Prevalence of subclinical hypothyroidism and longitudinal thyroid stimulating hormone changes in youth with metabolic dysfunction-associated steatotic liver disease: an observational study.

BACKGROUND: Studies on adults have shown an association between overt or subclinical hypothyroidism (SH) and metabolic dysfunction-associated steatotic liver disease (MASLD). The goal of this study was to assess the relationship between thyroid-stimulating hormone (TSH) levels and the histological characteristics of MASLD in youth. METHODS: This observational study used prospectively collected liver biopsy and clinical data from youth enrolled in two pediatric clinical trials in the Nonalcoholic Steatohepatitis Clinical Research Network (NASH CRN). Thyroid assays were compared between youth with MASLD and population-based controls aged ≤18 years from the National Health and Nutrition Examination Survey (NHANES). Individuals with overt hypothyroidism, abnormal anti-thyroid antibody, or thyroid-related medications were excluded. SH was defined as TSH between 4.5-10.0 uIU/L. Multinomial logistic regression was used to test the association between TSH and MASLD histological changes at baseline, adjusting for age, sex, race/ethnicity, and body mass index. Mixed-effect models, including treatment and time, were used for the longitudinal analysis. RESULTS: Mean TSH, total thyroxine (T4), total triiodothyronine (T3), and free T4 levels were higher ( p <0.001) in the NASH CRN cohort (n=218; 421 observations) than in the NHANES cohort (n=2,198). TSH levels were positively associated with increased steatosis over time ( p =0.03). SH was associated with borderline or definite metabolic-associated steatohepatitis on histology at baseline ( p =0.03) and with changes in fibrosis over time ( p =0.01). CONCLUSION: The association between TSH and steatosis severity in individuals with normal thyroid hormone concentrations suggests an independent role of TSH in MASLD.

Lack of Age-Appropriate Reference Intervals Causing Potentially Missed Alerts in Clinical Reports of Dyslipidemia.

This study shows that only 12.5% of laboratory reports (2/16) included age-appropriate pediatric reference ranges for all lipid and lipoproteins. The use of erroneous reference range(s) could lead to missed alerts of dyslipidemia in up to 97.3% (total cholesterol), 93.6% (high-density lipoprotein cholesterol), 94.8% (low-density lipoprotein cholesterol), and 87.8% (triglycerides) of youth in the population-based National Health and Nutrition Examination Survey cohort. These findings highlight the potential missed opportunities for reinforcing lifestyle counseling for dyslipidemia in addition to obesity in youth.

Endocrine and behavioural features of Lowe syndrome and their potential molecular mechanisms.

BACKGROUND: Lowe syndrome (LS) is an X linked disease caused by pathogenic variants in the OCRL gene that impacts approximately 1 in 500 000 children. Classic features include congenital cataract, cognitive/behavioural impairment and renal tubulopathy. METHODS: This study is a retrospective review of clinical features reported by family based survey conducted by Lowe Syndrome Association. Frequency of non-ocular clinical feature(s) of LS and their age of onset was summarised. An LS-specific therapy effectiveness scale was used to assess the response to the administered treatment. Expression of OCRL and relevant neuropeptides was measured in postmortem human brain by qPCR. Gene expression in the mouse brain was determined by reanalysis of publicly available bulk and single cell RNA sequencing. RESULTS: A total of 137 individuals (1 female, 89.1% white, median age 14 years (range 0.8-56)) were included in the study. Short stature (height <3rd percentile) was noted in 81% (n=111) individuals, and 15% (n=20) received growth hormone therapy. Undescended testis was reported in 47% (n=64), and median age of onset of puberty was 15 years. Additional features were dental problems (n=77, 56%), bone fractures (n=63, 46%), hypophosphataemia (n=60, 44%), developmental delay and behavioural issues. OCRL is expressed in human and mouse hypothalami, and in hypothalamic cell clusters expressing Ghrh, Sst, Oxt, Pomc and pituitary cells expressing Gh and Prl. CONCLUSIONS: There is a wide spectrum of the clinical phenotype of LS. Some of the features may be partly driven by the loss of function of OCRL in the hypothalamus and the pituitary.

Psychosocial, behavioral and clinical correlates of children with overweight and obesity.

