BACKGROUND AND PURPOSE:

• Non-alcoholic fatty liver disease (NAFLD) is a common liver disease, and a leading cause of liver related morbidity and mortality
• Riazi et al. (Lancet Gastroenterology and Hepatology, 2022) examined NAFLD worldwide temporal trends

METHODS:

• Systematic review and meta-analysis
• Inclusion criteria
  • Included observational cross-sectional or longitudinal studies
  • Studies done in
    • General adult populations | NAFLD diagnosed using an imaging method | Absence of excessive alcohol consumption and viral hepatitis
• Study design
  • Random-effects meta-analysis was used to calculate overall and sex-specific pooled effect estimates
• Primary outcomes
  • Prevalence and incidence of NAFLD

RESULTS:

• Prevalence analysis: 72 studies | 1,030,160 individuals from 17 countries
• Incidence analysis: 16 studies | 381,765 individuals from 5 countries
• There was considerable heterogeneity between studies of both
  • NAFLD prevalence: I²=99.9%
  • NAFLD incidence: I²=99.9%

NAFLD Prevalence

• Estimated overall prevalence of NAFLD worldwide
  • 32.4% (95% CI, 29.9 to 34.9)
• Prevalence increased significantly over time
  • ≤2005: 25.5% (95% CI, 20.1 to 31.0)
  • ≥2016: 37.8% (95% CI, 32.4 to 43.3)
  • P=0.013
• Overall prevalence of NAFLD was significantly higher in men than in women
  • Men: 39.7% (95% CI, 36.6 to 42.8)
  • Women: 25.6% (95% CI, 22.3 to 28.8)
  • P<0.0001

NAFLD Incidence

• Estimated overall incidence of NAFLD worldwide
  • 46.9 (95% CI, 36.4 to 57.5) cases per 1000 person-years
• Overall incidence of NAFLD was significantly higher in men than in women
  • Men: 70.8 (95% CI, 48.7 to 92.8) cases per 1000 person-years
  • Women: 29.6 (95% CI, 20.2 to 38.9) cases per 1000 person-years
  • P<0.0001

CONCLUSION:

• In this meta-analysis with a populations sample of over 1 million individuals, the prevalence of NAFLD was higher than originally thought, and appears to be increasing
• The disease had a significantly higher incidence and prevalence among men, compared to women
• The authors state

Greater awareness of NAFLD and the development of cost-effective risk stratification strategies are warranted to address the growing burden of NAFLD

Learn More – Primary Sources:

The prevalence and incidence of NAFLD worldwide: a systematic review and meta-analysis

Related ObG Topics:

Nonalcoholic Fatty Liver Disease (NAFLD) – Diagnosis and Management

Does Bariatric Surgery Reduce Cardiovascular Risk for Patients with NASH and Obesity?