An adult-based genetic risk score for liver fat associates with liver and plasma lipid traits in children and adolescents.

BACKGROUND & AIMS: Genome-wide association studies have identified steatogenic variants that also showed pleiotropic effects on cardiometabolic traits in adults. We investigated the effect of eight previously reported genome-wide significant steatogenic variants, individually and combined in a weighted genetic risk score (GRS), on liver and cardiometabolic traits, and the predictive ability of the GRS for hepatic steatosis in children and adolescents. APPROACH & RESULTS: Children and adolescents with overweight (including obesity) from an obesity clinic group (n = 1768) and a population-based group (n = 1890) were included. Cardiometabolic risk outcomes and genotypes were obtained. Liver fat was quantified using 1 H-MRS in a subset of 727 participants. Variants in PNPLA3, TM6SF2, GPAM and TRIB1 were associated with higher liver fat (p < .05) and with distinct patterns of plasma lipids. The GRS was associated with higher liver fat content, plasma concentrations of alanine transaminase (ALT), aspartate aminotransferase (AST) and favourable plasma lipid levels. The GRS was associated with higher prevalence of hepatic steatosis (defined as liver fat ≥5.0%) (odds ratio per 1-SD unit: 2.17, p = 9.7E-10). A prediction model for hepatic steatosis including GRS alone yielded an area under the curve (AUC) of 0.78 (95% CI 0.76-0.81). Combining the GRS with clinical measures (waist-to-height ratio [WHtR] SDS, ALT, and HOMA-IR) increased the AUC up to 0.86 (95% CI 0.84-0.88). CONCLUSIONS: The genetic predisposition for liver fat accumulation conferred risk of hepatic steatosis in children and adolescents. The liver fat GRS has potential clinical utility for risk stratification.

A Gut-Intrinsic Melanocortin Signaling Complex Augments L-Cell Secretion in Humans.

OBJECTIVE: Hypothalamic melanocortin 4 receptors (MC4R) are a key regulator of energy homeostasis. Brain-penetrant MC4R agonists have failed, as concentrations required to suppress food intake also increase blood pressure. However, peripherally located MC4R may also mediate metabolic benefits of MC4R activation. Mc4r transcript is enriched in mouse enteroendocrine L cells and peripheral administration of the endogenous MC4R agonist, α-melanocyte stimulating hormone (α-MSH), triggers the release of the anorectic hormones Glucagon-like peptide-1 (GLP-1) and peptide tyrosine tyrosine (PYY) in mice. This study aimed to determine whether pathways linking MC4R and L-cell secretion exist in humans. DESIGN: GLP-1 and PYY levels were assessed in body mass index-matched individuals with or without loss-of-function MC4R mutations following an oral glucose tolerance test. Immunohistochemistry was performed on human intestinal sections to characterize the mucosal MC4R system. Static incubations with MC4R agonists were carried out on human intestinal epithelia, GLP-1 and PYY contents of secretion supernatants were assayed. RESULTS: Fasting PYY levels and oral glucose-induced GLP-1 secretion were reduced in humans carrying a total loss-of-function MC4R mutation. MC4R was localized to L cells and regulates GLP-1 and PYY secretion from ex vivo human intestine. α-MSH immunoreactivity in the human intestinal epithelia was predominantly localized to L cells. Glucose-sensitive mucosal pro-opiomelanocortin cells provide a local source of α-MSH that is essential for glucose-induced GLP-1 secretion in small intestine. CONCLUSION: Our findings describe a previously unidentified signaling nexus in the human gastrointestinal tract involving α-MSH release and MC4R activation on L cells in an autocrine and paracrine fashion. Outcomes from this study have direct implications for targeting mucosal MC4R to treat human metabolic disorders.

Neonatal Anthropometrics and Obesity Treatment Response in Children and Adolescents.

