Childhood obesity alters monocytes and circulating chemokines, putting children at a greater risk of developing obesity-related chronic diseases in adulthood. Further characterization of early immune alterations in childhood obesity may provide additional clinical insight into the assessment of obesity-related disease risk.

BackgroundPeriodization of exercise is a method typically used in sports training, but the impact of periodized exercise on health outcomes in untrained adults is unclear.PurposeThis review aims to summarize existing research wherein aerobic or resistance exercise was prescribed to inactive adults using a recognized periodization method.MethodsA search of relevant databases, conducted between January and February of 2014, yielded 21 studies published between 2000 and 2013 that assessed the impact of periodized exercise on health outcomes in untrained participants.ResultsSubstantial heterogeneity existed between studies, even under the same periodization method. Compared to baseline values or non-training control groups, prescribing periodized resistance or aerobic exercise yielded significant improvements in health outcomes related to traditional and emerging risk factors for cardiovascular disease, low-back and neck/shoulder pain, disease severity, and quality of life, with mixed results for increasing bone mineral density.ConclusionsAlthough it is premature to conclude that periodized exercise is superior to non-periodized exercise for improving health outcomes, periodization appears to be a feasible means of prescribing exercise to inactive adults within an intervention setting. Further research is necessary to understand the effectiveness of periodizing aerobic exercise, the psychological effects of periodization, and the feasibility of implementing flexible non-linear methods.

Strenuous aerobic exercise is known to weaken the immune system, and while many nutritional supplements have been proposed to boost post-exercise immunity, few are known to be effective. The purpose of the present study was to evaluate whether 10 d of supplementation with a defined source of baker's yeast b-glucan (BG, Wellmune WGP w ) could minimise post-exercise immunosuppression. Recreationally active men and women (n 60) completed two 10 d trial conditions using a cross-over design with a 7 d washout period: placebo (rice flour) and baker's yeast BG (250 mg/d of b-1,3/1,6-glucans derived from Saccharomyces cerevisiae) before a bout of cycling (49^6 min) in a hot (38^28C), humid (45^2 % relative humidity) environment. Blood was collected at baseline (before supplement), pre-(PRE), post-(POST) and 2 h (2H) post-exercise. Total and subset monocyte concentration was measured by four-colour flow cytometry. Plasma cytokine levels and lipopolysaccharide (LPS)-stimulated cytokine production were measured using separate multiplex assays. Total (CD14 þ ) and pro-inflammatory monocyte concentrations (CD14 þ /CD16 þ ) were significantly greater at POST and 2H (P, 0·05) with BG supplementation. BG supplementation boosted LPS-stimulated production of IL-2, IL-4, IL-5 and interferon-g (IFN-g) at PRE and POST (P,0·05). Plasma IL-4, IL-5 and IFN-g concentrations were greater at 2H following BG supplementation. It appears that 10 d of supplementation with BG increased the potential of blood leucocytes for the production of IL-2, IL-4, IL-5 and IFN-g. The key findings of the present study demonstrate that BG may have potential to alter immunity following a strenuous exercise session.

High-fat meals promote transient increases in proatherogenic factors, implicating the postprandial state in cardiovascular disease (CVD) progression. Although low-grade inflammation is associated with CVD, little research has assessed postprandial inflammation. Because of its anti-inflammatory properties, premeal exercise may counteract postprandial inflammation. The purpose of this study was to determine postprandial alterations in monocytes and circulating markers of endothelial stress and inflammation following a high-fat meal in young adults with or without premeal cycle exercise. Each subject completed two trials and was randomized to rest or cycle at a moderate intensity prior to eating a high-fat meal. Flow cytometry was used to assess monocyte cell surface receptor expression and concentration of endothelial microparticles (EMP). Plasma cytokines were assessed using Luminex MagPix. Statistical analysis was completed using separate linear mixed models analyses with first-order autoregressive (AR(1)) heterogeneous covariance structure. Significance was set at P ≤ 0.05. Percentage increases in classic monocyte CD11a and CD18 were greater overall in the postprandial period in the meal-only condition compared with the meal + exercise condition (P < 0.05). EMP concentration was 47% greater 3 h after the meal compared with premeal values in the meal-only condition (P < 0.05); no significant increase was observed in the meal + exercise condition. Premeal cycling blunted postprandial increases in EMP and CD11a and CD18. Acute, moderate-intensity exercise may help counteract possibly deleterious postprandial monocyte and endothelial cell activation.

