Temporal impact of sugar metabolism on the liver
Purpose: Increased sugar consumption is associated with metabolic conditions that can result in poor health outcomes. To investigate the impact of sugars such as glucose and fructose in the body, this study aims to determine the timing of effects and assess the impact of these effects. This study aims to demonstrate acute effects in metabolism as a result of sugar metabolism.
Methods: Six male participants were imaged on a 3T MRI scanner at a fasted state then subsequently every hour for up to eight measurements. Between scanning sessions, they consume a 13C labeled glucose or fructose shake, have breath collected, and have blood drawn; this is repeated on a separate day to satisfy the other experimental condition. The MRI exam consists of Proton Density Fat Fraction (PDFF), proton Magnetic Resonance Spectroscopy (1H MRS), and 13C MRS. The images are processed to analyze liver volume and the spectra from the MR Spectroscopy are normalized and the peaks are quantified.
Results: Liver volume is significantly different from baseline measurements at 2-, 3-, and 4-hours post-feeding with p=0.032, p=0.003, and p=0.009 respectively. Fat content is significantly different from baseline measurements at 3- and 4-hours post-feeding with p=0.026 and p=0.048 respectively. Different MR measures of fat fraction in the body produce a significant positive correlation (p=0.003). The median change of lipids (CH2) positively correlates with the median change in glycerol (p=0.011). Fat fraction does not significantly correlate with the blood measures taken, but when high choline and low choline groups are separated, new formed lipids in the blood and long-term storage of fat differ significantly, p=0.021 and p=0.03 respectively.
Conclusions: Choline classification of participants resulted in a difference in new lipids in the blood and long-term storage in the liver. Low choline individuals tended to export less lipids in the blood and store more in the liver. High choline individuals exported more lipids and retained less in the liver. MR exams of the liver evaluate the health of the liver and burden to abdominal organs, whereas blood collection provided a glimpse into cardiovascular burden.