[Insulin Resistance and Abnormalities in Blood Values of Icelandic Children Receiving Obesity Treatment]

INTRODUCTION

Worldwide, the rates of childhood obesity have risen dramatically in recent decades. Obesity may cause serious sequelae during childhood and throughout adulthood. Insulin resistance is prevalent metabolic abnormality in pediatric obesity. The Pediatric Obesity Clinic was established in 2011 at the Children's Medical Center, Landspítali University Hospital. This study aimed to observe metabolic abnormalities and insulin resistance in blood values of children receiving obesity treatment.

METHODS

The study included all children (n = 180) who received obesity treatment at The Pediatric Obesity Clinic between 2016 and 2020 and had at least eight out of the nine following serum values analyzed while fasting: HbA1c, glucose, insulin, ALAT, total cholesterol, HDL-cholesterol, triglycerides, TSH and free T4. HOMA-IR value was calculated from insulin and glucose values. Decreased insulin sensitivity was defined as HOMA-IR > 3.42.

RESULTS

84% of the children had at least one abnormality in their tested blood values. 50% had abnormal insulin values and 44% had abnormal ALAT values. 78% had decreased insulin sensitivity, and their mean HOMA-IR was 7.3 (± 5.0), surpassing twice the normal value.

CONCLUSION

A large majority of the children undergoing obesity treatment already exhibited signs of metabolic sequelae during their treatment. The prevalence of affected children has increased compared to a similar study conducted in 2013. Of particular concern is the growing number of children with decreased insulin sensitivity. Proper measures must be taken to combat this alarming trend.

Usage and Daily Attrition of a Smartphone-Based Health Behavior Intervention: Randomized Controlled Trial

BACKGROUND

Although most adolescents have access to smartphones, few of them use mobile health (mHealth) apps for health improvement, highlighting the apparent lack of interest in mHealth apps among adolescents. Adolescent mHealth interventions have been burdened with high attrition rates. Research on these interventions among adolescents has frequently lacked detailed time-related attrition data alongside analysis of attrition reasons through usage.

OBJECTIVE

The objective was to obtain daily attrition rates among adolescents in an mHealth intervention to gain a deeper understanding of attrition patterns, including the role of motivational support, such as altruistic rewards, through analysis of app usage data.

METHODS

A randomized controlled trial was conducted with 304 adolescent participants (152 boys and 152 girls) aged 13-15 years. Based on 3 participating schools, participants were randomly assigned to control, treatment as usual (TAU), and intervention groups. Measures were obtained at baseline, continuously throughout the 42-day trial period (research groups), and at the trial end. The mHealth app is called SidekickHealth and is a social health game with the following 3 main categories: nutrition, mental health, and physical health. Primary measures were attrition based on time from launch, and the type, frequency, and time of health behavior exercise usage. Outcome differences were obtained through comparison tests, while regression models and survival analyses were used for attrition measures.

RESULTS

Attrition differed significantly between the intervention and TAU groups (44.4% vs 94.3%; χ²₁=61.220; P<.001). The mean usage duration was 6.286 days in the TAU group and 24.975 days in the intervention group. In the intervention group, male participants were active significantly longer than female participants (29.155 vs 20.433 days; χ²₁=6.574; P<.001). Participants in the intervention group completed a larger number of health exercises in all trial weeks, and a significant decrease in usage was observed from the first to second week in the TAU group (t₁₀₅=9.208; P<.001) but not in the intervention group. There was a significant increase in health exercises in the intervention group from the fifth to sixth week (t₁₀₅=3.446; P<.001). Such a significant increase in usage was not evident in the TAU group. The research group was significantly related to attrition time (hazard ratio 0.308, 95% CI 0.222-0.420), as well as the numbers of mental health exercises (P<.001) and nutrition exercises (P<.001).

CONCLUSIONS

Differences in attrition rates and usage between groups of adolescents were identified. Motivational support is a significant factor for lowering attrition in adolescent mHealth interventions. The results point to sensitivity periods in the completion of diverse health tasks, and emphasis on time-specific attrition, along with the type, frequency, and time of health behavior exercise usage, is likely a fruitful avenue for further research on mHealth interventions for adolescent populations, in which attrition rates remain excessive.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05912439; https://clinicaltrials.gov/study/NCT05912439.

Body Composition in Fussy-Eating Children, with and without Neurodevelopmental Disorders, and Their Parents, Following a Taste Education Intervention

Fussy eaters may have an increased risk of becoming overweight or obese as adolescents, with fussy eating and weight status also correlating with neurodevelopmental disorders (NDs) such as autism spectrum disorder (ASD) and attention deficit/hyperactivity disorder (ADHD). Further, maternal and children's weight status relationships are well-established. In this study, we analyzed the body composition of parent-child dyads using bioelectrical impedance analysis (BIA). Fifty-one children aged 8-12 years, with an ND (n = 18) and without (n = 33), and their parents, participated in a 7-week food-based Taste Education intervention with 6-month follow-up. The paired t-test was used to compare differences in body composition based on children's ND status. In logistic regression analysis, odds of children being in the overweight/obese or overfat/obese categories increased by a factor of 9.1 and 10.6, respectively, when having NDs, adjusting for parents' BMI (body mass index) or fat percentage (FAT%). Children with NDs and their parents had significantly higher mean BMI-SDS (BMI standard deviation score) and FAT% at pre-intervention than children without NDs and their parents. Mean BMI-SDS and FAT% lowered significantly between time points for children with NDs and their parents but not for children without NDs or their parents. The findings underline the need for additional exploration into the relationships between children's and parents' body composition based on children's ND status.

