Objective: The recent obesity epidemic has been accompanied by a parallel growth in chronic sleep deprivation. Physiologic studies suggest sleep deprivation may influence weight through effects on appetite, physical activity, and/or thermoregulation. This work reviews the literature regarding short sleep duration as an independent risk factor for obesity and weight gain.

Short sleep duration and weight gain : a systematic review

Recent studies have characterized how host genetics, prenatal environment and delivery mode can shape the newborn microbiome at birth. Following this, postnatal factors, such as antibiotic treatment, diet or environmental exposure, further modulate the development of the infant's microbiome and immune system, and exposure to a variety of microbial organisms during early life has long been hypothesized to exert a protective effect in the newborn. Furthermore, epidemiological studies have shown that factors that alter bacterial communities in infants during childhood increase the risk for several diseases, highlighting the importance of understanding early-life microbiome composition. In this review, we describe how prenatal and postnatal factors shape the development of both the microbiome and the immune system. We also discuss the prospects of microbiome-mediated therapeutics and the need for more effective approaches that can reconfigure bacterial communities from pathogenic to homeostatic configurations.

The microbiome in early life: implications for health outcomes

The role of noise as an environmental pollutant and its impact on health are being increasingly recognized. Beyond its effects on the auditory system, noise causes annoyance and disturbs sleep, and it impairs cognitive performance. Furthermore, evidence from epidemiologic studies demonstrates that environmental noise is associated with an increased incidence of arterial hypertension, myocardial infarction, and stroke. Both observational and experimental studies indicate that in particular night-time noise can cause disruptions of sleep structure, vegetative arousals (e.g. increases of blood pressure and heart rate) and increases in stress hormone levels and oxidative stress, which in turn may result in endothelial dysfunction and arterial hypertension. This review focuses on the cardiovascular consequences of environmental noise exposure and stresses the importance of noise mitigation strategies for public health.

https://www.klein-winternheim.de/lokale-agenda/d43d5e550c96630fc05d6c66ec88f0f4_Elsner-eurheartj.ehu030.full.pdf

Cardiovascular effects of environmental noise exposure

Exposure to traffic-related air pollution and risk of development of childhood asthma: A systematic review and meta-analysis

BackgroundAir pollution is hypothesized to be a risk factor for diabetes. Epidemiological evidence is inconsistent and has not been systematically evaluated.ObjectivesWe systematically reviewed epi...

Association between Ambient Air Pollution and Diabetes Mellitus in Europe and North America: Systematic Review and Meta-Analysis

Background

Asthma is the most common chronic illness among children. We aimed to better understand the association of neighbourhood context with asthma control and the moderating effect of obesity status on this association. Methods

Data were from an asthma clinic cohort (n = 4621) of Montreal youths aged 2-18 years, recruited in 2000-2007 and followed for up to 6 years. Clinical data were linked with medical records on acute care visits and hospitalizations. Neighbourhoods were defined by the 750 m buffer around youths’ postal codes. Using spatial data, neighbourhood context was described by high or low deprivation (D) and walkability (W). Asthma control was based on a composite indicator of all adverse events. The outcome was described by the event rate, i.e. total number of composite events by duration of exposure (time in neighourhood). A Poisson model was fitted to predict asthma control rates by neighbourhood context, controlling for individual covariates and an air pollution index based on spatial exposure estimates. We used the Baron-Kenny framework to test for effect modification by obesity status. Results

Asthma control was independently predicted by neighbourhood context. Youth living in low D, high W areas had better asthma control compared with those living in high D low W (IRR=0.83, 95%CI 0.69,0.99, p = 0.04) and those in high D high W (IRR=0.80, 95%CI 0.67,0.95, p = 0.01) areas. Within low D areas, higher W was associated with greater asthma control (IRR=0.88, 95%CI 0.76,1.01, p = 0.07). No other associations were found and obesity did not modify the association between neighbourhood context and asthma control. Conclusions

Higher deprivation is associated with lower rates of asthma control among youth; moreover, high walkability may have a protective effect in low deprivation areas. Efforts to reduce area deprivation may benefit youth suffering from poor asthma control; increasing walkability may be especially beneficial in the absence of area deprivation.

/pdf/influence-of-neighbourhood-characteristics-on-asthma-3nr46jc2go.pdf

Influence of neighbourhood characteristics on asthma outcomes in an asthma clinic cohort of youths

Optimizing the public health response to heat waves to minimize cardiovascular risk.

Risk estimates are frequently used in public health practice to guide authorities responsible for adopting policies that protect public health. There are uncertainties in all risk estimates, most of which do not invalidate their conclusions. Boivin and Savard point out that the flight trajectories used to estimate night-time noise levels are imprecise. As stated in the methods section of our article, we used five potential aerial trajec-tories to account for variations associated with winds, pilot habits, air traffic control, etc. This methodology is used worldwide and supported by institutions like the European Civil Aviation Conference. 1 Furthermore, to obtain an idea of the imprecision associated with the flight trajectories, we estimated how the sleep disturbance probabilities varied for the five trajectories. The mean difference between the trajectories was less than 10% additional or fewer awakenings per night. This suggests that while the use of precise trajectories would definitely be preferable to modeled trajecto-ries, the imprecision associated with modeled trajectories is low. Boivin and Savard also question the methodology used to assess the number of individuals exposed to aircraft noise that could generate one or more awakenings per night. As mentioned in the discussion and in the conclusion of our paper, we agree that our analysis only roughly estimates the number of individuals exposed. Yet, in order to quantify the magnitude of the imprecision, we revised our analysis to remove the number of residences built in 2009 and afterwards and used the 2011 census data. This new analysis modified our original results by 0.1%. In our discussion, we stated the limits to the external and internal validity of the function developed by Basner et al. 2 Thus, we agree with the limitations mentioned by the authors of the commentary. However, we disagree with their interpretation of these limitations. As presented in the article, the risk function could overestimate or underestimate the number of awakenings generated by aircraft noise. It is true that the subjects from whom the function was generated were more annoyed by aircraft noise than the general population, but not all individuals of the general population are exposed to aircraft noise. The subjects studied by Basner et al. are more likely to be representative of the population regularly exposed to aircraft noise. Furthermore, it is worth noting that Bas-ner's function curve was used in other locations in Europe. 3 The authors also claim that the noise attenuations used are …

/pdf/authors-response-to-boivin-and-savard-commentary-55jm8gn1zh.pdf

Louis-François Tétreault

Papers

Influence of neighbourhood characteristics on asthma outcomes in an asthma clinic cohort of youths

Optimizing the public health response to heat waves to minimize cardiovascular risk.

Authors' response to Boivin and Savard commentary.