Danish Adolescents Research Articles

National multi-centre study found a low prevalence of severely impaired lung function in children and adolescents.

As no data to our knowledge exist, the aim of the study was to describe the national prevalence and characteristics of Danish children and adolescents with severely impaired lung function. We performed a descriptive, cross-sectional Danish multi-centre study. Children and adolescents between 6 and 18years old demonstrating severely impaired lung function from 2015 to 2018, defined by forced expiratory volume in 1second (FEV1 ) <60% or who had lung transplantation, were eligible for inclusion. This study included 113 children with a mean age (standard deviation) of 12.9years (3.5years). The prevalence of severely impaired lung function was approximately 13 in 100,000. The mean (standard deviation) FEV1 was 46.1% (10.1%) of predicted, and z-score was -4.5 (0.8). The most frequent diagnosis was cystic fibrosis (20.4%), followed by asthma (19.5%) and bronchiolitis obliterans (16.8%), while almost 25% had different elements of airway malformations or non-pulmonary conditions. Two adolescents with cystic fibrosis underwent lung transplantation. The estimated prevalence of severely impaired lung function in Danish children and adolescents was low, and extremely, few children underwent lung transplantation. The most frequent diagnosis was cystic fibrosis, while almost 25% had different elements of airway malformations or non-pulmonary conditions, which may require clinical attention.

Youth's personal relationships, psychological symptoms, and the use of different substances: A population-based study.

Background: Externalising symptoms and peer influence are well-established predictors of youth's substance use in general. However, there is little integrative research that compares the relative contribution of psychological and social relationship characteristics as predictors of the use of specific substances among youth in different developmental stages. Methods: A representative sample of Danish adolescents (n = 1,168) and emerging adults (EA; n = 1,878) reported last-month prevalence use of cigarettes, cannabis, and other illicit drugs (OID), and four indices of alcohol use. Predictor variables included internalising and externalising symptoms, and major characteristics of the youth's relationships (e.g., parental drug use, number of close friends). Results: Having a close friend who used illicit drugs, and high externalising symptoms, predicted the risk for using all substances across both age groups. Alcohol use was more consistently related to peer-related variables than to symptoms. Smoking cigarettes, cannabis use, and OIDs use were related to peer and symptom variables. Age group moderated some associations. Parental separation was related more strongly to alcohol use among adolescents than among EA, and higher internalising symptoms were more strongly related to smoking and using OIDs among adolescents than among EA. Male EAs had higher risk for using alcohol than female EAs. Conclusion: Beyond having a close friend who used illicit drugs, and externalising problems, the use of each substance was better explained by a different group of variables. There were few but important moderations by age group. The findings highlight the need for research on risk factors for substance use that is developmentally sensitive, particularly for adolescents, and for specific substances. Thus, interventions and policies should address social, developmental, and psychological factors.

Association of serum surfactant protein D and SFTPD gene variants with asthma in Danish children, adolescents, and young adults.

BackgroundSurfactant Protein D (SP‐D) is a pattern recognition molecule belonging to the family of collectins expressed in multiple human organ systems, including the lungs. Previous studies have shown that SP‐D levels in bronchoalveolar lavage samples decrease and serum levels increase in patients suffering from asthma, possibly due to a combination of induced SP‐D synthesis and decreased air–blood barrier integrity. The aims of this study were to investigate whether serum levels of SP‐D and common variants in the SP‐D gene were associated with asthma in adolescents and young adults.MethodsProspective observational study including 449 adolescents and young adults (age 11–27 years) previously diagnosed with asthma during a 2‐year period from 2003 to 2005 (0–16 years). At follow‐up from 2016 to 2017, 314 healthy controls with no history of asthma were recruited. Serum SP‐D was analyzed on samples obtained at baseline as well as samples obtained at follow‐up. SP‐D genotyping was performed for rs721917, rs2243639, and rs3088308.ResultsNo differences were found in mean levels of sSP‐D and SFTPD genotype among subjects with current asthma, no current asthma, and controls. Serum SP‐D and SFTPD genotype were not associated with any clinical parameters of asthma. Furthermore, baseline sSP‐D was not associated with asthma at follow‐up.ConclusionSerum surfactant protein D and common SP‐D gene variants were not associated with asthma in Danish adolescents and young adults with mild to moderate asthma. Serum surfactant protein D did not demonstrate any value as a clinical biomarker of asthma.