Changes in Eating Behaviors Following Taste Education Intervention: Focusing on Children with and without Neurodevelopmental Disorders and Their Families: A Randomized Controlled Trial

Fussy-eating children often display problematic behaviors around mealtimes, such as irritation, opposition, or may even throw tantrums. This may lead to reduced food variety and poor nutritional profiles, which may increase parents' worries about their children's diet, particularly when the children also have neurodevelopmental disorders (ND) such as Autism Spectrum Disorder (ASD) and Attention-Deficit/Hyperactive Disorder (ADHD). To investigate the effect of Taste Education on problematic mealtime behaviors, 81 children aged 8-12 years, with ND (n = 33) and without (n = 48), and their parents, participated in a 7-week Taste Education intervention. Children were matched on age, sex, and ND, and allocated at random into Immediate-intervention and Delayed-intervention groups. Parents completed the Meals in Our Household Questionnaire (MiOH). To examine changes in MiOH-scores, repeated-measures analysis-of-variance with time-points were used, with condition as factors (Immediate intervention and Delayed intervention). Baseline measures were adjusted for, and a robust linear mixed-model was fitted. Results showed superior outcomes for Intervention compared to waiting on all measures of MiOH, with stable effects through six-month follow-up. Differences were non-significant between children with and without ND. The Taste Education program suggests a promising, simple, and non-intrusive way to reduce children's problematic mealtime behaviors in the long term.

Odds of fussy eating are greater among children with obesity and anxiety

BACKGROUND

Fussy eating has been associated with autism spectrum disorder (ASD), attention-deficit/hyperactive disorder (ADHD), anxiety, and depression. Despite these disorders being prevalent in obesity treatment, no studies have been published on the association of fussy eating in children with obesity and these disorders. Understanding fussy eating in children with obesity and comorbid disorders is important as acceptance of healthy foods tends to be low, especially in children with sensory sensitivities.

OBJECTIVES

Investigate the prevalence of fussy eating in a cross-sectional sample of children with obesity and ASD, ADHD, anxiety, and depression; and whether they were more likely to be fussy eaters, comparing those with and without these disorders.

METHODS

One hundred and four children referred to family-based obesity treatment in Iceland 2011-2016, mean age 12.0 (SD = 3.0), mean body mass index standard deviation score 3.5 (SD = 0.9). Binary logistic regression was used to estimate the relationship between fussy eating and disorders, adjusting for medication use.

RESULTS

A large minority (41.6%) were fussy eaters and 48.9% had at least one comorbid disorder. Over a third of children rejected bitter and sour tastes, and 1.9% and 7.9% rejected sweet and salty tastes, respectively. Compared with those without disorders, the odds of being a fussy eater were increased by a factor of 4.11 when having anxiety (95% confidence intervals) (1.02-16.58, p = 00.046), adjusting for medication use. The odds of being a fussy eater were not increased for other disorders; ASD, ADHD, or depression.

CONCLUSIONS

In children attending obesity treatment, fussy eating was common. Clinical care models in pediatric obesity treatment should address fussy eating, especially in children with anxiety.

Growth Rate in Childhood and Adolescence and the Risk of Breast and Prostate Cancer: A Population-Based Study

Growth rate is regulated by hormonal pathways that might affect early cancer development. We explored the association between rate of growth in height from ages 8 to 13 years (childhood) and from age 13 to attainment of adult height (adolescence), as measured at study entry, and the risk of breast or prostate cancer. Participants were 2,037 Icelanders born during 1915-1935, who took part in the Reykjavik Study, established in 1967. Height measurements were obtained from school records and at study entry. We used multivariable Cox regression models to calculate hazard ratios with 95% confidence intervals of breast and prostate cancer by rates of growth in tertiles. During a mean follow-up of 66 years (women) and 64 years (men), 117 women were diagnosed with breast cancer and 118 men with prostate cancer (45 with advanced disease). Women in the highest growth-rate tertile in adolescence had a higher risk of breast cancer (hazard ratio = 2.4, 95% confidence interval: 1.3, 4.3) compared with women in the lowest tertile. A suggestive inverse association was observed for highest adolescent growth rate in men and advanced prostate cancer: hazard ratio = 0.4, 95% confidence interval: 0.2, 1.0. Rapid growth, particularly in adolescence may affect cancer risk later in life.

