Using total plasma triacylglycerol to assess hepatic de novo lipogenesis as an alternative to VLDL triacylglycerol

Journal article

Background: Hepatic de novo lipogenesis (DNL) is ideally measured in very low-density lipoprotein (VLDL)-triacylglycerol (TAG). In the fasting state, the majority of plasma TAG typically represents VLDL-TAG, however the merits of measuring DNL in total plasma TAG has not been assessed.

Objective: To assess the performance of DNL measured in VLDL-TAG (DNLVLDL-TAG) to that measured in total plasma TAG (DNLPlasma-TAG).

Design: Using deuterated water, newly synthesized palmitate was determined in fasting plasma VLDL-TAG and total TAG in 63 subjects taking part in multiple studies resulting in n=123 assessments of DNL (%new palmitate of total palmitate). Subjects were split into tertiles to investigate if DNLPlasma-TAG could correctly classify subjects having “high” (top tertile) and “low” (bottom tertile) DNL. Repeatability was assessed in a subgroup (n=16) with repeat visits.

Results: DNLVLDL-TAG was 6.8% (IQR 3.6-10.7%) and DNLPlasma-TAG was 7.5% (IQR 4.0-11.0%) and the correlation between the methods was rs=0.62 (P<0.0001). Bland-Altman plots demonstrated similar performance (mean difference 0.81%, P=0.09) however the agreement interval was wide (-9.6 to 11.2%). Compared to DNLVLDL-TAG 54% of subjects with low DNL were correctly classified, whilst 66% of subjects with high DNL were correctly classified using DNLPlasma-TAG. Repeatability was acceptable (i.e. not different) at the group level but the majority of subjects had an intra-individual variability over 25%.

Conclusion: DNL in total plasma TAG performed similarly to DNL in VLDL-TAG at the group level but there was large variability at the individual level. We suggest that plasma TAG could be useful for comparing DNL between groups.

Authors: Hodson, L; Parry, S; Cornfield, T; Charlton, C; Low, WS

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Taylor & Francis
• Journal: Upsala Journal of Medical Sciences
• Volume: 125
• Issue: 3
• Pages: 211-216
• Publication date: 2020-03-25
• Acceptance date: 2020-03-04
• DOI: 10.1080/03009734.2020.1739789
• EISSN: 2000-1967
• ISSN: 0300-9734
• Language: English
• Keywords: de novo lipogenesis; human; VLDL; hepatic; DNL; triacylglycerol; FFR