Dyslipidemia is reported in 27 - 43% of children and adolescents with overweight/obesity and tracks into adulthood, increasing the risk of cardiovascular morbidity. Cut-off values for fasting plasma ...lipid concentrations are typically set at fixed levels throughout childhood. The objective of this cross-sectional study was to generate fasting plasma lipid references for a Danish/North-European White population-based cohort of children and adolescents, and investigate the prevalence of dyslipidemia in this cohort as well as in a cohort with overweight/obesity.
A population-based cohort of 2141 (1275 girls) children and adolescents aged 6 - 19 (median 11.5) years was recruited from 11 municipalities in Denmark. Additionally, a cohort of children and adolescents of 1421 (774 girls) with overweight/obesity aged 6 - 19 years (median 11.8) was recruited for the study. Height, weight, and fasting plasma lipid concentrations were measured on all participants. Smoothed reference curves and percentiles were generated using the Generalized Additive Models for Location Scale and Shape package in the statistical software R.
In the population-based cohort, plasma concentrations of total cholesterol (TC) (P < 0.05), low-density lipoprotein cholesterol (LDL) (P < 0.005), and high-density lipoprotein cholesterol (HDL) (P < 0.005) were higher in the youngest compared to the oldest tertile. Fasting plasma levels of triglycerides (TG) (P < 0.005) increased with age in both sexes. In boys, non-HDL was lower in the oldest compared to the youngest tertile (P < 0.0005). Concentrations of TC, LDL, non-HDL, and TG were higher (P < 0.05), and HDL lower (P < 0.05) in the cohort with overweight/obesity in both sexes and for all ages except for TC in the youngest girls. The overall prevalence of dyslipidemia was 6.4% in the population-based cohort and 28.0% in the cohort with overweight/obesity. The odds ratio for exhibiting dyslipidemia in the cohort with overweight/obesity compared with the population-based cohort was 6.2 (95% CI: 4.9 - 8.1, P < 2*10
).
Fasting plasma lipid concentrations change during childhood and adolescence and differ with sex and age. Children and adolescents with obesity have increased concentrations of circulating lipids and exhibit an increased prevalence of dyslipidemia.
The study is part of The Danish Childhood Obesity Biobank; ClinicalTrials.gov ID-no.: NCT00928473 retrospectively registered on June 25th 2009.
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.
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.
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).
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.
The body mass index (BMI) standard deviation score (SDS) may not adequately reflect changes in fat mass during childhood obesity treatment. This study aimed to investigate associations between BMI ...SDS, body composition, and fasting plasma lipid concentrations at baseline and during childhood obesity treatment.
876 children and adolescents (498 girls) with overweight/obesity, median age 11.2 years (range 1.6-21.7), and median BMI SDS 2.8 (range 1.3-5.7) were enrolled in a multidisciplinary outpatient treatment program and followed for a median of 1.8 years (range 0.4-7.4). Height and weight, body composition measured by dual-energy X-ray absorptiometry, and fasting plasma lipid concentrations were assessed at baseline and at follow-up. Lipid concentrations (total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), non-HDL, and triglycerides (TG)) were available in 469 individuals (264 girls). Linear regressions were performed to investigate the associations between BMI SDS, body composition indices, and lipid concentrations.
At baseline, BMI SDS was negatively associated with concentrations of HDL (p = 6.7*10-4) and positively with TG (p = 9.7*10-6). Reductions in BMI SDS were associated with reductions in total body fat percentage (p<2*10-16) and percent truncal body fat (p<2*10-16). Furthermore, reductions in BMI SDS were associated with improvements in concentrations of TC, LDL, HDL, non-HDL, LDL/HDL-ratio, and TG (all p <0.0001). Changes in body fat percentage seemed to mediate the changes in plasma concentrations of TC, LDL, and non-HDL, but could not alone explain the changes in HDL, LDL/HDL-ratio or TG. Among 81 individuals with available lipid concentrations, who increased their BMI SDS, 61% improved their body composition, and 80% improved their lipid concentrations.