BACKGROUND: Psychological and behavioral correlates are considered important in the development and persistence of obesity in both adults and youth. This study aimed to identify such features in youth with severe obesity (BMI ≥ 120% of 95thpercentile of sex-specific BMI-for-age) compared to those with overweight or non-severe obesity. METHODS: Youth with BMI ≥ 85th percentile were invited to participate in a prospective research registry where data was collected on attributes such as family characteristics, eating behaviors, dietary intake, physical activity, perception of health and mental well-being, and cardiometabolic parameters. RESULTS: In a racially/ethnically diverse cohort of 105 youth (65% female, median age 16.1 years, range 4.62-25.5), 51% had severe obesity. The body fat percent increased with the higher levels of obesity. There were no differences in the self-reported frequency of intake of sugar sweetened beverages or fresh produce across the weight categories. However, the participants with severe obesity reported higher levels of emotional eating and eating when bored (p = 0.022), levels of stress (p = 0.013), engaged in fewer sports or organized activities (p = 0.044), and had suboptimal perception of health (p = 0.053). Asthma, depression and obstructive sleep apnea were more frequently reported in youth with severe obesity. The presence of abnormal HDL-C, HOMA-IR, hs-CRP and multiple cardiometabolic risk factors were more common among youth with severe obesity. CONCLUSIONS: Youth with severe obesity have identifiable differences in psychosocial and behavioral attributes that can be used to develop targeted intervention strategies to improve their health.

Updates on Rare Genetic Variants, Genetic Testing, and Gene Therapy in Individuals With Obesity.

PURPOSE OF REVIEW: The goal of this paper is to aggregate information on monogenic contributions to obesity in the past five years and to provide guidance for genetic testing in clinical care. RECENT FINDINGS: Advances in sequencing technologies, increasing awareness, access to testing, and new treatments have increased the utilization of genetics in clinical care. There is increasing recognition of the prevalence of rare genetic obesity from variants with mean allele frequency < 5% -new variants in known genes as well as identification of novel genes- causing monogenic obesity. While most of these genes are in the leptin melanocortin pathway, those in adipocytes may also contribute. Common variants may contribute either to higher lifetime tendency for weight gain or provide protection from monogenic obesity. While specific genetic mutations are rare, these segregate in individuals with early-onset severe obesity; thus, collectively genetic etiologies are not as rare. Some genetic conditions are amenable to targeted treatment. Research into the discovery of novel genetic causes as well as targeted treatment is growing over time. The utility of therapeutic strategies based on the genetic risk of obesity is an advancing frontier.

Mitochondrial Health Markers and Obesity-Related Health in Human Population Studies: A Narrative Review of Recent Literature.

PURPOSE OF REVIEW: This narrative review summarizes current literature on the relationship of mitochondrial biomarkers with obesity-related characteristics, including body mass index and body composition. RECENT FINDINGS: Mitochondria, as cellular powerhouses, play a pivotal role in energy production and the regulation of metabolic process. Altered mitochondrial functions contribute to obesity, yet evidence of the intricate relationship between mitochondrial dynamics and obesity-related outcomes in human population studies is scarce and warrants further attention. We discuss emerging evidence linking obesity and related health outcomes to impaired oxidative phosphorylation pathways, oxidative stress and mtDNA variants, copy number and methylation, all hallmark of suboptimal mitochondrial function. We also explore the influence of dietary interventions and metabolic and bariatric surgery procedures on restoring mitochondrial attributes of individuals with obesity. Finally, we report on the potential knowledge gaps in the mitochondrial dynamics for human health for future study.

Exploring Genetic Testing for Rare Disorders of Obesity: Experience and Perspectives of Pediatric Weight Management Providers.

