Impact of elevated body mass index on burn injury-associated mortality in a representative US sample.

BACKGROUND: The impact of obesity on burn-related mortality is inconsistent and incongruent; despite being a risk factor for numerous comorbidities that would be expected to increase complications and worsen outcomes, there is evidence of a survival advantage for patients with high body mass index-the so-called obesity paradox. We used a national data set to explore further the relationship between body mass index and burn-related mortality. METHODS: Deidentified data from patients with second and third-degree burns between 2014 and 2018 were obtained from the Cerner Health Facts Database. Univariate and multivariate regression models were created to identify potential factors related to burn-related mortality. A restricted cubic spline model was built to assess the nonlinear association between body mass index and burn-related mortality. All statistical analyses were conducted using R (R Foundation for Statistical Computing). RESULTS: The study included 9,405 adult burn patients. Univariate and multivariate analyses revealed that age (odds ratio = 2.189 [1.771, 2.706], P < .001), total burn surface area (odds ratio = 1.824 [1.605, 2.074], P < .001), full-thickness burns (odds ratio = 1.992 [1.322, 3.001], P < .001), and comorbidities (odds ratio = 2.03 [1.367, 3.014], P < .001) were associated with increased mortality. Sensitivity analysis showed similar results. However, a restricted cubic spline indicated a U-shaped relation between body mass index and burn-related mortality. The nadir of body mass index was 28.92 kg/m2, with the lowest mortality. This association persisted even after controlling for age, total burn surface area, full-thickness burns, and comorbidities, which all remained significant. CONCLUSION: This study confirms a U-shaped association between body mass index and burn-related mortality along with age, total burn surface area, full-thickness burns, and comorbidities as risk factors.

Distinct mtDNA lineages in free-ranging Ammotragus(aoudad) from the United States indicate multiple introductions from northern Africa.

Translocation records indicate aoudad (Ammotragus lervia) populations in the United States are a product of multiple human-mediated introductions. Two mitochondrial markers (cytochrome b, cytb; displacement loop, D loop) and one nuclear gene (prion protein gene exon 3, PRNP) were used to determine: (1) genetic variation, (2) if genetic units correspond to taxonomic designations, (3) the number and geographic origin of translocations, and (4) divergence times. Three phylogenetic analyses (Bayesian inference, maximum likelihood, and parsimony) produced similar topologies with two clades (I and II). Clade I contained progeny of individuals resulting from introductions to Texas and Spain, and individuals from Algeria. Individuals in Clade II were progeny of past introductions to the United States and Europe, and northern Algeria. Clade II was subdivided into two subclades (A and B) representing two haplogroups. No genetic variation was detected in the PRNP sequences. Three haplogroups appeared to correspond to the subspecies A. l. lervia and A. l. sahariensis whose native distribution includes northwestern Africa. Network analyses assigned haplogroups to two major groups similar to those depicted in the phylogenetic analyses. Genetic distances ranged from 0.80% to 5.17% and 2.99% to 15.42% for cytb and D loop, respectively; and were higher than normally recovered for caprids, warranting a reexamination of subspecific status. Divergence dates indicated a major split between A. l. lervia and A. l. sahariensis circa 2.38 mya. Together, the high level of genetic divergences among US populations and apparent presence of two subspecies of aoudad in the United States support the hypothesis of multiple introductions from multiple sources.