Reductions in the degree of obesity during multidisciplinary childhood obesity treatment are accompanied by improvements in body composition and fasting plasma lipid concentrations. Even in individuals increasing their BMI SDS, body composition and lipid concentrations may improve.
Summary
Background
Diagnosis of nonalcoholic fatty liver disease in children and adolescents currently requires advanced or invasive technologies.
Objectives
We aimed to develop a method to improve ...diagnosis, using body composition indices and liver biochemical markers.
Methods
To diagnose non‐alcoholic fatty liver disease, 767 Danish children and adolescents underwent clinical examination, blood sampling, whole‐body dual‐energy X‐ray absorptiometry scanning and proton magnetic resonance spectroscopy for liver fat quantification. Fourteen variables were selected as a starting point to construct models, narrowed by stepwise selection. Individuals were split into a training set for model construction and a validation test set. The final models were applied to 2120 Danish children and adolescents to estimate the prevalence.
Results
The final models included five variables in different combinations: body mass index–standard deviation score, android‐to‐gynoid‐fat ratio, android‐regional fat percent, trunk‐regional fat percent and alanine transaminase. When validated, the sensitivity and specificity ranged from 38.6% to 51.7% and 87.6% to 91.9%, respectively. The estimated prevalence was 24.2%–35.3%. Models including alanine transaminase alongside body composition measurements displayed higher sensitivity.
Conclusions
Body composition indices and alanine transaminase can be used to estimate non‐alcoholic fatty liver disease, with 38.6%–51.7% sensitivity and 87.6%–91.9%, specificity, in children and adolescents with overweight (including obesity). These estimated a 24.2%–35.3% prevalence in 2120 patients.
Purpose To investigate the effects of a multidisciplinary childhood obesity treatment programme on subjective evaluations of psychosocial well-being and quality of life. Methods This longitudinal ...observational study included 1291 children, adolescents and young adults, 6-22 years of age, with overweight or obesity. At entry and after 2-82 months of obesity treatment, the patients evaluated the following domains of psychosocial well-being on a visual analogue scale: quality of life, mood, appetite, bullying, motivation for weight loss and body image satisfaction. The degree of overweight was calculated using a body mass index (BMI) standard deviation score (SDS) at each visit. Results At entry, the mean BMI SDS was 2.81 (range: 1.35-6.65, 95% confidence interval (95% CI): 2.44-3.18). After a median of 14 months of treatment, the median reduction in BMI SDS was 0.29 (95% CI: 0.26-0.31, p < 0.0001). Improvements were observed in the domains of quality of life, mood, appetite, bullying and body image satisfaction (p < 0.0001). Larger reductions in BMI SDS were associated with greater improvements in the domains of quality of life (p = 0.001), mood (p = 0.04) and body image satisfaction (p < 0.0001), independent of BMI SDS at entry. However, improvements in psychosocial well-being were also observed in those increasing their BMI SDS (n = 315). Conclusions In a large group of children and youths, psychosocial well-being improved during a multidisciplinary childhood obesity treatment programme, irrespective of the degree of obesity at treatment entry. Greater reductions in BMI SDS were associated with greater improvements in psychosocial well-being, but even in the group increasing their BMI SDS improvements were observed.
Ectopic fat deposition in liver and skeletal muscle tissue is related to cardiovascular disease risk and is a common metabolic complication in obese children. We evaluated the hypotheses of ectopic ...fat in these organs could be diminished following 1 year of multidisciplinary care specialized in childhood obesity, and whether this reduction would associate with changes in other markers of metabolic function.
This observational longitudinal study evaluated 40 overweight children and adolescents enrolled in a multidisciplinary treatment protocol at the Children's Obesity Clinic, Holbæk, Denmark. The participants were assessed by anthropometry, fasting blood samples (HbA1c, glucose, insulin, lipids, and biochemical variables of liver function), and liver and muscle fat content assessed by magnetic resonance spectroscopy at enrollment and following an average of 12.2 months of care. Univariate linear regression models adjusted for age, sex, treatment duration, baseline degree of obesity, and pubertal developmental stage were used for investigating possible associations.
