Decreased Adipose Lipid Turnover Associates With Cardiometabolic Risk and the Metabolic Syndrome

Area of Science:

• Metabolic Research
• Adipose Tissue Biology
• Cardiovascular Health

Background:

• Disturbed white adipose tissue function is a key factor in cardiometabolic risk and metabolic syndrome (MetS).
• The specific role of adipose lipid turnover, including lipolysis and triglyceride synthesis, in MetS was previously unknown.
• This study investigated adipose lipid turnover in subcutaneous adipose tissue, the body's largest fat depot.

Purpose of the Study:

• To investigate adipose lipid turnover in subcutaneous adipose tissue.
• To determine the relationship between adipose lipid age, lipid storage capacity, and metabolic syndrome (MetS).
• To identify the mechanisms underlying altered lipid metabolism in MetS.

Main Methods:

• Adipose lipid age and lipid storage capacity were assessed using ¹⁴C incorporation in 78 subjects.
• Adipose lipid age was also calculated using an algorithm of adipocyte lipolysis and clinical parameters in 185 subjects.
• MetS was defined by Adult Treatment Panel III (ATPIII) scoring; statistical comparisons used ANOVA, ANCOVA, and t-tests.

Main Results:

• Adipose lipid age significantly increased with incremental ATPIII score and was twofold higher in MetS.
• This correlation was independent of age, sex, BMI, waist-to-hip ratio, sedentary lifestyle, obesity status, and adipose insulin resistance.
• Lipid storage capacity was not associated with ATPIII score or MetS, while adipocyte lipolysis activation was decreased in MetS.

Conclusions:

• Abdominal subcutaneous adipose lipid turnover is reduced in MetS and with high ATPIII scores.
• This decrease is primarily due to impaired lipid mobilization, characterized by reduced adipocyte lipolysis activation.
• Despite normal lipid assimilation capacity, impaired lipid mobilization contributes to metabolic dysfunction in MetS.