Apolipoprotein E polymorphism influences postprandial retinyl palmitate but not triglyceride concentrations

Area of Science:

• Genetics
• Metabolic Studies
• Nutritional Science

Background:

• Apolipoprotein E (apo E) polymorphism is a known factor influencing lipid metabolism.
• Understanding its role in postprandial lipemia is crucial for assessing cardiovascular disease (CAD) risk.
• Previous studies have established apo E's effect on fasting lipid levels.

Purpose of the Study:

• To quantify the effect of apo E polymorphism on postprandial lipemia.
• To determine the role of apo E in the metabolic response to a high-fat meal.
• To investigate the impact of apo E genotypes on specific lipid and lipoprotein profiles.

Main Methods:

• Analysis of a large cohort (N=474) from the Atherosclerosis Risk in Communities Study.
• Monitoring plasma triglyceride, TGRL-triglyceride, apo B-48/apo B-100 ratio, and retinyl palmitate over 8 hours post-meal.
• Determination of apo E polymorphism via DNA amplification and digestion.

Main Results:

• Postprandial retinyl palmitate response was significantly different among apo E genotypes, with delayed clearance in epsilon 2 carriers.
• The apo E polymorphism explained 7.1% of the interindividual variation in postprandial retinyl palmitate response.
• No significant differences in postprandial triglyceride response were observed among apo E genotypes.

Conclusions:

• The apo E polymorphism significantly affects postprandial vitamin A clearance, indicating delayed remnant particle removal in epsilon 2 carriers.
• While apo E influences postprandial lipemia, its direct link to coronary artery disease (CAD) via the epsilon 2 allele remains unproven.
• These findings provide mechanistic insights into apo E's role in postprandial lipemia and its potential implications for cardiovascular health.