Background: This study describes experiences and perspectives of pediatric weight management (PWM) providers on the implementation of genetic testing for rare causes of obesity. Methods: Purposive and snowball sampling recruited PWM providers via email to complete a 23-question survey with multiple choice and open-ended questions. Analyses include descriptive statistics, Fisher's exact test, one-way ANOVA with Tukey's post hoc test, and qualitative analysis. Results: Of the 55 respondents, 80% reported ordering genetic testing. Respondents were primarily physicians (82.8%) in practice for 11-20 years (42%), identified as female (80%), White (76.4%), and non-Hispanic (92.7%) and provided PWM care 1-4 half day sessions per week. Frequently reported patient characteristics that prompted testing did not vary by provider years of experience (YOE). These included obesity onset before age 6, hyperphagia, dysmorphic facies, and developmental delays. The number of patient characteristics that prompted testing varied by YOE (p = 0.03); respondents with 6-10 YOE indicated more patient characteristics than respondents with >20 YOE (mean 10.3 vs. mean 6.2). The reported primary benefit of testing was health information for patients/families; the primary drawback was the high number of indeterminate tests. Ethical concerns expressed were fear of increasing weight stigma, discrimination, and impact on insurance coverage. Respondents (42%) desired training and guidance on interpreting results and counseling patients and families. Conclusions: Most PWM providers reported genetic testing as an option for patient management. Provider training in genetics/genomics and research into provider and family attitudes on the genetics of obesity and the value of genetic testing are next steps to consider.

The association of higher offspring early-childhood weight gain with prepregnancy metabolic and bariatric surgery.

OBJECTIVE: The objective of this study was to assess maternal gestational outcomes and offspring growth trajectories following prepregnancy metabolic and bariatric surgery (MBS) compared with non-MBS controls. METHODS: Single-center deliveries between January 2020 and March 2023 with prepregnancy Roux-en-Y gastric bypass (herein referred to as "bypass"), sleeve gastrectomy (herein referred to as "sleeve"), and non-MBS controls were included. Offspring growth trajectories were compared with the World Health Organization child growth standards. Linear mixed models assessed MBS-bypass and MBS-sleeve offspring weight, length, and BMI trajectories with a prepregnancy BMI 27 to 37 kg/m2 and propensity score-matched controls. RESULTS: The study included 440 participants with prepregnancy MBS (MBS-bypass, 185; MBS-sleeve, 225; 76% Hispanic/Latino) and 13,434 non-MBS controls. Gestational weight gain and gestational diabetes mellitus were similar, whereas hypertensive disorders of pregnancy were more common after MBS. The post-MBS offspring had lower birth weight but higher weight gain at 24 months (sleeve, +1.4 kg [95% CI: 1.0-1.9]; bypass, +0.5-0.7 kg [95% CI: 0.0-1.2]) compared with non-MBS groups. Male children had higher weight gain than females. The post-MBS-sleeve but not the post-MBS-bypass offspring had higher BMI z scores. CONCLUSIONS: The higher early-life weight gain and sex differences in the post-MBS-sleeve group compared with the post-MBS-bypass group provide a window toward elucidating pathways to mitigate intergenerational metabolic risk transfer.

Metabolite signature of diabetes remission in individuals with obesity undergoing weight loss interventions.

OBJECTIVE: This observational study investigated metabolomic changes in individuals with type 2 diabetes (T2D) after weight loss. We hypothesized that metabolite changes associated with T2D-relevant phenotypes are signatures of improved health. METHODS: Fasting plasma samples from individuals undergoing bariatric surgery (n = 71 Roux-en-Y gastric bypass [RYGB], n = 22 gastric banding), lifestyle intervention (n = 66), or usual care (n = 14) were profiled for 139 metabolites before and 2 years after weight loss. Principal component analysis grouped correlated metabolites into factors. Association of preintervention metabolites was tested with preintervention clinical features and changes in T2D markers. Association between change in metabolites/metabolite factors and change in T2D remission markers, homeostasis model assessment of ß-cell function, homeostasis model assessment of insulin resistance, and glycated hemoglobin (HbA1c) was assessed. RESULTS: Branched-chain amino acids (BCAAs) were associated with preintervention adiposity. Changes in BCAAs (valine, leucine/isoleucine) and branched-chain ketoacids were positively associated with change in HbA1c (false discovery rate q value ≤ 0.001) that persisted after adjustment for percentage weight change and RYGB (p ≤ 0.02). In analyses stratified by RYGB or other weight loss method, some metabolites showed association with non-RYGB weight loss. CONCLUSIONS: This study confirmed known metabolite associations with obesity/T2D and showed an association of BCAAs with HbA1c change after weight loss, independent of the method or magnitude of weight loss.

Amygdala AVPR1A mediates susceptibility to chronic social isolation in females.