OBJECTIVE: To investigate the relationship between in utero growth conditions, as indicated by neonatal anthropometric measures, and childhood obesity treatment response, to examine the potential usefulness of neonatal anthropometrics as a potential childhood obesity treatment stratification tool. STUDY DESIGN: The study included 2474 children and adolescents with obesity (mean age, 11.2 years; range, 5.0-18.9 years) treated at the Children's Obesity Clinic in Holbæk, Denmark. Treatment response was registered prospectively, and neonatal data were collected from national electronic registers. RESULTS: Birth weight, birth length, birth weight for gestational age, and large for gestational age status were positively associated with the degree of obesity at treatment initiation. After a mean (SD) of 1.27 (0.69) years of enrollment in obesity treatment, the children exhibited a mean reduction of -0.32 (0.50) in body mass index SD score. No significant associations between neonatal anthropometric measures and childhood obesity treatment response were detected. CONCLUSIONS: Neonatal anthropometric measures were positively associated with the degree of obesity at treatment initiation but not with response to multidisciplinary treatment of childhood obesity. Individualization of obesity treatment based on neonatal anthropometry does not seem warranted.

A trans-ancestral meta-analysis of genome-wide association studies reveals loci associated with childhood obesity.

Although hundreds of genome-wide association studies-implicated loci have been reported for adult obesity-related traits, less is known about the genetics specific for early-onset obesity and with only a few studies conducted in non-European populations to date. Searching for additional genetic variants associated with childhood obesity, we performed a trans-ancestral meta-analysis of 30 studies consisting of up to 13 005 cases (≥95th percentile of body mass index (BMI) achieved 2-18 years old) and 15 599 controls (consistently <50th percentile of BMI) of European, African, North/South American and East Asian ancestry. Suggestive loci were taken forward for replication in a sample of 1888 cases and 4689 controls from seven cohorts of European and North/South American ancestry. In addition to observing 18 previously implicated BMI or obesity loci, for both early and late onset, we uncovered one completely novel locus in this trans-ancestral analysis (nearest gene, METTL15). The variant was nominally associated with only the European subgroup analysis but had a consistent direction of effect in other ethnicities. We then utilized trans-ancestral Bayesian analysis to narrow down the location of the probable causal variant at each genome-wide significant signal. Of all the fine-mapped loci, we were able to narrow down the causative variant at four known loci to fewer than 10 single nucleotide polymorphisms (SNPs) (FAIM2, GNPDA2, MC4R and SEC16B loci). In conclusion, an ethnically diverse setting has enabled us to both identify an additional pediatric obesity locus and further fine-map existing loci.

Obesity treatment effect in Danish children and adolescents carrying Melanocortin-4 Receptor mutations.

OBJECTIVES: To determine the prevalence of Melanocortin-4 Receptor (MC4R) mutations in a cohort of children and adolescents with overweight or obesity and to determine whether treatment responses differed between carriers and noncarriers. METHODS: Using target region capture sequencing, an MC4R mutation screen was performed in 1261 Danish children and adolescents enrolled at a tertiary multidisciplinary childhood obesity treatment center. Measurements of anthropometrics, blood pressure, fasting blood biochemistry including lipid and hormone levels, and dual-energy X-ray absorptiometry were performed at baseline and throughout treatment. RESULTS: Of 1209 children and adolescents that met all criteria to be included in the described analyses, 30 (2.5%) carried damaging or unresolved MC4R mutations. At baseline, mutation carriers exhibited higher concentrations of plasma thyroid-stimulating hormone (p = 0.003), and lower concentrations of plasma thyroxine (p = 0.010) compared to noncarriers. After a median of 1 year of treatment (range 0.5-4.0 years), body mass index (BMI) standard deviation score (SDS) was reduced in noncarriers but not in carriers, and this difference in treatment response was statistically significant (p = 0.005). Furthermore, HDL cholesterol was reduced in carriers, a response significantly different from that of noncarriers (p = 0.017). CONCLUSION: Among Danish children and adolescents with overweight or obesity entering a tertiary lifestyle intervention, 2.5% carried damaging or unresolved MC4R mutations. In contrast to noncarriers, carriers of damaging or unresolved MC4R mutations failed to reduce their BMI SDS during obesity treatment, indicating a need for personalized treatment based on the MC4R genotype.

Human Milk Oligosaccharides Modulate Fecal Microbiota and Are Safe for Use in Children With Overweight: A Randomized Controlled Trial.

