44.9% (40.3% in males and 49.2% in females), which has increased significantly over the past decades. This condition is a significant factor contributing to the rising incidence of nonalcoholic fatty liver disease (NAFLD) among the Thai population. NAFLD refers to fatty liver disease in individuals who consume alcohol in amounts less than 140 grams per week for females or less than 210 grams per week for males. Those with clinical features of metabolic dysfunction have been newly defined as having metabolic-associated steatotic liver disease (MASLD).

In this survey of 18,588 individuals, the prevalence of NAFLD was 19.7%, with rates of 20.9% in males and 18.6% in females. It was notably higher at 43.5% in individuals with abdominal obesity (metabolic syndrome) and 35.6% in individuals with diabetes. Factors such as age, sex, physical activity, smoking, and metabolic characteristics such as overweight or obesity, abdominal obesity, high triglyceride levels, diabetes, hypertension, and low HDL cholesterol levels are significantly associated with NAFLD.

MASLD, a type of fatty liver disease, is directly associated with insulin resistance, a key risk factor for cardiovascular diseases. Current treatment guidelines for MASLD have clear evidence that weight loss through dietary control and appropriate physical activity or exercise can reduce fat accumulation in the liver, inflammation, and fibrosis. Importantly, it also improves various metabolic parameters such as blood sugar and lipid levels, as well as the effectiveness of insulin.

The etiology of MASLD is related to behavioral and environmental factors, such as high-calorie diets combined with low physical activity and sedentary lifestyles. These factors promote insulin resistance, stimulating lipolysis and the movement of free fatty acids to various organs, including the liver. This leads to fat accumulation in the liver, insulin-resistant hepatic tissue, abnormal β-oxidation processes, oxidative stress, hepatic inflammation, increased stellate cell activation, and subsequent fibrosis, eventually increasing the risk of liver cirrhosis and hepatocellular carcinoma.

Genetic polymorphisms play a significant role in MASLD pathogenesis, with single nucleotide polymorphisms (SNPs) in the patatin like phospholipase domain containing-3 gene, particularly the rs738409 variant, being strongly associated with fat accumulation and fibrosis in the liver.