Females are more sensitive to social exclusion, which could contribute to their heightened susceptibility to anxiety disorders. Chronic social isolation stress (CSIS) for at least 7 weeks after puberty induces anxiety-related behavioral adaptations in female mice. Here, we show that Arginine vasopressin receptor 1a ( Avpr1a )-expressing neurons in the central nucleus of the amygdala (CeA) mediate these sex-specific effects, in part, via projections to the caudate putamen. Loss of function studies demonstrate that AVPR1A signaling in the CeA is required for effects of CSIS on anxiety-related behaviors in females but has no effect in males or group housed females. This sex-specificity is mediated by AVP produced by a subpopulation of neurons in the posterodorsal medial nucleus of the amygdala that project to the CeA. Estrogen receptor alpha signaling in these neurons also contributes to preferential sensitivity of females to CSIS. These data support new therapeutic applications for AVPR1A antagonists in women.

The metabolic conditioning of obesity: A review of the pathogenesis of obesity and the epigenetic pathways that "program" obesity from conception.

Understanding the developmental origins of health and disease is integral to overcome the global tide of obesity and its metabolic consequences, including atherosclerotic cardiovascular disease, type 2 diabetes, hyperlipidemia, and nonalcoholic fatty liver disease. The rising prevalence of obesity has been attributed, in part, to environmental factors including the globalization of the western diet and unhealthy lifestyle choices. In this review we argue that how and when such exposures come into play from conception significantly impact overall risk of obesity and later health outcomes. While the laws of thermodynamics dictate that obesity is caused by an imbalance between caloric intake and energy expenditure, the drivers of each of these may be laid down before the manifestation of the phenotype. We present evidence over the last half-century that suggests that the temporospatial evolution of obesity from intrauterine life and beyond is, in part, due to the conditioning of physiological processes at critical developmental periods that results in maladaptive responses to obesogenic exposures later in life. We begin the review by introducing studies that describe an association between perinatal factors and later risk of obesity. After a brief discussion of the pathogenesis of obesity, including the systemic regulation of appetite, adiposity, and basal metabolic rate, we delve into the mechanics of how intrauterine, postnatal and early childhood metabolic environments may contribute to adult obesity risk through the process of metabolic conditioning. Finally, we detail the specific epigenetic pathways identified both in preclinical and clinical studies that synergistically "program" obesity.

Derivation and characterization of the induced pluripotent stem cell line CUIMCi004-A from a patient with a novel frameshift variant in exon 18a of OCRL.

OCRL encodes for an inositol polyphosphate 5-phosphatase, located in the trans-Golgi network, endosomes, endocytic clathrin-coated pits, primary cilia. Mutations in OCRL causes Lowe syndrome (LS), a rare and complex disorder characterized by congenital cataracts, renal tubular dysfunction, and mental retardation. Here we generated an induced pluripotent stem cell (iPSC) line from Peripheral Blood Mononuclear Cell (PBMCs) of a 5-year-old boy with severe obesity carrying a novel pathogenic variant in the brain-expressed isoform of OCRL. The Sendai virus approach was used for reprogramming. The iPSC line CUIMCi004-A may serve as a useful resource to further investigate the tissue-specific function of OCRL.

Relationship of TSH Levels with Cardiometabolic Risk Factors in US Youth and Reference Percentiles for Thyroid Function.