OBJECTIVES: Human milk oligosaccharides (HMOs) impact the intestinal microbiota by increasing beneficial bacteria in infants and adults, and are safe and well tolerated in these age groups. Effects on intestinal microbiota, safety, and digestive tolerance in children have not been, however, assessed. The aims of this trial were to evaluate if HMOs are able to specifically modulate the intestinal microbiota in children, and to assess safety and digestive tolerance. METHODS: In this randomized, double-blinded, placebo-controlled trial, 75 children with overweight (including obesity) ages 6 to 12 years were randomized to receive 2'-fucosyllactose (2'FL), a mix of 2'FL and lacto-N-neotetraose (Mix), or a glucose placebo orally administrated once per day for 8 weeks. RESULTS: The relative abundance of bifidobacteria increased significantly after 4 (P < 0.001) and 8 (P = 0.025) weeks of intervention in the 2'FL-group and after 4 weeks (P = 0.033) in the Mix-group, whereas no change was observed in the placebo group. Compared with placebo, the 2'FL-group had a significant increase in bifidobacteria abundance after 4 weeks (P < 0.001) and 8 weeks (P = 0.010) and the Mix-group showed a tendency to increased bifidobacteria abundance after 4 (P = 0.071) and 8 weeks (P = 0.071). Bifidobacterium adolescentis drove the bifidogenic effect in the 2 groups. Biochemical markers indicated no safety concerns, and the products did not induce digestive tolerance issues as assessed by Gastrointestinal Symptoms Rating Scale and Bristol Stool Form Scale. CONCLUSIONS: Both 2'FL and the Mix beneficially modulate intestinal microbiota by increasing bifidobacteria. Furthermore, supplementation with either 2'FL alone or a Mix is safe and well tolerated in children.

Allergen-specific IgG+ memory B cells are temporally linked to IgE memory responses.

BACKGROUND: IgE is the least abundant immunoglobulin and tightly regulated, and IgE-producing B cells are rare. The cellular origin and evolution of IgE responses are poorly understood. OBJECTIVE: The cellular and clonal origin of IgE memory responses following mucosal allergen exposure by sublingual immunotherapy (SLIT) were investigated. METHODS: In a randomized double-blind, placebo-controlled, time course SLIT study, PBMCs and nasal biopsy samples were collected from 40 adults with seasonal allergic rhinitis at baseline and at 4, 8, 16, 28, and 52 weeks. RNA was extracted from PBMCs, sorted B cells, and nasal biopsy samples for heavy chain variable gene repertoire sequencing. Moreover, mAbs were derived from single B-cell transcriptomes. RESULTS: Combining heavy chain variable gene repertoire sequencing and single-cell transcriptomics yielded direct evidence of a parallel boost of 2 clonally and functionally related B-cell subsets of short-lived IgE+ plasmablasts and IgG+ memory B cells. Mucosal grass pollen allergen exposure by SLIT resulted in highly diverse IgE and IgGE repertoires. These were extensively mutated and appeared relatively stable as per heavy chain isotype, somatic hypermutations, and clonal composition. Single IgGE+ memory B-cell and IgE+ preplasmablast transcriptomes encoded antibodies that were specific for major grass pollen allergens and able to elicit basophil activation at very low allergen concentrations. CONCLUSION: For the first time, we have shown that on mucosal allergen exposure, human IgE memory resides in allergen-specific IgG+ memory B cells. These cells rapidly switch isotype, expand into short-lived IgE+ plasmablasts, and serve as a potential target for therapeutic intervention.

Adults with pathogenic MC4R mutations have increased final height and thereby increased bone mass.

Pathogenic mutations in the melanocortin-4 receptor (MC4R) are associated with obesity, increased linear growth, and higher bone mass in children, and rodent studies have indicated an effect of the MC4R on bone turnover. Furthermore, GLP-1 receptor agonists (GLP-1 RAs) may influence bone metabolism. However, these associations have not been assessed in adults with pathogenic MC4R mutations. Thus, we wished to assess the impact of the MC4R on bone mass and metabolism. Secondly, we wished to investigate the impact of the GLP-1 RA liraglutide on bone mass in adults with pathogenic MC4R mutations. 17 patients with obesity-causing MC4R mutations (BMI: 35.5 ± 7.6) and 35 matched control participants with common obesity (BMI: 34.3 ± 7.1) underwent a DEXA scan for assessment of bone mineral density (BMD), bone mineral apparent density [BMAD = (BMD/√(bone area)], and bone turnover markers (BTMs). Individuals with a BMI above 28 (14 MC4R mutation carriers and 28 matched control participants) underwent 16 weeks treatment with liraglutide 3.0 mg. The MC4R group had higher BMD [mean difference: 0.065 g/m2 (- 0.008 to 0.138), p = 0.03], but BMAD and BTMS were not different compared to the control group. In response to liraglutide, BMAD increased in the control group, compared to no change in the MC4R group [mean group difference: 0.0007 (0.0001-0.001), p = 0.04]. In conclusion, BMD is increased in MC4R causal obesity compared to common obesity, but when corrected for body size (BMAD), bone mass was not increased, and no evidence of an influence of the MC4R on bone metabolism in adults was found. Liraglutide treatment did not change bone metabolism in MC4R causal obesity, but increased bone mass as measured by BMAD in common obesity.

