Study protocol: DexaDays-2, hydrocortisone for treatment of dexamethasone-induced neurobehavioral side effects in pediatric leukemia patients: a double-blind placebo controlled randomized intervention study with cross-over design.

BACKGROUND: Dexamethasone, a highly effective drug in treating pediatric acute lymphoblastic leukemia (ALL), can induce serious neurobehavioral side effects. These side effects are experienced by patients and parents as detrimental with respect to health related quality of life (HRQoL). Based on previous studies, it has been suggested that neurobehavioral side effects are associated to cortisol depletion of the mineralocorticoid receptor in the brain. Our previously reported randomized controlled trial, the Dexadagen study (NTR3280), suggests that physiological hydrocortisone addition during dexamethasone treatment may overcome clinically relevant neurobehavioral problems in patients who experience these problems during dexamethasone treatment. With our current study, we aim to replicate these results in a targeted larger sample before further implementing this intervention into standard of care. METHODS: In a national center setting, pediatric ALL patients between 3 and 18 years are enrolled in an Identification study, which identifies patients with clinically relevant dexamethasone-induced neurobehavioral side effects using the Strengths and Difficulties Questionnaire (SDQ). Contributing factors, such as genetic susceptibility, dexamethasone pharmacokinetics as well as psychosocial and family factors are studied to determine their influence in the inter-patient variability for developing dexamethasone-induced neurobehavioral side effects. Patients with clinically relevant problems (i.e. a rise of ≥ 5 points on the SDQ Total Difficulties Score after 5 days of dexamethasone) are subsequently included in a randomized double-blind placebo-controlled trial with a cross-over design. They receive two courses placebo followed by two courses hydrocortisone during dexamethasone treatment, or vice versa, each time at least 16 days without study medication in between. The primary endpoint is change in SDQ score. The secondary endpoints are sleep (measured with actigraphy and the Sleep Disturbance Scale for Children) and HRQoL (Pediatric Quality of Life Questionnaire). DISCUSSION: The results of our current study may contribute to the management of future ALL patients who experience dexamethasone-induced neuropsychological problems as it may improve HRQoL for patients who suffer most from dexamethasone-induced neurobehavioral side effects. Furthermore, by investigating multiple risk factors that could be related to inter-patient variability in developing these side effects, we might be able to identify and treat patients who are at risk earlier during treatment. TRIAL REGISTRATION: Medical Ethical Committee approval number: NL62388.078.17. Affiliation: Erasmus Medical Centre. Netherlands Trial Register: NL6507 ( NTR6695 ). Registered 5 September 2017.

Long-term glucocorticoid concentrations as a risk factor for childhood obesity and adverse body-fat distribution.

BACKGROUND: Childhood obesity is an important risk factor for premature development of the metabolic syndrome (MetS) at adulthood. There is need for understanding of the mechanisms underlying the MetS and obesity. Patients with Cushing's disease suffer from similar metabolic complications, leading to the hypothesis that inter-individual cortisol variation may contribute to the onset of obesity. In addition, glucocorticoid receptor (GR)-gene polymorphisms resulting in differential glucocorticoid (GC) sensitivity, have been associated with an adverse metabolic profile. AIM: To study associations of GC levels in scalp hair, as a marker of long-term systemic GC concentrations, and genetically determined GC sensitivity with obesity and body-fat distribution in children. METHODS: We performed a cross-sectional study of cortisol and cortisone concentrations over a 3-month period, measured by LC-MS/MS (Liquid Chromatography Tandem Mass Spectrometry) in hair of 3019 6-year-old children participating in the Generation R study. Genotyping of GR-gene polymorphisms was performed. RESULTS: Of all children, 4.3% was obese and 13.4% overweight. Cortisol was significantly associated with risk of obesity (odd ratio (OR): 9.4 (3.3-26.9)) and overweight (OR: 1.4 (1.0-2.0)). Cortisone was associated with risk of obesity (OR: 1.9 (1.0-3.5)). Cortisol and cortisone were significantly positively associated with body mass index, fat mass (FM) index and android/gynecoid FM ratio. GR polymorphisms were not associated with adiposity parameters. CONCLUSION: Long-term cortisol concentrations are strongly associated with an increased risk of childhood obesity and adverse body-fat distribution. Future research may reveal whether these are causal relations and may be a target for therapy.

Reproducibility and utility of an overnight 0.25 mg dexamethasone suppression test as a marker for glucocorticoid sensitivity in children with asthma.