CONTEXT: Thyroid hormones play an important role in metabolic homeostasis, and higher levels have been associated with cardiometabolic risk. OBJECTIVE: To examine the association of cardiometabolic risk factors with TSH levels in US youth. METHODS: Cross-sectional study of youth aged 12 to 18 years without known thyroid abnormalities from 5 National Health and Nutrition Examination Survey cycles (n = 2818) representing 15.4 million US children. Subclinical hypothyroidism (SH) was defined as thyrotropin (TSH) levels of 4.5 to 10 mIU/L. Assessed cardiometabolic risk factors include abdominal obesity (waist circumference >90th percentile), hypertriglyceridemia (triglyceride ≥130 mg/dL), low high-density lipoprotein cholesterol (<40 mg/dL), elevated blood pressure (systolic and diastolic blood pressure ≥90th percentile), hyperglycemia (fasting blood glucose ≥100 mg/dL, or known diabetes), insulin resistance (homeostatic model for insulin resistance > 3.16), and elevated alanine transferase (≥ 50 for boys and ≥44 U/L for girls). Age and sex- specific percentiles for thyroid parameters were calculated. RESULTS: In this cohort of youth (51.3% male), 31.2% had overweight/obesity. The prevalence of SH was 2.0% (95% CI 1.2-3.1). The median TSH levels were higher in youth with overweight/obesity (P < 0.001). Adjusting for age, sex, race/ethnicity, and obesity, youth with TSH in the fourth quantile had higher odds of abdominal obesity (OR 2.53 [1.43-4.46], P = .002), insulin resistance (OR 2.82 [1.42-5.57], P = .003), and ≥2 cardiometabolic risk factors (CMRF) (OR 2.20 [1.23-3.95], P = .009). CONCLUSION: The prevalence of SH is low in US youth. The higher odds of insulin resistance and cardiometabolic risk factors in youth with TSH levels >75th percentile requires further study.

Effect of TSH on Non-Alcoholic Fatty Liver Disease (NAFLD) independent of obesity in children of predominantly Hispanic/Latino ancestry by causal mediation analysis.

BACKGROUND: Nonalcoholic Fatty Liver Disease (NAFLD) is a common co-morbidity of obesity. Elevated TSH levels (eTSH), also associated with obesity, may contribute to the dysmetabolic state that predisposes to NAFLD. OBJECTIVE: To assess the relationship between TSH levels and NAFLD in children with biopsy-proven NAFLD compared to controls. DESIGN AND METHODS: In this retrospective study of children with biopsy-proven NAFLD and age-matched controls, the association of eTSH with NAFLD was investigated and the role of TSH as a mediator between obesity and NAFLD was assessed. RESULTS: Sixty-six cases and 4067 controls (69.7 vs 59% Hispanic/Latino ancestry, p = 0.1) of the same age range seen in the same time duration at an urban Children's Hospital were studied. Children with NAFLD were more likely to be male (74.6 vs 39.4%, p < 0.001), have higher modified BMI-z scores (median 2.4 (IQR 1.7) vs 1.9 (IQR 1.7), p < 0.001), and abnormal metabolic parameters (TSH, ALT, HDL-C, non-HDL-C, and TG). Multivariate analyses controlling for age, sex and severity of obesity showed significant association between the 4th quartile of TSH and NAFLD. Causal mediation analysis demonstrates that TSH mediates 33.8% of the effect of modified BMI-z score on NAFLD. This comprises of 16.0% (OR = 1.1, p = 0.002) caused by the indirect effect of TSH and its interaction with modified BMI-z, and 17.7% (OR = 1.1, p = 0.05) as an autonomous effect of TSH on NAFLD. Overall, 33.8% of the effect can be eliminated by removing the mediator, TSH (p = 0.001). CONCLUSIONS: The association of eTSH and biopsy-proven NAFLD is demonstrated in children of Hispanic/Latino ancestry. Further, a causal mediation analysis implicates an effect of TSH on NAFLD, independent of obesity.

Clinical Course of Nonfunctional Pituitary Microadenoma in Children: A Single-Center Experience.

CONTEXT: Pituitary lesions consistent with microadenomas are increasingly discovered by MRI. Sparse data are available on the long-term clinical and imaging course of such lesions in children. OBJECTIVE: The aim of this study was to define the clinical and imaging course of pituitary lesions representing or possibly representing nonfunctioning microadenomas in children to guide clinical management. DESIGN: Retrospective observational study. METHODS: The clinical data warehouse at a tertiary care academic children's hospital was queried with the terms "pituitary" AND "microadenoma" and "pituitary" AND "incidentaloma." The electronic health records of the identified subjects were reviewed to extract data on the clinical and imaging course. RESULTS: A total of 78 children had nonfunctioning pituitary lesions incidentally discovered during clinical care, of which 44 (56%) were reported as presumed or possible microadenomas. In the children with microadenoma (median age 15 years, interquartile range 2), a majority (70%) underwent imaging for nonendocrine symptoms, the most common being headache (n = 16, 36%). No significant increase in the size of the microadenoma or cysts or worsening of pituitary function was seen over the average clinical follow-up of 4.5 ± 2.6 years. Four cases of drug-induced hyperprolactinemia resolved with discontinuation of the offending medication. CONCLUSIONS: Asymptomatic pituitary lesions representing cysts, microadenomas, or possible microadenomas follow a benign course in children. In the absence of new endocrine or visual symptoms, repeat MRI may not be needed, and if performed, should be done in no less than a year. When possible, it is prudent to discontinue hyperprolactinemia-inducing medications before imaging.

