Fibroblast Growth Factor 21 Levels Are Associated With Perception and Neural Responses to Sweetness in Type 2 Diabetes Mellitus.

Backgruound: The relationship between fibroblast growth factor 21 (FGF21) and sweet taste perception and preference in type 2 diabetes mellitus (T2DM) remains unclear. This study aims to investigate this relationship and examine the neural responses of T2DM patients to high-calorie sweet (HCS) food pictures, further exploring its correlation with FGF21 levels.

Methods: We assessed sweet taste perception and preference in 40 T2DM patients and 41 controls using classical scales. Subsequently, the neural responses of 11 T2DM patients and 11 controls to HCS pictures were examined using functional magnetic resonance imaging. FGF21 levels were measured using chemiluminescent immunoassay, and the correlations with taste perception and neural responses were analyzed.

Results: Increased FGF21 levels were associated with decreased sweet perception and increased sweet taste preference in T2DM patients. Compared to control, T2DM patients exhibited greater neural activations in the orbitofrontal cortex, anterior cingulate cortex (ACC), thalamus, and hippocampus (HCS vs. non-food) as well as the putamen (HCS vs. low-calorie food). Notable differences were observed in the parahippocampal gyrus, insula, ACC, and hippocampus in T2DM patients (HCS vs. high-calorie non-sweet). Additionally, FGF21 accounted for 30.39% and 32.4% of the associations between T2DM and ACC, and parahippocampal gyrus, respectively.

Conclusion: FGF21 levels were independently associated with changes in sweet taste perception and preference in T2DM patients and were significantly associated with activation in reward-related brain regions. This study reveals the potential role of FGF21 in regulating responses to sweet foods in T2DM and provides insight to develop new therapeutic strategies for diabetes.