Large-Scale Screening for Monogenic and Clinically Defined Familial Hypercholesterolemia in Iceland

Objective: Familial hypercholesterolemia (FH) is traditionally defined as a monogenic disease characterized by severely elevated LDL-C (low-density lipoprotein cholesterol) levels. In practice, FH is commonly a clinical diagnosis without confirmation of a causative mutation. In this study, we sought to characterize and compare monogenic and clinically defined FH in a large sample of Icelanders. Approach and Results: We whole-genome sequenced 49 962 Icelanders and imputed the identified variants into an overall sample of 166 281 chip-genotyped Icelanders. We identified 20 FH mutations in LDLR, APOB, and PCSK9 with combined prevalence of 1 in 836. Monogenic FH was associated with severely elevated LDL-C levels and increased risk of premature coronary disease, aortic valve stenosis, and high burden of coronary atherosclerosis. We used a modified version of the Dutch Lipid Clinic Network criteria to screen for the clinical FH phenotype among living adult participants (N=79 058). Clinical FH was found in 2.2% of participants, of whom only 5.2% had monogenic FH. Mutation-negative clinical FH has a strong polygenic basis. Both individuals with monogenic FH and individuals with mutation-negative clinical FH were markedly undertreated with cholesterol-lowering medications and only a minority attained an LDL-C target of <2.6 mmol/L (<100 mg/dL; 11.0% and 24.9%, respectively) or <1.8 mmol/L (<70 mg/dL; 0.0% and 5.2%, respectively), as recommended for primary prevention by European Society of Cardiology/European Atherosclerosis Society cholesterol guidelines. Conclusions: Clinically defined FH is a relatively common phenotype that is explained by monogenic FH in only a minority of cases. Both monogenic and clinical FH confer high cardiovascular risk but are markedly undertreated.

Taste education - A food-based intervention in a school setting, focusing on children with and without neurodevelopmental disorders and their families. A randomized controlled trial

Children with neurodevelopmental disorders (ND) such as Autism Spectrum Disorder (ASD) and Attention-Deficit/Hyperactive Disorder (ADHD) have high levels of fussy eating. However, no school-based food interventions exist for children with ASD and ADHD. To investigate the effect of Taste Education, 81 children with ND (n = 33), and without (n = 48), aged 8-12 years, and their parents, participated in a 7-week food intervention. Children were matched on age, ND, and sex, and randomized into Immediate-intervention and Delayed-intervention groups. Parents completed the Children's Eating Behaviour Questionnaire (CEBQ), and a food-variety questionnaire. After adjusting for baseline measures, repeated-measures analysis-of-variance with time-points, and condition as factors (Immediate intervention and Delayed intervention) were used to examine changes in CEBQ-scores, with a robust linear mixed-model fitted. Changes in percentage of accepted foods were tested using a logistic-regression model adjusting for baseline acceptance. Results showed superior results for Intervention compared to waiting, on Food fussiness, but not Enjoyment of food, with stable effects through six-months follow-up. There were non-significant differences between children with and without ND. Results also showed increased odds of accepting vegetables by a factor of 1.6 (95% Confidence Interval [CI]: 1.33-1.93, p < .001); nuts and seeds by a factor of 1.4 (95% CI: 1.27-1.6, p < .001), but no significant association for fruit (OR 1.12, 95% CI: 0.92-1.34, p = .244). Trends were similar for children regardless of ND-status. The Taste Education program, shows promise, as a simple, non-invasive way to decrease fussy eating and increase food variety in the long-term.

Mode of delivery was associated with transient changes in the metabolomic profile of neonates

AIMS

To estimate potential differences in neonatal metabolomic profiles at birth and at the time of newborn screening by delivery mode.

METHODS

A prospective study at Women's Clinic at Landspitali-The National University Hospital of Iceland. Women having normal vaginal birth or elective caesarean section from November 2013 to April 2014 were offered participation. Blood samples from mothers before birth and umbilical cord at birth were collected and amino acids and acylcarnitines measured by tandem mass spectrometry. Results from the Newborn screening programme in Iceland were collected. Amino acids and acylcarnitines from different samples were compared by delivery mode.

RESULTS

Eighty three normal vaginal births and 32 elective caesarean sections were included. Mean differences at birth were higher for numerous amino acids, and some acylcarnitines in neonates born vaginally compared to elective caesarean section. Maternal blood samples and newborn screening results showed small differences that lost significance after correction for multiple testing. Many amino acids and some acylcarnitines were numerically higher in cord blood compared to maternal. Many amino acids and most acylcarnitines were numerically higher in newborn screening results compared to cord blood.

CONCLUSION

We observed transient yet distinct differences in metabolomic profiles between neonates by delivery mode.

Pubertal development and risk of premenstrual disorders in young adulthood

STUDY QUESTION

Is pubertal timing associated with risk of premenstrual disorders (PMDs) in young adulthood?

SUMMARY ANSWER

Late pubertal development is associated with decreased premenstrual symptom burden and risk of PMDs in young adulthood.

WHAT IS KNOWN ALREADY

PMDs, including premenstrual syndrome and premenstrual dysphoric disorder, may begin during the teenage years. Few risk factors in early life have been identified for PMD development.

STUDY DESIGN, SIZE, DURATION

A prospective cohort study of 6495 female participants during 1996–2013.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We included participants from the Growing Up Today Study (GUTS). Pubertal development was indicated by the timing of menarche, breast and pubic hair growth. Self-reported age at menarche was longitudinally assessed at enrollment (in 1996/2004 for GUTS I/II) and onwards, and classified as early (age ≤ mean − SD, 11.64 years), normative and late menarche (age ≥ mean + SD, 13.95 years). Timing of pubic hair and breast growth were assessed multiple times during follow-up via Tanner scales, and classified into early, normative and late development according to mean ± SD. Using a validated questionnaire based on the Calendar of Premenstrual Experiences, we assessed premenstrual symptoms and identified probable cases of PMDs in 2013. We examined the associations of timing of pubertal development with premenstrual symptom score and disorders using multivariable linear and logistic regressions, respectively.

