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Objective: Identify factors contributing to time a family spends in a Multidisciplinary Craniofacial Team Clinic (MDCT) and implement an intervention to reduce this time. Design: Interventional: a restructuring of clinics to serve those patients requiring fewer provider encounters separately. Setting: An American Cleft Palate-Craniofacial Association-accredited MDCT in an academic children’s hospital. Patients/Participants: One hundred sixty-seven patients with craniofacial diagnoses. Interventions: Time data were tabulated over ∼2 years. Following 9 months of data collection, patients requiring fewer provider encounters were scheduled to a separate clinic serving children with craniosynostosis, and data were collected in the same fashion for another 14 months. Main Outcome Measures: Principal outcome measures included total visit time and proportion of the visit spent without a provider in the room before and after clinic restructuring. Results: The average time spent by family in a clinic session was 161.53 minutes, of which 64.3% was spent without a provider in the room. Prior to clinic restructuring, a greater number of provider encounters was inversely associated with percentage of time spent without a provider ( P < .001). Upon identifying this predictor, scheduling patients who needed fewer provider encounters to a Craniosynostosis Clinic session resulted in reduction in absolute and percentage of time spent without a provider ( P < .001). Conclusions: The number of provider encounters is a significant predictor of the proportion of a clinic visit spent without a provider. Clinic restructuring to remove patient visits that comprise fewer provider encounters resulted in a greater percentage of time spent with a provider in an MDCT.

Background Early childhood (0–3 years) is a critical period for obesity prevention, when tendencies in eating behaviors and physical activity are established. Yet, little is understood about how the environment shapes children's genetic predisposition for these behaviors during this time. The Baylor Infant Twin Study (BITS) is a two phase study, initiated to study obesity risk factors from infancy. Data collection has been completed for Phase 1 in which three sub‐studies pilot central measures for Phase 2. A novel infant temperament assessment, based on observations made by trained researchers was piloted in Behavior Observation Pilot Protocol (BOPP) study, a new device for measuring infant feeding parameters (the “orometer”) in the Baylor Infant Orometer (BIO), and methods for analyzing DNA methylation in twins of unknown chorionicity in EpiTwin. Methods EpiTwin was a cross‐sectional study of neonatal twins, while up to three study visits occurred for the other studies, at 4‐ (BOPP, BIO), 6‐ (BOPP), and 12‐ (BOPP, BIO) of age. Measurements for BOPP and BIO included temperament observations, feeding observations, and body composition assessments while EpiTwin focused on collecting samples of hair, urine, nails, and blood for quantifying methylation levels at 10 metastable epialleles. Additional data collected include demographic information, zygosity, chorionicity, and questionnaire‐based measures of infant behaviors. Results Recruitment for all three studies was completed in early 2020. EpiTwin recruited 80 twin pairs (50% monochorionic), 31 twin pairs completed the BOPP protocol, and 68 singleton infants participated in BIO. Conclusions The psychometric properties of the data from all three studies are being analyzed currently. The resulting findings will inform the development of the full BITS protocol, with the goal of completing assessments at 4‐, 6‐, 12‐, and 14‐month of age for 400 twin pairs.

The pathophysiology underlying pseudotumor cerebri syndrome (PTCS) is complex and not well understood. There are clear differences between PTCS in adults and pediatrics. Few and isolated case reports have suggested that adrenal function may be involved, yet no large cohort study has examined this relationship.We conducted a retrospective single-center study of children who presented with a diagnosis of PTCS and had cortisol testing measured between January 2010 and September 2019. We included all subjects meeting the revised PTCS diagnostic criteria after the chart review. Based on morning, random or 1-μg cosyntropin stimulated cortisol levels, adrenal functioning was classified as: (1) insufficient (peak cortisol16 μg/dL and AM cortisol5 μg/dL), (2) at risk (peak cortisol 16-20 μg/dL, AM cortisol 5-13 μg/dL, or random13 μg/dL), or (3) sufficient (peak cortisol20 μg/dL and AM or random cortisol13 μg/dL).A total of 398 individuals were reviewed, and 64 were included for analysis. Of these, 40.6% were men, of mixed race and ethnicity with a mean age of 10.5 (SD 4.7) years. Of these, 23% and 52% had insufficient or at-risk cortisol levels. The majority of those in the insufficient (70%) or at-risk (80%) groups were exposed to topical, nasal, or inhaled glucocorticoids but not systemic. Only 60% and 12% of those with PTCS with insufficient or at-risk cortisol testing, respectively, underwent definitive testing with a stimulation test.Glucocorticoid use and hypocortisolism are prevalent in PTCS and need consideration as a potential underlying cause. Most children had insufficient or at-risk cortisol levels, and many did not undergo further testing/workup. Children who present with PTCS, particularly young, males should be evaluated for adrenal insufficiency and its risk factors, including nonsystemic steroids. Prospective studies are necessary to further evaluate the effect of cortisol in relation to pediatric PTCS.

Aim To investigate the role of the gut microbiome in regulating key insulin homeostasis traits (insulin sensitivity, insulin secretion and insulin clearance) whose dysfunction leads to type 2 diabetes (T2D). Materials and methods The Microbiome and Insulin Longitudinal Evaluation Study (MILES) focuses on African American and non-Hispanic white participants aged 40-80 years without diabetes. Three study visits are planned (at baseline, 15 and 30 months). Baseline measurements include assessment of the stool microbiome and administration of an oral glucose tolerance test, which will yield indexes of insulin sensitivity, insulin secretion and insulin clearance. The gut microbiome profile (composition and function) will be determined using whole metagenome shotgun sequencing along with analyses of plasma short chain fatty acids. Additional data collected include dietary history, sociodemographic factors, health habits, anthropometry, medical history, medications and family history. Most assessments are repeated 15 and 30 months following baseline. Results After screening 875 individuals, 129 African American and 224 non-Hispanic white participants were enrolled. At baseline, African American participants have higher blood pressure, weight, body mass index, waist and hip circumferences but similar waist-hip ratio compared with the non-Hispanic white participants. On average, African American participants are less insulin-sensitive and have higher acute insulin secretion and lower insulin clearance. Conclusions The longitudinal design and robust characterization of potential mediators will allow for the assessment of glucose and insulin homeostasis and gut microbiota as they change over time, improving our ability to discern causal relationships between the microbiome and the insulin homeostasis traits whose deterioration determines T2D, setting the stage for future microbiome-directed therapies to prevent and treat T2D.

