“Purpose of review
Studies over the last 2 years have added important new information on the relationship between air pollution and asthma incidence and severity.
Outdoor air pollution has been
associated with asthma exacerbations, including emergency department visits and hospitalizations, p38 MAPK assay as well as with the onset of asthma. Possible mechanisms mediating both incidence and severity effects include the induction of oxidative stress, and/or allergic sensitization, as well as increased susceptibility to viral infections. Some of these mechanisms may be occurring in utero including epigenetic changes that may increase risk for development of asthma. Factors related to increased susceptibility for air pollution-related asthma severity include age, season and genetic polymorphisms related to antioxidant enzymes.
Ambient pollution levels may be associated with both asthma incidence and severity. Susceptibility to air pollution may be higher in children with genetic polymorphisms related to the ‘oxidant stress pathways’. Potential interventions for susceptible children at risk for asthma development and/or severity HDAC inhibitor mechanism include decreased exposure on high air pollution days, especially in the summer months, and antioxidant supplementation. On the
population level, changes in school and home zoning to increase distance from busy roadways may help reduce both asthma incidence and severity.”
“Background: Emerging epidemiological evidence suggest an association between metabolic syndrome and fractures. However,
whether metabolic syndrome is an independent risk or protective factor of fractures remains controversial. Our goal is to provide a quantitative assessment see more of the association between metabolic syndrome and bone fractures by conducting a meta-analysis of observational studies.
Methods: The PubMed and Embase database were searched through to March 2013 to identify studies that met pre-established inclusion criteria. Reference lists of retrieved articles were also reviewed. Summary effect estimates with 95% confidence intervals (CI) were derived using a fixed or random effects model, depending on the heterogeneity of the included studies.
Results: Eight epidemiologic studies involving 39,938 participants were included in the meta-analysis. In overall analysis, metabolic syndrome was not associated with prevalent fractures [pooled odds ratio (OR) 0.93, 95% CI 0.84 - 1.03] in cross-sectional studies or incident fractures [pooled relative risk (RR) 0.88, 95% CI 0.37 - 2.12] in prospective cohort studies. No evidence of heterogeneity was found in cross-sectional studies (p = 0.786, I-2 = 0.0%). A substantial heterogeneity was detected in cohort studies (p = 0.001, I-2 = 85.7%). No indication of significant publication bias was found either from Begg’s test or Egger’s test.