The importance of adverse childhood experiences for labour market trajectories over the life course: a longitudinal study

BackgroundTransitioning from school to work is important in influencing people’s trajectories throughout their life course. This study investigated the extent to which adverse childhood experiences (ACEs) were associated with differences in labour market trajectories for young adults in the context of a Nordic child care regime with low levels of child poverty.MethodsInformation on labour market participation, educational events, and public transfer records was recoded into seven state spaces for each month between ages 16 and 32 for a cohort of Danish adolescents born in a rural county in 1983 (N = 3373). Cluster analysis of the sequences using the optimal matching algorithm was used to identify groups with similar trajectories. Multinomial regression was used to assess the association between self-reported ACEs and cluster membership, taking gender and family of origin into account.Results‘In employment’ was the state space in which the young adults spent the most time over their early life courses (mean: 85 out of 204 months; 42%). Cluster analysis identified three clusters. Cluster 3 was most distinct, where the mean time ‘outside the labour market’ was 149 months (73%), and only 17 months (8%) were spent ‘in employment’. Cumulative ACEs increased the probability of being included in Cluster 3 (OR: 1.51). Experiencing parental divorce (OR: 3.05), witnessing a violent event (OR: 3.70), and being abused (OR: 5.64) were most strongly associated with Cluster 3 membership.ConclusionsLabour market trajectories among adolescents with a higher number of ACEs consisted of more time outside the labour market, compared to adolescents who had experienced fewer adversities. The lasting consequences of childhood adversity should be taken more into account in welfare policies, even in countries such as Denmark, with high social security levels and high-quality universal childcare.

Population-based Incidence of Myopericarditis After COVID-19 Vaccination in Danish Adolescents.

In this prospective nationwide multicenter study from Denmark, myopericarditis after Pfizer-BioNTech mRNA COVID-19 vaccination was identified in 13 males and 2 females between May 15 and September 15, 2021, among 133,477 vaccinated males and 127,857 vaccinated females 12–17 years of age, equaling 97 males and 16 females per million. In conclusion, the incidence of myopericarditis after COVID-19 vaccination among males appears higher than reports from the United States.

Impact of timing of PERT on gastrointestinal symptoms in Danish children and adolescents with CF.

Gastrointestinal (GI) symptoms are often reported by CF patients. Despite a proven relation to exocrine pancreatic insufficiency (PI), it remains unclear whether GI symptoms are related to the timing of pancreatic enzyme replacement therapy (PERT). Whereas most international recommendations suggest administration of PERT at the beginning of meals, it has not been studied whether such a proceeding is associated with lower burden of symptoms. Thirty CF patients aged 0-17years of age with PI were randomised to four weeks of PERT prior to meals followed by four weeks of PERT after meals or vice versa. Using the CF-specific validated CFAbd-Score, abdominal pain, dysfunctional bowel habits and Quality of Life (QoL) related to GI symptoms were assessed in relation to the timing of PERT. Data were analysed using a linear mixed model. There was no significant difference regarding abdominal pain, bowel habits or QoL related to GI symptoms when timing of PERT was changed from prior to after meals. No significant difference was found when administration mode of PERT changed from prior to after meals or vice versa. However, after an individual assessment, some patients may profit from changing administration mode of PERT from prior to after meals.

Obesity treatment effect in danish children and adolescents carrying melanocortin-4 receptor mutations

This study investigated the influence of MC4R variants on treatment effectiveness in a large cohort undergoing an outpatient treatment program. Carriers of MC4R loss-of-function (LoF) variants showed a lack of improvement in BMI, in contrast to non LoF carriers.

Exceeding 2-h sedentary time per day is not associated with moderate to severe spinal pain in 11- to 13-year-olds: a cross-sectional analysis.