Leptin, adiponectin, and their ratio as markers of insulin resistance and cardiometabolic risk in childhood obesity.

BACKGROUND: It is imperative to develop markers for risk stratification and detection of cardiometabolic comorbidities in children with obesity. The adipokines leptin and adiponectin are both involved in fat mass regulation and the development of obesity-related disorders; furthermore, their ratio (leptin/adiponectin ratio) is suggested to be associated with insulin resistance and cardiometabolic risk. OBJECTIVE: To evaluate associations between fasting serum concentrations of the adipokines (total leptin and adiponectin as well as the L/A ratio) and cardiometabolic comorbidities in children with overweight/obesity. METHODS: A total of 2258 children with overweight/obesity or normal weight aged 6 to 18 years were studied. Differences in anthropometrics and adipokine concentrations were tested using Wilcoxon rank-sum test. Associations between the adipokines and cardiometabolic risk were tested using Spearman's correlation and logistic regression, adjusted for age and body mass index SD score (BMI-SDS). RESULTS: Compared to normal weight children; children with overweight/obesity exhibited higher leptin concentrations, lower adiponectin concentrations, and higher L/A ratios. After adjusting for age and degree of obesity, girls with overweight/obesity in the upper quartile range for the L/A ratio, when compared with girls in the lower quartile range, were more likely to have insulin resistance (odds ratio [OR]: 7.78 [95% confidence interval [CI], 3.78-16.65]), dysglycemia (OR: 3.08 [95% CI, 1.35-7.31]), and dyslipidemia (OR: 2.53 [95% CI, 1.18-5.59]); while boys were more likely to have insulin resistance (OR: 4.45 [95% CI, 2.03-10.10]). CONCLUSIONS: Independent of the degree of obesity, leptin, adiponectin, and the L/A ratio were associated with insulin resistance and other cardiometabolic comorbidities in children with overweight/obesity, but the L/A ratio exhibited stronger associations than the respective adipokines.

Low-grade inflammation independently associates with cardiometabolic risk in children with overweight/obesity.

BACKGROUND AND AIMS: Pediatric obesity associates with both low-grade inflammation and cardiometabolic risk on the population level. Yet on an individual patient level, overweight/obesity does not always equal increased cardiometabolic risk. In this study, we examine whether low-grade inflammation associates with cardiometabolic risk in Danish children, independent of degree of adiposity. We further assess the value of integrating multiple inflammation markers to identify children with very-high cardiometabolic risk profiles. METHOD AND RESULTS: We studied 2192 children and adolescents aged 6-18 years from an obesity clinic cohort and a population-based cohort, in a cross-sectional study design. Anthropometry, blood pressure, pubertal stage and body composition by dual-energy X-ray absorptiometry were assessed, and biomarkers including fasting serum high sensitivity C-reactive protein (hsCRP), white blood cells (WBC), resistin, lipid profile and glucose metabolism were measured. Adjusted correlation analysis and odds ratios were calculated. We found that, independent of degree of adiposity, having high-normal inflammation marker concentrations associated with increased cardiometabolic risk: for girls, hsCRP >0.57-9.98 mg/L (mid/upper tertile) associated with ~2-fold higher odds of dyslipidemia and hepatic steatosis (vs. lower tertile). For both sexes, WBC >7.0-12.4 109/L (upper tertile) associated with 2.5-fold higher odds of insulin resistance. Lastly, children with multiple inflammation markers in the high-normal range exhibited the most severe cardiometabolic risk profile. CONCLUSION: Low-grade inflammation associates with cardiometabolic risk in children independent of degree of adiposity. The associations vary with sex and inflammation marker measured. Finally, integrating multiple low-grade inflammation markers identifies a very-high-risk subgroup of children with overweight/obesity and may have clinical value.

