Hepatic steatosis-and not type 2 diabetes, body mass index or hepatic fibrosis-associates with hyperglucagonemia in individuals with steatotic liver disease.

ABSTRACT

Increased plasma concentrations of glucagon (hyperglucagonemia) are reported in patients with type 2 diabetes (T2D) and act as a prediabetogenic risk factor. Emerging evidence suggests that hepatic steatosis in obesity is causing a condition of glucagon resistance towards amino acid catabolism, resulting in a compensatory hyperglucagonemia. We investigated the presence of hyperglucagonemia in individuals with biopsy-verified metabolic dysfunction-associated steatotic liver disease (MASLD), and whether body mass index (BMI), T2D, hepatic steatosis and/or fibrosis contribute to this relationship. To dissect potential mechanisms, we determined hepatic gene expression related to amino acid transport and catabolism. Individuals with MASLD had hyperglucagonemia (controls (n=74) versus MASLD (n=106); median [Q1, Q3]; 4 [3, 7] versus 8 [6, 13] pM), p<.0001) and were glucagon resistant (assessed by the glucagon-alanine index) (1.3 [0.9, 2.1] versus 3.3 [2.1, 5.3] pM*mM, p<.0001). These changes associated with hepatic steatosis (p<.001, R2>.25) independently of BMI, sex, age, and T2D. Plasma levels of glucagon were similar in individuals with MASLD when stratified on T2D status (MASLD-T2D (n=52) versus MASLD+T2D (n=54); 8 [6, 11] versus 8 [6, 13] pM, p=.34) and hepatic fibrosis (MASLD+F0 (n=25) versus MASLD+F1-F3 (n=67); 8.4 [7.0, 13.3] versus 7.9 [5.2, 11.6] pM, p=.43). Obesity (BMI=30kg/m2) did not alter glucagon levels (p=.65) within groups (control/MASLD). The mRNA expression of proteins involved in amino acid transport and catabolism were downregulated in MASLD. Thus, prediabetogenic hyperglucagonemia is present in individuals with biopsy-verified MASLD, and hepatic steatosis partially drives hyperglucagonemia and glucagon resistance, irrespective of T2D, BMI, and hepatic fibrosis.