Oral fat load effects on inflammation and endothelial stress markers in healthy subjects

The aim was to study the effect of a standardized oral fat load (OFL) on different inflammatory parameters in a large sample of adult healthy subjects (n = 286) of both sexes. The fat load was given between 08:00 and 09:00 h after a 12-h fast. Blood samples were drawn before and 3, 6, 9, and 12 h after the OFL. All patients underwent a measurement of body mass index (BMI), blood glucose (BG), systolic blood pressure (SBP), diastolic blood pressure (DBP), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (Tg), soluble intercellular adhesion molecule-1 (sICAM-1), interleukin-6 (IL-6), high-sensitivity C-reactive protein (hsCRP), soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble E-selectin (sE-selectin), and tumor necrosis factor-alpha (TNF-alpha). Fasting plasma glucose (FPG) increase was +3.26\% at 3 h, +4.35\% at 6 h, +1.09\% at 9 h while FPG decrease was -1.09\% at 12 h. High-density lipoprotein cholesterol increase was +2.08\% at 3 h, and at 12 h during OFL study; a significant HDL-C decrease was present in subjects after 6 h (-4.17\%; P < 0.05 vs 0). A significant Tg change was observed after 6 h (+70.37\%; P < 0.01 vs 0) and 9 h (+58.33\%; P < 0.05 vs 0) respectively, and the increase was +22.22\% at 3 h and +18.52\% at 12 h. Total cholesterol increase was +0.52\% after 3 h, +1.04\% after 6 h, while after 12 h the decrease was -0.52\%. Low-density lipoprotein cholesterol increase was +1.64\% after 6 h with a decrease of -0.82\% at 9 and 12 h. A significant sICAM-1, hsCRP, and sE-selectin variation was observed after 6 and 9 h, while a significant sVCAM-1 change occurred after 3, 6, and 9 h. Soluble ICAM-1 increase was +20.58\% at 3 h, +34.10\% at 6 h (P < 0.05 vs 0) +25.94\% at 9 h (P < 0.01 vs 0), and +19.14\% at 12 h; sVCAM-1 increase was +13.97\% (P < 0.05 vs 0) at 3 h, +18.55\% at 6 h (P < 0.01 vs 0), +12.02\% at 9 h (P < 0.05 vs 0), and +8.70\% at 12 h. High-sensitivity CRP increase was +36.36\% at 3 h, +90.91\% at 6 h (P < 0.01 vs 0), +63.64\% at 9 h (P < 0.05 vs 0), and +36.36\% at 12 h. Soluble E-selectin increase was +27.11\% at 3 h, +51.90\% at 6 h (P < 0.05 vs 0), +45.19\% at 9 h (P < 0.01 vs 0), and +20.12\% at 12 h. Interleukin-6 increase was +61.11\% at 3 h (P < 0.05 vs 0), +83.33\% at 6 h (P < 0.001 vs 0), +55.56\% at 9 h (P < 0.01 vs 0), and +22.22\% at 12 h. Tumor necrosis factor-alpha increase was +42.86\% at 3 h (P < 0.05 vs 0), +71.43\% at 6 h (P < 0.01 vs 0), (+50.00\% at 9 h (P < 0.05 vs 0), and +28.57\% at 12 h. We observed that the OFL induces a complex and massive systemic inflammatory response that includes IL-6, TNF-alpha, hsCRP, and cell adhesion molecules, even before Tg significantly rises.