The standard deviation score (SDS) of baseline median body mass index (BMI) was 2.80 (range: 1.49-3.85) and the median age was 14 years (10-17). At the end of the observational period, the 40 children and adolescents (21 girls) significantly decreased their BMI SDS, liver fat, muscle fat, and visceral adipose tissue volume. The prevalence of hepatic steatosis changed from 28 to 20 % (p = 0.26) and the prevalence of muscular steatosis decreased from 75 to 45 % (p = 0.007). Changes in liver and muscle fat were independent of changes in BMI SDS, baseline degree of obesity, duration of treatment, age, sex, and pubertal developmental stage.
A 1-year multidisciplinary intervention program in the setting of a childhood obesity outpatient clinic confers a biologically important reduction in liver and muscle fat; metabolic improvements that are independent of the magnitude of concurrent weight loss.
ClinicalTrials.gov registration number: NCT00928473 , the Danish Childhood Obesity Biobank. Registered June 25, 2009.
This cross sectional study aims to investigate the associations between ectopic lipid accumulation in liver and skeletal muscle and biochemical measures, estimates of insulin resistance, ...anthropometry, and blood pressure in lean and overweight/obese children.
Fasting plasma glucose, serum lipids, serum insulin, and expressions of insulin resistance, anthropometry, blood pressure, and magnetic resonance spectroscopy of liver and muscle fat were obtained in 327 Danish children and adolescents aged 8-18 years.
In 287 overweight/obese children, the prevalences of hepatic and muscular steatosis were 31% and 68%, respectively, whereas the prevalences in 40 lean children were 3% and 10%, respectively. A multiple regression analysis adjusted for age, sex, body mass index z-score (BMI SDS), and pubertal development showed that the OR of exhibiting dyslipidemia was 4.2 (95%CI: 1.8; 10.2, p = 0.0009) when hepatic steatosis was present. Comparing the simultaneous presence of hepatic and muscular steatosis with no presence of steatosis, the OR of exhibiting dyslipidemia was 5.8 (95%CI: 2.0; 18.6, p = 0.002). No significant associations between muscle fat and dyslipidemia, impaired fasting glucose, or blood pressure were observed. Liver and muscle fat, adjusted for age, sex, BMI SDS, and pubertal development, associated to BMI SDS and glycosylated hemoglobin, while only liver fat associated to visceral and subcutaneous adipose tissue and intramyocellular lipid associated inversely to high density lipoprotein cholesterol.
Hepatic steatosis is associated with dyslipidemia and liver and muscle fat depositions are linked to obesity-related metabolic dysfunctions, especially glycosylated hemoglobin, in children and adolescents, which suggest an increased cardiovascular disease risk.
Hypothyroidism is associated with obesity, and thyroid hormones are involved in the regulation of body composition, including fat mass. Genome-wide association studies (GWAS) in adults have ...identified 19 and 6 loci associated with plasma concentrations of thyroid stimulating hormone (TSH) and free thyroxine (fT4), respectively.
This study aimed to identify and characterize genetic variants associated with circulating TSH and fT4 in Danish children and adolescents and to examine whether these variants associate with obesity.
Genome-wide association analyses of imputed genotype data with fasting plasma concentrations of TSH and fT4 from a population-based sample of Danish children, adolescents, and young adults, and a group of children, adolescents, and young adults with overweight and obesity were performed (N = 1,764, mean age = 12.0 years range 2.5-24.7). Replication was performed in additional comparable samples (N = 2,097, mean age = 11.8 years 1.2-22.8). Meta-analyses, using linear additive fixed-effect models, were performed on the results of the discovery and replication analyses.