Disturbed eating behaviours do not impact treatment response in a paediatric obesity chronic care treatment programme.

AIM: This study investigates the prevalence of disturbed eating behaviours in children and adolescents initiating obesity treatment, and how the prevalence varies with age, sex and body mass index (BMI) standard deviation score (SDS). Secondly, it examines whether the presence of disturbed eating behaviours at enrolment is associated with the degree of weight loss after 12 months of treatment. METHODS: A total of 3621 patients aged 3-18 years enrolled in a multidisciplinary obesity treatment programme were studied. Follow-up data after a median of 12.4 months were available for 2055 patients. Upon entry, patients were assessed for the following disturbed eating behaviours: meal skipping, emotional eating, overeating and rapid eating. Height and weight were measured at baseline and follow-up. RESULTS: At enrolment, median age was 11.4 years, median BMI SDS was 2.87, and 82.2% of patients exhibited one or more disturbed eating behaviours. The prevalence of meal skipping, emotional eating and rapid eating increased with age (P < 0.01). Patients who reported overeating or rapid eating exhibited a 0.06-0.11 higher BMI SDS at enrolment than patients without these disturbed eating behaviours (P < 0.02). After 1 year of treatment, BMI SDS was reduced in 75.7% of patients, and the median reduction was 0.24 (95% confidence interval: 0.22-0.27). Overeating was associated with a higher degree of weight loss, while meal skipping, emotional eating and rapid eating did not associate with the degree of weight loss at follow-up. CONCLUSIONS: Disturbed eating behaviours were highly prevalent in children and adolescents with overweight or obesity, and varied with age and sex. After 1 year of treatment, the degree of obesity improved, regardless of the presence of disturbed eating behaviours at treatment initiation.

Genetic predisposition to higher body fat yet lower cardiometabolic risk in children and adolescents.

BACKGROUND: Most obese children show cardiometabolic impairments, such as insulin resistance, dyslipidemia, and hypertension. Yet some obese children retain a normal cardiometabolic profile. The mechanisms underlying this variability remain largely unknown. We examined whether genetic loci associated with increased insulin sensitivity and relatively higher fat storage on the hip than on the waist in adults are associated with a normal cardiometabolic profile despite higher adiposity in children. METHODS: We constructed a genetic score using variants previously linked to increased insulin sensitivity and/or decreased waist-hip ratio adjusted for body mass index (BMI), and examined the associations of this genetic score with adiposity and cardiometabolic impairments in a meta-analysis of six cohorts, including 7391 European children aged 3-18 years. RESULTS: The genetic score was significantly associated with increased degree of obesity (higher BMI-SDS beta = 0.009 SD/allele, SE = 0.003, P = 0.003; higher body fat mass beta = 0.009, SE = 0.004, P = 0.031), yet improved body fat distribution (lower WHRadjBMI beta = -0.014 SD/allele, SE = 0.006, P = 0.016), and favorable concentrations of blood lipids (higher HDL cholesterol: beta = 0.010 SD/allele, SE = 0.003, P = 0.002; lower triglycerides: beta = -0.011 SD/allele, SE = 0.003, P = 0.001) adjusted for age, sex, and puberty. No differences were detected between prepubertal and pubertal/postpubertal children. The genetic score predicted a normal cardiometabolic profile, defined by the presence of normal glucose and lipid concentrations, among obese children (OR = 1.07 CI 95% 1.01-1.13, P = 0.012, n = 536). CONCLUSIONS: Genetic predisposition to higher body fat yet lower cardiometabolic risk exerts its influence before puberty.

Glucose metabolism in children and adolescents: Population-based reference values and comparisons to children and adolescents enrolled in obesity treatment.

