Postchallenge plasma lipoprotein retinoids: chylomicron remnants in endogenous hypertriglyceridemia

Area of Science:

• Biochemistry
• Cardiovascular Medicine
• Nutritional Science

Background:

• Endogenous hypertriglyceridemia is a condition characterized by elevated triglyceride levels.
• The role of chylomicron remnants in the pathophysiology of hypertriglyceridemia requires further elucidation.
• Lipoprotein remnants are implicated as potential atherogenic factors in humans.

Purpose of the Study:

• To investigate the accumulation of chylomicron remnants in patients with endogenous hypertriglyceridemia.
• To utilize retinyl esters as markers for chylomicrons and their remnants due to their intestinal origin.
• To assess the correlation between retinyl ester levels and triglyceride concentrations in hypertriglyceridemic individuals.

Main Methods:

• Seventy-six fasting patients (normotriglyceridemic and hypertriglyceridemic) ingested vitamin A.
• Plasma retinol and retinyl esters were quantified using reversed-phase high-performance liquid chromatography.
• Chylomicronemia was assessed via ultracentrifugation and flocculation; plasma lipids and retinoids were analyzed in a subset.

Main Results:

• Progressively elevated plasma retinyl ester concentrations were observed with increasing severity of hypertriglyceridemia.
• All subjects with fasting chylomicronemia exhibited retinyl ester retention.
• A significant positive correlation was found between plasma retinyl ester and triglyceride concentrations (rs = 0.721, P < 0.001) in non-chylomicronemic subjects.

Conclusions:

• Chylomicron remnant accumulation is evident in patients with endogenous hypertriglyceridemia.
• Elevated retinyl ester levels serve as a marker for chylomicron remnant retention in this population.
• Chylomicron remnant retention may contribute to accelerated atherogenesis in individuals with hypertriglyceridemia.