Ghrelin agonist does not foster insulin resistance but improves cognition in an Alzheimer's disease mouse model.

The orexigenic hormone ghrelin, a potential antagonist of the insulin system, ensures sufficient serum glucose in times of fasting. In the race for new therapeutics for diabetes, one focus of study has been antagonizing the ghrelin system in order to improve glucose tolerance. We provide evidence for a differential role of a ghrelin agonist on glucose homeostasis in an Alzheimer's disease mouse model fed a high-glycemic index diet as a constant challenge for glucose homeostasis.

Best (but oft-forgotten) practices: designing, analyzing, and reporting cluster randomized controlled trials.

Cluster randomized controlled trials (cRCTs; also known as group randomized trials and community-randomized trials) are multilevel experiments in which units that are randomly assigned to experimental conditions are sets of grouped individuals, whereas outcomes are recorded at the individual level. In human cRCTs, clusters that are randomly assigned are typically families, classrooms, schools, worksites, or counties. With growing interest in community-based, public health, and policy interventions to reduce obesity or improve nutrition, the use of cRCTs has increased.

Double sampling with multiple imputation to answer large sample meta-research questions: introduction and illustration by evaluating adherence to two simple CONSORT guidelines.

Background: Meta-research can involve manual retrieval and evaluation of research, which is resource intensive. Creation of high throughput methods (e.g.

Ignoring regression to the mean leads to unsupported conclusion about obesity.

Childhood obesity remains a substantial health concern for our population and thoughtful attempts to develop and evaluate the utility of programs to reduce childhood obesity levels are needed. Unfortunately, we believe the conclusion by Burke et al. that the HealthMPowers program produces positive change in body composition is incorrect because the results obtained are likely due to regression to the mean (RTM), a well-known threat to the validity of studies that is often overlooked.

Second-hand eating? Maternal perception of the food environment affects reproductive investment in mice.

Objective: Little information exists on how perception of the food (or "energetic") environment affects body composition and reproductive investment. The hypothesis was tested that female mice, who are themselves consuming standard chow diets but who are exposed to conspecifics eating a rich "cafeteria diet," will exhibit altered weight gain and reproductive investment.

Methods: Female C57BL/6 mice were raised on a cafeteria diet.

Linkage and association analysis of obesity traits reveals novel loci and interactions with dietary n-3 fatty acids in an Alaska Native (Yup'ik) population.

Objective: To identify novel genetic markers of obesity-related traits and to identify gene-diet interactions with n-3 polyunsaturated fatty acid (n-3 PUFA) intake in Yup'ik people.

Material And Methods: We measured body composition, plasma adipokines and ghrelin in 982 participants enrolled in the Center for Alaska Native Health Research (CANHR) Study. We conducted a genome-wide SNP linkage scan and targeted association analysis, fitting additional models to investigate putative gene-diet interactions.

Do altered energy metabolism or spontaneous locomotion 'mediate' decelerated senescence?

That one or multiple measures of metabolic rate may be robustly associated with, or possibly even causative of, the progression of aging-resultant phenotypes such as lifespan is a long-standing, well-known mechanistic hypothesis. To broach this hypothesis, we assessed metabolic function and spontaneous locomotion in two genetic and one dietary mouse models for retarded aging, and subjected the data to mediation analyses to determine whether any metabolic or locomotor trait could be identified as a mediator of the effect of any of the interventions on senescence. We do not test the hypothesis of causality (which would require some experiments), but instead test whether the correlation structure of certain variables is consistent with one possible pathway model in which a proposed mediating variable has a causal role.

Risk and injury severity of obese child passengers in motor vehicle crashes.

Objective: To investigate the risk and injury severity on the regional body (head, neck, and chest) of obese children in frontal motor vehicle crashes (MVCs).

Methods: No physical surrogates (i.e.

A statistical framework for testing the causal effects of fetal drive.

Maternal genetic and phenotypic characteristics (e.g., metabolic and behavioral) affect both the intrauterine milieu and lifelong health trajectories of their fetuses.

A free-knot spline modeling framework for piecewise linear logistic regression in complex samples with body mass index and mortality as an example.

This paper details the design, evaluation, and implementation of a framework for detecting and modeling nonlinearity between a binary outcome and a continuous predictor variable adjusted for covariates in complex samples. The framework provides familiar-looking parameterizations of output in terms of linear slope coefficients and odds ratios. Estimation methods focus on maximum likelihood optimization of piecewise linear free-knot splines formulated as B-splines.

Baseline participant characteristics and risk for dropout from ten obesity randomized controlled trials: a pooled analysis of individual level data.

Introduction: Understanding participant demographic characteristics that inform the optimal design of obesity RCTs have been examined in few studies. The objective of this study was to investigate the association of individual participant characteristics and dropout rates (DORs) in obesity randomized controlled trials (RCT) by pooling data from several publicly available datasets for analyses. We comprehensively characterize DORs and patterns in obesity RCTs at the individual study level, and describe how such rates and patterns vary as a function of individual-level characteristics.

Even modest prediction accuracy of genomic models can have large clinical utility.

Whole Genome Prediction (WGP) jointly fits thousands of SNPs into a regression model to yield estimates for the contribution of markers to the overall variance of a particular trait, and for their associations with that trait. To date, WGP has offered only modest prediction accuracy, but in some cases even modest prediction accuracy may be useful. We provide an illustration of this using a theoretical simulation that used WGP to predict weight loss after bariatric surgery with moderate accuracy (R (2) = 0.

Unscientific beliefs about scientific topics in nutrition.

Humans interact with food daily. Such repeated exposure creates a widespread, superficial familiarity with nutrition. Personal familiarity with nutrition from individual and cultural perspectives may give rise to beliefs about food not grounded in scientific evidence.

Novel mathematical models for investigating topics in obesity.

There is limited insight into the mechanisms, progression, and related comorbidities of obesity through simple modeling tools such as linear regression. Keeping in mind the words of the late George E. P.