Background De novo lipogenesis (DNL) is the primary metabolic pathway synthesizing fatty acids from carbohydrates, protein, or alcohol. Our aim was to examine associations of in vivo levels of selected fatty acids (16:0, 16:1n7, 18:0, 18:1n9) in DNL with incidence of type 2 diabetes (T2D). Methods and findings Seventeen cohorts from 12 countries (7 from Europe, 7 from the United States, 1 from Australia, 1 from Taiwan; baseline years = 1970–1973 to 2006–2010) conducted harmonized individual-level analyses of associations of DNL-related fatty acids with incident T2D. In total, we evaluated 65,225 participants (mean ages = 52.3–75.5 years; % women = 20.4%–62.3% in 12 cohorts recruiting both sexes) and 15,383 incident cases of T2D over the 9-year follow-up on average. Cohort-specific association of each of 16:0, 16:1n7, 18:0, and 18:1n9 with incident T2D was estimated, adjusted for demographic factors, socioeconomic characteristics, alcohol, smoking, physical activity, dyslipidemia, hypertension, menopausal status, and adiposity. Cohort-specific associations were meta-analyzed with an inverse-variance-weighted approach. Each of the 4 fatty acids positively related to incident T2D. Relative risks (RRs) per cohort-specific range between midpoints of the top and bottom quintiles of fatty acid concentrations were 1.53 (1.41–1.66; p < 0.001) for 16:0, 1.40 (1.33–1.48; p < 0.001) for 16:1n-7, 1.14 (1.05–1.22; p = 0.001) for 18:0, and 1.16 (1.07–1.25; p < 0.001) for 18:1n9. Heterogeneity was seen across cohorts (I2 = 51.1%–73.1% for each fatty acid) but not explained by lipid fractions and global geographical regions. Further adjusted for triglycerides (and 16:0 when appropriate) to evaluate associations independent of overall DNL, the associations remained significant for 16:0, 16:1n7, and 18:0 but were attenuated for 18:1n9 (RR = 1.03, 95% confidence interval (CI) = 0.94–1.13). These findings had limitations in potential reverse causation and residual confounding by imprecisely measured or unmeasured factors. Conclusions Concentrations of fatty acids in the DNL were positively associated with T2D incidence. Our findings support further work to investigate a possible role of DNL and individual fatty acids in the development of T2D., Fumiaki Imamura and colleagues investigate the association between concentrations of fatty acid involved in de-novo lipogensis and incidence of Type 2 diabetes., Author summary Why was this study done? De novo lipogenesis (DNL) is a metabolic pathway involved in the endogenous synthesis of specific fatty acids, such as 16:0, 16:1n7, 18:0, and 18:1n9, and it is linked to the pathophysiology of cardiometabolic diseases, including type 2 diabetes (T2D). Circulating or tissue concentrations of these fatty acids have been investigated for the associations with T2D incidence in epidemiological research. However, published studies reported inconsistent associations inconsistently and were subject to publication bias. Summary evidence is not available to date for the associations between these fatty acids and T2D incidence. An integration of available cohort studies would increase statistical power and allow assessment of generalizability, standardization of analytical strategies, and evidence synthesis with the potential publication bias minimized. What did the researchers do and find? As a part of the Fatty Acids and Outcomes Research Consortium (FORCE), we conducted new individual-participant data analyses of 17 cohort studies of a total of 65,225 adults free of T2D at baseline, among whom 15,383 developed incident T2D over up to 20 years of follow-up. The cohort studies analyzed the associations between fatty acids (16:0, 16:1n7, 18:0, and 18:1n9) and the risk of developing T2D with standardized analytic strategy. In pooled analyses, each of the fatty acids was positively associated with a higher risk of developing T2D. The associations were independent of major risk factors for T2D, such as age, sex, race/ethnicity, socioeconomic characteristics, smoking status, physical activity, and obesity. What do these findings mean? The findings provide the first summary evidence to date for the positive relationships of concentrations of the DNL-related fatty acids with a risk of T2D, indicating the strong relevance of DNL and its determinants to the development of T2D. These fatty acids potentially reflect the status of DNL activity, which may be stimulated or suppressed by a combination of carbohydrate intake, alcohol intake, polyunsaturated fatty acid intake, and other lifestyle and clinical factors. Therefore, the current findings indicate the need for investigation into determinants and consequences of elevated concentrations of these fatty acids. Despite several advantages of our individual-level data analysis in this pooling project, the results cannot establish whether elevated concentrations of these fatty acids caused the development of T2D or whether underlying peripheral or hepatic insulin resistance, for example, may elevate both the fatty acid concentrations and the risk of T2D independently.

Although hyperlipidemia is traditionally considered a risk factor for type 2 diabetes (T2D), evidence has emerged from statin trials and candidate gene investigations suggesting that lower LDL cholesterol (LDL-C) increases T2D risk. We thus sought to more comprehensively examine the phenotypic and genotypic relationships of LDL-C with T2D. Using data from the UK Biobank, we found that levels of circulating LDL-C were negatively associated with T2D prevalence (odds ratio 0.41 [95% CI 0.39, 0.43] per mmol/L unit of LDL-C), despite positive associations of circulating LDL-C with HbA1c and BMI. We then performed the first genome-wide exploration of variants simultaneously associated with lower circulating LDL-C and increased T2D risk, using data on LDL-C from the UK Biobank (n = 431,167) and the Global Lipids Genetics Consortium (n = 188,577), and data on T2D from the Diabetes Genetics Replication and Meta-Analysis consortium (n = 898,130). We identified 31 loci associated with lower circulating LDL-C and increased T2D, capturing several potential mechanisms. Seven of these loci have previously been identified for this dual phenotype, and nine have previously been implicated in nonalcoholic fatty liver disease. These findings extend our current understanding of the higher T2D risk among individuals with low circulating LDL-C and of the underlying mechanisms, including those responsible for the diabetogenic effect of LDL-C–lowering medications.

Introduction In observational studies, the association between the Dietary Approaches to Stop Hypertension (DASH) diet and incident heart failure has been inconsistent. It was hypothesized that higher DASH diet concordance has a protective effect on heart failure in a multi-ethnic cohort. Methods The Multi-Ethnic Study of Atherosclerosis cohort includes men and women of multiple ethnicities who were aged 45–84 years and free of clinical cardiovascular disease at baseline. Participants were recruited between 2000 and 2002 from six U.S. communities and followed for incident cardiovascular health events through 2015 for the purpose of this data set. Diet was measured using food-frequency questionnaires. Cox proportional hazards analysis was used to investigate the associations of the DASH diet concordance with incident heart failure in 2017–2018. Results During a median 13 years of follow-up, 179 of 4,478 participants developed heart failure, corresponding to a rate of 3.4 per 1,000 person years. Heart failure incidence rates did not vary significantly by DASH quintile for the population as a whole. In participants younger than 75 years, highest DASH concordance was associated with a lower risk of incident heart failure compared with those in the lowest quintile (hazard ratio=0.4, 95% CI=0.2, 0.9 vs all participants hazard ratio=1.0, 95% CI=0.2, 0.9) after adjusting for demographics, energy consumption, and known cardiovascular confounders. Conclusions This study supports the hypothesis that DASH is beneficial in heart failure prevention within the individuals aged less than 75 years subgroup, an idea that to date was substantiated only by much smaller studies or in less diverse patient populations.

Background and Purpose— Dietary sodium reduction with concurrent increase in potassium intake is a current public health priority to reduce risk of cardiovascular events. This study explored associations between the spot urine sodium-to-potassium ratio and cardiovascular events in the MESA (Multi-Ethnic Study of Atherosclerosis) longitudinal cohort. Methods— The MESA is a prospective cohort study of 6814 adults from 4 ethnic groups (European-, Asian-, African- and Hispanic-American) with a mean age of 62 (±10.2) years and an average of 11.7 (±2.2) years of follow-up. Participants were free of clinical cardiovascular disease at baseline. Spot urine sodium and potassium excretion, as a marker of dietary intake, was collected at baseline. The impact of urinary sodium-to-potassium ratio on adjudicated cardiovascular events was assessed using Cox proportional hazards models. Results— Only 39% of MESA participants had a urinary sodium-to-potassium ratio ≤1, and these participants experienced only 74 of the 236 strokes. A sodium-to-potassium ratio >1 was associated with a hazard ratio of 1.47 (95% CI,1.07–2.00) for risk of stroke, adjusting for age, sex, race, cardiovascular risk factors, socio-demographic characteristics, body size, and kidney function. Conclusions— The spot urine sodium-to-potassium ratio (measurable in routine care) is associated with stroke. A urine sodium-to-potassium ratio of ≤1, may be related to a clinically relevant reduction in stroke risk and is a feasible target for health interventions.

Long chain polyunsaturated fatty acids (LC-PUFAs) have critical signaling roles that regulate dyslipidemia and inflammation. Genetic variation in the FADS gene cluster accounts for a large portion of interindividual differences in circulating and tissue levels of LC-PUFAs, with the genotypes most strongly predictive of low LC-PUFA levels at strikingly higher frequencies in Amerind ancestry populations. In this study, we examined relationships between genetic ancestry and FADS variation in 1102 Hispanic American participants from the Multi-Ethnic Study of Atherosclerosis. We demonstrate strong negative associations between Amerind genetic ancestry and LC-PUFA levels. The FADS rs174537 single nucleotide polymorphism (SNP) accounted for much of the AI ancestry effect on LC-PUFAs, especially for low levels of n-3 LC-PUFAs. Rs174537 was also strongly associated with several metabolic, inflammatory and anthropomorphic traits including circulating triglycerides (TGs) and E-selectin in MESA Hispanics. Our study demonstrates that Amerind ancestry provides a useful and readily available tool to identify individuals most likely to have FADS-related n-3 LC-PUFA deficiencies and associated cardiovascular risk., Yang et al. examine whether genetic ancestry is associated with genetic variation in fatty acid desaturases and plasma phospholipid levels of long chain polyunsaturated fatty acids (LC-PUFAs) in Hispanic Americans. They find strong associations between Amerind genetic ancestry and LC-PUFA levels; and report that the well-known FADS rs174537 variant was associated with several metabolic, inflammatory and anthropomorphic traits including circulating triglycerides.

