Predictors of Subclinical Inflammatory Obesity: Plasma Levels of Leptin, Very Low-Density Lipoprotein Cholesterol and CD14 Expression of CD16+ Monocytes

Objective : Predictors of subclinical inflammatory obesity (SIO) can be important tools for early therapeutic interventions in obesity-related comorbidities. Waist circumference (WC) and BMI have different SIO sensitivity. We aimed to i) identify SIO predictors and ii) investigate whether CD16+ monocytes are associated with BMI- (generally) or WC-defined (centrally) obesity. Methods : Anthropometric and metabolic/endocrine (namely catecholamines, adrenaline and noradrenaline) parameters were evaluated, and CD16+ monocytes were studied by flow cytometry in the peripheral blood from 63 blood donors, and compared and correlated to each other. Multiple linear regression analysis was performed to identify variables that best predict SIO. Results : CD16+ monocyte counts were similar in BMI and WC groups. CD16+ monocytes from centrally obese (CO) showed a more inflammatory pattern, as compared to non-CO subjects. WC was sensitive to lipidemia and, in CO subjects, lipidemia was associated with a more inflammatory phenotype of CD16+ monocytes. These differences were not noticed between BMI groups. Adrenaline was correlated with CD16+ monocyte expansion with a lower inflammatory pattern. Leptin, very low-density lipoprotein cholesterol (VLDL-C), and CD14 expression of CD16+ monocytes were found to be CO predictors. Conclusions : WC-, but not BMI-defined obesity, was associated with a more inflammatory pattern of CD16+ monocytes, without monocyte expansion, suggesting that a monocyte maturation process rather than an independent arise of CD16+ monocytes occurs in CO. Thus, in a population with low cardiovascular risk, leptin, VLDL-C, and CD14 expression of CD16+ monocytes predict CO, constituting a putative tool for screening of SIO.