Power and sample size for reversible linear mixed models with clustering and longitudinality: GLIMMPSE Version 3.

GLIMMPSE Version 3 is a free, web-based, open-source software tool, which calculates power and sample size for general linear mixed models with Gaussian errors. The software permits power calculations for clinical trials, randomized experiments, and observational studies with clustering, repeated measures, and both, and almost any testable hypothesis. The software has been supported by five United States National Institutes of Health (NIH) grants, is used for more than 14,000 power or sample size calculations per year, has been cited in almost 500 peer-reviewed manuscripts, and used to design more than 200 million dollars in NIH-funded studies.

A Randomised Controlled Trial Testing a Behavioural Intervention Program for the Prevention of Type 2 Diabetes Among American Indian Youth: The Tribal Turning Point Study.

Background: American Indian youth experience a high risk of overweight/obesity and type 2 diabetes.

Objectives: To evaluate the effect of a behavioural intervention on diabetes risk factors among American Indian youth with overweight/obesity.

Methods: Between 2018 and 2023, youth (7-10 years) were randomised to the tribal turning point (TTP) intervention (n = 87) or control arm (n = 95).

Responsiveness of the Serum Carbon Isotope Ratio to Dietary Added Sugar Reduction in a Randomized Controlled Trial among Youth with Steatotic Liver Disease.

Background: The carbon isotope ratio (CIR) has been proposed as a biomarker for added sugar intake, but few studies have been conducted in youth, with data from controlled, feeding studies particularly lacking.

Objectives: This study aims to examine associations of added sugar intake with serum CIR in a randomized, controlled dietary sugar reduction intervention in youth.

Methods: Data were collected from 40 boys (11-16 y) with histologically diagnosed steatotic liver disease who completed a randomized controlled trial and were provided either a low-free sugar diet (<3% of calories from added sugar or juice) or usual diet for 8 wk.

GLP-1R Polymorphisms Modify the Relationship Between Exposure to Gestational Diabetes Mellitus and Offspring BMI Growth: The EPOCH Study.

Objective: Exposure to maternal gestational diabetes mellitus (GDM) is associated with childhood BMI. Among youth, we explored whether three different glucagon-like peptide 1 receptor gene (GLP-1R) polymorphisms modified the associations between 1) GDM and BMI trajectories and 2) GDM and markers of glucose-insulin homeostasis.

Research Design And Methods: For 464 participants from the Exploring Perinatal Outcomes Among Children (EPOCH) study, microarray genotyping was performed during childhood (∼10 years).

GLP-1R Gene Polymorphisms and Metabolic Traits During Childhood and Adolescence: The EPOCH Study.

Context: This is the first study to examine the association between variants of the glucagon-like-peptide-1 receptor gene (GLP-1R) and metabolic characteristics among youth.

Objective: We explored separate associations of 3 GLP-1R polymorphisms (rs10305420, rs6923761, and rs1042044) with body mass index (BMI) trajectories and markers of glucose-insulin homeostasis.

Methods: Mixed models examined associations between GLP-1R polymorphisms and trajectories of BMI.

Systematic review on maternal dietary patterns during pregnancy and offspring allergy.

Allergic diseases including food allergy, atopic dermatitis, asthma, and allergic rhinitis are increasing. Nutritional intake may play a role in this increase. Systematic reviews indicate that intake of specific nutrients and foods does not prevent allergic diseases.

Prenatal black carbon exposure and DNA methylation in umbilical cord blood.

Background/objectives: Prenatal exposure to ambient air pollution is associated with adverse cardiometabolic outcomes in childhood. We previously observed that prenatal black carbon (BC) was inversely associated with adiponectin, a hormone secreted by adipocytes, in early childhood. Changes to DNA methylation have been proposed as a potential mediator linking in utero exposures to lasting health impacts.

A better performing algorithm for identification of implausible growth data from longitudinal pediatric medical records.

Tracking trajectories of body size in children provides insight into chronic disease risk. One measure of pediatric body size is body mass index (BMI), a function of height and weight. Errors in measuring height or weight may lead to incorrect assessment of BMI.

Using Power Analysis to Choose the Unit of Randomization, Outcome, and Approach for Subgroup Analysis for a Multilevel Randomized Controlled Clinical Trial to Reduce Disparities in Cardiovascular Health.

