Abstract 13791: Effects of Omega-3 Fatty Acids on Post-Prandial Triglyceride Tolerance and Monocyte Activation
Background: Epidemiologic studies suggest that post-prandial triglycerides (ppTG) are associated with cardiovascular events. Monocyte activation plays an important role in lipid-mediated vascular diseases. Omega-3 fatty acids (ω-3 FAs) are known to lower fasting TG levels. The effects of ω-3 FAs on ppTG metabolism and the role of ppTG for monocyte activation have not been studied in detail.
Methods and Results: 23 healthy volunteers and 30 patients with documented coronary artery disease and normal glucose tolerance were subjected to an oral TG tolerance test (OTT) encompassing 250 ml of cream (OTT) or to water as control (H2O) in a crossover design. Additional 30 patients with a ppTG increase above the median were treated with 4g ω-3 FAs/day or placebo for 3 weeks in a randomized, placebo-controlled, double-blind, crossover study. Relative TG increase reached its maximum 4h after fat intake (185.1±10.9% of baseline). ω-3 FAs reduced fasting TG from 137.1±12.9 to 112.2±8.6mg/dl (p<0.05), while placebo had no effect. Maximal ppTG concentrations were decreased from 243.6±24.6 to 205.8±17.1mg/dl (p<0.05), while relative TG increase after treatment with ω-3 FAs (192.8±12.7%) was comparable to placebo. The area under the curve of TG during OTTT was reduced from 1042±99 to 873±60mg/dl (p<0.05) by ω-3 FAs and did not change after placebo (988±71 vs. 1033±88mg/dl, p=ns). Differential blood count showed relative monocytopenia and neutrophilia following fat intake, which was unaffected by ω-3 FAs and also detectable in the H2O group, making circadian regulation likely. Similarly, the OTT-induced decrease of MCP1 in serum and the MCP1-receptor CCR2 on monocytes was also detectable in the H2O group and was not influenced by treatment with ω-3 FAs. Monocyte adhesion molecule CD11b, LPS-co-receptor CD14, monocyte subpopulations CD16+CD14high and CD16+CD14low, sICAM serum levels and inflammatory cytokine gene expression in resting and stimulated monocytes were not affected by OTT or ω-3 FAs.
Conclusion: Post-prandial TG increase did not stimulate monocytes beyond their diurnal activation patterns. ω-3 FAs lower fasting TG and potently attenuate the post-prandial TG increase. The prognostic and pathophysiological role of TG still needs to be further unraveled.
- © 2011 by American Heart Association, Inc.