FGF21 Response to Sucrose is Associated with BMI and Dorsal Striatal Signaling in Humans

Abstract

Objective:

This study examined associations between BMI and dietary sugar intake with sucrose-induced fibroblast growth factor 21 (FGF21) and whether circulating FGF21 is associated with brain signaling following sucrose ingestion in humans.

Methods:

68 adults (29 male; 23.2 ± 3.8 years; BMI 27.1 ± 4.9 kg/m ²) attended visits after a 12h fast. Plasma FGF21 was measured at baseline, +15, +30, and +120min after sucrose (75g in 300 mL water). Brain CBF responses to sucrose were measured using arterial spin labeling magnetic resonance imaging (MRI).

Results:

Higher circulating FGF21 levels were associated with reduced blood flow in the striatum in response to sucrose (ß=−7.63, p=0.03). This association was greatest among persons with healthy-weight (ß=−15.70 p=0.007) and attenuated in people with overweight (ß=−4.00, p=0.63) and obesity (ß=−12.45, p=0.13). BMI was positively associated with FGF21 levels in response to sucrose (ß=0.53, p=0.02). High vs low dietary sugar intake was associated with greater FGF21 responses to acute sucrose ingestion in healthy-weight individuals (ß=8.51, p=0.04), but not individuals with overweight or obesity (p>0.05).

Conclusions:

Our correlative findings support evidence in animals showing FGF21 acts on the brain to regulate sugar consumption through a negative feedback loop.