BACKGROUND: Alterations in glucose metabolism that lead to the development of metabolic and cardiovascular disease may begin already in childhood. OBJECTIVE: This study aims to generate pediatric age and sex-specific reference values for fasting concentrations of glucose, hemoglobin A1c (HbA1c), insulin, C-peptide, and homeostasis model assessment: insulin resistance (HOMA-IR) in Danish/North-European white children and adolescents from a population-based cohort and to compare values from children and adolescents with overweight/obesity with this reference. METHODS: The population- and obesity clinic-based cohorts consisted of 2451 and 1935 children and adolescents between 6 and 18 years of age. Anthropometric measurements and blood samples were obtained and percentile curves were calculated. RESULTS: In the population-based cohort, glucose, insulin, and HOMA-IR values increased before the expected onset of puberty (P < .05). Thereafter, all variables decreased in girls (P < .05) and HbA1c decreased in boys (P < .05). Concentrations of all measured markers of glucose metabolism were higher in the obesity clinic-based cohort than the population-based cohort (both sexes P < .001). Specifically, insulin and HOMA-IR continued to increase to 18 years in the clinic-based cohort, particularly among boys. CONCLUSIONS: Fasting glucose, insulin, and HOMA-IR change during childhood, making pediatric reference values essential for timely identification of derangements in glucose metabolism. Children and adolescents with obesity exhibit increased concentrations of these biomarkers.

Reference values for fasting serum concentrations of thyroid-stimulating hormone and thyroid hormones in healthy Danish/North-European white children and adolescents.

Thyroid-stimulating hormone (TSH) and thyroid hormones influence the functions of many organ systems, as well as child development and growth. Several studies have reported an association between ethnicity and thyroid hormones. This study aims to explore pediatric serum concentrations of TSH, free triiodothyronine (fT3), and free thyroxine (fT4) and their relation to age and sex and subsequently to present pediatric reference intervals from healthy Danish/North-European white children. A population-based cohort in Denmark of 2411 (1435 girls) healthy school children and adolescents aged 6.0-18.9 years were included. Fasting concentrations of serum TSH, fT3, and fT4 were determined from venous blood samples using immunologic chemiluminescent assays. Age- and sex-dependent percentiles were generated using the GAMLSS function. Median values of fT3 and fT4, but not TSH, were lower in the older age group compared with the youngest age group for both sexes (all p < .05). A significant difference for fT3 was found between the sexes for all age groups (all p < .001). fT4 was negatively correlated with body mass index standard deviation scores in boys. In conclusion, serum concentrations of thyroid hormones vary during childhood and adolescence and differ with age and sex.

Obstructive sleep apnea in children and adolescents with and without obesity.

PURPOSE: To investigate the prevalence of obstructive sleep apnea (OSA) in children referred for obesity treatment, and to compare the prevalence with that of a normal-weight group. Moreover, we examined the association between Body Mass Index Standard Deviation Score (BMI SDS) and the Apnea-Hypopnea Index (AHI). METHODS: This cross-sectional study included 139 children aged 7-18 years with overweight/obesity (BMI SDS >1.28) recruited from an obesity treatment clinic. The normal-weight group consisted of 33 children (BMI SDS ≤ 1.28) aged 7-18 years recruited from schools. Sleep examinations were performed using a type 3 portable sleep monitor (Nox T3). OSA was defined as AHI ≥ 2. Height and weight were measured and the tonsillar size was clinically estimated using the Brodsky scale. RESULTS: The OSA prevalence was 44.6% in children with overweight/obesity compared with 9.1% in the normal-weight group (p = 0.0002), and the relative risk of OSA was 4.9 (95% CI 1.6-14.7). In a logistic regression, a one-unit increase in the BMI SDS increased the odds of having OSA by a factor of 1.92 independent of age, sex, tonsillar hypertrophy, and asthma (95% CI 1.33-2.76, p = 0.0005). A generalized linear regression adjusted for the same variables revealed an association between BMI SDS and AHI (a one-unit increase in the BMI SDS equaled an average increase in the AHI of 35% (95% CI 19-53%, p < 0.0001)). CONCLUSIONS: In this study, children with overweight/obesity had a significantly higher prevalence of OSA compared with a normal-weight group. Increased BMI SDS was associated with increased AHI.

An adult-based insulin resistance genetic risk score associates with insulin resistance, metabolic traits and altered fat distribution in Danish children and adolescents who are overweight or obese.