Neck, mid-back and low back pain, collectively known as spinal pain, become more common with increasing age across childhood and adolescence. A common belief among the general community is that sedentary time, including screen time, in adolescents is associated with spinal pain. We aimed to investigate whether exceeding 2-h of sedentary time per day is associated with moderate to severe spinal pain in a sample of Danish adolescents aged 11-13years. We performed a cross-sectional analysis of the SPACE study baseline data (2010). Adolescents self-reported their spinal pain (outcome) via the Young Spine Questionnaire and duration of engagement in sedentary behaviours (exposure). We provide estimates of associations as odds ratios with 95% confidence intervals, stratified by age and sex. The sample comprised 1,303 adolescents (48.7% female, mean age 12.5years, range 10.9-14.3years). Approximately 9 out of 10 adolescents exceeded 2-h sedentary time on weekdays outside of school(88.9%) and weekend days(89.9%). Close to one-quarter, 23.3% (95%CI: 21.0-25.6), of participants experienced moderate to severe spinal pain. We found no association between exceeding 2-h sedentary time per day and experiencing moderate to severe spinal pain; odds ratios ranged from 0.34 (95%CI: 0.04-3.20) to 4.65 (95%CI: 0.26-82.44).Conclusion: We found no association between exceeding 2- or 5-h of sedentary time per day and moderate to severe spinal pain in this sample of 11-13-year-old Danish adolescents. Our cross-sectional analysis does not consider thelongitudinal or complex sequences of events necessary to address predictive or causal questions. What is Known: • Up to a third of adolescents experience moderate to severe spinal pain, predisposing them to chronic spinal pain in adulthood. • Frequent and excessive sedentary time is associated with poor overall health in adolescents; there is conflicting evidence to suggest whether it is also related to spinal pain. What is New: • We found no association between sedentary time and moderate to severe spinal pain in 11- to 13-year-oldDanes.

Alcohol drinking patterns and occurrence of genital warts among Danish adolescents

BackgroundUnder the influence of alcohol adolescents are more prone to engage in unprotected sex, which increases the risk of acquiring genital warts. The study aim was to examine whether alcohol consumption among adolescents is associated with acquiring genital warts. MethodsHealth behavior data were extracted from the Danish National Youth Study 2014. Complete data were available for 63,648 students. Number of binge drinking episodes in the past 30 days, frequency of drinking on weekends and total number of drinks consumed during 7-day week were collected by a questionnaire. Information on genital warts for the period between filling the questionnaire in 2014 and December 31, 2018 was retrieved from the Danish National Prescription Register and Danish National Patient Register. ResultsAdjusted analysis showed that, compared to students who did not drink alcohol, increasing frequency of binge drinking in the past 30 days was independently associated with greater hazard of acquiring genital warts (1−3 times hazard ratio [HR]: 1.36, 95 % confidence interval [CI]: 1.09−1.69; 4−6 times HR: 1.55, 95 % CI: 1.22−1.96; >6 times HR: 1.84, 95 % CI 1.39−2.45). Compared to students who did not drink alcohol, consistent alcohol drinking every weekend was associated with greater risk of developing genital warts (HR: 1.62, 95 % CI: 1.20−2.17). Total weekly number of alcohol drinks consumed was not associated with occurrence of genital warts. ConclusionIncreased alcohol intake was associated with occurrence of genital warts over 4 year of follow-up. There is an urgent need for change of excessive alcohol intake tendencies among adolescents.

Who are the young users of tobacco products? Prevalence and characteristics of Danish adolescents who have either smoked cigarettes, used alternative tobacco products, or used both.

Aims:We examined characteristics (smoking in social relations, binge drinking, and well-being measures) of Danish 13-year-olds in relation to their tobacco use patterns. Ever use of cigarettes exclusively, ever use of alternative tobacco products (ATPs; e-cigarettes, snus, or waterpipe) exclusively, and use of both cigarettes and ATPs were studied.Methods:We used self-reported data from students at 46 Danish schools in 2017 comprising 2,307 students (response rate = 86%). Multi-level logistic regression analyses were used to examine the associations between student characteristics and the odds for having ever used any tobacco products, smoked cigarettes exclusively, used ATPs exclusively, or used both cigarettes and ATPs compared with never use of any tobacco products. Unadjusted estimates and estimates adjusted for gender were reported.Results:A significant minority of youth (13.2%) had used one or more tobacco products. Of these, 2.0% had exclusively smoked cigarettes, 7.2% had exclusively used ATPs, and 4.0% had used both. Findings showed that all included characteristics (families’ and friends’ smoking, binge drinking, and well-being characteristics) were associated with using any tobacco product; however, students with friends who smoked, had been binge drinking, and had low well-being at home had notably higher odds for having both smoked cigarettes and used ATPs compared to the other tobacco use patterns.Conclusion:ATPs were popular among Danish adolescents compared with conventional cigarettes. Thus, prevention efforts among adolescents should not merely focus on the health risks of conventional cigarette smoking but also on ATPs. Students with diverse tobacco use patterns were similar on various characteristics. However, findings indicate that adolescents who had used both conventional cigarettes and ATPs constitute a more risk-averse group in special need of prevention efforts. Gender did not markedly influence the results. These findings may help future strategies aiming at the youngest adolescents at risk of using tobacco products.

