Abstract
The aim of this study was to assess the impact of dietary control on VLDL1- and VLDL2-TG kinetics and associated metabolic parameters. Twelve overweight/obese men were
randomized to a provided 3 day isocaloric diet with fixed macronutrient composition
(diet group, n=6) or to their regular unrestricted diet (non-diet group, n=6). VLDL1- and VLDL2-TG turnovers were measured twice 2–4 weeks apart, using primed-constant infusion
of ex vivo labeled [1-14C]VLDL1-TG and [9,10-3H]VLDL2-TG. Isocaloric diet intervention lowered the difference in the mean of both VLDL2-TG secretion and clearance rate (p<0.01), and the coefficient of variation (CV) of
VLDL2-TG clearance rate (p<0.05). The difference in mean and CV of the other kinetic estimates
(VLDL1-TG secretion, clearance and oxidation rate) were lowered, but not significantly.
The CV’s of total triglyceride, VLDL1-TG, and VLDL2-TG concentrations were significantly lowered by diet intervention compared to regular
diet; total triglyceride (31%–5%, p<0.01), VLDL1-TG (42%–9%, p<0.01), and VLDL2-TG (36%–10%, p<0.01). In conclusion, VLDL1- and VLDL2-TG kinetics show great day-to-day variability, which may be diminished by diet intervention.
Therefore, standardized macronutrient intake prior to study days improves the probability
of demonstrating significant outcomes of cross-sectional and intervention studies
of VLDL1-TG and VLDL2-TG kinetics and metabolism.
Key words
diet intervention - fatty acid/oxidation - human - triglycerides - VLDL kinetics