Characterization of Rare Variants in MC4R in African American and Latino Children With Severe Early-Onset Obesity.

CONTEXT: Mutations in melanocortin receptor (MC4R) are the most common cause of monogenic obesity in children of European ancestry, but little is known about their prevalence in children from the minority populations in the United States. OBJECTIVE: This study aims to identify the prevalence of MC4R mutations in children with severe early-onset obesity of African American or Latino ancestry. DESIGN AND SETTING: Participants were recruited from the weight management clinics at two hospitals and from the institutional biobank at a third hospital. Sequencing of the MC4R gene was performed by whole exome or Sanger sequencing. Functional testing was performed to establish the surface expression of the receptor and cAMP response to its cognate ligand α-melanocyte-stimulating hormone. PARTICIPANTS: Three hundred twelve children (1 to 18 years old, 50% girls) with body mass index (BMI) >120% of 95th percentile of Centers for Disease Control and Prevention 2000 growth charts at an age <6 years, with no known pathological cause of obesity, were enrolled. RESULTS: Eight rare MC4R mutations (2.6%) were identified in this study [R7S, F202L (n = 2), M215I, G252D, V253I, I269N, and F284I], three of which were not previously reported (G252D, F284I, and R7S). The pathogenicity of selected variants was confirmed by prior literature reports or functional testing. There was no significant difference in the BMI or height trajectories of children with or without MC4R mutations in this cohort. CONCLUSIONS: Although the prevalence of MC4R mutations in this cohort was similar to that reported for obese children of European ancestry, some of the variants were novel.

Functional identity of hypothalamic melanocortin neurons depends on Tbx3.

Heterogeneous populations of hypothalamic neurons orchestrate energy balance via the release of specific signatures of neuropeptides. However, how specific intracellular machinery controls peptidergic identities and function of individual hypothalamic neurons remains largely unknown. The transcription factor T-box 3 (Tbx3) is expressed in hypothalamic neurons sensing and governing energy status, whereas human TBX3 haploinsufficiency has been linked with obesity. Here, we demonstrate that loss of Tbx3 function in hypothalamic neurons causes weight gain and other metabolic disturbances by disrupting both the peptidergic identity and plasticity of Pomc/Cart and Agrp/Npy neurons. These alterations are observed after loss of Tbx3 in both immature hypothalamic neurons and terminally differentiated mouse neurons. We further establish the importance of Tbx3 for body weight regulation in Drosophila melanogaster and show that TBX3 is implicated in the differentiation of human embryonic stem cells into hypothalamic Pomc neurons. Our data indicate that Tbx3 directs the terminal specification of neurons as functional components of the melanocortin system and is required for maintaining their peptidergic identity. In summary, we report the discovery of a key mechanistic process underlying the functional heterogeneity of hypothalamic neurons governing body weight and systemic metabolism.

Diagnosis, Evaluation, and Management of High Blood Pressure in Children and Adolescents.

