NAFLD is a Multisystem Disease

Healthy Aging

Where liver & heart health meet

Yep, we’re back after a few weeks of relaxing, recovering, and of course – reading lots of science. This week, we provide an update on nonalcoholic fatty liver disease (NAFLD) as a disease not only of the liver, but of our whole bodies. As Byrne et al. described nearly 10 years ago, NAFLD is a multisystem disease, and the heart is getting all kinds of attention these days.

What is NAFLD and what’s up with the term, MAFLD?

As the name suggests, nonalcoholic fatty liver disease (NAFLD) involves excessive fat deposition in the liver not attributed to alcohol consumption. NAFLD can progress to angry, inflamed livers with dying and scarring cells (aka cirrhosis) – this condition is called nonalcoholic steatohepatitis (NASH).

While NAFLD was an unknown disease 40 years ago, Younossi et al. show that 1 in 3 people today have NAFLD, which is rapidly becoming the leading cause of liver cancer and liver transplants globally. Exercise and healthy diets help to manage NAFLD, but there is currently no cure.

In an effort to help doctors and patients better understand a core driver of NAFLD, a new name has been proposed: MAFLD, which stands for Metabolic (dysregulated)-Associated Fatty Liver Disease. As described by Gofton et al., MAFLD acknowledges the co-occurring conditions of:

• Elevated LDL cholesterol and triglycerides
• Elevated blood pressure
• Elevated glucose
• High body mass index

Okay, enough acronyms. Let’s talk about NAFLD/MAFLD beyond the liver.

Wait, NAFLD/MAFLD goes beyond the liver?

Unfortunately, yes. NAFLD/MAFLD involves imbalanced metabolism, including insulin resistance and type 2 diabetes. While doctors weren’t initially concerned about NAFLD unless a person progressed to NASH, the latest studies show that just having NAFLD meaningfully increases our risk of shorter lives.

In particular, Younossi et al. share that the most common cause of early death among people with NAFLD is heart disease, followed by cancer outside the liver, and then liver disease. These risks are not just among older people. Alarmingly, the same findings were reported by Simon et al. in children and young adults.

What is the connection between NAFLD and heart disease?

As described by Chew et al. in their editorial titled “The heart of NAFLD”,  people with NAFLD are 45% more likely to have a heart-related event and have a higher risk of having coronary heart disease and heart failure.

So, what’s the link? Here are a few reasons why NAFLD affects heart health:

• NAFLD can cause higher LDL cholesterol, which increases the risk of heart disease
• NALFD can cause our heart to be “remodeled”, resulting in poorer heart function
• Heart disease and NAFLD have shared risk factors (see bulleted list above)

This all means that we really (really) need to care about NAFLD, and how to keep our metabolic, liver and heart health as a top priority for 2024 – and beyond.