The Circulating Lipidome In Severe Obesity.

Area of Science:

• Metabolomics
• Obesity Research
• Cardiovascular Disease

Background:

• Severe obesity (BMI ≥40 kg/m²), a growing global health issue, disproportionately impacts minority populations and is understudied mechanistically.
• Lipid metabolism is central to obesity-related cardiometabolic disease (CMD), but its specific molecular underpinnings in severe obesity, especially in high-risk groups, remain unclear.

Purpose of the Study:

• To investigate the relationship between circulating lipid species and severe obesity in a high-risk Hispanic cohort.
• To identify specific lipid signatures and potential causal links associated with severe obesity and cardiometabolic risk factors.

Main Methods:

• Lipidomic and genetic data from 578 participants (185 severe obesity, 393 controls) in the Cameron County Hispanic Cohort were analyzed.
• Logistic regression, OPLS-DA, and network deconvolution Mendelian randomization (NDMR) were used to assess lipid associations and causality.
• Influential lipids were correlated with cardiometabolic risk traits and body composition.

Main Results:

• Individuals with severe obesity exhibited more adverse cardiometabolic risk factors.
• Elevated short-chain triacylglycerols and reduced lysophospholipids, plasmalogens, cholesteryl esters, and long-chain lipids were observed in severe obesity.
• Over 300 influential lipid species predicted severe obesity status, with specific triacylglycerols implicated as potentially causal.

Conclusions:

• Severe obesity is characterized by significant, lipid class-specific dysregulation of the circulating lipidome, strongly associated with cardiometabolic risk.
• Short-chain acyl chain triacylglycerols represent a distinct lipid signature of severe obesity, showing consistent elevation, discriminative power, and a causal link.
• These findings suggest a novel lipidomic pathway in severe obesity, warranting further research into its determinants.