Quantum coherence spectroscopy to measure dietary fat retention in the liver
Lucas Lindeboom, … , Patrick Schrauwen, Vera B. Schrauwen-Hinderling
Lucas Lindeboom, … , Patrick Schrauwen, Vera B. Schrauwen-Hinderling
Published August 18, 2016
Citation Information: JCI Insight. 2016;1(13):e84671. https://doi.org/10.1172/jci.insight.84671.
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Resource and Technical Advance Hepatology Metabolism

Quantum coherence spectroscopy to measure dietary fat retention in the liver

Abstract

The prevalence of fatty liver reaches alarming proportions. Fatty liver increases the risk for insulin resistance, cardiovascular disease, and nonalcoholic steatohepatitis (NASH). Although extensively studied in a preclinical setting, the lack of noninvasive methodologies hampers our understanding of which pathways promote hepatic fat accumulation in humans. Dietary fat retention is one of the pathways that may lead to fatty liver. The low (1.1%) natural abundance (NA) of carbon-13 (13C) allows use of 13C-enriched lipids for in vivo MR studies. Successful implementation of such methodology, however, is challenging due to low sensitivity of 13C-magnetic resonance spectroscopy (13C-MRS). Here, we investigated the use of 1-dimensional gradient enhanced heteronuclear single quantum coherence (ge-HSQC) spectroscopy for the in vivo detection of hepatic 1H-[13C]-lipid signals after a single high-fat meal with 13C-labeled fatty acids in 5 lean and 6 obese subjects. Postprandial retention of orally administered 13C-labeled fatty acids was significant (P < 0.01). Approximately 1.5% of the tracer was retained in the liver after 6 hours, and retention was similar in both groups (P = 0.92). Thus, a substantial part of the liver fat can originate directly from storage of meal-derived fat. The ge-HSQC can be used to noninvasively reveal the contribution of dietary fat to the development of hepatic steatosis over time.

Authors

Lucas Lindeboom, Robin A. de Graaf, Christine I. Nabuurs, Petronella A. van Ewijk, Matthijs K.C. Hesselink, Joachim E. Wildberger, Patrick Schrauwen, Vera B. Schrauwen-Hinderling

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Figure 5

Pulse sequences used in this study.

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Pulse sequences used in this study. (A) The 1D ge-HMQC (heteronuclear mu...
(A) The 1D ge-HMQC (heteronuclear multiple quantum coherence) sequence is shown. The HMQC block was placed after PRESS (point resolved spectroscopy) localization. Two additional 13C inversion pulses were used to refocus the 13C chemical shift evolution. Minimum evolution time (t1) was 7.6 ms. In contrast to the conventional ge-HMQC sequence, 5 gradients were used for coherence selection. Gradients were applied in a ratio of 1:–1:–1:1:1. (B) The 1D ge-HSQC (heteronuclear single quantum coherence) sequence, based on STEAM (stimulated echo acquistion mode) localization. The inversion pulse during the t1, which was used on the 1H channel previously, was now applied on the 13C channel to again refocus 13C chemical shift evolution. Minimum t1 was 4.2 ms, and gradients were applied in a 2:–2:1 ratio. In both sequences, 1/2JCH was chosen as 3.95 (J = 127 Hz for CH2 lipids). No decoupling was applied.