BACKGROUND Patients with chiasmatic-hypothalamic low-grade glioma (CHLGG) have frequent MRIs with gadolinium-based contrast agents (GBCA) for disease monitoring. Cumulative gadolinium deposition in the brains of children is a potential concern. The purpose of this study is to evaluate whether MRI with GBCA is necessary for determining radiographic tumor progression in children with CHLGG. METHODS Children who were treated for progressive CHLGG from 2005 to 2019 at Texas Children's Cancer Center were identified. Pre- and post-contrast MRI sequences were separately reviewed by one neuroradiologist who was blinded to the clinical course. Three dimensional measurements and tumor characteristics were evaluated. Radiographic progression was defined as a 25% increase in size (product of two largest dimensions) compared with baseline or best response after initiation of therapy. RESULTS A total of 28 patients with progressive CHLGG were identified with a total of 683 MRIs with GBCA reviewed (mean 24 MRIs/patient; range, 11-43 MRIs). Radiographic progression was observed 92 times, 91 (99%) on noncontrast and 90 (98%) on contrast imaging. Sixty-seven progressions necessitating management changes were identified in all (100%) noncontrast sequences and 66 (99%) contrast sequences. Tumor growth > 2 mm in any dimension was identified in 184/187 (98%) noncontrast and 181/187 (97%) with contrast imaging. Metastatic tumors were better visualized on contrast imaging in 4/7 (57%). CONCLUSION MRI without GBCA effectively identifies patients with progressive disease. When imaging children with CHLGG, eliminating GBCA should be considered unless monitoring patients with metastatic disease.

Insulin resistance and insufficient insulin secretion lead to type 2 diabetes. A role of reduced insulin clearance has been suggested, but few studies have investigated the contribution of insulin clearance while simultaneously examining insulin sensitivity and secretion. The goal of this study was to conduct such an investigation in 224 non-Hispanic White and 129 African Americans individuals from MILES (mean age 59, 62% female). Participants underwent oral glucose tolerance tests from which insulin sensitivity, insulin secretion, insulin clearance, and disposition index were calculated. Logistic regression models (controlling for age, sex, race, and BMI) examined the individual contributions of these traits separately, as well as the joint contribution of insulin sensitivity, clearance, and secretion, to early dysglycemia (prediabetes plus newly diagnosed diabetes; 46% of cohort). Models used standardized predictors such that odds ratios (OR) represent the change in odds of dysglycemia per standard deviation change. Model performance was assessed via Akaike’s Information Criterion (AIC) and area under the receiver operator characteristic curves (AUROC). In separate models, dysglycemia was associated with insulin sensitivity (OR 0.2; 0.14-0.30; P Disclosure A. Wood: None. E. T. Jensen: None. G. Ramesh: None. Z. Arzumanyan: None. K. Lam: None. A. Bertoni: None. J. I. Rotter: None. Y. Chen: None. M. O. Goodarzi: None. Funding National Institutes of Health (R01DK109588)

Introduction: Quality and quantity of skeletal muscle decrease with age, largely due to adipose tissue infiltration, and are important determinants of metabolic health. To inform efforts to slow aging-related decline in muscle mass and prevent myosteatosis, a better understanding of the biological determinants of muscle atrophy and quality is needed. We used targeted lipidomics to identify, with a greater specificity, lipoproteins associated with muscle and intermuscular adipose tissue (IMAT) area (quantity) and density (quality) of the total abdominal, locomotion, and stabilization muscles in the Multi-Ethnic Study of Atherosclerosis. Hypothesis: Lower density lipoproteins will be positively associated with muscle and IMAT quantity, but negatively associated with quality. Methods: At visit one, 105 serum lipoproteins were measured by Bruker lipoprotein subclass analysis with 1 H-Nuclear Magnetic Resonance spectroscopy. Muscle and IMAT area (cm 2 ) and density (Hounsfield units) were estimated 2.6 years, on average, after visit 1 for the total abdominal, locomotion (psoas), and stabilization (paraspinal, oblique, and rectus abdominis) muscles from computed-tomography scans at the L4/L5 spinal junction. We identified lipoproteins associated with body composition using linear regression adjusting for age, gender, race, diet, physical activity, lipid-lowering medication, and multiple comparisons using a 1% false discovery rate. Results: Participants (N=947) were 44-84 years old (mean: 63), 51% men, 40% White, 16% Black, 16% Chinese American, and 27% Hispanic American. Among 105 lipoproteins, 24 were associated with total muscle area, whereas none were associated with muscle density. When examining specific muscle groups, 25 lipoproteins were associated with stabilization muscle area, driven by the oblique muscles. As for total IMAT area, there were 27 associations with lipoproteins. Specifically, 27 lipoproteins were associated with stabilization muscle IMAT area, driven by oblique and rectus abdominis muscles. Last, 39 lipoproteins were associated with total IMAT density, with 28 and 33 associated with locomotion and stabilization (driven by obliques) IMAT density, respectively. Higher VLDL: cholesterols, free cholesterols, phospholipids, and triglycerides and lower HDL: cholesterols and free cholesterols were associated with higher muscle area and IMAT area, but lower IMAT density (

Hispanic populations have higher rates of obesity, elevated triglycerides, and a greater prevalence of diabetes. Long chain polyunsaturated fatty acids (LC-PUFAs) and LC-PUFA metabolites have critical signaling roles that regulate dyslipidemia and inflammation. Genetic variation in the FADS cluster accounts for a large part of the interindividual differences in circulating and tissue levels of LC-PUFAs, with the genotypes most strongly predictive of low LC-PUFA levels at strikingly higher frequencies in Amerind (AI) ancestry populations. In this study, we examined relationships between genetic ancestry and FADS variation, plasma phospholipid levels of LC-PUFAs, anthropometric measures, and circulating metabolic and inflammatory biomarkers in 1,102 Hispanic American participants, representing six distinct ancestry populations from the Multi-Ethnic Study of Atherosclerosis. We demonstrate strong negative associations between AI genetic ancestry and LC-PUFA levels. The FADS rs174537 single nucleotide polymorphism (SNP) accounted for much of the AI ancestry effect on LC-PUFAs, especially for low levels of n-3 LC-PUFAs. Rs174537 was also strongly associated with several metabolic, inflammatory and anthropomorphic traits including circulating triglycerides (TGs) and E-selectin in MESA Hispanics. We further replicated the association with circulating TGs in two additional Hispanic cohorts: the Hispanic Community Health Study/Study of Latinos and the Arizona Insulin Resistance Registry. Our study demonstrates that Amerind ancestry provides a useful and readily available tool to identify individuals most likely to have FADS-related n-3 LC-PUFA deficiencies and associated cardiovascular risk.

OBJECTIVE Prospective associations between n-3 fatty acid biomarkers and type 2 diabetes (T2D) risk are not consistent in individual studies. We aimed to summarize the prospective associations of biomarkers of α-linolenic acid (ALA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) with T2D risk through an individual participant-level pooled analysis. RESEARCH DESIGN AND METHODS For our analysis we incorporated data from a global consortium of 20 prospective studies from 14 countries. We included 65,147 participants who had blood measurements of ALA, EPA, DPA, or DHA and were free of diabetes at baseline. De novo harmonized analyses were performed in each cohort following a prespecified protocol, and cohort-specific associations were pooled using inverse variance–weighted meta-analysis. RESULTS A total of 16,693 incident T2D cases were identified during follow-up (median follow-up ranging from 2.5 to 21.2 years). In pooled multivariable analysis, per interquintile range (difference between the 90th and 10th percentiles for each fatty acid), EPA, DPA, DHA, and their sum were associated with lower T2D incidence, with hazard ratios (HRs) and 95% CIs of 0.92 (0.87, 0.96), 0.79 (0.73, 0.85), 0.82 (0.76, 0.89), and 0.81 (0.75, 0.88), respectively (all P < 0.001). ALA was not associated with T2D (HR 0.97 [95% CI 0.92, 1.02]) per interquintile range. Associations were robust across prespecified subgroups as well as in sensitivity analyses. CONCLUSIONS Higher circulating biomarkers of seafood-derived n-3 fatty acids, including EPA, DPA, DHA, and their sum, were associated with lower risk of T2D in a global consortium of prospective studies. The biomarker of plant-derived ALA was not significantly associated with T2D risk.

