Lipoprotein quality and increased epicardial fat volume in non-diabetic normolipidemic individuals with obesity normalize after bariatric surgery.

Abstract

Background and aims: Even in the absence of dyslipidemia or diabetes, individuals with obesity have increased cardiovascular risk (CVR). Increased epicardial adipose tissue (EAT) volume, common in obesity, contributes to CVR. However, it is not known whether these individuals with obesity show early qualitative alterations in lipoproteins related to increased EAT volume and CVR. Our aim was to analyze the relationship between EAT and the qualitative properties of lipoproteins in normolipidemic and normoglycemic individuals with obesity, and the effect of bariatric surgery.

Methods and results: The study included 13 individuals with obesity (OB group) before and after bariatric surgery, and 13 healthy controls (HC group). Cardiac computed tomography showed that EAT volume was higher in OB than in HC, and decreased after surgery. Biochemical, inflammatory and lipid plasma profiles were assessed using standard methods. Lipoproteins were isolated by ultracentrifugation, and 34 variables of lipoprotein composition and function were determined. Lipoproteins in the OB group showed larger VLDL size, increased evidence of LDL modification, and smaller HDL particles compared with the HC group. Surgery normalized most of these alterations. Multivariable lineal regression analysis showed that EAT volume are closely associated with the adiponectin/leptin ratio, and several parameters related with abnormal VLDL and HDL size.

Conclusion: Despite normolipidemia and normoglycemia, individuals with obesity exhibit early qualitative alterations in lipoproteins associated with EAT volume. These alterations are largely reversible after bariatric surgery, supporting the role of EAT and lipoprotein qualitative properties as early markers of CVR in metabolically healthy obesity.