MAIN RESULTS AND THE ROLE OF CHANCE

In 2013 (mean age = 26), 1001 (15.4%) individuals met criteria for a PMD. An inverse association was found between age at menarche and premenstrual symptom z-score (β −0.05 per year, 95% CI −0.07 to −0.03) and risk of PMDs (odds ratio (OR) 0.93 per year, 95% CI 0.88 to 0.99). Compared to individuals with normative menarche, individuals with late menarche had a lower risk of PMDs (OR 0.73, 95% CI 0.59 to 0.91), while individuals with early menarche had comparable odds (OR 0.98, 95% CI 0.81 to 1.18). Moreover, early growth of pubic hair was associated with increased premenstrual symptoms (z-score β 0.09 per year, 95% CI 0.02 to 0.17) and PMD risk (OR 1.28, 95% CI 1.04 to 1.56), independent of age at menarche. No associations were noted for breast development.

LIMITATIONS, REASONS FOR CAUTION

One major limitation is some misclassification of menarche due to recall. We, however, showed robust association among participants who were premenarcheal at baseline.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings suggest that pubertal timing, particularly timing of menarche, is inversely associated with the risk of developing premenstrual symptoms in young adulthood, and that women with later menarche have significantly lower risk of PMDs. Information on PMDs should be provided to teenage girls and their parents. If these findings are confirmed in independent populations, prevention strategies and early detection programs may be considered for women with early pubertal development.

STUDY FUNDING/COMPETING INTEREST(S)

The work is supported by the National Institutes of Health and Swedish Research Council.

TRIAL REGISTRATION NUMBER

N/A

Does metabolomic profile differ with regard to birth weight?

BACKGROUND

Macrosomia and child obesity are growing health-care issues worldwide. The purpose of the study was to evaluate how extremely high or low birth weight affects metabolic markers evaluated in newborn screening.

METHODS

The study was register-based and included full-term singletons born in Iceland from 2009 to 2012 with newborn screening samples taken 72-96 h after birth. Three groups based on birth weight were compared: low birth weight (<2500 g), appropriate-for-gestational age, and extreme macrosomia (≥5000 g). The comparison was adjusted for possible confounding factors.

RESULTS

Compared to appropriate-for-gestational age neonates, both low birth weight and extreme macrosomia were associated with higher levels of glutamic acid. The amino acids alanine and threonine were increased in low birth weight neonates. Free carnitine and some medium- and long-chain acylcarnitines were higher in low birth weight infants. Hydroxybutyrylcarnitine was lower in low birth weight infants, but higher in extremely macrosomic neonates. Acetylcarnitine was higher in low birth weight and extremely macrosomic neonates. Succinylcarnitine was lower and hexadecenoylcarnitine higher in macrosomic newborns.

CONCLUSION

Low birth weight and extremely macrosomic neonates show distinctive differences in their metabolomic profile compared to appropriate-for-gestational age newborns. The differences are not explained by gestational age.

IMPACT

The key message of this article is that both low birth weight and extremely macrosomic newborns show dissimilar metabolomic profiles compared to appropriate-for-gestational age neonates. The article contributes to knowledge on what affects evaluation of results in newborn screening. The impact of this article is to provide information on metabolism at both ends of the birth weight range after accounting for confounding factors including gestational age.

Usage and Weekly Attrition in a Smartphone-Based Health Behavior Intervention for Adolescents: Pilot Randomized Controlled Trial

Background

The majority of adolescents own smartphones, although only 8% of them use health apps. Attrition rates from adolescent mobile health (mHealth) interventions for treating mental health problems such as anxiety and depression are an issue with a high degree of variation. Attrition in mHealth interventions targeting adolescent populations is frequently presented in a two-point fashion, from initiation of the intervention to the end of treatment, lacking more time-specific information on usage and times of attrition. Self-efficacy could provide an avenue to lower attrition rates, although a better understanding of the relationship between mental health factors and time-specific attrition rates is needed.

Objective

The aims of this study were to obtain time-specific attrition rates among adolescents in an mHealth intervention, and to describe the intervention’s usage and feasibility in relation to adolescent self-efficacy levels, and emotional and physical health.

Methods

A single-center randomized controlled public school pilot trial was undertaken with 41 adolescents. Outcome measures were assessed at baseline and after 6 weeks, while in-app activity and attrition rates were continually assessed throughout the intervention period. The primary outcome was attrition based on time and type of in-app health behavior usage, and feasibility of the mHealth app. Secondary outcome measures were self-efficacy levels, depressive and anxiety symptoms, as well as standardized BMI and sleep. Analyses of group mean variances with adjusted α levels through Bonferroni corrections were used to assess main outcome effects.

