Effects of glucose ingestion on circulating inflammatory mediators: Influence of sex and weight excess

Abstract

Background & aims: Low-grade chronic inflammation is involved in the pathophysiology of obesity. However, little is known about the influence of sex and sex hormones on surrogate inflammatory markers and mediators, particularly after glucose ingestion.

Design: Observational study.

Methods: We measured the circulating concentrations of interleukin-6, interleukin-18, macrophage migration inhibitory factor, matrix metallopeptidase-9, monocyte chemotactic protein-1 and pentraxin-3, in the fasting state and during a 75 g oral glucose tolerance test, in 24 women and 25 men. Eleven men and 11 women were lean whereas 14 men and 13 women had weight excess.

Results: Anti-inflammatory cytokines (interleukin-6 and interleukin-18) were increased in the fasting state and/or decreased in some women during the oral glucose tolerance test, as opposed to inflammatory mediators such as macrophage migration inhibitory factor and matrix metallopeptidase-9 that increased during the oral glucose tolerance test especially in subjects with weight excess. Body mass index and waist circumference were the main determinants of these changes. Fasting pentraxin-3 levels were especially increased in lean women in parallel to a decrease in free testosterone levels, and decreased during the oral glucose tolerance test as opposed to the increase in insulin concentrations.

Conclusions: The circulating concentrations of markers of low-grade chronic inflammation in young healthy adults are not only influenced by obesity but also by abdominal adiposity, fasting and glucose ingestion and, in some cases, by sex and sex hormones. These influences should be considered when these markers are used as surrogate markers of the inflammatory milieu associated with obesity.

Keywords: AUC; BMI; Chemokines; Cytokines; E(2); IL-18; Low-grade chronic inflammation; MCP1; MIF; MMP9; PTX3; SHBG; Sexual dimorphism; T; Weight excess; area under the curve; body mass index; high sensitivity C-reactive protein; high-sensitivity interleukin-6; hsCRP; hsIL-6; interleukin-18; macrophage migration inhibitory factor; matrix metallopeptidase 9; monocyte chemotactic protein 1; oGTT; oral glucose tolerance test; pentraxin-3; sex hormone-binding globulin; total estradiol; total testosterone.