New Test Exposes Hidden Diabetes Driver

Doctor holding tablet about type 2 diabetes — Photo: one photo / Shutterstock

A fatty liver may be deaf to one of the body’s most important blood sugar signals, and that discovery could change how doctors treat type 2 diabetes.

Quick Take

New research links fatty liver disease to a condition called glucagon resistance, where the liver stops responding properly to a key blood sugar hormone.
Scientists built a new test, called GLUSENTIC, to measure this resistance in people with obesity and liver fat.
Patients with fatty liver and type 2 diabetes show weaker glucagon suppression after meals than those without liver fat.
Losing weight and reducing liver fat appears to improve how well the liver responds to glucagon again.

What Glucagon Does And Why It Matters

Glucagon is a hormone the pancreas releases to raise blood sugar when levels drop too low. It tells the liver to release stored sugar into the bloodstream. In a healthy body, this system balances insulin, which lowers blood sugar. When the liver stops listening to glucagon correctly, that balance breaks down, and blood sugar control gets harder to manage.

Researchers now believe fatty liver disease, known medically as metabolic dysfunction-associated steatotic liver disease, may be the reason the liver stops responding well. Fat buildup inside liver cells appears to interfere with how those cells process glucagon’s signal. The result is a liver that acts resistant to the hormone, much like muscle and fat tissue can become resistant to insulin.

A New Test Measures The Problem Directly

In 2024, scientists published a peer-reviewed study introducing a tool called the GLUSENTIC test and index. It measures glucagon resistance directly in people with obesity and liver fat, rather than relying only on indirect blood markers. The study, led by researcher Sasha Kjeldsen and colleagues, gave doctors a concrete way to diagnose a condition that previously could only be inferred from scattered lab values.

Other studies back up the pattern. One review of the evidence concluded that patients with fatty liver disease show a metabolic profile consistent with glucagon resistance, and that the condition may actually help drive the disease forward rather than just ride along with it. That distinction matters because it reframes fatty liver as an active player in blood sugar problems, not a passive side effect.

Meal-Time Blood Sugar Spikes Tell The Story

Normally, glucagon levels should drop after eating, since the body does not need extra sugar released when food is already supplying it. Research comparing patients with and without fatty liver found that those with the liver condition had significantly weaker glucagon suppression after meals, across every stage of digestion measured. Each increase in liver fat content independently predicted worse suppression, regardless of other health factors.

A separate study found that hyperglucagonemia, meaning excess glucagon in the blood, shows up in fatty liver patients independent of body weight, diabetes status, or liver scarring. The researchers concluded this points to impaired hepatic glucagon action itself, not just more hormone being released. In plain terms, the liver is getting the message and ignoring it.

Weight Loss Appears To Reverse The Resistance

The encouraging part of this research is that the resistance does not look permanent. A systematic review of weight-loss studies found that shedding body fat improved glucagon sensitivity, measured through markers like fasting plasma glucagon and alanine levels. Earlier observational work from Copenhagen researchers reached a similar conclusion, noting that hepatic steatosis itself, separate from diabetes or body mass, partially drives both excess glucagon and resistance to it.

That earlier study also noted its own limits, since it observed patterns in patients rather than proving direct cause and effect in a controlled trial. Still, the consistency across multiple independent research teams, using different methods and patient groups, builds a strong case that liver fat and glucagon resistance are closely tied together.

Why This Changes The Diabetes Conversation

For decades, insulin resistance has dominated the conversation around type 2 diabetes. This research suggests glucagon resistance deserves equal attention, especially in patients who also carry fatty liver disease. Doctors already lean on tools like GLP-1 receptor agonist drugs for weight loss in these patients, and guidelines increasingly treat fatty liver as a serious player in blood sugar control rather than an afterthought.

Standard diabetes screening looks at fasting glucose and A1C. Both stay normal for years while insulin resistance builds underneath.

The Whitehall II study followed 6,538 British civil servants and tracked the 505 who developed type 2 diabetes back across up to 13 years before… pic.twitter.com/SBeQAv5QGW

— William A. Wallace, Ph.D. (@WilliamWallace) November 3, 2026

The practical takeaway for patients is straightforward. Reducing liver fat through weight loss and dietary change does not just protect the liver itself. It may also restore the body’s ability to properly regulate a hormone central to blood sugar balance, offering another real lever against type 2 diabetes progression.