Results

The attrition from initiation of the intervention to 6-week follow up was 35%. Attrition started in the third week of the intervention and was related to daily time of app usage (R_t=0.43, P<.001). The number of average weekly in-app health exercises completed decreased significantly from the first week of the intervention (mean 55.25, SD 10.96) to the next week (mean 13.63, SD 2.94). However, usage increased by 22% between week 2 and the last week of the intervention (mean 16.69, SD 8.37). Usability measures revealed satisfactory scores (mean 78.09, SD 9.82) without gender differences (P=.85). Self-reported daily physical activity increased by 19.61% in the intervention group but dropped by 26.21% among controls. Self-efficacy levels increased by 8.23% in the invention arm compared to a 3.03% decrease in the control group.

Conclusions

This pilot study demonstrated the feasibility and usability of an mHealth intervention among adolescent participants. Indications were toward beneficial effects on physical and mental health that warrant further research. Focus on time-specific attrition measures alongside daily times of usage and ways to increase participants’ self-efficacy levels appear to be a promising avenue for research on mHealth interventions for adolescent populations with the aim to ultimately lower attrition rates.

Spermatogonia Loss Correlates with LAMA 1 Expression in Human Prepubertal Testes Stored for Fertility Preservation

Fertility preservation for male childhood cancer survivors not yet capable of producing mature spermatozoa, relies on experimental approaches such as testicular explant culture. Although the first steps in somatic maturation can be observed in human testicular explant cultures, germ cell depletion is a common obstacle. Hence, understanding the spermatogonial stem cell (SSC) niche environment and in particular, specific components such as the seminiferous basement membrane (BM) will allow progression of testicular explant cultures. Here, we revealed that the seminiferous BM is established from 6 weeks post conception with the expression of laminin alpha 1 (LAMA 1) and type IV collagen, which persist as key components throughout development. With prepubertal testicular explant culture we found that seminiferous LAMA 1 expression is disrupted and depleted with culture time correlating with germ cell loss. These findings highlight the importance of LAMA 1 for the human SSC niche and its sensitivity to culture conditions.

Fertility preservation in boys: recent developments and new insights †

BACKGROUND

Infertility is an important side effect of treatments used for cancer and other non-malignant conditions in males. This may be due to the loss of spermatogonial stem cells (SSCs) and/or altered functionality of testicular somatic cells (e.g. Sertoli cells, Leydig cells). Whereas sperm cryopreservation is the first-line procedure to preserve fertility in post-pubertal males, this option does not exist for prepubertal boys. For patients unable to produce sperm and at high risk of losing their fertility, testicular tissue freezing is now proposed as an alternative experimental option to safeguard their fertility.

OBJECTIVE AND RATIONALE

With this review, we aim to provide an update on clinical practices and experimental methods, as well as to describe patient management inclusion strategies used to preserve and restore the fertility of prepubertal boys at high risk of fertility loss.

SEARCH METHODS

Based on the expertise of the participating centres and a literature search of the progress in clinical practices, patient management strategies and experimental methods used to preserve and restore the fertility of prepubertal boys at high risk of fertility loss were identified. In addition, a survey was conducted amongst European and North American centres/networks that have published papers on their testicular tissue banking activity.

OUTCOMES

Since the first publication on murine SSC transplantation in 1994, remarkable progress has been made towards clinical application: cryopreservation protocols for testicular tissue have been developed in animal models and are now offered to patients in clinics as a still experimental procedure. Transplantation methods have been adapted for human testis, and the efficiency and safety of the technique are being evaluated in mouse and primate models. However, important practical, medical and ethical issues must be resolved before fertility restoration can be applied in the clinic.Since the previous survey conducted in 2012, the implementation of testicular tissue cryopreservation as a means to preserve the fertility of prepubertal boys has increased. Data have been collected from 24 co-ordinating centres worldwide, which are actively offering testis tissue cryobanking to safeguard the future fertility of boys. More than 1033 young patients (age range 3 months to 18 years) have already undergone testicular tissue retrieval and storage for fertility preservation.

LIMITATIONS REASONS FOR CAUTION

The review does not include the data of all reproductive centres worldwide. Other centres might be offering testicular tissue cryopreservation. Therefore, the numbers might be not representative for the entire field in reproductive medicine and biology worldwide. The key ethical issue regarding fertility preservation in prepubertal boys remains the experimental nature of the intervention.

WIDER IMPLICATIONS

The revised procedures can be implemented by the multi-disciplinary teams offering and/or developing treatment strategies to preserve the fertility of prepubertal boys who have a high risk of fertility loss.

STUDY FUNDING/COMPETING INTERESTS

The work was funded by ESHRE. None of the authors has a conflict of interest.

Geographical variation in the incidence of type 1 diabetes in the Nordic countries: A study within NordicDiabKids

BACKGROUND

The incidence of type 1 diabetes (T1D) is high in the Nordic countries with geographic differences between as well as within countries.

OBJECTIVE

To describe the geographical distribution of the incidence of T1D among children in four Nordic countries, an area where the population is considered genetically similar.

METHODS

Data on children 0 to 14 years of age and diagnosed with T1D 2006 to 2011 was collected from four Nordic national pediatric quality diabetes registries. Data included year of diagnosis (2006-2011), sex, and age at diagnosis. Figures for number of children at risk during 2006 to 2011-as well as total population, proportion with foreign background and size of populated areas of geographic regions-were collected from official statistics.

