NAFLD Is a Growing Driver of Chronic Liver Disease and Related Deaths

Over the last decade, nonalcoholic fatty liver disease (NAFLD) has become the main driver of chronic liver disease (CLD) incidence, although viral hepatitis remains the most common cause of CLD deaths, according to a study published in Hepatology.

Deaths from cirrhosis have increased significantly from 1.9% of total global deaths in 1990 to 2.4%, the authors noted, and nonalcoholic steatohepatitis (NASH) is the main culprit since the age-specific death rates for all other causes of liver disease have decreased.

They added that “obesity and type 2 diabetes mellitus have been considered the most important drivers of changes in the profile of liver disease in the United States and across the globe. This growing burden has led to recent data suggesting that NAFLD will become the most common indication for liver transplantation in the near future.”

The researchers described the global burden of CLD among individuals between the ages of 15 and 29 years using data from the Global Burden of Disease (GBD). The GBD is coordinated by the Institute for Health Metrics and Evaluation. The Cause of Death database was utilized to model deaths due to CLD.

In 2019, there were 290 million CLD prevalent cases, 17.2% of which were among individuals aged 15 to 29 years; 232,072 CLD incident cases, 11.2% of which were in the 15-29–year age group; and 55,515 CLD deaths, 3.8% of which were in the 15-29–year age group.

The Middle East and North Africa region had the highest prevalence of CLD with 79% of those aged 15 to 19 years, 85% of those aged 20 to 24 years, and 87% of those aged 25 to 29 years having CLD. The prevalence was largely driven by NAFLD, according to the authors. The next highest prevalence of CLD was in the regions of Western Sub-Saharan Africa, East Asia, Central Sub-Saharan Africa, Southern Sub-Saharan Africa, Central Asia, and Southeast Asia. The regions with the lowest prevalence of CLD were Southern Latin America, high-income North America, high-income Asia Pacific, and Western Europe.

Central Asia, South Asia, and Central Sub-Saharan Africa had the highest death rates from CLD compared with Australasia, high-income Asia Pacific, Western Europe, and high-income North America, which had the lowest CLD death rate (≥4.5 per 100,000 vs <0.51 per 100,000).

The researchers identified the following trends:

• From 2009 to 2019, CLD prevalence increased annually for the 25-29–year age group, was stable for the 20-24–year age group, and decreased for the 15-19–year age group.
• The proportion of NALFD increased among all age groups:
  • 40.8% to 52.9% (P < .001) for those aged 15 to 19 years
  • 57.6% to 62.7% (P > .001) for those aged 20 to 24 years
  • 66.9% to 70.1% (P < .001) for those aged 25 to 29 years
• As NALFD increased in all age groups, the proportion of hepatitis B virus (HBV) decreased.
• The overall annual CLD death rate decreased in all age groups, driven by the decreasing proportion of cirrhosis deaths related to HBV.

The researchers noted that NAFLD/NASH is an increasingly important cause of CLD and the finding that the proportion of CLD deaths with NAFLD worsened in almost every region of the world was “alarming.”

“Global policies to address NAFLD and its associated risk factors of obesity and type 2 diabetes with targeted interventions for both adults and the young population (ages 15-29) must be developed as this younger age group are the drivers of future socioeconomic prosperity across the world,” they concluded.

Reference

Paik JM, Kabbara K, Eberly KE, Younossi Y, Henry L, Younossi ZM. Global burden of non-alcoholic fatty liver disease (NAFLD) and chronic liver disease (CLD) among adolescents and young adults. Hepatology. Published online November 6, 2021. doi:10.1002/hep.32228