PURPOSE: Inhaled corticosteroids (ICS) are the cornerstone of asthma treatment in children. However, there is considerable inter-individual variation in glucocorticoid sensitivity, leading to over- as well as undertreatment. A simple and fast test to predict glucocorticoid sensitivity would enable more tailored therapy in children with asthma. AIM: To study reproducibility and utility of an overnight 0.25 mg dexamethasone suppression test (DST) with salivary cortisol levels as marker for glucocorticoid sensitivity in asthmatic children. METHODS: 23 children with atopic asthma were recruited for two overnight 0.25 mg DST's, 1 month apart. RESULTS: Baseline cortisol levels correlated well between both tests. However, cortisol levels, change in cortisol levels or fractional suppression of cortisol levels after dexamethasone did not correlate between the two tests. Bland-Altman plots showed that the difference in salivary cortisol levels between test 1 and 2 of an individual patient could go up to 12 nmol/l, which is a clinically relevant difference. ICS dose did not correlate with baseline cortisol levels, height and BMI SDS. CONCLUSION: The low-dose salivary DST test in its current form is not suitable for use in clinical practice in children with asthma, due to low reproducibility. Therefore, studies using the 0.25 mg salivary DST should be interpreted cautiously.

The melanocortin-4 receptor as target for obesity treatment: a systematic review of emerging pharmacological therapeutic options.

Obesity is one of the greatest public health challenges of the 21st century. Obesity is currently responsible for ∼0.7-2.8% of a country's health costs worldwide. Treatment is often not effective because weight regulation is complex. Appetite and energy control are regulated in the brain. Melanocortin-4 receptor (MC4R) has a central role in this regulation. MC4R defects lead to a severe clinical phenotype with lack of satiety and early-onset severe obesity. Preclinical research has been carried out to understand the mechanism of MC4R regulation and possible effectors. The objective of this study is to systematically review the literature for emerging pharmacological obesity treatment options. A systematic literature search was performed in PubMed and Embase for articles published until June 2012. The search resulted in 664 papers matching the search terms, of which 15 papers remained after elimination, based on the specific inclusion and exclusion criteria. In these 15 papers, different MC4R agonists were studied in vivo in animal and human studies. Almost all studies are in the preclinical phase. There are currently no effective clinical treatments for MC4R-deficient obese patients, although MC4R agonists are being developed and are entering phase I and II trials.

Elevated hair cortisol concentrations in children with adrenal insufficiency on hydrocortisone replacement therapy.

BACKGROUND: Glucocorticoid replacement therapy in patients with adrenal insufficiency needs to be tailored to the individual patient based on body composition and clinical signs and symptoms as no objective method for assessment of treatment adequacy is available. Current treatment regimens are often not satisfactory, which is shown by the adverse metabolic profile and doubled mortality rates in treated adrenal insufficiency patients. Measurement of cortisol concentrations in hair reflect the long-term systemic cortisol exposure and may be of use in refinement of hydrocortisone treatment. OBJECTIVE: We aimed to study whether long-term cortisol (hydrocortisone) levels, as measured in scalp hair, are similar in children with adrenal insufficiency and healthy children. MATERIAL AND METHODS: We set up a case control study, measuring anthropometric characteristics and hair cortisol concentrations (HCC) in 54 hydrocortisone substituted children with adrenal insufficiency (AI patients) in the age of 4-18 years and 54 healthy children matched for gender and age. RESULTS: Mean HCC were significantly higher in AI patients compared with healthy controls (mean 13·3 vs 8·2 pg/mg, P = 0·02). AI patients also had a higher BMI (P < 0·001) and waist circumference (WC) (P = 0·02). HCC was significantly associated with BMI (P = 0·002) and WC (P = 0·002). HCC explained 13% of the difference in BMI and 29% of the difference in WC between AI patients and controls. CONCLUSION: Hydrocortisone-treated AI patients have increased HCC and adverse anthropometric characteristics compared with healthy controls. HCC measurement may be of value in identifying overtreatment and thereby improve hydrocortisone replacement therapy.

Does dexamethasone induce more neuropsychological side effects than prednisone in pediatric acute lymphoblastic leukemia? A systematic review.

Steroid-induced neuropsychological side effects impact quality of life in children with acute lymphoblastic leukemia. Dexamethasone induces more metabolic side effects than prednisone. To evaluate whether dexamethasone also leads to more neuropsychological side effects, we reviewed all available literature. Randomized controlled trials with neuropsychological function as the primary or secondary outcome did not show clinically meaningful differences between dexamethasone and prednisone on cognition, mood or behavior.

