Alterations in systemic levels of Th1, Th2, and Th17 cytokines in overweight adolescents and obese mice.

BACKGROUND: Obesity represents a major problem for patients and health care systems in most industrialized countries. A chronic inflammatory state in obese individuals leads to disease conditions associated with activation of cellular immune mechanisms. Here, we sought to investigate the role of Th1-, Th2-, and Th17-related cytokines in overweight adolescents and mice on a high-fat diet. METHODS: Plasma samples were obtained from 79 male adolescents aged 13-17 years. Thirty-seven of them had a body mass index (BMI) above the 90th age-specific percentile. Th1, Th2, and Th17 cytokines were measured using Bio-Plex multiplex technology (Bio-Rad, Hercules, USA). In an experimental approach, mice were fed with high-fat (HFD) or normal chow for 15 weeks. RESULTS: Interleukin (IL)-17 concentrations were significantly decreased in overweight adolescents compared to lean controls [99.8 ± 7.3 pg/mL standard error of the mean (SEM) vs 146.6 ± 11.5 pg/mL SEM P = .001]. Levels of IL-17 correlated significantly with anthropometrical parameters of obesity. A concordant response was found in mice consuming a HFD for 15 weeks compared to controls (861 ± 165 pg/mL SEM vs 1575 ± 187 pg/ml SEM, P = .0183). However, a biphasic response was evident for most Th1, Th2, and Th17 cytokines as levels initially increased within the first 5 weeks on HFD and showed a decline afterwards. CONCLUSIONS: In contrast to previous studies showing elevated levels of IL-17 in obese adults, we found a decreasing trend in overweight adolescents. This difference could possibly be related to the fact that disease conditions associated with obesity such as hypertension, vascular pathologies, diabetes, and a triggering of the Th1/Th17 axis were not yet present in overweight teenagers.

Macrophage migration inhibitory factor is elevated in obese adolescents.

OBJECTIVES: The prevalence of obesity in childhood and adolescence is continuing rising. Macrophage migration inhibitory factor (MIF) participates in inflammatory and immune responses as a pro-inflammatory cytokine. The present study aimed to investigate MIF in overweight adolescents. METHODS: Seventy-nine male adolescents were enrolled. Thirty-eight were overweight according to the 90th%ile of the age-specific waist circumference. Various parameters were recorded at one visit, including body mass index. MIF was determined using multiplex immune-assay technology. RESULTS: Overweight adolescents had increased systolic blood pressure and CRP levels. Furthermore, increased circulating MIF concentrations were observed (Median: 964.6 pg/ml, Interquartile range: 590.3-2019.4 versus Median: 562.7 pg/ml, Interquartile range: 430.6-813.7, p = 0.003). Increased MIF concentrations were associated with increased markers of inflammation and obesity. CONCLUSIONS: We demonstrated elevated MIF levels in obese adolescents. Taken together with other markers, this indicates the presence of low-grade inflammation in these young subjects, possibly representing a link between obesity and related co-morbidities.