A substantial body of research suggests that efforts to prevent pediatric obesity may benefit from targeting not just what a child eats, but how they eat. Specifically, child obesity prevention should include a component that addresses reasons why children have differing abilities to start and stop eating in response to internal cues of hunger and satiety, a construct known as eating self‐regulation . This review summarizes current knowledge regarding how caregivers can be an important influence on children's eating self‐regulation during early childhood. First, we discuss the evidence supporting an association between caregiver feeding and child eating self‐regulation. Second, we discuss what implications the current evidence has for actions caregivers may be able to take to support children's eating self‐regulation. Finally, we consider the broader social, economic, and cultural context around the feeding environment relationship and how this intersects with the implementation of any actions. As far as we are aware, this is the first American Heart Association (AHA) scientific statement to focus on a psychobehavioral approach to reducing obesity risk in young children. It is anticipated that the timely information provided in this review can be used not only by caregivers within the immediate and extended family but also by a broad range of community‐based care providers.

Background Hypothalamic obesity causes unrelenting weight gain for childhood brain tumor survivors. No single therapy has proven effective for treatment. We aimed to evaluate effectiveness of long-term methylphenidate therapy on body mass index (BMI) change in children with hypothalamic obesity. Methods A retrospective analysis included children with a history of brain tumor and hypothalamic obesity receiving methylphenidate (10-60 mg/day) for hypothalamic obesity. Subjects were evaluated for BMI trajectory before and after methylphenidate start. Given that z-scores can be skewed in severely obese children, we calculated BMI as a percent of the BMI at the 95th percentile for the child's age and gender (BMI% 95th). Results Twelve patients with hypothalamic obesity completed methylphenidate therapy for at least 6 months (median 3.1 years, range 1.0-5.8 years). All subjects had a suprasellar tumor (nine [75%] with craniopharyngioma) and pituitary dysfunction. Pretreatment median BMI percent of the 95th percentile was 125.6% (interquartile range [IQR] 25-75: 115.3-138.3%) with BMI z-score of 2.4 (IQR 25-75: 2.1-2.6). Following methylphenidate treatment, there was a 69.9% reduction in the median slope of BMI change. Eleven of 12 patients (92%) had a reduction in the slope of their BMI change on methylphenidate treatment. Postmethylphenidate median BMI percent of the 95th percentile decrease to 115.2% (IQR 25-75: 103.6-121.2%) with median BMI z-score of 2.1 (IQR 25-75: 1.8-2.2). Mild side effects were noted in six patients. Conclusions Methylphenidate use reduced and sustained BMI change in children with hypothalamic obesity. Stimulant therapy is an effective first-line agent for treatment of hypothalamic obesity.

Background: The use of gonadotropins is a recent strategy for inducing puberty in adolescent males with hypogonadotropic hypogonadism (HH). Testosterone use has been discouraged in patients who desire to preserve fertility. Human chorionic gonadotropin (hCG) has been recommended for inducing puberty in HH; however, several clinicians administer hCG in combination with other gonadotropins. The benefits of using combination gonadotropin therapies (hCG+) over hCG monotherapy in pre-pubertal adolescent males with HH has not been clearly established. We performed a meta-analysis to assess the outcomes of hCG compared to hCG+ in terms of virilizing effects and testicular growth in peripubertal boys with HH. Methods: We evaluated for heterogeneity among studies. We calculated pooled means for the post-treatment mean testicular volume (MTV), testosterone (T) level, and penile length for the hCG monotherapy and hCG+ treatment groups. We performed a meta-regression analysis to examine the contribution of various factors to post-treatment outcomes including baseline T level, age, treatment duration, and study quality. Results: The meta-analysis included seven studies. All participants were prepubertal (age range: 13.3–25.9 years), with weighted mean treatment durations of 10.95 months for hCG monotherapy and 28.2 months for hCG. There was significant heterogeneity in baseline age (Q = 121.71; df = 1; P < 0.001) and T levels (Q = 436.74; df = 1; P < 0.001) between the two treatment groups. The hCG+ group had a larger post-treatment MTV, but it was not significantly different between the two groups (6.60 mL [95% CI, 3.18–10.02] for hCG monotherapy vs. 10.02 mL [95% CI, 8.30–11.75] for hCG+; P = 0.079). Post-treatment T levels differed significantly between the two groups (101.89 ng/dL [95% CI, 50.7–153.08] for hCG monotherapy vs. 424.10 ng/dL [95% CI, 304.59–543.62] for hCG+; P < 0.0001). A meta-regression analysis of post-treatment T levels showed that baseline age, baseline T level, and study grade did not contribute significantly to the difference between treatment groups. Treatment duration explained 3.04% of the difference between the two groups (P < 0.0001). After adjusting for treatment duration, the post-treatment T level remained significantly higher in the hCG+ group compared to the hCG monotherapy group. The hCG+ was also associated with better outcomes for post-treatment penile length, although these findings relied on data from only three studies. Conclusion: Our study indicates that hCG+ therapies provide potential benefits over hCG monotherapy for pubertal induction in males with HH, regarding T levels and penile growth, with no difference in testicular growth between treatments. Prospective pediatric studies are needed to assess the benefits of these therapies in patients with HH and, ultimately, to establish guidelines for gonadotropin therapy in the adolescent population.

Background Copy number variation (CNV) in the salivary amylase gene (AMY1) modulates salivary α-amylase levels and is associated with postprandial glycemic traits. Whether AMY1-CNV plays a role in age-mediated change in insulin resistance (IR) is uncertain. Methods We measured AMY1-CNV using duplex quantitative real-time polymerase chain reaction in two studies, the Boston Puerto Rican Health Study (BPRHS, n = 749) and the Genetics of Lipid-Lowering Drug and Diet Network study (GOLDN, n = 980), and plasma metabolomic profiles in the BPRHS. We examined the interaction between AMY1-CNV and age by assessing the relationship between age with glycemic traits and type 2 diabetes (T2D) according to high or low copy numbers of the AMY1 gene. Furthermore, we investigated associations between metabolites and interacting effects of AMY1-CNV and age on T2D risk. Results We found positive associations of IR with age among subjects with low AMY1-copy-numbers in both studies. T2D was marginally correlated with age in participants with low AMY1-copy-numbers but not with high AMY1-copy-numbers in the BPRHS. Metabolic pathway enrichment analysis identified the pentose metabolic pathway based on metabolites that were associated with both IR and the interactions between AMY1-CNV and age. Moreover, in older participants, high AMY1-copy-numbers tended to be associated with lower levels of ribonic acid, erythronic acid, and arabinonic acid, all of which were positively associated with IR. Conclusions We found evidence supporting a role of AMY1-CNV in modifying the relationship between age and IR. Individuals with low AMY1-copy-numbers tend to have increased IR with advancing age.

PURPOSE OF REVIEW: Current feeding advice to prevent pediatric obesity focusses on caregiver feeding behaviors. This review integrates newer data showing that child appetitive traits also have a genetic component. RECENT FINDINGS: Caregiver feeding behaviors robustly correlate with child eating behaviors; however there is also a strong heritable component. SUMMARY: The satiety cascade delineates the biological drive underlying hunger, satiation and satiety. Innate individual differences exist for the components of the satiety cascade, which may explain the heritability of child eating behaviors. However, given the correlation of caregiver feeding behaviors with child eating behaviors any etiological model should include both genetic/biological components and environmental. Integrating the biological etiology of child eating behaviors into the current environmental model has implications for tailoring feeding advice which needs to move from a “one size fits all” approach, to one that is tailored to individual differences in children’s biological drives to appetite.