Long-term cortisol levels are not associated with nasal carriage of Staphylococcus aureus.

Staphylococcus aureus (S. aureus) colonizes the anterior nares in part of the population and the persistent carrier state is associated with increased infection risk. Knowledge concerning the determinants of S. aureus nasal carriage is limited. Previously, we found that glucocorticoid receptor polymorphisms influence carrier risk, suggesting involvement of glucocorticoids. Our aim was to study long-term cortisol levels in non-carriers, intermittent, and persistent carriers of S. aureus. We hypothesized that cortisol levels are higher in carriers, since cortisol-induced immune suppression would enhance S. aureus colonization. We determined nasal carrier state and long-term hair cortisol levels in 72 healthy subjects. Nasal swabs were collected twice with an interval of 2 weeks. Cortisol levels were determined in hair segments of 3 cm, which corresponds to a period of roughly 3 months. Of all 72 participants, 38 were non-carriers, 10 were intermittent carriers, and 24 were persistent carriers of S. aureus. Cortisol levels did not differ between these carrier groups (p=0.638). Long-term cortisol levels are not associated with S. aureus nasal carriage.

Appetite- and weight-inducing and -inhibiting neuroendocrine factors in Prader-Willi syndrome, Bardet-Biedl syndrome and craniopharyngioma versus anorexia nervosa.

Obesity is reaching an epidemic state and has a major impact on health and economy. In most cases, obesity is caused by lifestyle factors. However, the risk of becoming obese differs highly between people. Individual's differences in lifestyle, genetic, and neuroendocrine factors play a role in satiety, hunger and regulation of body weight. In a small percentage of children and adults with obesity, an underlying hormonal or genetic cause can be found. The aim of this review is to present and compare data on the extreme ends of the obesity and undernutrition spectrum in patients with Prader-Willi syndrome (PWS), Bardet-Biedl syndrome (BBS), acquired hypothalamic obesity in craniopharyngioma patients, and anorexia nervosa. This may give more insight into the role of neuroendocrine factors and might give direction for future research in conditions of severe obesity and underweight.

[Pharmacotherapy for obesity]. / Farmacotherapie voor obesitas.

Obesity is a complex endocrine disease, mainly caused by environmental, behavioral and biological factors. Maintaining weight loss is extremely difficult due to the neuro-endocrine dysregulations that stimulate the body to return to the previous, increased, weight. Identifying underlying weight-gaining factors is needed, including medication-related, psychological and endocrine factors, as well as monogenic obesity. The cornerstone of treatment is optimization of lifestyle and all other contributing factors. Achieving at least 5% weight loss already has important health benefits. If combined lifestyle intervention (CLI) alone is not successful, pharmacotherapy or bariatric surgery can be added for patients with increased weight-related health risks. Recently, novel pharmacotherapy became available, among which, liraglutide 3 mg and the combination therapy naltrexone/bupropion, which leads to an additional 5-6% mean weight loss compared to CLI alone. For rare forms of obesity there are specific drugs that target defects in the regulation of hunger and satiety. Promising new pharmacotherapy for obesity is under development.

Clinical management of patients with genetic obesity during COVID-19 pandemic: position paper of the ESE Growth & Genetic Obesity COVID-19 Study Group and Rare Endo-ERN main thematic group on Growth and Obesity.

This article aims to provide guidance on prevention and treatment of COVID-19 in patients with genetic obesity. Key principals of the management of patients with genetic obesity during COVID-19 pandemic for patients that have contracted COVID-19 are to be aware of: possible adrenal insufficiency (e.g., POMC deficiency, PWS); a more severe course in patients with concomitant immunodeficiency (e.g., LEP and LEPR deficiency), although defective leptin signalling could also be protective against the pro-inflammatory phenotype of COVID-19; disease severity being masked by insufficient awareness of symptoms in syndromic obesity patients with intellectual deficit (in particular PWS); to adjust medication dose to increased body size, preferably use dosing in m2; the high risk of malnutrition in patients with Sars-Cov2 infection, even in case of obesity. Key principals of the obesity management during the pandemic are to strive for optimal obesity management and a healthy lifestyle within the possibilities of the regulations to prevent weight (re)gain and to address anxiety within consultations, since prevalence of anxiety for COVID-19 is underestimated.

Cushing syndrome as a presenting symptom of renal tumors in children.

