Urban/rural residence effect on emergency department visits arising from food-induced anaphylaxis.

BACKGROUND: Anaphylaxis is a severe and potentially fatal allergic response. Early-life exposure to rural environments may help protect against allergic reaction. This study assesses urban/rural differences by age and race/ethnicity in emergency department (ED) pediatric visit rates for food-induced anaphylaxis. METHODS: This observational study examined 2009-2014 inpatient and ED data from New York and Florida, using ICD-9-CM diagnostic code (995.6) to identify food-induced anaphylaxis cases <18 y/o. Primary predictor of interest was urban/rural setting, with race/ethnicity and age also evaluated. Associations between ED visit rates and urban/rural setting were evaluated by multivariable hierarchical negative binomial regression with state and year fixed effects. RESULTS: ED visit rates (per 100,000) for food-induced anaphylaxis were 12.31 and 4.60 in urban and rural settings, respectively. Rates were highest among Blacks (15.26) younger urban children (17.29) and older rural children (6.99). Compared to rural, urban children had significantly higher anaphalaxis ED visit rates (IRR 2.77). CONCLUSIONS: Food-induced anaphylaxis ED visit rates were highest among younger urban children and Black children, with a notable contrast in age distribution between urban and rural rates. Higher urban rates may be attributed to Hygiene Hypothesis, though racial, economic and emergency care access disparities may also influence these outcomes.

Patient Characteristics and Emergency Department Factors Associated with Survival After Sudden Cardiac Arrest in Children and Young Adults: A Cross-Sectional Analysis of a Nationally Representative Sample, 2006-2013.

The purpose of the study is to examine (1) nationally representative incidence rates of Emergency Department (ED) visits due to sudden cardiac arrest (SCA) in pediatric and young adult populations, (2) basic characteristics of the ED visits with SCA, and (3) patient and hospital factors associated with survival after SCA. We used the Nationwide Emergency Department Sample from 2006 to 2013. ICD-9-CM diagnostic codes identified ED visits due to SCA for patients ≤ 30 years old. Outcomes included yearly incidence of ED visits for SCA, and survival to hospital discharge. Predictors of interest were age groups, sex, and SCA case volume. A logistic regression model adjusted by patient- and hospital-level variables was used. Stratified analyses of age by (< 12 and ≥ 12 years old) were performed to explore the effect of pubertal development on SCA. With 71,881 ED visits due to SCA, the total incidence rate was 6.9 per 100,000 population, with a mortality rate of 89.6% and male/female ratio of 1.7. With the adjusted regression models, there were no differences in survival rate by sex; however, when stratified at 12 years old, males were less likely to survive than females above 12 years old (odds ratio [OR] 0.71, P < 0.01), but not under 12 years old. No statistically significant differences in survival rates between low- and high-SCA volume EDs were detected (OR 1.03, P = 0.77). Data showed no benefit of regionalized care for post-SCA in ≤ 30-year-old populations. With further examination of the differences between sexes, new management strategies for SCA cases can be developed.

ACTN3 allele frequency in humans covaries with global latitudinal gradient.

A premature stop codon in ACTN3 resulting in α-actinin-3 deficiency (the ACTN3 577XX genotype) is common in humans and reduces strength, muscle mass, and fast-twitch fiber diameter, but increases the metabolic efficiency of skeletal muscle. Linkage disequilibrium data suggest that the ACTN3 R577X allele has undergone positive selection during human evolution. The allele has been hypothesized to be adaptive in environments with scarce resources where efficient muscle metabolism would be selected. Here we test this hypothesis by using recently developed comparative methods that account for evolutionary relatedness and gene flow among populations. We find evidence that the ACTN3 577XX genotype evolved in association with the global latitudinal gradient. Our results suggest that environmental variables related to latitudinal variation, such as species richness and mean annual temperature, may have influenced the adaptive evolution of ACTN3 577XX during recent human history.