School-based interventions are an effective way to treat childhood obesity. The purpose of the present study was to biologically validate an established school-based intervention designed to reduce standardised body mass index (zBMI) over a period of 12 months. This intervention focused on a subset of Mexican-American children who were participating in a larger clinical weight loss study. Plasma samples were analysed from self-identified Mexican-American children (12-14 years) who were randomised to either a school-based intervention (IN, n = 152) or self-help control (CN, n = 69). Treatment was 4 days week⁻¹ of exercise (45 min day⁻¹) and 1 day week⁻¹ of nutritional counselling for 6 months. Fasting (>8 h) blood samples were collected at baseline, 6 months (end of active intervention) and 12 months (6 months after the end of the active intervention). Plasma resistin, adiponectin and leptin concentration were measured using a multiplex assay. Separate linear mixed models and a P < 0.05 were used to test for significance. Significant group × time interactions were found for resistin (P < 0.0001), adiponectin (P = 0.001) and leptin (P = 0.013). For resistin, IN was 12% lower at 6 months than CN. Adiponectin concentration in IN was greater at 6 months (26%) and 12 months (8%) than CN. Leptin concentration was 22% lower for IN at 12 months than CN. We have previously reported that our school-based intervention reduced zBMI and now reported alterations in biologically relevant disease biomarkers. Some of the observed changes were only present at the end of the active intervention (resistin), while others persisted until 12 months (leptin and adiponectin). These changes underscore the effectiveness of our school-based intervention at not only improving zBMI but also at reducing disease risk.

The purpose of this study was to compare weight gain and food intake during high-fat feeding in outbred CD-1 male mice while considering several different experimental designs. This study was completed using data from three separate experiments and was designed to address different experimental design issues. Experiment 1 compared mice housed in groups or singly. Experiment 2 compared adolescent and young adult mice. Experiment 3 examined mice that had been previously exercise-trained prior to diet-induced weight gain. Data from each experiment were analysed using repeated measures analysis of variance and linear regression. While housing and age did not significantly affect weight gain, mice that were previously exercise-trained consumed significantly more kilocalories than sedentary mice while maintaining comparable body weights. We generated a linear prediction model using data from Experiments 1 and 2 that will allow investigators to calculate the weeks of high-fat feeding needed to reach a target body weight. Our key findings characterize the issues related to and affecting experimental design when utilizing an outbred mouse diet-induced weight gain model and will serve as a guide for future researchers.

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The expression of monocyte cell-surface receptors represents one index of immune dysfunction, which is common with aging. Although mouse models of aging are prevalent, monocyte subset assessment is rare. Our purpose was to compare cell receptor expression on classic (CD115+/Gr-1 high) and non-classic (CD115+/Gr-1 low) monocytes from 80- or 20-week-old CD-1 mice. Three-colour flow cytometry was used to determine the concentration of monocyte subsets and their respective cell-surface expression of TLR2, TLR4, CD80, CD86, MHC II and CD54. These receptors were selected because they have been previously associated with altered monocyte function. Data were analysed with independent t-tests; significance was set at P less than 0.05. Old mice had a greater concentration of both classic (258%, P=0.003) and non-classic (70%, P=0.026) monocytes. The classic : non-classic monocyte ratio doubled in old as compared with that in young mice (P=0.006), indicating a pro-inflammatory shift. TLR4 ( 27%, P=0.001) and CD80 ( 37%, P=0.004) were decreased on classic monocytes from old as compared with those from young mice. TLR2 ( 24%, P=0.002) and MHCII ( 21%, P=0.026) were altered on non-classic monocytes from old as compared with those from young mice. The increased classic : non-classic monocyte ratio combined with changes in the cell-surface receptor expression on both monocyte subsets is indicative of immune dysfunction, which may increase age-associated disease risk.