Obesity Affects HDL Metabolism, Composition and Subclass Distribution.

Area of Science:

• Cardiovascular Science
• Metabolic Health
• Lipid Metabolism

Background:

• Obesity is linked to atherogenic dyslipidemia, increasing coronary heart disease risk.
• Functional impairment of high-density lipoprotein (HDL) may contribute to cardiovascular mortality.
• The impact of obesity on HDL composition, structure, and function requires further elucidation.

Purpose of the Study:

• To investigate the effects of obesity on HDL composition, subclass distribution, and function.
• To examine the activities of key enzymes, lecithin-cholesterol acyltransferase (LCAT) and cholesteryl ester transfer protein (CETP), in lipoprotein remodeling.
• To compare these parameters across normal weight, overweight, and obese women.

Main Methods:

• Assessed HDL composition, subclass distribution, and functional parameters.
• Measured LCAT and CETP activities in lipoprotein remodeling.
• Analyzed data from normal weight (n=26), overweight (n=22), and obese (n=20) women.

Main Results:

• Obesity was associated with altered LCAT and CETP activities and decreased HDL components (apolipoprotein A-I, cholesterol, phospholipids).
• Increased serum amyloid A content and a shift towards smaller HDL subclasses were observed in obese women, correlating with reduced anti-oxidative capacity.
• HDL alterations were linked to soluble leptin receptor, adiponectin, and liver enzyme activities, primarily in obese individuals.

Conclusions:

• Obesity significantly impacts HDL metabolism, composition, and subclass distribution, influenced by liver and adipose tissue changes.
• Dysfunctional HDL resulting from obesity may contribute to elevated cardiovascular risk.
• These alterations were specific to obese women, not overweight women.