RESULTS

The total incidence during the study period for all four countries was 35.7/100 000 person years but differed between the countries (range 18.2-44.1; P < .001). The incidence difference between the countries was most obvious in the highest age group, 10 to 14 years of age, whereas there was no difference in the youngest age group 0 to 5 years of age. Iceland had similar incidence in the entire country, whereas the other countries had areas with different incidence. Densely populated areas, such as major cities, had the lowest incidence.

CONCLUSION

The incidence of T1D differed between the Nordic countries and also between the neighboring countries and generally decreased with population density. This indicates that environmental factors may contribute to the level of incidence of T1D.

Incorporating Appetite Awareness Training Within Family-Based Behavioral Treatment of Pediatric Obesity: A Randomized Controlled Pilot Study

Objective

To assess additive effects of incorporating appetite awareness training (AAT), a strategy to encourage eating in response to hunger and satiety cues, within a family-based behavioral treatment (FBT) for childhood obesity.

Methods

Total 84 families with a child with obesity in the age range of 8-12 years, Body Mass Index Standard Deviation Score (BMI-SDS)  ≥ 2, and a participating parent were randomly allocated to two conditions; standard FBT was compared with FBT incorporating AAT strategies (FBT-AAT). Treatment consisted of group therapy sessions (held separately for children and parents) as well as single-family (parent-child dyad) sessions (24 sessions total) delivered over 18 weeks at a tertiary care outpatient clinic. One booster session was provided 1-year posttreatment and a final follow-up assessment was conducted at 2 years. The primary outcome was change in child standardized body mass index (BMI-SDS).

Results

The two conditions did not differ significantly at posttest, but the FBT-AAT group was at a significantly lower weight compared with FBT at both the first-year, F(1, 82) = 4.150, p<.05, and the second-year follow-ups, F(1, 82) = 14.912, p <.001. It was notable that over the second-year of follow-up, the FBT-AAT group continued to show improvement, whereas the FBT group did not.

Conclusions

Incorporating specific self-regulatory training in attending to hunger and fullness signals during a standardized family-based treatment may have enhanced the long-term maintenance of treatment effects. Findings are promising and warrant further study.

Body mass index standard deviation score and obesity in children with type 1 diabetes in the Nordic countries. HbA1c and other predictors of increasing BMISDS

BACKGROUND

Intensified insulin therapy may increase body weight and cause obesity. This study compared body mass index standard deviation score (BMISDS) and obesity rate in children with type 1 diabetes (T1D) in Denmark, Iceland, Norway and Sweden, and uncovered predictors for increasing BMISDS.

METHODS

Data registered in the Nordic national childhood diabetes databases during the period 2008-2012 on children below 15 years with T1D for more than 3 months were compiled, including information on gender, age, diabetes duration, hemoglobin A_1c (HbA_1c ), insulin dose, severe hypoglycemia (SH), treatment modality, height and weight. The Swedish reference chart for BMI was used for calculating BMISDS.

RESULTS

Totally, 11 025 children (48% females) (30 994 registrations) were included. Medians by the last recorded examination were: age, 13.5 years; diabetes duration, 4.3 years; HbA_1c , 7.9% (63 mmol/mol); insulin dose, 0.8 IU/kg/d and BMISDS, 0.70. Obesity rate was 18.5%. Adjusted mean BMISDS (BMISDS adj) was inversely related to HbA_1c and directly to diabetes duration. Higher BMISDS adj was found in those with an insulin dose above 0.6 IU/kg/d, and in girls above 10 years. Pump users had higher BMISDS adj than pen users, and patients with registered SH had higher BMISDS adj than patients without SH (both P < .001).

CONCLUSION

Obesity rate in children with T1D in the Nordic countries is high, however, with country differences. Low HbA_1c , long diabetes duration, higher insulin dose, pump treatment and experiencing a SH predicted higher BMISDS. Diabetes caregivers should balance the risk of obesity and the benefit of a very low HbA_1c.

Spermatogonial quantity in human prepubertal testicular tissue collected for fertility preservation prior to potentially sterilizing therapy

STUDY QUESTION

Does chemotherapy exposure (with or without alkylating agents) or primary diagnosis affect spermatogonial quantity in human prepubertal testicular tissue?

SUMMARY ANSWER

Spermatogonial quantity is significantly reduced in testes of prepubertal boys treated with alkylating agent therapies or with hydroxyurea for sickle cell disease.

WHAT IS KNOWN ALREADY

Cryopreservation of spermatogonial stem cells, followed by transplantation into the testis after treatment, is a proposed clinical option for fertility restoration in children. The key clinical consideration behind this approach is a sufficient quantity of healthy cryopreserved spermatogonia. However, since most boys with malignancies start therapy with agents that are not potentially sterilizing, they will have already received some chemotherapy before testicular tissue cryopreservation is considered.