Although hyperlipidemia is traditionally considered a risk factor for type-2 diabetes (T2D), evidence has emerged from statin trials and candidate gene investigations suggesting that lower LDL-C increases T2D risk. We thus sought to comprehensively examine the phenotypic and genotypic relationships of LDL-C with T2D. Using data from the UK Biobank, we found that LDL-C was negatively associated with T2D (OR=0.43[0.41, 0.45] per mmol/L unit of LDL-C), despite positive associations of LDL-C with HbA1c and BMI. We then performed the first genome-wide exploration of variants simultaneously associated with lower LDL-C and increased T2D risk, using data on LDL-C from the UK Biobank (n=431,167) and the GLGC consortium (n=188,577), and T2D from the DIAGRAM consortium (n=898,130). We identified 31 loci associated with lower LDL-C and increased T2D, capturing several potential mechanisms. Seven of these loci have previously been identified for this phenotype, and 9 have previously been implicated in non-alcoholic fatty liver disease. Finally, two-sample Mendelian randomization analyses suggest that low LDL-C causes T2D, although causal interpretations are challenging due to pleiotropy. Our findings extend our current understanding of the higher T2D risk among individuals with low LDL-C, and of the underlying mechanisms, including those underlying the diabetogenic effect of LDL-C-lowering medications.

Background: Global dietary recommendations for and cardiovascular effects of linoleic acid, the major dietary omega-6 fatty acid, and its major metabolite, arachidonic acid, remain controversial. To address this uncertainty and inform international recommendations, we evaluated how in vivo circulating and tissue levels of linoleic acid (LA) and arachidonic acid (AA) relate to incident cardiovascular disease (CVD) across multiple international studies. Methods: We performed harmonized, de novo, individual-level analyses in a global consortium of 30 prospective observational studies from 13 countries. Multivariable-adjusted associations of circulating and adipose tissue LA and AA biomarkers with incident total CVD and subtypes (coronary heart disease, ischemic stroke, cardiovascular mortality) were investigated according to a prespecified analytic plan. Levels of LA and AA, measured as the percentage of total fatty acids, were evaluated linearly according to their interquintile range (ie, the range between the midpoint of the first and fifth quintiles), and categorically by quintiles. Study-specific results were pooled using inverse-variance–weighted meta-analysis. Heterogeneity was explored by age, sex, race, diabetes mellitus, statin use, aspirin use, omega-3 levels, and fatty acid desaturase 1 genotype (when available). Results: In 30 prospective studies with medians of follow-up ranging 2.5 to 31.9 years, 15 198 incident cardiovascular events occurred among 68 659 participants. Higher levels of LA were significantly associated with lower risks of total CVD, cardiovascular mortality, and ischemic stroke, with hazard ratios per interquintile range of 0.93 (95% CI, 0.88–0.99), 0.78 (0.70–0.85), and 0.88 (0.79–0.98), respectively, and nonsignificantly with lower coronary heart disease risk (0.94; 0.88–1.00). Relationships were similar for LA evaluated across quintiles. AA levels were not associated with higher risk of cardiovascular outcomes; in a comparison of extreme quintiles, higher levels were associated with lower risk of total CVD (0.92; 0.86–0.99). No consistent heterogeneity by population subgroups was identified in the observed relationships. Conclusions: In pooled global analyses, higher in vivo circulating and tissue levels of LA and possibly AA were associated with lower risk of major cardiovascular events. These results support a favorable role for LA in CVD prevention.

International audience; BACKGROUND:Saturated fatty acids (SFAs) of different chain lengths have unique metabolic and biological effects, and a small number of recent studies suggest that higher circulating concentrations of the very-long-chain SFAs (VLSFAs) arachidic acid (20:0), behenic acid (22:0), and lignoceric acid (24:0) are associated with a lower risk of diabetes. Confirmation of these findings in a large and diverse population is needed.OBJECTIVE:We investigated the associations of circulating VLSFAs 20:0, 22:0, and 24:0 with incident type 2 diabetes in prospective studies.METHODS:Twelve studies that are part of the Fatty Acids and Outcomes Research Consortium participated in the analysis. Using Cox or logistic regression within studies and an inverse-variance-weighted meta-analysis across studies, we examined the associations of VLSFAs 20:0, 22:0, and 24:0 with incident diabetes among 51,431 participants.RESULTS:There were 14,276 cases of incident diabetes across participating studies. Higher circulating concentrations of 20:0, 22:0, and 24:0 were each associated with a lower risk of incident diabetes. Pooling across cohorts, the RR (95% CI) for incident diabetes comparing the 90th percentile to the 10th percentile was 0.78 (0.70, 0.87) for 20:0, 0.84 (0.77, 0.91) for 22:0, and 0.75 (0.69, 0.83) for 24:0 after adjustment for demographic, lifestyle, adiposity, and other health factors. Results were fully attenuated in exploratory models that adjusted for circulating 16:0 and triglycerides.CONCLUSIONS:Results from this pooled analysis indicate that higher concentrations of circulating VLSFAs 20:0, 22:0, and 24:0 are each associated with a lower risk of diabetes.

Insulin resistance and insufficient insulin secretion are well-recognized contributors to type 2 diabetes. A potential role of reduced insulin clearance has been suggested, but few studies have investigated the contribution of insulin clearance while simultaneously examining decreased insulin sensitivity and secretion. The goal of this study was to conduct such an investigation in a cohort of 353 non-Hispanic White and African American individuals recruited in the Microbiome and Insulin Longitudinal Evaluation Study (MILES). Participants underwent oral glucose tolerance tests from which insulin sensitivity, insulin secretion, insulin clearance, and disposition index were calculated. Regression models examined the individual and joint contributions of these traits to early dysglycemia (prediabetes or newly diagnosed diabetes). In separate models, reduced insulin sensitivity, reduced disposition index, and reduced insulin clearance were associated with dysglycemia. In a joint model, only insulin resistance and reduced insulin secretion were associated with dysglycemia. Models with insulin sensitivity, disposition index, or three insulin traits had the highest discriminative value for dysglycemia (area under the receiver operating characteristics curve of 0.82 to 0.89). These results suggest that in the race groups studied, insulin resistance and compromised insulin secretion are the main independent underlying defects leading to early dysglycemia.

Objectives To determine how baseline weight status contributes to differences in postmenopausal weight gain among non-Hispanic Blacks (NHBs) and non-Hispanic Whites (NHWs). Methods Data were included from 70,750 NHW and NHB postmenopausal women from the Women’s Health Initiative Observational Study (WHI OS). Body Mass Index (BMI) at baseline was used to classify women as having normal weight, overweight, obese class I, obese class II or obese class III. Cox proportional hazards was used to estimate the hazard of a 10% or more increase in weight from baseline. Results In both crude and adjusted models, NHBs were more likely to experience ≥10% weight gain than NHWs within the same category of baseline weight status. Moreover, NHBs who were normal weight at baseline were most likely to experience ≥10% weight gain in both crude and adjusted models. Age-stratified results were consistent with overall findings. In all age categories, NHBs who were normal weight at baseline were most likely to experience ≥10% weight gain. Based on the results of adjusted models, the joint influence of NHB race/ethnicity and weight status on risk of postmenopausal weight gain was both sub-additive and sub-multiplicative. Conclusion NHBs are more likely to experience postmenopausal weight gain than NHWs, and the disparity in risk is most pronounced among those who are normal weight at baseline. To address the disparity in postmenopausal obesity, future studies should focus on identifying and modifying factors that promote weight gain among normal weight NHBs.