AIMS/HYPOTHESIS: A genetic risk score (GRS) consisting of 53 insulin resistance variants (GRS53) was recently demonstrated to associate with insulin resistance in adults. We speculated that the GRS53 might already associate with insulin resistance during childhood, and we therefore aimed to investigate this in populations of Danish children and adolescents. Furthermore, we aimed to address whether the GRS associates with components of the metabolic syndrome and altered body composition in children and adolescents. METHODS: We examined a total of 689 children and adolescents who were overweight or obese and 675 children and adolescents from a population-based study. Anthropometric data, dual-energy x-ray absorptiometry scans, BP, fasting plasma glucose, fasting serum insulin and fasting plasma lipid measurements were obtained, and HOMA-IR was calculated. The GRS53 was examined for association with metabolic traits in children by linear regressions using an additive genetic model. RESULTS: In overweight/obese children and adolescents, the GRS53 associated with higher HOMA-IR (ß = 0.109 ± 0.050 (SE); p = 2.73 × 10-2), fasting plasma glucose (ß = 0.010 ± 0.005 mmol/l; p = 2.51 × 10-2) and systolic BP SD score (ß = 0.026 ± 0.012; p = 3.32 × 10-2) as well as lower HDL-cholesterol (ß = -0.008 ± 0.003 mmol/l; p = 1.23 × 10-3), total fat-mass percentage (ß = -0.143 ± 0.054%; p = 9.15 × 10-3) and fat-mass percentage in the legs (ß = -0.197 ± 0.055%; p = 4.09 × 10-4). In the population-based sample of children, the GRS53 only associated with lower HDL-cholesterol concentrations (ß = -0.007 ± 0.003 mmol/l; p = 1.79 × 10-2). CONCLUSIONS/INTERPRETATION: An adult-based GRS comprising 53 insulin resistance susceptibility SNPs associates with insulin resistance, markers of the metabolic syndrome and altered fat distribution in a sample of Danish children and adolescents who were overweight or obese.

Genome-wide association analysis identifies three new susceptibility loci for childhood body mass index.

A large number of genetic loci are associated with adult body mass index. However, the genetics of childhood body mass index are largely unknown. We performed a meta-analysis of genome-wide association studies of childhood body mass index, using sex- and age-adjusted standard deviation scores. We included 35 668 children from 20 studies in the discovery phase and 11 873 children from 13 studies in the replication phase. In total, 15 loci reached genome-wide significance (P-value < 5 × 10(-8)) in the joint discovery and replication analysis, of which 12 are previously identified loci in or close to ADCY3, GNPDA2, TMEM18, SEC16B, FAIM2, FTO, TFAP2B, TNNI3K, MC4R, GPR61, LMX1B and OLFM4 associated with adult body mass index or childhood obesity. We identified three novel loci: rs13253111 near ELP3, rs8092503 near RAB27B and rs13387838 near ADAM23. Per additional risk allele, body mass index increased 0.04 Standard Deviation Score (SDS) [Standard Error (SE) 0.007], 0.05 SDS (SE 0.008) and 0.14 SDS (SE 0.025), for rs13253111, rs8092503 and rs13387838, respectively. A genetic risk score combining all 15 SNPs showed that each additional average risk allele was associated with a 0.073 SDS (SE 0.011, P-value = 3.12 × 10(-10)) increase in childhood body mass index in a population of 1955 children. This risk score explained 2% of the variance in childhood body mass index. This study highlights the shared genetic background between childhood and adult body mass index and adds three novel loci. These loci likely represent age-related differences in strength of the associations with body mass index.

Impaired fasting glucose and the metabolic profile in Danish children and adolescents with normal weight, overweight, or obesity.

OBJECTIVE: Whether the definitions of impaired fasting glucose (IFG) from the American Diabetes Association (ADA) and the World Health Organization (WHO) differentially impact estimates of the metabolic profile and IFG-related comorbidities in Danish children and adolescents is unknown. METHODS: Two thousand one hundred and fifty four (979 boys) children and adolescents with overweight or obesity (median age 12 years) and 1824 (728 boys) children with normal weight (median age 12 years) from The Danish Childhood Obesity Biobank were studied. Anthropometrics, blood pressure, puberty, and fasting concentrations of glucose, insulin, glycosylated hemoglobin (HbA1c), and lipids were measured. RESULTS: About 14.1% of participants with overweight or obesity exhibited IFG according to the ADA and 3.5% according to the WHO definition. Among individuals with normal weight, the corresponding prevalences were 4.3% and 0.3%. IFG was associated with a higher systolic blood pressure, higher concentrations of HbA1c, insulin, C-peptide (P < .0001) and triglycerides (P = .03), and lower HOMA2-IS and HOMA2-B (P < .0001) independent of sex, age, puberty, waist-to-height ratio, and degree of obesity. Furthermore, IFG was associated with a higher risk for hypertension (OR = 1.66 [95%CI: 1.21; 2.28], P = .002) and dyslipidemia (OR = 1.90 [95%CI: 1.38; 2.56], P < .0001) compared with the group without IFG independent of age, sex, and puberty. CONCLUSIONS: The prevalence of IFG, when applying the ADA criterion compared with the WHO criterion, was 4 times higher in individuals with overweight and obesity and 14 times higher in individuals with normal weight in this study sample of children and adolescents. IFG was associated with a higher risk of hypertension and dyslipidemia compared with their normoglycemic peers regardless of the definition applied.