We give examples of three features in the design of randomized controlled clinical trials which can increase power and thus decrease sample size and costs. We consider an example multilevel trial with several levels of clustering. For a fixed number of independent sampling units, we show that power can vary widely with the choice of the level of randomization.

Epigenetic age acceleration is associated with speed of pubertal growth but not age of pubertal onset.

Using data from a longitudinal cohort of children, we examined whether epigenetic age acceleration (EAA) was associated with pubertal growth and whether these associations were mediated by adiposity. We examined associations between EAA at approximately 10 years of age with pubertal growth metrics, including age at peak height velocity (PHV), PHV, and sex steroid levels and whether these associations were mediated by measures of adiposity including body mass index (BMI) and MRI-assessed visceral adipose tissue (VAT) and subcutaneous adipose tissue (SAT). Children (n = 135) with accelerated EAA had higher PHV (β 0.

Prenatal Exposure to Poly- and Perfluoroalkyl Substances (2009-2014) and Vaccine Antibody Titers of Measles, Mumps, Rubella, and Varicella in Children Four to Eight Years Old from the Healthy Start Cohort.

Background: Prenatal exposures to certain poly- and perfluoroalkyl substances (PFAS) are associated with reduced humoral responses to some childhood immunizations.

Objective: We estimated associations between prenatal PFAS exposure and child antibody titers for measles, mumps, rubella (MMR), and varicella after immunization.

Methods: We measured serum antibody titers of 145 children (4-8 y old) enrolled in the Healthy Start cohort in Colorado, whose mothers had PFAS quantified mid-pregnancy (2009-2014).

Prenatal exposure to per- and polyfluoroalkyl substances and early childhood adiposity and cardiometabolic health in the Healthy Start study.

Background/objectives: Observational and experimental studies have suggested that prenatal exposure to per- and polyfluoroalkyl substances (PFAS) can increase childhood adiposity and cardiometabolic disruption. However, most previous studies have used weight-based measures that cannot distinguish between fat mass and lean mass. We evaluated associations of prenatal PFAS exposure with precisely measured body composition and cardiometabolic biomarkers in early childhood.

Associations of infant feeding practices with abdominal and hepatic fat measures in childhood in the longitudinal Healthy Start Study.

Background: Infant feeding patterns have been linked with obesity risk in childhood, but associations with precise measures of body fat distribution are unclear.

Objective: We examined associations of infant feeding practices with abdominal fat and hepatic fat trajectories in childhood.

Methods: This study included 356 children in the Healthy Start Study, a prospective prebirth cohort in Colorado.

Diabetes Study of Children of Diverse Ethnicity and Race: Study design.

Aims: Determining diabetes type in children has become increasingly difficult due to an overlap in typical characteristics between type 1 diabetes (T1D) and type 2 diabetes (T2D). The Diabetes Study in Children of Diverse Ethnicity and Race (DISCOVER) programme is a National Institutes of Health (NIH)-supported multicenter, prospective, observational study that enrols children and adolescents with non-secondary diabetes. The primary aim of the study was to develop improved models to differentiate between T1D and T2D in diverse youth.

Early-life exposure to residential black carbon and childhood cardiometabolic health.

Background: Early life exposure to air pollution, such as particulate matter ≤2.5 μm (PM), may be associated with obesity and adverse cardiometabolic health outcomes in childhood. However, the toxicity of PM varies according to its chemical composition.

Identifying Foods That Optimize Intake of Key Micronutrients During Pregnancy.

Background: Most pregnant women in the United States are at risk of inadequate intake of vitamin A, vitamin D, folic acid, calcium, iron, and omega-3 fatty acids from foods alone. Very few United States dietary supplements provide sufficient doses of all 6 nutrients without inducing excess intake.

Objective: We aimed to identify energy-efficient foods that provide sufficient doses of these nutrients and could be consumed in lieu of dietary supplements to achieve the recommended intake in pregnancy.

A pre-conception clinical trial to reduce intergenerational obesity and diabetes risks: The NDPP-NextGen trial protocol.

Background: Intrauterine exposure to maternal overweight/obesity or diabetes transmits risks to offspring, perpetuating a disease cycle across generations. Prenatal interventions to reduce maternal weight or dysglycemia have limited impact, while postpartum interventions can alter the intrauterine environment only if child-bearing continues. Efficacious preconception interventions are needed, especially for underserved populations, and with the potential to be scaled up sustainably.