H.G. was funded by the NIHR Imperial College Health Care NHS Trust and Imperial College London Biomedical Research Centre. I.K. was supported by the EU PhenoMeNal project (Horizon 2020, grant no. 654241) and the UK Dementia Research Institute, which is supported by the MRC, the Alzheimer’s Society and Alzheimer’s Research UK. S. Thériault was supported by the Canadian Institutes of Health Research and Université Laval (Quebec City, Canada). L.R. was supported by Forschungs- und Förder-Stiftung INOVA, Vaduz, Liechtenstein. D.C. holds a McMaster University Department of Medicine Mid-Career Research Award. M.B. is supported by NIH grant R01-DK062370. P.v.d.H. was supported by ICIN-NHI and Marie Skłodowska-Curie GF (call: H2020-MSCA-IF-2014; Project ID: 661395). C.H. was supported by a core MRC grant to the MRCHGU QTL in Health and Disease research programme. N.V. was supported by Marie Skłodowska-Curie GF (grant no. 661395) and ICIN-NHI. Q.L. is partially supported by the National Natural Sciences Foundation of China (No. 81873909), Shanghai Municipal Science and Technology Major Project(No.2018SHZDZX01) and ZJLab. P.E. acknowledges support from the NIHR Biomedical Research Centre at Imperial College Healthcare NHS Trust and Imperial College London, the NIHR Health Protection Research Unit in Health Impact of Environmental Hazards (HPRU-2012-10141), the Medical Research Council (MRC) and Public Health England (PHE) Centre for Environment and Health (MR/L01341X/1) and Health Data Research (HDR) UK. P.E. is supported by a UK Dementia Research Institute (DRI) professorship, UK DRI at Imperial College London, funded by the MRC, Alzheimer’s Society and Alzheimer’s Research UK. This work received support from the following sources: the European Union-funded FP6 Integrated Project IMAGEN (Reinforcement-related behaviour in normal brain function and psychopathology; LSHM-CT- 2007-037286), the Horizon 2020 funded ERC Advanced Grant ‘STRATIFY’ (Brain network based stratification of reinforcement-related disorders; grant no. 695313), ERANID (Understanding the interplay between cultural, biological and subjective factors in drug use pathways; PR-ST-0416-10004), BRIDGET (JPND: BRain Imaging, cognition Dementia and next generation GEnomics; MR/N027558/1), the FP7 projects IMAGEMEND (grant no. 602450; IMAging GEnetics for MENtal Disorders) and MATRICS (grant no. 603016), the Innovative Medicine Initiative Project EU-AIMS (grant. no115300-2), the Medical Research Council Grant ‘c-VEDA’ (Consortium on Vulnerability to Externalizing Disorders and Addictions; MR/N000390/1), the Swedish Research Council FORMAS, the Medical Research Council, the National Institute for Health Research (NIHR) Biomedical Research Centre at South London and Maudsley NHS Foundation Trust and King’s College London, the Bundesministeriumfür Bildung und Forschung (BMBF grants 01GS08152; 01EV0711; eMED SysAlc01ZX1311A; and Forschungsnetz AERIAL 01EE1406A and 01EE1406B), the Deutsche Forschungsgemeinschaft (DFG grants SM 80/7-2 and SFB 940/2), the Medical Research Foundation and Medical Research Council (MR/R00465X/1), the Human Brain Project (HBP SGA 2). Further support was provided by grants from ANR (project AF12-NEUR0008-01-WM2NA, and ANR-12-SAMA-0004), the Fondation de France, the Fondation pour la Recherche Médicale, the Mission Interministérielle de Lutte-contre-les-Drogues-et-les-Conduites-Addictives (MILDECA), the Assistance-Publique-Hôpitaux-de-Paris and INSERM (interface grant), Paris Sud University IDEX 2012; the National Institutes of Health, Science Foundation Ireland (16/ERCD/3797), USA (Axon, Testosterone and Mental Health during Adolescence; RO1 MH085772-01A1); and by NIH Consortium grant U54 EB020403, supported by a cross-NIH alliance that funds Big Data to Knowledge Centres of Excellence.

Excessive alcohol consumption is one of the main causes of death and disability worldwide. Alcohol consumption is a heritable complex trait. We conducted a genome-wide association study (GWAS) of alcohol use in ~480,000 people of European descent to decipher the genetic architecture of alcohol intake. We identified 46 novel, common loci, and investigated their potential functional significance using magnetic resonance imaging data, gene expression and behavioral studies in Drosophila. Our results identify new genetic pathways associated with alcohol consumption and suggest common genetic mechanisms with several neuropsychiatric disorders including schizophrenia.

RATIONALE: Although short sleep duration has been linked to unhealthy dietary patterns, little is known about the association of obstructive sleep apnea (OSA), a disorder characterized by sleep fragmentation and diet. STUDY OBJECTIVES: Investigate associations between diet quality and OSA in the Multi-Ethnic Study of Atherosclerosis and assess whether reductions in slow-wave sleep (stage N3) and rapid eye movement (REM) sleep are potential mediators for these associations. METHODS: A diverse population (N = 1813) completed a food frequency questionnaire and underwent Type 2 in-home polysomnography, which included measurement of N3 and REM sleep and apnea–hypopnea index (AHI). Moderate-to-more severe OSA was defined as having an AHI > 15 events/hr. RESULTS: Participants were 53.9% female with a mean age of 68.3 (SD 9.1) years. Approximately 33.8% were categorized as having moderate-to-more severe OSA. In adjusted analyses, OSA was associated with lower intakes of whole grains, (β = −0.200, SE = 0.072, p < 0.01), higher intakes of red/processed meat, (β = −0.440, SE = 0.136, p < 0.01), and lower overall diet quality (β = −1.286, SE = 0.535, p = 0.02). Stage N3 sleep partially explained the associations between red/processed meat and overall diet quality score with OSA. CONCLUSIONS: Moderate-to-more severe OSA is associated with a less healthy dietary profile that is partially explained by reduced N3 sleep. These findings suggest the opportunity to target sleep quality in interventions aimed at improving cardio-metabolic risk factors in patients with OSA.

Obstructive sleep apnea (OSA) is a common disorder associated with increased risk of cardiovascular disease and mortality. Its prevalence and severity vary across ancestral background. Although OSA traits are heritable, few genetic associations have been identified. To identify genetic regions associated with OSA and improve statistical power, we applied admixture mapping on three primary OSA traits [the apnea hypopnea index (AHI), overnight average oxyhemoglobin saturation (SaO2) and percentage time SaO2&nbsp

Background Food neophobia hinders the acceptance of healthy foods in young children, and may be overcome by repeated food exposure. Prevalent literature states that children exhibit five sensory-based exploratory behaviors (SBEBs): smelling, licking, spitting, manipulating and/or swallowing as they progress towards accepting a novel food, yet there is a paucity of research on these behaviors. This study aimed to use direct observations of SBEBs across first-time exposures to hummus to (1) determine the prevalence of five SBEBs (smelling, licking, spitting, manipulating and swallowing) in 12–35 month olds, (2) quantify the psychometric properties of the SBEB assessment; and (3) examine the association of SBEBs with parent-assessed food fussiness, and consumption of the novel food. Methods Direct observations of SBEBs during a 15–20 min snack time were conducted by trained staff members for 55 hummus-naive toddlers ages 12–35 months, across 16 exposures to a novel food (hummus). Parents completed the child eating behavior questionnaire. Hummus consumption was measured using digital plate waste method. Results Very low base rates of spitting (0.06%), smelling (0.97%) and licking (1.95%) were observed but manipulation (26.36%) and swallowing (62.15%) were more prevalent. Observation data on two behaviors over 16 occasions gave rise to a reliability coefficient from our G study portion of our generalizability analyses of Eρ2 = 0.65. SBEBs did not significantly associate with parent-assessed food fussiness, nor hummus consumption. Conclusions Although literature refers to the prevalence of SBEBs, we did not observe this for three proposed behaviors. We did observe manipulation, but more research is needed to determine if there are additional SBEBs not noted in the literature, and to better delineate the process that leads to acceptance/rejection of novel food.

Pediatric eating behaviors are a core component of obesity in the general population. Data from twin and family studies show that child eating behaviors are moderately-to-strongly heritable. However, the heritable variance in child eating behaviors remains largely unaccounted for by named genetic variants. This chapter will describe the progress of genetic studies to date, centering around a single variant in the FTO gene. In order to understand how genetic research can overcome current difficulties and identify additional genetic variants underlying child eating behaviors, this chapter will also discuss difficulties concomitant with genetic studies of behavioral traits, including psychometric measurement issues.