The effect of impaired glucose metabolism on weight loss in multidisciplinary childhood obesity treatment.

OBJECTIVE: To investigate whether children and adolescents exhibiting an impaired glucose metabolism are more obese at treatment entry and less likely to reduce their degree of obesity during treatment. METHODS: The present study is a longitudinal observational study, including children and adolescents from the Children's Obesity Clinic, Holbaek, Denmark. Anthropometrics, pubertal development, socioeconomic status (SES), and fasting concentrations of plasma glucose, serum insulin, serum C-peptide, and whole blood glycosylated hemoglobin (HbA1c) were collected at treatment entry and at follow-up. Proxies of Homeostasis Model Assessment 2-insulin sensitivity (HOMA2-IS) and Homeostasis Model Assessment 2-ß-cell function (HOMA2-B) were calculated with the Homeostasis Model Assessment 2 program. RESULTS: In total, 569 (333 boys) patients, median 11.5 years of age (range 6-22 years), and median body mass index (BMI) z-score 2.94 (range 1.34-5.54) were included. The mean BMI z-score reduction was 0.31 (±0.46) after 13 months (range 6-18) of treatment. At treatment entry, patients with impaired estimates of glucose metabolism were more obese than normoglycemic patients. Baseline concentration of C-peptide was associated with a lower weight loss during treatment in girls (P = .02). Reduction in the insulin concentrations was associated with reduction in BMI z-score in both sexes (P < .0001, P = .0005). During treatment, values of glucose, HbA1c, HOMA2-IS, and HOMA2-B did not change or impact the treatment outcome, regardless of age, sex, SES, or degree of obesity at treatment entry. CONCLUSION: The capability to reduce weight during multidisciplinary treatment in children and adolescents with overweight/obesity is not influenced by an impaired glucose metabolism at study entry or during the course of treatment.

Immunoproteomic analysis of house dust mite antigens reveals distinct classes of dominant T cell antigens according to function and serological reactivity.

BACKGROUND: House dust mite (HDM) allergens are a common cause of allergy and allergic asthma. A comprehensive analysis of proteins targeted by T cells, which are implicated in the development and regulation of allergic disease independent of their antibody reactivity, is still lacking. OBJECTIVE: To comprehensively analyse the HDM-derived protein targets of T cell responses in HDM-allergic individuals, and investigate their correlation with IgE/IgG responses and protein function. METHODS: Proteomic analysis (liquid chromatography-tandem mass spectrometry) of HDM extracts identified 90 distinct protein clusters, corresponding to 29 known allergens and 61 novel proteins. Peripheral blood mononuclear cells (PBMC) from 20 HDM-allergic individuals were stimulated with HDM extracts and assayed with a set of ~2500 peptides derived from these 90 protein clusters and predicted to bind the most common HLA class II types. 2D immunoblots were made in parallel to elucidate IgE and IgG reactivity, and putative function analyses were performed in silico according to Gene Ontology annotations. RESULTS: Analysis of T cell reactivity revealed a large number of T cell epitopes. Overall response magnitude and frequency was comparable for known and novel proteins, with 15 antigens (nine of which were novel) dominating the total T cell response. Most of the known allergens that were dominant at the T cell level were also IgE reactive, as expected, while few novel dominant T cell antigens were IgE reactive. Among known allergens, hydrolase activity and detectable IgE/IgG reactivity are strongly correlated, while no protein function correlates with immunogenicity of novel proteins. A total of 106 epitopes accounted for half of the total T cell response, underlining the heterogeneity of T cell responses to HDM allergens. CONCLUSIONS AND CLINICAL RELEVANCE: Herein, we define the T cell targets for both known allergens and novel proteins, which may inform future diagnostics and immunotherapeutics for allergy to HDM.