Key points

INTRODUCTION

• Non-alcoholic fatty liver disease (NAFLD/NAFLD) encompasses a spectrum of conditions characterized by evidence of hepatic steatosis on imaging or histology and secondary absence of hepatic steatosis, such as alcohol consumption or chronic medication use
• Non-alcoholic fatty liver disease is a silent disease.
  • It has several phases of progression: simple steatosis, steatohepatitis, fibrosis, cirrhosis and could progress to hepatocellular carcinoma
• The presence of liver injury with inflammation + with or without fibrosis constitutes non-alcoholic steatohepatitis (NASH/NASH)

ETIOLOGY

• Obesity, diabetes, dyslipidemia, insulin resistance and metabolic syndrome, associated with the appearance of NAFLD
  • Therefore, they present cardiovascular risk factors.

EPIDEMIOLOGY

• Incidence is on the rise in Western countries
• NAFLD prevalence
  • 80% – 90% in obese adults
  • 30% – 50% in adults with Diabetes Mellitus
  • 90% or higher in adults with dyslipidemia
  • 40% to 70% in children with obesity

PATHOPHYSIOLOGY

• Environmental and genetic factors intervene
  • first degree relatives
  • SIRT1 activation
• Insulin resistance causes:
  • Accumulation of triglycerides in the cytoplasm of hepatocytes
  • Accumulation of fatty acids and triglycerides in the liver due to an excessive supply of them
  • Sinusoidal collagen deposition and portal fibrosis develops NASH
• Accumulation of fatty acids makes the liver more vulnerable to injury
• Excess of CHOs stimulates hepatic synthesis of fatty acids
• Obesity releases inflammatory mediators that damage hepatocytes

HISTOPATHOLOGY

• In NAFLD, liver biopsy shows more than 10% from hepatocytes with fat droplets

CLINICAL PRESENTATION

• NAFLD:
  • Most asymptomatic, some with nonspecific symptoms
    • Fatigue is one of the most common symptoms
    • Upper abdominal pain, thirst, bloating, and sleep disturbances
  • Moderate hepatomegaly is the most common clinical sign.

EVALUATION

• Slightly elevated serum aminotransferases (main biochemical data), although they may appear normal.
• GGT elevation, marker of increased mortality
• Ultrasound, routine method
• Liver biopsy, gold standard for NAFLD diagnosis
• “NAFLD in metabolic syndrome score”, is a non-invasive score to predict the development of NAFLD, it includes:
  • BMI > 25
  • AST/ALT > or = 1
  • DM2
  • Obesity

DRIVING

• Changes in lifestyle
• With simple steatosis, weight loss of 3% – 5%
• Before NASH, weight loss from 7% – 10%
  • Control of risk factors (Statins in dyslipidemias, control SAH and DM)
• multidisciplinary treatment