Consumption of a high-fat meal was associated with an increase in monocyte adhesion molecules, scavenger receptors, and Propensity to Form Foam Cells.

BACKGROUND: Macrophage-derived foam cells are the predominant component of arterial plaques in the early stages of atherosclerosis. One factor that poses a major risk for plaque development is high levels of plasma low-density lipoprotein (LDL) as a result of a high-fat meal. In order to better understand how an individuals' diet affects arterial plaque deposition via the process of foam cell formation, we measured the acute circulating monocyte activity response after consuming a high-fat meal (85% of daily fat allowance). MATERIALS AND METHODS: Venous blood samples from 17 participants were acquired on a FlowSight. Samples were analyzed to identify nonclassical (CD14+/16+) and classical (CD14+/16-) monocytes. We measured monocyte concentration, adhesion molecule expression, CD36 expression, and oxidized LDL (oxLDL) endocytosis for preprandial 1, 3, and 5 h postprandial. RESULTS: Consuming a high-fat meal caused increases in oxLDL uptake, adhesion molecule expression, and CD36 expression in both classical and nonclassical monocytes, with the nonclassical monocytes responding with larger increases than the classical monocytes. CONCLUSION: These results suggest that consumption of a high-fat meal increased the potential of monocytes to become foam cells, and implicates nonclassical monocytes as having greater potential than classical monocytes to become foam cells. © 2016 International Clinical Cytometry Society.

Consumption of a high-fat breakfast on consecutive days alters preclinical biomarkers for atherosclerosis.

BACKGROUND/OBJECTIVES: Recent research has speculated that the risk of developing atherosclerosis is due to the accumulation of the effects of daily diet choices. The purpose of this study was to examine which of our previously identified preclinical disease risk biomarkers were further elevated when consuming a high-fat (644±50 kcal; 100% recommended dietary allowance for fat), high-calorie (1118±100 kcal; 70% daily caloric needs) breakfast on consecutive days. Young, normal weight females (N=7) participated in this study. SUBJECTS/METHODS: Blood samples were taken premeal and hourly for 5-h postprandial. Serum biomarkers (C-peptide, eotaxin, gastric inhibitory polypeptide, granulocyte colony-stimulating factor (G-CSF), granulocyte-monocyte colony-stimulating factor (GM-CSF), insulin, leptin, monocyte chemoattractant protein 1, pancreatic polypeptide (PPY) and tumor necrosis factor-α), monocyte concentration, and adhesion molecule expression (CD11a, CD18 and CD54) were measured. Area under the curve was calculated for each outcome variable as a function of day and data were analyzed for significance. RESULTS: We found significant (P<0.05) increases on Day 2 for: GM-CSF (+47%; P=0.041), G-CSF (+31%; P=0.012), PPY (+51%; P=0.049), total monocyte (+110%; P=0.043), pro-inflammatory (PI) monocyte (+60%; P=0.012), PI monocyte CD18 (+960%; P=0.003), PI monocyte CD11a (+230%; P=0.006), and PI monocyte CD54 (+208%; P=0.015). CONCLUSIONS: To our knowledge, the present study is the first to report changes in selected biomarkers and monocytes following eating a high-fat, high-calorie breakfast on consecutive days in humans. More research is needed to determine how transient the observed changes are and what the long-term implications for disease risk are.