Postprandial inflammation and coagulation responses to high-fat meals rich in saturated fatty acids

Objective: It has been largely shown that high-fat meals are pro-thrombotic and pro-inflammatory in animal models, especially high-fat meals rich in saturated fatty acids (SFAs). However, there is little evidence to support a clearly defined impact of a high-fat meal on postprandial increases in fibrinolytic and inflammatory markers in healthy normal weight humans. Purpose: To test whether high-fat meal consumption that is rich in SFAs leads to increases in markers of inflammation (Tumor Necrosis Factor Alpha (TNF-α)) and coagulation (Plasminogen Activator Inhibitor-1 (PAI-1)) in normal weight adult men and women. Methods: Twenty-five sedentary (perform < 3h/week of structured exercise), normal weight (BMI=18-24.9 kg/m2) adult men and women between the ages of 18-35 years were recruited for the study (13 men and 12 women). Prior to the meal challenge visit, all participants consumed a 3-day lead-in diet (50% carbohydrate, 35% fat, 15% protein) that was provided by research personnel. No other food or drink was permitted during the lead-in diet period, and all diets were designed to keep subjects in energy balance. On the day of testing, participants were given 2 high-fat meals rich in SFAs for breakfast and lunch. Each liquid meal contained Ensure®, butter, coconut oil and palm oil so that 70% of total energy was derived from fat with 45% of total energy being SFAs. Blood draws were taken at fasting, 2h and 4h post breakfast, and 2h and 4h post lunch. To look at coagulation potential, PAI-1 was measured at all 5 time-points of blood collection, and to study inflammation, TNF-α was measured at the fasting and 2h postprandial time-points. Results: There was no significant change in PAI-1 from fasting to postprandial time-points (35.06±5.86ng/mL to 30.11±5.39ng/mL for fasting and postprandial values, respectively; ns). Additionally, there was no change in TNF-α from fasting to 2h postprandial (1.60±0.51pg/mL to 1.10±0.52pg/mL (log transformed) for fasting and postprandial values, respectively; ns). When analyzed by sex, women had significantly lower fasting TNF-α levels than men (0.84±0.57pg/mL and 2.29±0.81pg/mL for women and men, respectively; p=0.02) but there was no difference in the postprandial TNF-α response between sexes. Additionally, there was no difference between men and women for fasting or postprandial PAI-1 concentrations. Finally, a correlation analysis between fasting PAI-1 and TNF-α values showed a significant positive relationship (R2=0.19, p=0.03); however, no relationship was found with postprandial PAI-1 and TNF-α concentrations (R2=0.02, ns). Conclusion: Two SFA-rich, high-fat meals did not lead to changes in select markers of coagulation or inflammation in either normal weight men or women.