Translation, validity and reliability of the Danish version of the Adolescent Insomnia Questionnaire.

Background: The Adolescent Insomnia Questionnaire (AIQ), English version, is the only validated screening measure developed specifically to identify insomnia symptoms in adolescents. To date, no specific screening tool for adolescent insomnia is present in Danish language. The aim of this study was to translate and validate the AIQ in a sample of Danish adolescents. Methods: The AIQ underwent a process of forward-backward translation and pilot testing. Subsequently, data were collected at baseline and two-week follow-up from adolescents aged 11-19, who completed both the AIQ and an available adult measure of insomnia (the Athens Insomnia Scale, AIS). The internal consistency, test-retest reliability and convergent validity were assessed. Exploratory factor analysis was conducted to identify the latent factors underlying the questionnaire. Results: At baseline 185 adolescents (18% males and 82% females, mean age 16.0 years) and 102 (55.1%) at two-week follow-up completed the questionnaires. The AIQ showed excellent internal consistency for the total score (Cronbach's a: 0.88) and good convergent validity with the AIS total score (Pearson's correlation value= 0.86, P<0.001). The test-retest reliability at two weeks was very satisfactory (ICC coefficient = 0.89; 95% CI 0.84, 0.92). Results from the exploratory factor analysis identified a three-model solution corresponding to the same three-model solution identified within the original development sample. Conclusions: The Danish version of the AIQ demonstrated satisfactory psychometric properties in terms of internal consistency, test-retest reliability and validity, which supports its use as a screening tool for the identification of insomnia symptoms in adolescents, including Danish-speaking adolescents.

Translation, validity and reliability of the Danish version of the Adolescent Insomnia Questionnaire

Background: The Adolescent Insomnia Questionnaire (AIQ), English version, is the only validated screening measure developed specifically to identify insomnia symptoms in adolescents. To date, no specific screening tool for adolescent insomnia is present in Danish language. The aim of this study was to translate and validate the AIQ in a sample of Danish adolescents. Methods: The AIQ underwent a process of forward-backward translation and pilot testing. Subsequently, data were collected at baseline and two-week follow-up from adolescents aged 11-19, who completed both the AIQ and an available adult measure of insomnia (the Athens Insomnia Scale, AIS). The internal consistency, test-retest reliability and convergent validity were assessed. Exploratory factor analysis was conducted to identify the latent factors underlying the questionnaire. Results: At baseline 185 adolescents (18% males and 82% females, mean age 16.0 years) and 102 (55.1%) at two-week follow-up completed the questionnaires. The AIQ showed excellent internal consistency for the total score (Cronbach's a: 0.88) and good convergent validity with the AIS total score (Pearson’s correlation value= 0.86, P<0.001). The test-retest reliability at two weeks was very satisfactory (ICC coefficient = 0.89; 95% CI 0.84, 0.92). Results from the exploratory factor analysis identified a three-model solution corresponding to the same three-model solution identified within the original development sample. Conclusions: The Danish version of the AIQ demonstrated satisfactory psychometric properties in terms of internal consistency, test-retest reliability and validity, which supports its use as a screening tool for the identification of insomnia symptoms in adolescents, including Danish-speaking adolescents.

High Prevalence of Celiac Disease Among Danish Adolescents: A Population-based Study.

