Postprandial increase of complement component 3 in normolipidemic patients with coronary artery disease: effects of...

Area of Science:

• Cardiovascular Science
• Immunology
• Metabolic Research

Background:

• Plasma concentrations of the third complement component (C3) are predictive of myocardial infarction risk.
• Chylomicrons, stimulated by adipocytes in vitro, influence C3 production, suggesting a link between lipid metabolism and complement activation.

Purpose of the Study:

• To investigate in vivo changes in plasma C3 concentrations following an oral fat load.
• To explore the relationship between C3 levels, insulin resistance parameters, and postprandial lipemia.
• To evaluate the effect of simvastatin on fasting and postprandial C3 levels in patients with coronary artery disease.

Main Methods:

• Thirty-seven subjects (20 with coronary artery disease, 17 healthy controls) consumed an oral fat load (50 g/m²).
• Plasma C3 levels were measured at baseline and every 2 hours for 10 hours post-ingestion.
• The impact of simvastatin treatment on C3 levels was assessed in 16 patients.

Main Results:

• Fasting C3 levels were higher in coronary artery disease patients than controls and correlated with insulin resistance markers, notably waist circumference and postprandial triglyceridemia.
• Plasma C3 levels significantly increased 2, 4, and 6 hours after the oral fat load in both groups, with a greater maximal increase observed in patients.
• Simvastatin treatment significantly reduced both fasting (6%) and postprandial (39%) C3 concentrations.

Conclusions:

• Postprandial increases in plasma C3 concentrations occur in both healthy individuals and coronary artery disease patients.
• Fasting C3 is associated with central obesity and insulin resistance, while the postprandial C3 increment is primarily determined by postprandial lipemia.
• Simvastatin effectively lowers both fasting and postprandial C3 levels, suggesting a role for lipid-lowering therapy in modulating complement activation.