STUDY DESIGN, SIZE, DURATION

We examined histological sections of prepubertal testicular tissue to elucidate whether chemotherapy exposure or primary diagnosis affects spermatogonial quantity. Quantity of spermatogonia per transverse tubular cross-section (S/T) was assessed in relation to treatment characteristics and normative reference values in histological sections of paraffin embedded testicular tissue samples collected from 32 consecutive boy patients (aged 6.3 ± 3.8 [mean ± SD] years) between 2014 and 2017, as part of the NORDFERTIL study, and in 14 control samples (from boys aged 5.6 ± 5.0 [mean ± SD] years) from an internal biobank.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Prepubertal boys in Sweden, Finland and Iceland who were facing treatments associated with a very high risk of infertility, were offered the experimental procedure of testicular cryopreservation. Exclusion criteria were testicular volumes >10 ml and high bleeding or infection risk. There were 18 patients with a diagnosis of malignancy and 14 patients a non-malignant diagnosis. While 20 patients had the testicular biopsy performed 1-45 days after chemotherapy, 12 patients had not received any chemotherapy. In addition, 14 testicular tissue samples of patients with no reported testicular pathology, obtained from the internal biobank of the Department of Pathology at Karolinska University Hospital, were included as control samples in addition to reference values obtained from a recently published meta-analysis. The quantity of spermatogonia was assessed by both morphological and immunohistochemical analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

The main finding was a significant reduction in spermatogonial cell counts in boys treated with alkylating agents or with hydroxyurea for sickle cell disease. The mean S/T values in boys exposed to alkylating agents (0.2 ± 0.3, n = 6) or in boys with sickle cell disease and exposed to hydroxyurea (0.3 ± 0.6, n = 6) were significantly lower (P = 0.003 and P = 0.008, respectively) than in a group exposed to non-alkylating agents or in biobank control samples (1.7 ± 1.0, n = 8 and 4.1 ± 4.6, n = 14, respectively). The mean S/T values of the testicular tissue samples included in the biobank control group and the patient group exposed to non-alkylating agents were within recently published normative reference values.

LIMITATIONS, REASONS FOR CAUTION

Normal testicular tissue samples included in this study were obtained from the internal biobank of Karolinska University Hospital. Samples were considered normal and included in the study if no testicular pathology was reported in the analysed samples. However, detailed information regarding previous medical treatments and testicular volumes of patients included in this biobank were not available.

WIDER IMPLICATIONS OF THE FINDINGS

This study summarizes, for the first time, spermatogonial quantity in a prepubertal patient cohort just before and after potentially sterilizing treatments. Boys facing cancer and cytotoxic therapies are regarded as the major group who will benefit from novel fertility preservation techniques. There are no previous reports correlating spermatogonial quantity to cumulative exposure to alkylating agents and anthracyclines (non-alkylating agents) and no information about the timing of cytotoxic exposures among this particular patient cohort. For prepubertal boys in whom fertility preservation is indicated, testicular tissue should be obtained before initiation of chemotherapy with alkylating agents, whilst for those with sickle cell disease and treated with hydroxyurea, this approach to fertility preservation may not be feasible.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by grants from The Swedish Childhood Cancer Foundation (PR2016-0124; TJ2016-0093; PR2015-0073, TJ2015-0046) (J.-B.S. and K.J.), the Jane and Dan Olssons Foundation (2016-33) (J.-B.S.), the Finnish Cancer Society (K.J.), the Foundation for Paediatric Research (J.-B.S.), Kronprinsessan Lovisas Förening För Barnasjukvård/ Stiftelsen Axel Tielmans Minnesfond, Samariten Foundation (J.-B.S.), the Väre Foundation for Paediatric Cancer Research (K.J.) and the Swedish Research Council (2012-6352) (O.S.). R.T.M. was supported by a Wellcome Trust Fellowship (09822). J.P.A.-L. and M.K. were supported by the ITN Marie Curie program 'Growsperm' (EU-FP7-PEOPLE-2013-ITN 603568). The authors declare no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

Cross-sectional study of randomly selected 18-year-old students showed that body mass index was only associated with sleep duration in girls

AIM

This study investigated the associations, by sex, between sleep and adiposity, dietary habits, cardiorespiratory fitness and metabolic risk in 18-year-old students.

METHODS

We carried out a cross-sectional study of 199 randomly chosen, healthy 18-year-old students (53% girls) in Iceland's capital region. The data collection took place in the winter months of 2012 to 2015. The anthropometric measurements were body mass index, waist circumference and body fat percentage. Sleep duration and dietary habits were self-reported. Cardiorespiratory fitness was measured on a stationary bicycle. A subsample of 152 participants gave blood samples.

RESULTS

A quarter of the adolescents failed to reach the minimum recommended sleep duration of seven hours per night on weekdays. In girls, the average sleep score was associated with body mass index and waist circumference, after adjusting for cardiorespiratory fitness and unhealthy eating scores. In boys, the average sleep score was not associated with anthropometric measurements, but cardiorespiratory fitness was an independent predictor (p < 0.001). No associations were found between average sleep scores and metabolic profiles in either sex.

CONCLUSION

Sleep duration and adiposity only appeared to be associated in girls and were independent of cardiorespiratory fitness and unhealthy eating. Sleep duration was not related to metabolic risk.

Thyrotoxicosis in a 13-year-old girl following pituitary adenectomy for Cushing's disease

Our objective is to report a case of thyrotoxicosis following pituitary adenectomy for Cushing′s disease, the only pediatric case to our knowledge. No thyroid antibodies were detected, and the thyrotoxicosis was successfully treated for 3 months with no relapse after 5 years of follow‐up. The cause of thyrotoxicosis remains unknown.