The objective of this study was to establish an unselected cohort of Danish adolescents and estimate the prevalence of undiagnosed celiac disease (CeD). The Glutenfunen cohort participants were recruited from an unselected subsample of the Danish National Birth Cohort, defined as participants living in the Island of Funen, Denmark. We invited all 7431 eligible participants in the age range of 15 to 21 years to a clinical visit. CeD diagnosis was based on screening with IgA transglutaminase antibodies (TG2-IgA) and if positive, was followed by duodenal biopsies compatible with CeD (Marsh 2-3). We calculated the prevalence of CeD in the Glutenfunen cohort as the number of CeD cases diagnosed before and during the study divided by the number of participants in the Glutenfunen cohort. We included 1266 participants in the Glutenfunen cohort (17%, 1266/7431). 1.1% (14 of 1266 participants) had CeD diagnosed before entering the cohort and based on the Danish National Patient Register, 0.2% of the nonparticipants (14 of 6165) had a diagnosis of CeD. In total, 2.6% (33 participants) had TG2 IgA above the upper limit of normal. Nineteen participants had duodenal biopsies compatible with CeD. The prevalence of CeD in the Glutenfunen cohort was 2.6% [(14 + 19)/1266]. Our study suggests that CeD is much more common than expected among Danish adolescents, comparable to other European countries, and that the majority were asymptomatic or oligosymptomatic and were only found because of the screening procedure.

Adolescent gambling advertising awareness: A national survey

AbstractWhile influence of gambling advertisements on adolescents in some jurisdictions is recognised as an important public health issue, research examining this influence is currently limited. The present study examined gambling advertising awareness among adolescents, how they perceive gambling advertisement's impact, and how gambling advertisement awareness relates to adolescent's gambling behaviour. A sample of Danish adolescents (n = 1137) aged 12–16 were surveyed using a self‐administered web questionnaire. It was found that (a) participants reported high exposure to gambling advertising with males reporting higher exposure to advertising than females, (b) the general self‐perceived impact of these advertisements was relatively low, and (c) self‐perceived impact of gambling advertising was associated with monetary spending on gambling activities and at‐risk or a problematic gambling. Restrictions on gambling advertisements and collaboration between national gambling authorities with social media platforms in order to identify and remove youth‐targeted gambling advertisements were specified as relevant policy implications.

Yes I can cook a fish; effects of a five week sensory-based experiential theme course with fish on 11- to 13- year old children’s food literacy and fish eating behaviour – A quasi-experimental study

Danish early-phase adolescents only consume one-third of the officially recommended amount of fish. The objective of this study is to investigate the effect of a five week sensory-based experiential theme course with fish on 11- to 13-year old early-phased adolescents’ food literacy and acceptance of fish. Study design was a quasi-experimental intervention. 32 Food Knowledge school classes were recruited from the eastern part of Denmark. Classes were assigned to intervention group (n = 185), control group 1 (n = 123), only baseline and follow-up survey, or control group 2 (n = 75): one oral lecture between baseline and follow-up survey. Mixed methods strategy was applied: baseline and follow-up survey, participant observation, telephone-, and group interviews. Before between study group analysis control groups were pooled. The following key effects of the intervention were observed: knowledge on fish and cooking increased within specific areas, skills related to fish and cooking increased, especially in girls. Furthermore, the social dimension and helping each other were important elements. In the intervention group no positive effects were observed for liking or assessment of fish disgust; however, theme course evaluation showed that 47% had become curious on tasting other kinds of fish and 38% stated a higher liking for fish after participation. Furthermore, teachers reported an increase in acceptance of fish in the children as a result of participating. In conclusion food literacy and fish acceptance were increased through participation in a five week sensory-based experiential theme course with fish.

Reference intervals in Danish children and adolescents for bone turnover markers carboxy-terminal cross-linked telopeptide of type I collagen (β-CTX), pro-collagen type I N-terminal propeptide (PINP), osteocalcin (OC) and bone-specific alkaline phosphatase (bone ALP)