BackgroundTwin and sibling studies have identified specific cognitive phenotypes that may mediate the association between genes and the clinical symptoms of attention deficit hyperactivity disorder (ADHD). ADHD is also associated with lower IQ scores. We aimed to investigate whether the familial association between measures of cognitive performance and the clinical diagnosis of ADHD is mediated through shared familial influences with IQ.MethodMultivariate familial models were run on data from 1265 individuals aged 6–18 years, comprising 920 participants from ADHD sibling pairs and 345 control participants. Cognitive assessments included a four-choice reaction time (RT) task, a go/no-go task, a choice–delay task and an IQ assessment. The analyses focused on the cognitive variables of mean RT (MRT), RT variability (RTV), commission errors (CE), omission errors (OE) and choice impulsivity (CI).ResultsSignificant familial association (rF) was confirmed between cognitive performance and both ADHD (rF=0.41–0.71) and IQ (rF=−0.25 to −0.49). The association between ADHD and cognitive performance was largely independent (80–87%) of any contribution from etiological factors shared with IQ. The exception was for CI, where 49% of the overlap could be accounted for by the familial variance underlying IQ.ConclusionsThe aetiological factors underlying lower IQ in ADHD seem to be distinct from those between ADHD and RT/error measures. This suggests that lower IQ does not account for the key cognitive impairments observed in ADHD. The results have implications for molecular genetic studies designed to identify genes involved in ADHD.

Objective To describe the utility of twin studies for attention-deficit/hyperactivity disorder (ADHD) research and demonstrate their potential for the identification of alternative phenotypes suitable for genomewide association, developmental risk assessment, treatment response, and intervention targets. Method Brief descriptions of the classic twin study and genetic association study methods are provided, with illustrative findings from ADHD research. Biometrical genetics refers to the statistical modeling of data gathered from one or more group of known biological relation; it was apparently coined by Francis Galton in the 1860s and led to the "Biometrical School" at the University of London. Twin studies use genetic correlations between pairs of relatives, derived using this theoretical framework, to parse the individual differences in a trait into latent (unmeasured) genetic and environmental influences. This method enables the estimation of heritability, i.e., the percentage of variance due to genetic influences. It is usually implemented with a method called structural equation modeling , which is a statistical technique for fitting models to data, typically using maximum likelihood estimation. Genetic association studies aim to identify those genetic variants that account for the heritability estimated in twin studies. Measurements other than those used for the clinical diagnosis of the disorder are popular phenotype choices in current ADHD research. It is argued that twin studies have great potential to refine phenotypes relevant to ADHD. Results Prior studies have consistently found that the majority of the variance in ADHD symptoms is due to genetic factors. To date, genomewide association studies of ADHD have not identified replicable associations that account for the heritable variation. Possibly, the application of genomewide association studies to these alternative phenotypic measurements will assist in identifying the pathways from genetic variants to ADHD. Conclusion Power to detect associations should be improved by the study of highly heritable endophenotypes for ADHD and by reducing the number of phenotypes to be considered. Therefore, twin studies are an important research tool in the development of endophenotypes, defined as alternative, more highly heritable traits that act at earlier stages of the pathway from genes to behavior. Although genetic variation in liability to ADHD is likely polygenic, the proposed approach should help to identify improved alternative measurements for genetic association studies.

Previous studies have documented the primarily genetic aetiology for the stronger phenotypic covariance between reading disability and ADHD inattention symptoms, compared to hyperactivity-impulsivity symptoms. In this study, we examined to what extent this covariation could be attributed to "generalist genes" shared with general cognitive ability or to "specialist" genes which may specifically underlie processes linking inattention symptoms and reading difficulties. We used multivariate structural equation modeling on IQ, parent and teacher ADHD ratings and parent ratings on reading difficulties from a general population sample of 1312 twins aged 7.9-10.9 years. The covariance between reading difficulties and ADHD inattention symptoms was largely driven by genetic (45%) and child-specific environment (21%) factors not shared with IQ and hyperactivity-impulsivity; only 11% of the covariance was due to genetic effects common with IQ. Aetiological influences shared among all phenotypes explained 47% of the variance in reading difficulties. The current study, using a general population sample, extends previous findings by showing, first, that the shared genetic variability between reading difficulties and ADHD inattention symptoms is largely independent from genes contributing to general cognitive ability and, second, that child-specific environment factors, independent from IQ, also contribute to the covariation between reading difficulties and inattention symptoms.

BackgroundAttention deficit hyperactivity disorder (ADHD) shows a strong phenotypic and genetic association with reaction time (RT) variability, considered to reflect lapses in attention. Yet we know little about whether this aetiological pathway is shared with other affected cognitive processes in ADHD, such as lower IQs or the generally slower responses (mean RTs). We aimed to address the question of whether a shared set of genes exist that influence RT variability, mean RT, IQ and ADHD symptom scores, or whether there is evidence of separate aetiological pathways.MethodMultivariate structural equation modelling on cognitive tasks data (providing RT data), IQ and ADHD ratings by parents and teachers collected on general population sample of 1314 twins, at ages 7–10 years.ResultsMultivariate structural equation models indicated that the shared genetic influences underlying both ADHD symptom scores and RT variability are also shared with those underlying mean RT, with both types of RT data largely indexing the same underlying liability. By contrast, the shared genetic influences on ADHD symptom scores and RT variability (or mean RT) are largely independent of the genetic influences that ADHD symptom scores share with IQ.ConclusionsThe finding of unique aetiological pathways between IQ and RT data, but shared components between mean RT, RT variability and ADHD symptom scores, illustrates key influences in the genetic architecture of the cognitive and energetic processes that underlie the behavioural symptoms of ADHD. In addition, the multivariate genetic model fitting findings provide valuable information for future molecular genetic analyses.

Contains fulltext : 89372.pdf (Publisher’s version ) (Closed access) Burt (2009) recently published a meta-analysis of twin studies on behaviors associated with childhood psychopathologies, concluding that the finding that traits associated with attention-deficit/hyperactivity disorder (ADHD) were the only behaviors that did not show a significant influence of shared environment (C) was surprising. We agree, highlighting four methodological issues that may account for this finding: (a) the use of nonlinear transformations to normalize skewed data; (b) low power to detect C and the subsequent presentation of reduced models; (c) the negative confounding of dominant genetic (D) and C influences in twin models with data exclusively from monozygotic and dizygotic twin pairs reared together; and (d) the correction used for contrast effects (a form of rater bias), which may lead to an overestimate of additive genetic (A) or D parameters at the expense of C. We offer suggestions for future research to address these issues, and we emphasize the need for additional research to examine possible shared environmental factors related to ADHD. 01 mei 2010

Objective Symptoms of overactivity form part of the DSM-IV criteria for the combined or hyperactive-impulsive subtypes of attention-deficit/hyperactivity disorder (ADHD); yet little data exist that would quantify the nature of the overactivity component. We aimed to quantify the ability of four different measures of motion sensor data, taken from actigraphs, and the intraindividual variability (IIV) in these measures, to distinguish ADHD cases from controls. Furthermore, we aimed to investigate the degree of shared familial influences on these measures and the ADHD diagnosis. Method Receiver operating characteristic analysis and multivariate structural equation modeling were used on actigraph data collected during a cognitive testing session in a sample of 116 ADHD combined-type probands, 119 of their siblings, and 218 control siblings (age range 6–18 years). Results Three measures of actigraph data—the number of movements made, the magnitude of these movements, and the IIV in the magnitude of movements—yielded an area under the curve of up to 0.8, indicating an ability to distinguish between cases and controls. The latter two of these measures showed significant shared familial vulnerability with an ADHD diagnosis, with high ADHD-actigraph familial correlations. Conclusions The actigraph data support the DSM-IV conceptualization of including overactivity as one of the core features within ADHD combined subtype. The magnitude of movements made, and the IIV of these movements, may be suitable candidates for future molecular genetic studies seeking to identify polymorphisms associated with the risk for ADHD. Further research should investigate if these findings generalize to a more naturalistic, homelike setting.