Systemic hypertension is a major cause of morbidity and mortality in adulthood. High blood pressure (HBP) and repeated measures of HBP, hypertension (HTN), begin in youth. Knowledge of how best to diagnose, manage, and treat systemic HTN in children and adolescents is important for primary and subspecialty care providers. OBJECTIVES: To provide a technical summary of the methodology used to generate the 2017 "Clinical Practice Guideline for Screening and Management of High Blood Pressure in Children and Adolescents," an update to the 2004 "Fourth Report on the Diagnosis, Evaluation, and Treatment of High Blood Pressure in Children and Adolescents." DATA SOURCES: Medline, Cochrane Central Register of Controlled Trials, and Excerpta Medica Database references published between January 2003 and July 2015 followed by an additional search between August 2015 and July 2016. STUDY SELECTION: English-language observational studies and randomized trials. METHODS: Key action statements (KASs) and additional recommendations regarding the diagnosis, management, and treatment of HBP in youth were the product of a detailed systematic review of the literature. A content outline establishing the breadth and depth was followed by the generation of 4 patient, intervention, comparison, outcome, time questions. Key questions addressed: (1) diagnosis of systemic HTN, (2) recommended work-up of systemic HTN, (3) optimal blood pressure (BP) goals, and (4) impact of high BP on indirect markers of cardiovascular disease in youth. Once selected, references were subjected to a 2-person review of the abstract and title followed by a separate 2-person full-text review. Full citation information, population data, findings, benefits and harms of the findings, as well as other key reference information were archived. Selected primary references were then used for KAS generation. Level of evidence (LOE) scoring was assigned for each reference and then in aggregate. Appropriate language was used to generate each KAS based on the LOE and the balance of benefit versus harm of the findings. Topics that could not be researched via the stated approach were (1) definition of HTN in youth, and (2) definition of left ventricular hypertrophy. KASs related to these stated topics were generated via expert opinion. RESULTS: Nearly 15 000 references were identified during an initial literature search. After a deduplication process, 14 382 references were available for title and abstract review, and 1379 underwent full text review. One hundred twenty-four experimental and observational studies published between 2003 and 2016 were selected as primary references for KAS generation, followed by an additional 269 primary references selected between August 2015 and July 2016. The LOE for the majority of references was C. In total, 30 KASs and 27 additional recommendations were generated; 12 were related to the diagnosis of HTN, 13 were related to management and additional diagnostic testing, 3 to treatment goals, and 2 to treatment options. Finally, special additions to the clinical practice guideline included creation of new BP tables based on BP values obtained solely from children with normal weight, creation of a simplified table to enhance screening and recognition of abnormal BP, and a revision of the criteria for diagnosing left ventricular hypertrophy. CONCLUSIONS: An extensive and detailed systematic approach was used to generate evidence-based guidelines for the diagnosis, management, and treatment of youth with systemic HTN.

GENETIC AND EPIGENETIC CAUSES OF OBESITY.

Obesity is a complex, heritable trait influenced by the interplay of genetics, epigenetics, metagenomics and the environment. With the increasing access to high precision diagnostic tools for genetic investigations, numerous genes influencing the phenotype have been identified, especially in early onset severe obesity. This review summarizes the current knowledge on the known genetic causes of obesity and the available therapeutic options. Furthermore, we discuss the role and potential mechanism of epigenetic changes that may be involved as mediators of the environmental influences and that may provide future opportunities for intervention.

Hypothyroidism in Infants With Congenital Heart Disease Exposed to Excess Iodine.

Thyroid hormone is critical for neonatal brain development, and even transient hypothyroidism can cause adverse neurocognitive outcomes. Infants exposed to excess iodine are at risk of developing hypothyroidism, especially those with congenital heart disease (CHD), because they are routinely exposed to excess iodine from intravenous iodinated contrast media and topical antiseptics. The aim of the present study was to identify the proportion of neonates with CHD exposed to iodine who developed hypothyroidism and to identify the associated risk factors. This was a retrospective study of neonates undergoing cardiac catheterization at Boston Children's Hospital during a 3-year period, some of whom also underwent cardiac surgery. Hypothyroidism was defined as an elevated thyroid-stimulating hormone level (>20 mIU/L at 24 to 96 hours of age and >15 mIU/L at >96 hours of age by heel-stick sampling and >9.1 mIU/L at 1 to 20 weeks of age by serum testing). Multivariate logistic regression was performed to predict the odds of developing hypothyroidism. Hypothyroidism was diagnosed incidentally in 46 of 183 infants (25%) with CHD after iodine exposure. Controlling for baseline cardiac risk, postnatal age, and gestational age, we found a fourfold increase in odds of developing hypothyroidism in neonates with serum creatinine >0.9 mg/dL and a fourfold increase in those who underwent more than three procedures. Hypothyroidism in neonates with CHD exposed to excess iodine is associated with multiple procedures and impaired renal function. Routine serial monitoring of thyroid function in these neonates is warranted. Future studies should examine the association between hypothyroidism and neurocognitive function in this population.