Cushing syndrome as the presenting symptom of a malignant renal tumor in children is rare. We report the first case of paraneoplastic Cushing syndrome due to a Wilms tumor, in which clinical and biological signs of hypercortisolism regressed during preoperative chemotherapy. Additionally, we reviewed the literature on paraneoplastic Cushing syndrome secondary to pediatric renal tumors.

Effects of a high-protein intake on metabolic targets for weight loss in children with obesity: a randomized trial.

OBJECTIVE: The objective of this research is to study effects of a 4-week high-protein (HP) diet on energy intake, resting energy expenditure (REE), protein turnover and body composition in children with obesity. METHODS: In this randomized placebo-controlled single-blind crossover study, children with obesity (n = 14; mean age: 10.1 years ± 1.2 standard deviation; body mass index-standard deviation score [BMI-SDS]: 2.8 ± 0.5) received an ad libitum HP (+50 g protein per day) or normal-protein (NP) diet for 4 weeks with a washout period of ≥2 weeks. Energy intake, REE, protein turnover, weight, BMI-SDS and body composition were measured. RESULTS: No differences were found in energy intake or REE between HP and NP. There was an increased urea production and phenylalanine hydroxylation after HP compared with NP (p < 0.05). There was an increased rise in fat-free mass after HP compared with NP (∆HP: 0.8 ± 0.8 kg vs. ∆NP: 0.1 ± 0.6 kg, p < 0.05). BMI and BMI-SDS increased during the study (BMI-SDS start: 2.8 ± 0.5, end: 2.9 ± 0.5, p < 0.05) without a difference between groups. CONCLUSIONS: A 4-week HP diet with ad libitum food intake did not affect energy intake and energy expenditure in children with obesity. BMI increased, although that could be partly explained by an increase in fat-free mass.

[Obesity in the clinic room: diagnostics first, followed by effective treatment]. / Obesitas in de spreekkamer.

In clinical practice, relatively little attention is directed towards identifying underlying causes and contributing factors to weight gain in patients with obesity. However, recognising these "hidden fattening factors" is important as it can lead to more effective treatment strategies. In particular if underlying causes can be solved first, this could help to realise sustainable weight reduction. Besides the well-known lifestyle-related aspects, obesity may be caused or maintained by medication use, endocrine or hypothalamic disorders, monogenetic or syndromic diseases, and mental factors, which may require specific (medical) treatment. For lifestyle-related obesity, a combined lifestyle intervention (CLI) is a first step to combat obesity. This treatment comprises intensive guidance regarding healthy nutrition, physical activity, and behavioural psychology. In case of morbid obesity and insufficient effects of CLI after one year, weight-reducing medication or a bariatric intervention can be considered. This systematic strategy for diagnostics and treatment of obesity is illustrated by two clinical cases.

Brain structure, executive function and appetitive traits in adolescent obesity.

BACKGROUND: Children with obesity show differences in brain structure, executive function and appetitive traits when compared with lean peers. Little is known on the relationship between brain structure and these traits. OBJECTIVES: To investigate the relationship between differences in brain structure and executive function and appetitive traits, in obese and lean adolescents. METHODS: MRI was used to measure cortical thickness and subcortical volumes. Executive function was measured by a Stop Signal-and a Choice Delay Task. Appetitive traits were measured using the Child Eating Behaviour Questionnaire. RESULTS: Adolescents with obesity had greater volumes of the pallidum; 1.78 mL (SE 0.03, p=0.014), when compared with controls; 1.65 mL (SE 0.02). In the group with obesity, greater pallidum volume was positively associated with the ability to delay reward in the Choice Delay Task (p=0.012). CONCLUSION: The association between pallidum volumes and Choice Delay Task in obese adolescents supports the hypothesis that the pallidum plays an important role in executive dysfunction in obese children.

Changes in thyroid hormone concentrations during neonatal extracorporeal membrane oxygenation.