No novel loci associated with TSH or fT4 were identified. Four loci previously associated with TSH in adults were confirmed in this study population (PDE10A (rs2983511: β = 0.112SD, p = 4.8 ∙ 10-16), FOXE1 (rs7847663: β = 0.223SD, p = 1.5 ∙ 10-20), NR3C2 (rs9968300: β = 0.194SD), p = 2.4 ∙ 10-11), VEGFA (rs2396083: β = 0.088SD, p = 2.2 ∙ 10-10)). Effect sizes of variants known to associate with TSH or fT4 in adults showed a similar direction of effect in our cohort of children and adolescents, 11 of which were associated with TSH or fT4 in our study (p<0.0002). None of the TSH or fT4 associated SNPs were associated with obesity in our cohort, indicating no pleiotropic effects of these variants on obesity.
In a group of Danish children and adolescents, four loci previously associated with plasma TSH concentrations in adults, were associated with plasma TSH concentrations in children, suggesting comparable genetic determinants of thyroid function in adults and children.
•PTH, vitamin D, calcium, and phosphate measured in 2211 children and adolescents.•Biomarkers of bone metabolism vary with sex and age in a population-based cohort.•The concentration of vitamin D was ...lowest in February/March and highest in August.•Vitamin D insufficiency is common in high-latitude countries.•Almost half of the participants exhibited vitamin D insufficiency during winter.
Parathyroid hormone (PTH) and vitamin D are essential hormones in bone metabolism, especially during pediatric growth. Vitamin D insufficiency is often asymptomatic and is prevalent in high-latitude countries.
In a Danish population-based cohort of 2211 6–18-year-olds, sex- and age-specific pediatric reference values for fasting concentrations of intact serum PTH, vitamin D (25-hydroxycholecalciferol, 25-OH-D), total calcium, and phosphate were generated in accordance with Clinical and Laboratory Standards Institute (CLSI) EP28-A3c guidelines. The effect of season on these biomarkers of bone metabolism was evaluated.
In boys, PTH concentrations increased with age, while the vitamin D and phosphate concentrations decreased (all p < .001). In girls, a peak in PTH concentrations and a nadir in vitamin D concentrations were observed in the 10–14-year-olds (both p < .001). Calcium and phosphate decreased with age for both sexes (girls: both p < .001; boys calcium: p < .05, boys phosphate: p < .001). Vitamin D was 20% lower in winter than summer for both sexes (both p < .001). Individuals with vitamin D sufficiency (25-OH-D > 50 nmol/L) exhibited a 5% lower level of PTH compared to the whole sample population (p < .001).
The concentrations of PTH, vitamin D, calcium, and phosphate vary during childhood and adolescence, and is dependent on sex and season. These factors should be considered when screening for and treating imbalances in bone metabolism.
Thyroid abnormalities are common in obese children. The aim of the present study was to examine the prevalence of subclinical hypothyroidism (SH) and to determine how circulating thyroid hormone ...concentrations correlate with anthropometrics in Danish lean and obese children and adolescents.
In this cross-sectional study, we included 3006 children and adolescents, aged 6-18 years, from the Registry of the Danish Childhood Obesity Biobank. The overweight/obese group (n=1796) consisted of study participants with a body mass index (BMI) standard deviation score (SDS) ≥1.28. The control group (n=1210) comprised lean children with a BMI SDS <1.28. All participants were characterized by anthropometrics (weight, height, and waist circumference) and fasting serum concentrations of thyroid-stimulating hormone (TSH), free triiodothyronine, and free thyroxine (fT4) at baseline.
The prevalence of SH was higher among overweight/obese compared to lean study participants (10.4% vs. 6.4%, p=0.0001). In the overweight/obese group, fasting serum TSH concentrations were associated positively with BMI SDS (p<0.0001) and waist-height ratio (WHtR) (p<0.0001) independent of age, sex, and pubertal developmental stage, whereas fasting serum fT4 concentrations were associated positively only with WHtR. The odds ratio of exhibiting SH was 1.8 when being overweight/obese compared with lean (p=0.0007) and 1.8 when presenting with a WHtR >0.5 (p=0.0003).
The prevalence of SH was higher among overweight/obese study participants. The positive correlations of circulating TSH and fT4 with WHtR suggest that central obesity, independent of the overall degree of obesity, augments the risk of concurrent thyroid abnormalities in children and adolescents with obesity.
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