Skipping Breakfast Is Associated with an Atherogenic Lipid Profile in Overweight and Obese Prepubertal Children.

BACKGROUND: Skipping breakfast has been associated with a higher risk of obesity and cardiovascular (CV) risk factors. However, it is not known if skipping breakfast is also correlated with CV risk factors independently from obesity. The mechanisms explaining the role of skipping breakfast on promoting fat accumulation as well as CV risk are not known. Hormones, in particular, insulin-like growth factor-1 (IGF-1), may potentially play a role in the metabolic profile of breakfast skippers. AIM: This cross-sectional study aims to test, in a sample of overweight/obese children, the hypotheses that skipping breakfast is associated with a worse metabolic profile and that IGF-1 levels are associated with this unfavorable metabolic profile. METHODS AND RESULTS: We enrolled 112 overweight/obese prepubertal children (3-12 years). Anthropometric characteristics (height SDS, weight SDS, and body mass index (BMI) z-score) were measured. Blood samples were collected to evaluate glucose and lipid metabolisms and hormone profile (growth hormone (GH), IGF-1, insulin, and cortisol). The triglycerides/high-density lipoprotein (HDL) cholesterol ratio was calculated as a predictor of cardiovascular risk. Children were divided into two groups according to breakfast habits: consumers (≥5 weekly; N = 76) and skippers (≤4 weekly; N = 36). Glycaemia, total and low-density lipoprotein (LDL) cholesterol, triglycerides (p < 0.05), and triglycerides/HDL cholesterol ratio (p < 0.001) were higher, while HDL cholesterol was lower (p < 0.01) in skippers as compared to consumers. IGF-1 concentrations were inversely correlated with LDL cholesterol (r = -0.279, p=0.013) and directly correlated with HDL cholesterol (r = 0.226, p=0.047). IGF-1 correlated positively with HDL cholesterol (r = 0.266, p=0.045) in consumers and correlated negatively with LDL cholesterol (r = -0.442, p=0.024) in skippers. Breakfast consumption among prepubertal overweight/obese children showed a better lipid profile in comparison with those who skipped breakfast [OR: 0.165 (95% CI: 0.053-0.518), p=0.001]; these latter odds of the increased triglycerides/HDL cholesterol ratio was 6.1-fold higher. CONCLUSIONS: Breakfast skippers show a worse lipid profile when compared to breakfast consumers. IGF-1 might play a role as an independent modulator of lipid metabolism.

Effect of water table management and elevated CO2 on radish productivity and on CH4 and CO2 fluxes from peatlands converted to agriculture.

Anthropogenic activity is affecting the global climate through the release of greenhouse gases (GHGs) e.g. CO2 and CH4. About a third of anthropogenic GHGs are produced from agriculture, including livestock farming and horticulture. A large proportion of the UK's horticultural farming takes place on drained lowland peatlands, which are a source of significant amounts of CO2 into the atmosphere. This study set out to establish whether raising the water table from the currently used -50cm to -30cm could reduce GHGs emissions from agricultural peatlands, while simultaneously maintaining the current levels of horticultural productivity. A factorial design experiment used agricultural peat soil collected from the Norfolk Fens (among the largest of the UK's lowland peatlands under intensive cultivation) to assess the effects of water table levels, elevated CO2, and agricultural production on GHG fluxes and crop productivity of radish, one of the most economically important fenland crops. The results of this study show that a water table of -30cm can increase the productivity of the radish crop while also reducing soil CO2 emissions but without a resultant loss of CH4 to the atmosphere, under both ambient and elevated CO2 concentrations. Elevated CO2 increased dry shoot biomass, but not bulb biomass nor root biomass, suggesting no immediate advantage of future CO2 levels to horticultural farming on peat soils. Overall, increasing the water table could make an important contribution to global warming mitigation while not having a detrimental impact on crop yield.

Environmental controls on ozone fluxes in a poplar plantation in Western Europe.

Tropospheric O3 is a strong oxidant that may affect vegetation and human health. Here we report on the O3 fluxes from a poplar plantation in Belgium during one year. Surprisingly, the winter and autumn O3 fluxes were of similar magnitude to ones observed during most of the peak vegetation development. Largest O3 uptakes were recorded at the beginning of the growing season in correspondence to a minimum stomatal uptake. Wind speed was the most important control and explained 44% of the variability in the nighttime O3 fluxes, suggesting that turbulent mixing and the mechanical destruction of O3 played a substantial role in the O3 fluxes. The stomatal O3 uptake accounted for a seasonal average of 59% of the total O3 uptake. Multiple regression and partial correlation analyses showed that net ecosystem exchange was not affected by the stomatal O3 uptake.

Light-stress avoidance mechanisms in a Sphagnum-dominated wet coastal Arctic tundra ecosystem in Alaska.

The Arctic experiences a high-radiation environment in the summer with 24-hour daylight for more than two months. Damage to plants and ecosystem metabolism can be muted by overcast conditions common in much of the Arctic. However, with climate change, extreme dry years and clearer skies could lead to the risk of increased photoxidation and photoinhibition in Arctic primary producers. Mosses, which often exceed the NPP of vascular plants in Arctic areas, are often understudied. As a result, the effect of specific environmental factors, including light, on these growth forms is poorly understood. Here, we investigated net ecosystem exchange (NEE) at the ecosystem scale, net Sphagnum CO2 exchange (NSE), and photoinhibition to better understand the impact of light on carbon exchange from a moss-dominated coastal tundra ecosystem during the summer season 2006. Sphagnum photosynthesis showed photoinhibition early in the season coupled with low ecosystem NEE. However, later in the season, Sphagnum maintained a significant CO2 uptake, probably for the development of subsurface moss layers protected from strong radiation. We suggest that the compact canopy structure of Sphagnum reduces light penetration to the subsurface layers of the moss mat and thereby protects the active photosynthetic tissues from damage. This stress avoidance mechanism allowed Sphagnum to constitute a significant percentage (up to 60%) of the ecosystem net daytime CO2 uptake at the end of the growing season despite the high levels of radiation experienced.

Development and field evaluation of a new diffusive sampler for hydrogen sulphide in the ambient air.

A diffusive sampler for the determination of hydrogen sulphide (H2S) based on collection on a paper filter coated with silver nitrate followed by optical densitometric determination of the metal sulphide was developed. Laboratory tests were conducted in controlled atmosphere to evaluate linearity, uptake rate, face velocity effects, sample stability, influence of relative humidity and of interferents, precision and accuracy. The measured uptake rate for H2S was determined in experiments involving sampling at different concentration levels in comparison to a wet standard colorimetric technique. The precision of the measurements for co-located passive samplers was lower than 15%. The accuracy of the data collected is within 20% of the actual value measured by the wet method. The sampler is capable of reliable measurements of H2S at common levels of a polluted atmosphere in urban settings yielding average concentration levels over one month and beyond. Diffusive sampling can be adopted to analyse in detail the temporal and spatial trends of H2S concentration in ambient air and in specific historic buildings or in museums.