OBJECTIVE: Thyroid hormone concentrations can be disturbed during critical illness. Our aim was to determine changes in thyroid hormone concentrations during neonatal extracorporeal membrane oxygenation (ECMO). STUDY DESIGN: We included 21 ECMO-treated neonates. Age-specific s.d. scores (SDS) of free and total thyroxine (FT4; TT4), reverse and total triiodothyronine (rT3; TT3), thyroid-stimulating hormone (TSH) and thyroxine-binding globulin (TBG) were determined at six fixed time-points. Data were analyzed using general linear models. RESULTS: At baseline, mean SDS FT4 (-0.78, 95% CI: -1.37 to -0.19), TT4 (-1.97, 95% CI: -2.76 to -1.18), TT3 (-0.88, 95% CI: -1.13 to -0.63), TSH (-2.14, 95% CI: -2.93 to -1.35) and TBG (-3.52, 95% CI: -4.55 to -2.50) were low with high mean SDS rT3 (0.53, 95% CI: 0.28 to 0.78). One hour after start ECMO, TT4, TSH and TBG had further declined; 12 h after start ECMO TT3 had declined (all P<0.05). After this decline, mean SDS TSH increased to the baseline level 12 h after start ECMO (-2.50, 95% CI: -3.22 to -1.79), and was higher than baseline 48 h after start ECMO (-0.56, 95% CI: -1.29 to 0.17). This TSH increase was followed by increases in TT4 and TT3. FT4 remained constant within the normal range during ECMO. CONCLUSIONS: Thyroid hormone concentrations before ECMO were suggestive of non-thyroidal illness syndrome (NTIS). During ECMO, increases in TSH, TT4 and TT3 after an initial decline possibly reflect spontaneous restoration of the hypothalamic-pituitary-thyroid axis. FT4 remained constant within the normal range. This suggests that thyroxine therapy is not required during ECMO.

Minor disturbances in central nervous system function in familial neurohypophysial diabetes insipidus.

Familial neurohypophysial diabetes insipidus (FNDI) is caused by a defect in vasopressin synthesis and release as a result of a heterozygous mutation in the gene for the vasopressin prohormone. The predominant characteristic of FNDI is excessive thirst and urine production. However, vasopressin not only has peripheral endocrine effects, but also regulates numerous brain functions. We investigated whether central functions are affected in FNDI, by studying neuropsychological functioning of 23 affected members (15 males, 8 females) of a large family carrying a T/G transition mutation at nucleotide 2110 (codon 116) of the vasopressin prohormone gene (Cys116Gly). The relatively large number of family members with FNDI made it possible to compare cognitive and other CNS effects in these subjects with those of family members without FNDI. Thirty-seven adult volunteers (20 males, 17 females) from the same family and 11 non-family members (2 males, 9 females) from northern part of The Netherlands were tested. The mean age of the subjects was 35+/-12 years. Of the 63 quantified neuropsychological parameters few were statistically different between the subjects with FDNI and control subjects. Memory retrieval processes and sustained attention were worse in the subjects with FDNI. Moreover, these individuals reported significantly fewer symptoms of agoraphobia and miscellaneous symptoms, and had significantly lower scores on a scale measuring anger. The performance of FNDI subjects on an auditory verbal learning test (the 15-word test learning trial) was worse, but not significantly so, than that of the subjects without FDNI. There were subjective complaints of forgetfulness and slow recalls and those were observed in daily life by non-affected family members. These moderate differences in neuropsychological performance indicate that in human FNDI parvocellular vasopressin systems that supply the brain may be less affected or give no such serious disabilities, than the magnocellular hypothalamo-neurohypophysial system that provides vasopressin for endocrine regulation of water homeostasis.

Socioeconomic status in children is associated with hair cortisol levels as a biological measure of chronic stress.

INTRODUCTION: Low socioeconomic status (SES) may be associated with a high risk of lifestyle-related diseases such as cardiovascular diseases. There is a strong association between parental SES, stress and indicators of child health and adult health outcome. The exact mechanisms underlying this association have not yet been fully clarified. Low SES may be associated with chronic stress, which may lead to activation of the hypothalamic-pituitary-adrenal (HPA)-axis, resulting in a higher circulating level of the stress hormone cortisol. Therefore, chronic stress may mediate the association between low SES and elevated cortisol levels and its adverse outcomes. AIM: We investigated whether SES was associated with a chronic measure of cortisol exposure in a child population. METHODS: Cortisol and cortisone were measured in scalp hair in 270 children and adolescents, aged 4-18 years, enrolled through school visits. Neighborhood level SES was based on a score developed by the Netherlands Institute for Social Research using postal codes, and this includes neighborhood measures of income education and unemployment. Maternal and paternal education level were used as indicators of family SES. RESULTS: Neighborhood level socioeconomic status score was significantly associated with hair cortisol (ß=-0.103, p=0.007, 95%CI [-0.179, -0.028]) and hair cortisone (ß=-0.091, p=0.023, 95%CI [-0.167, -0.015]), adjusted for age and sex. Additionally, hair cortisol was significantly correlated with maternal education level and hair cortisone was significantly correlated with paternal education level. CONCLUSION: The results of our study suggest that the widely shown association between low family SES and adverse child health outcomes may be mediated by chronic stress, given the chronically higher levels of cortisol in children and adolescents in families with low SES. It is especially notable that the association between SES and cortisol was already found in children of young age as this can have major consequences, such as increased risk of cardio metabolic diseases in later life.