Bone turnover markers (BTM) are gaining ground in clinical practice but to fully use their potential there is a need for establishing valid reference intervals (RI). Consequently, the purpose of the study was to establish general RI as well as suggested clinical RI for carboxy-terminal cross-linked telopeptide of type I collagen (β-CTX), pro-collagen type I N-terminal propeptide (PINP), osteocalcin (OC) and bone-specific alkaline phosphatase (bone ALP) in children and adolescents. BTM were measured on Danish children and adolescents participating in the CHAMPS-study DK. A total of 762 participants were included (8-18years, 50.4% girls) contributing a total of 1410 study visits. The RI was calculated based on 2-years age spans. Participants with biochemical signs of metabolic bone disease were excluded. The differences in RI between age groups clearly reflect changes in growth with an initial increase in BTM, greatest in boys, and a subsequent decrease most pronounced in girls. β-CTX and PINP are markers most affected by these changes, compared to OC and bone ALP. The suggested clinical 95% RI included participants with vitamin D insufficiency but no biochemical signs of metabolic bone disease which did not markedly alter the RI. RI for β-CTX, PINP, OC and bone ALP varies with age and sex. β-CTX and PINP which reflect bone resorption and formation processes are mostly affected by these changes. We suggest a set of clinically applicable 95% RI for the four BTM to heighten the usefulness and generalizability of the RI.

Places to Smoke: Exploring Smoking-Related Practices among Danish Adolescents.

Several established school smoking prevention initiatives involve restrictions on places to smoke. The focus on tobacco control in schools is due to the risk of smoking initiation during adolescence and the perception of this life stage as a period of time when health behavior is established. Hence, this period of time is considered to be ideal for health-promoting initiatives. This paper is part of an ethnographic study on adolescents’ perceptions of tobacco use. Focus groups and field observations were used to explore adolescents’ smoking-related practices related to smoking bans at schools. The findings show that smoking, as a place-based practice, is influenced by locally embedded rules and carries social implications resulting in a distinction between smokers and non-smokers. The distinction between smokers and non-smokers contributes to the retention of a stereotypical view of smokers and, moreover, stigmatizes smokers. According to this, restrictions on places to smoke within the school should be considered carefully in order to avoid stigma or ethical issues.

Prevalence of Aggregatibacter actinomycetemcomitans and Periodontal Findings among 14 to 15-Year Old Danish Adolescents: A Descriptive Cross-Sectional Study.

Aggregatibacter actinomycetemcomitans (Aa) is a keystone pathogen associated with periodontitis in adolescents. The knowledge on the prevalence of Aa and periodontitis among adolescents in Northern Europe is sparse. A total of 525 14- to 15-year-old adolescents from the municipality of Aarhus, Denmark, underwent a full-mouth clinical examination. Plaque score (PS), bleeding on probing (BOP), probing pocket depth (PPD), and clinical attachment loss (CAL) were recorded. Subgingival plaque samples (SPS) and stimulated saliva samples (SSS) were collected and analyzed for the presence of JP2 and non-JP2 genotypes of Aa using real-time PCR. A total of 70 (13.3%) individuals were positive for Aa, with 17 found in SPS, 19 in SSS, and 35 in both. The highly leukotoxic JP2 genotype of Aa was not detected. The individuals positive for Aa in both SPS and SSS had poorer periodontal outcomes (PPD and CAL) than individuals without Aa and individuals carrying Aa in either SPS or SSS only. In conclusion, 13% of 14- to 15-year-old Danish adolescents were positive for Aa, and the presence of Aa in both SPS and SSS was associated with poorer periodontal outcomes.

User Experiences with a Virtual Alcohol Prevention Simulation for Danish Adolescents.

This pilot study explores 31 Danish adolescent user experiences for the newly developed virtual party simulation app—Virtual Reality (VR) FestLab. The main objective of this study was to investigate usability for VR FestLab, which aims to improve alcohol resistance skills for Danish adolescents. A secondary objective was to understand gameplay experiences. The study is a mixed method study that draws on questionnaire data (n = 31) and focus group interviews (n = 10) of boarding school students participating in the pilot study. Descriptive statistics were used to examine quantitative data, and qualitative data were analyzed thematically. Quantitative findings indicated that gameplay experiences of the VR simulation were positive, and all User Experience Questionnaire (UEQ) items were answered positively. The focus group interviews showed that adolescents found the simulation to be realistic. Feedback indicated that the group pressure experienced in the simulation was regarded to be less than in real life. Adolescents had varying approaches to playing the VR simulation, they thought the quality of the simulation was good, and only a few users experienced technical difficulties. These initial study findings indicate that VR FestLab is a promising tool for the prevention of alcohol use among adolescents.

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

ObjectivesTo 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.MethodsUsing 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.ResultsOf 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).ConclusionAmong 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.