Background: Activity level is an important component of children’s temperament, as well as being part of the core symptom domain of hyperactivity-impulsivity within attention deficit hyperactivity disorder (ADHD). Yet it is poorly understood, due partly to limitations on parent and teacher ratings, which are typically used as measurements of these symptoms. Methods: We aimed to study the etiology of objectively-measured activity level across two situations, using actigraphs. A population-based sample of 463 7–9-year-old twin pairs were assessed individually both when apart undergoing laboratory-based cognitive testing and when together during a break in testing. Results: Heritability of activity level was estimated as 24% during the test session and at 30% during the break in testing. Shared environmental influences accounted for 27% of the variance in activity level during the test session and 42% of activity level measured during the break. A genetic correlation of 1.0 indicated that the same genes influenced activity level across the two situations, justifying the use of a composite measure of the two situations. This produced a heritability estimate of 36%. Conclusions: Objectively-measured activity level shows a moderate degree of genetic influence, with a common set of genes influencing activity level across situations. This supports the use of actigraphs as an additional source of information in studies that aim to improve phenotype definition for molecular genetic studies of activity level and ADHD. Keywords: Activity level, actigraph, etiology, heritability, twin study, genetic effects, attention deficit hyperactivity disorder. Abbreviations: ADHD: attention deficit hyperactivity disorder; CI: confidence interval; MZ: monozygotic; DZ: dizygotic; A: variance due to additive genetic effects; C: variance due to shared environmental effects; E: variance due to child-specific environmental effects; rA: genetic correlation; rC: shared environment correlation; rE: child-specific environment correlation.

Previous research suggests an association between hyperactivity-impulsivity – one of the two behavioural dimensions that form attention deficit hyperactivity disorder – and the temperament characteristic of novelty seeking. We aimed to examine etiological links underlying the co-occurrence between these behaviours using a general population sample of 668 twin pairs, ages 7-10, for whom we obtained parent ratings in middle childhood; and pilot longitudinal data on 76 children. Structural equation modelling confirmed a shared genetic etiology (genetic correlation, rD=.81; 95% confidence intervals [CI]= .34-1.00) and showed that much (64%) of the covariation can be accounted for by shared genetic effects. In addition, causal paths were modelled between the two behaviours; 12% of the variance in novelty seeking at age 7 was accounted for by hyperactive-impulsive behaviors at the same age. The causal effects model fits with the current characterization of hyperactive-impulsive behaviors reflecting a heightened need for stimulation. This has important implications for the management of hyperactive-impulsive behaviors in clinical settings.

Attention deficit hyperactivity disorder and oppositional behaviours frequently co-occur, We aimed to study the etiology of this overlap in a general population-based twin sample, assessing the symptom domains of hyperactivity-impulsivity and inattentiveness separately for their overlap with oppositionality. We further aimed to investigate whether rater bias may contribute to the overlap in previous data which used one rater only. Using parent and teacher ratings on hyperactivity-impulsivity, inattentiveness and oppositionality, and actigraph measurements of activity level, for 668 7-9-year-old twin pairs, oppositionality showed a higher overlap with hyperactivity-impulsivity (r = 0.95) than with inattentiveness (r = 0.52) and all etiological influences on hyperactivity-impulsivity were shared with those on oppositionality, indicated by a genetic correlation of 0.95 and a child-specific environmental correlation of 0.94. Actigraph data did not show an overlap with ratings of oppositionality. In middle childhood, symptoms of hyperactivity-impulsivity and oppositional behaviour may represent the same underlying liability, whereas the inattentive domain is more distinct.

Focusing on symptoms of attention deficit hyperactivity disorder (ADHD) in a sample obtained from the general population, we aimed to investigate the effects of incentives and event rate on reaction time (RT) performance and response inhibition. We assessed 1156 children, at a mean age of 8 years, on their performance on an inhibition task and a RT task under different experimental conditions that manipulated event rate and incentives. Children with high ADHD (ADHD-H) symptoms showed cognitive performance deficits only under some of the experimental conditions compared to a control group. The fast-incentive condition of the RT task succeeded in normalizing the RT variability, as well as the slow overall speed, in the ADHD-H group. Analyses of ADHD symptom scores as a quantitative trait in the total sample were overall consistent with these findings. The findings suggest that at least some cognitive performance deficits in children with high ADHD symptoms do not reflect stable cognitive deficits. The degree to which cognitive impairments in ADHD can be modulated by energetic or motivational factors has important implications for clinical and educational interventions. (JINS, 2009, 15, 570–579.)

Despite the high heritability of children's activity level, which forms part of the core symptom domain of hyperactivity-impulsivity within attention deficit hyperactivity disorder (ADHD), there has only been a limited success with identifying candidate genes involved in its etiology. This may reflect a lack of understanding about the different measures used to define activity level across studies. We aimed to study the genetic and environmental etiology across three measures of activity level: parent and teacher ratings of hyperactivity-impulsivity and actigraph measurements, within a population-based sample of 463 7-9 year old twin pairs. We further examined ways in which the three measures could be combined for future molecular studies. Phenotypic correlations across measures were modest, but a common underlying phenotypic factor was highly heritable (92%); as was a simple aggregation of all three measurements (77%). This suggests that distilling what is common to all three measures may be a good method for generating a quantitative trait suitable for molecular studies of activity level in children. The high heritabilities found are encouraging in this respect.

Background Previous analysis clustered 1,238 individuals from the general population Genetics of Lipid Lowering Drugs Network (GOLDN) study by the size of their fasting very low-density, low-density and high-density lipoproteins (VLDL, LDL, HDL) using latent class analysis. From two of the eight identified groups (N = 251), ~75% of individuals met Adult Treatment Panel III criteria for the metabolic syndrome (MetS). Both showed small LDL diameter (mean = 19.9 nm); however, group 1 (N = 200) had medium VLDL diameter (mean = 53.1 nm) while group 2 had very large VLDL diameter (mean = 65.74 nm). Group 2 additionally showed significantly more insulin resistance (IR), and accompanying higher waist circumference and fasting glucose and triglycerides (all P < .01). Since lipoprotein lipase hydrolyzes triglyceride in the VLDL-LDL cascade, we examined whether these two patterns of lipoprotein diameter were associated with differences across two lipoprotein lipase (LPL) gene variants: D9N (rs1801177) and S447X (rs328). Findings Mixed linear models that controlled for age, sex, center of data collection, and family pedigree revealed no differences between the two groups for the D9N polymorphism (P = .36). However, group 2 contained significantly more carriers (25%) of the 447X variant than group 1 (14%; P = .04). Conclusions This was the first study this kind to show an association between LPL and large VLDL particle size within the MetS, a pattern associated with higher IR. Future work should extend this to larger samples to confirm these findings, and examine the long term outcomes of those with this lipoprotein diameter pattern.

Contains fulltext : 89304.pdf (Publisher’s version ) (Open Access) CONTEXT: Attention-deficit/hyperactivity disorder (ADHD) is associated with widespread cognitive impairments, but it is not known whether the apparent multiple impairments share etiological roots or separate etiological pathways exist. A better understanding of the etiological pathways is important for the development of targeted interventions and for identification of suitable intermediate phenotypes for molecular genetic investigations. OBJECTIVES: To determine, by using a multivariate familial factor analysis approach, whether 1 or more familial factors underlie the slow and variable reaction times, impaired response inhibition, and choice impulsivity associated with ADHD. DESIGN: An ADHD and control sibling-pair design. SETTING: Belgium, Germany, Ireland, Israel, Spain, Switzerland, and the United Kingdom. PARTICIPANTS: A total of 1265 participants, aged 6 to 18 years: 464 probands with ADHD and 456 of their siblings (524 with combined-subtype ADHD), and 345 control participants. MAIN OUTCOME MEASURES: Performance on a 4-choice reaction time task, a go/no-go inhibition task, and a choice-delay task. RESULTS: The final model consisted of 2 familial factors. The larger factor, reflecting 85% of the familial variance of ADHD, captured 98% to 100% of the familial influences on mean reaction time and reaction time variability. The second, smaller factor, reflecting 13% of the familial variance of ADHD, captured 62% to 82% of the familial influences on commission and omission errors on the go/no-go task. Choice impulsivity was excluded in the final model because of poor fit. CONCLUSIONS: The findings suggest the existence of 2 familial pathways to cognitive impairments in ADHD and indicate promising cognitive targets for future molecular genetic investigations. The familial distinction between the 2 cognitive impairments is consistent with recent theoretical models--a developmental model and an arousal-attention model--of 2 separable underlying processes in ADHD. Future research that tests the familial model within a developmental framework may inform developmentally sensitive interventions. 01 november 2010