[Seizures in foreign newborns due to maternal vitamin-D deficiency]. / Convulsies bij allochtone pasgeborenen door hypovitaminose D bij de moeder.

In a Moroccan male, a Turkish female and a Sudanese male newborn who presented with seizures in the second week of life, hypocalcaemia was found. The hypocalcaemia was caused by neonatal vitamin-D deficiency as a result of maternal vitamin-D deficiency during pregnancy. The vitamin-D deficiency of the mothers was caused by the diminished exposure to sunlight as a result of wearing a veil and the dark pigmentation of the skin. The infants were cured by vitamin-D suppletion. With the increasing numbers of dark-skinned women and women who wear veils in the Dutch population, the group of pregnant women and newborns running a risk of vitamin-D deficiency is becoming larger. Therefore, the risk of hypocalcaemia and vitamin-D deficiency rickets in newborns is also increasing. In newborns with seizures, one should think of the possibility of neonatal vitamin-D deficiency, especially if the mothers belong to the group at risk.

Variable loss of functional activities of androgen receptor mutants in patients with androgen insensitivity syndrome.

Androgen receptor (AR) mutations in androgen insensitivity syndrome (AIS) are associated with a variety of clinical phenotypes. The aim of the present study was to compare the molecular properties and potential pathogenic nature of 8 novel and 3 recurrent AR variants with a broad variety of functional assays. Eleven AR variants (p.Cys177Gly, p.Arg609Met, p.Asp691del, p.Leu701Phe, p.Leu723Phe, p.Ser741Tyr, p.Ala766Ser, p.Arg775Leu, p.Phe814Cys, p.Lys913X, p.Ile915Thr) were analyzed for hormone binding, transcriptional activation, cofactor binding, translocation to the nucleus, nuclear dynamics, and structural conformation. Ligand-binding domain variants with low to intermediate transcriptional activation displayed aberrant Kd values for hormone binding and decreased nuclear translocation. Transcriptional activation data, FxxFF-like peptide binding and DNA binding correlated well for all variants, except for p.Arg609Met, p.Leu723Phe and p.Arg775Leu, which displayed a relatively higher peptide binding activity. Variants p.Cys177Gly, p.Asp691del, p.Ala766Ser, p.Phe814Cys, and p.Ile915Thr had intermediate or wild type values in all assays and showed a predominantly nuclear localization in living cells. All transcriptionally inactive variants (p.Arg609Met, p.Leu701Phe, p.Ser741Tyr, p.Arg775Leu, p.Lys913X) were unable to bind to DNA and were associated with complete AIS. Three variants (p.Asp691del, p.Arg775Leu, p.Ile915Thr) still displayed significant functional activities in in vitro assays, although the clinical phenotype was associated with complete AIS. The data show that molecular phenotyping based on 5 different functional assays matched in most (70%) but not all cases.

Bone age assessment by dual-energy X-ray absorptiometry in children: an alternative for X-ray?

OBJECTIVE: The aim of the study was to validate dual-energy X-ray absorptiometry (DXA) as a method to assess bone age in children. METHODS: Paired dual-energy X-ray absorptiometry (DXA) scans and X-rays of the left hand were performed in 95 children who attended the paediatric endocrinology outpatient clinic of University Hospital Rotterdam, the Netherlands. We compared bone age assessments by DXA scan with those performed by X-ray. Bone age assessment was performed by two blinded observers according to the reference method of Greulich and Pyle. Intra-observer and interobserver reproducibility were investigated using the intraclass correlation coefficient (ICC), and agreement was tested using Bland and Altman plots. RESULTS: The intra-observer ICCs for both observers were 0.997 and 0.991 for X-ray and 0.993 and 0.987 for DXA assessments. The interobserver ICC was 0.993 and 0.991 for X-ray and DXA assessments, respectively. The mean difference between bone age assessed by X-ray and DXA was 0.11 years. The limits of agreement ranged from -0.82 to 1.05 years, which means that 95% of all differences between the methods were covered by this range. CONCLUSIONS: Results of bone age assessment by DXA scan are similar to those obtained by X-ray. The DXA method seems to be an alternative for assessing bone age in a paediatric hospital-based population.