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20 result(s) for "Thaker, Vidhu V."
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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 4.sup.th 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.
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 95 th percentile of sex-specific BMI-for-age) compared to those with overweight or non-severe obesity. Methods Youth with BMI ≥ 85 th 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.
Severe Phenotype of De Novo TSHR Activating Pathogenic Variants
The phenotypic spectrum of thyroid-stimulating hormone (TSH) receptor (TSHR) pathogenic variants is broad. Germline variants causing constitutive TSHR activation in the absence of TSH result in familial nonautoimmune hyperthyroidism (FNAH) or sporadic nonautoimmune hyperthyroidism (SNAH). This hyperthyroid state, if present in utero or early childhood, can impact multisystem development. The consequences of severe early-onset hyperthyroidism have not been well described. Here, we report two unrelated individuals, each with a distinct monoallelic de novo TSHR pathogenic variant leading to severe congenital hyperthyroidism that required multistep thyroidectomies. Both patients had thyroid hypertrophy and vulnerable anatomic positioning of recurrent laryngeal nerves (RLNs), complicating surgical management. Case 1 is a 4-year-old boy with craniosynostosis and mitral valve dysplasia with SNAH caused by a heterozygous TSHR variant c.1515C >A; p.S505R. Hyperthyroidism was detected with thyroid storm at 17 months of age. Case 2 is a 9-year-old girl with SNAH and craniosynostosis from a novel heterozygous TSHR variant c.1897G >C; p.D633H identified in the neonatal period. The severe hyperthyroidism and complex course seen in these individuals contrast with previously reported cases. These cases highlight the wide phenotypic spectrum of TSHR activating variants and the persistent clinical sequelae of SNAH.
Relationship of TSH Levels with Cardiometabolic Risk Factors in US Youth and Reference Percentiles for Thyroid Function
Abstract 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.
Clinical Course of Nonfunctional Pituitary Microadenoma in Children: A Single-Center Experience
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. 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. Retrospective observational study. 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. 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. 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.
Endocrine and behavioural features of Lowe syndrome and their potential molecular mechanisms
BackgroundLowe 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.MethodsThis 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.ResultsA 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.ConclusionsThere 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.
Characterization of Rare Variants in MC4R in African American and Latino Children With Severe Early-Onset Obesity
Abstract 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. This study identifies pathogenic variants in the MC4R gene in children with severe early-onset obesity from African American race and Latino ancestry.
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.
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.Exposure to excess iodine increases the risk of hypothyroidism in infants with congenital heart disease that is likely exacerbated by renal dysfunction and multiple procedures.
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. Hypothalamic melanocortin neurons control energy homoeostasis by modulating appetite. Here, the authors reveal a role for the transcription factor Tbx3 as a regulator of the peptidergic identity and function of immature and mature mouse melanocortin neurons.