Incidence of severe hypoglycemia in children with type 1 diabetes in the Nordic countries in the period 2008-2012: association with hemoglobin A 1c and treatment modality

OBJECTIVE

Treatment of type 1 diabetes has been intensified aiming at normalizing blood glucose, which may increase the risk of severe hypoglycemia (SH). We aimed to compare the incidence of SH events in the four Nordic countries Denmark, Iceland, Norway and Sweden, and to assess the influence of hemoglobin A1c (HbA_1c) and treatment modalities on the frequency of SH; particularly, to explore if a HbA_1c target ≤6.7% (50 mmol/mol) is feasible.

RESEARCH DESIGN AND METHODS

Data on children below 15 years with a diabetes duration more than 1 year, registered in the national childhood diabetes databases in the four Nordic countries from 2008 to 2012, were compiled. Data completeness was more than 95%.

RESULTS

Totally 8806 (48% females) patients with 29 715 person years were included, mean age and diabetes duration were 11 years and 5.1 years, respectively. The overall rate of SH was 6.0 per 100 patient-years, and did not change during the study period. The Swedish population constantly had the lowest SH incidence while it decreased significantly in the Danish population. HbA_1c decreased significantly over time (p<0.01), while the number of pump users increased (p<0.01). Stratifying for HbA_1c levels showed the lowest risk of SH in patients with HbA_1c ≤6.7% (≤50 mmol/mol), but in the statistical models adjusting for possible confounders the difference between the HbA_1c groups disappeared. Pump users had the lowest SH risk, also after adjusting for possible confounders.

CONCLUSIONS

Risk of SH differs between the Nordic countries with the lowest risk in Sweden. Pump therapy was associated with decreased risk of SH. The low HbA_1c group had the same or a lower risk of SH compared with the highest HbA_1c groups. A target HbA_1c ≤6.7% (≤50 mmol/mol) seems achievable without increasing the risk of SH.

Equal access to health care may diminish the differences in outcome between native and immigrant patients with type 1 diabetes

BACKGROUND/OBJECTIVE

Previous studies have found that ethnicity influences glycemic control. We hypothesized that differences between Nordic and non-Nordic patients are less pronounced for children with type 1 diabetes in high incidence countries in Northern Europe.

RESEARCH DESIGN AND METHODS

We investigated patients aged 0-15 yr in national pediatric registers in Denmark (D), Iceland (I), Norway (N), and Sweden (S) (2006-2009). Ethnic origin was defined by maternal country of birth as being Nordic or non-Nordic (other countries).

RESULTS

The cohort (n = 11,908, 53.0% boys, onset age 7.7 (3.9) yr, diabetes duration 6.1 (3.6) yr, [mean, (SD)]) comprised 921 (7.7%) non-Nordic patients. The frequencies of non-Nordic patients according to country of residence were: 5.7% (D), 2.7% (I), 5.5% (N), and 9.4% (S). Sex distribution and BMI z-score did not differ between Nordic and non-Nordic patients, but non-Nordic patients were 0.5 yr younger at onset than Nordic patients (p < 0.0006). Non-Nordic patients had a lower number of daily insulin bolus injections and higher daily insulin doses compared to their Nordic peers. Patients of non-Nordic origin had slightly higher HbA1c levels (0.6-2.9 mmol/mol, p < 0.001) and, with the exception of Norway, were less frequently treated with CSII (p = 0.002) after adjusting for confounders.

CONCLUSIONS

The reported differences in glycemic regulation between Nordic and non-Nordic type 1 diabetes children and adolescents in four Nordic countries are diminutive, but persist after accounting for treatment intensity.

Childhood diabetes in the Nordic countries: a comparison of quality registries

In 2008 a Nordic collaboration was established between the quality registries in Denmark, Iceland, Norway, and Sweden to improve quality of care for children with diabetes. This study aimed to describe those registries and confirm that the registry variables are comparable. Selected variables were used to demonstrate outcome measurements. The organization of the registries and methodology are described. Cross-sectional data for patients between birth and 14.9 years with type 1 diabetes mellitus in 2009 (n = 6523) from 89 centers were analyzed. Variables were age, gender, and diabetic ketoacidosis at onset, together with age, gender, HbA1c, insulin regimen, and severe hypoglycemia at follow-up in 2009. All 4 registries use a standardized registration at the onset of diabetes and at follow-up, conducted at the local pediatric diabetes centers. Methods for measuring HbA1c varied as did methods of registration for factors such as hypoglycemia. No differences were found between the outcomes of the clinical variables at onset. Significant variations were found at follow-up for mean HbA1c, the proportion of children with HbA1c < 57 mmol/mol (NGSP/DCCT 7.4%), (range 15-31%), the proportion with insulin pumps (range 34-55%), and the numbers with severe hypoglycemia (range 5.6-8.3/100 patient years). In this large unselected population from 4 Nordic countries, a high proportion did not reach their treatment target, indicating a need to improve the quality of pediatric diabetes care. International collaboration is needed to develop and harmonize quality indicators and offers possibilities to study large geographic populations, identify problems, and share knowledge.

Cultural bias in the AAP's 2012 Technical Report and Policy Statement on male circumcision

The American Academy of Pediatrics recently released its new Technical Report and Policy Statement on male circumcision, concluding that current evidence indicates that the health benefits of newborn male circumcision outweigh the risks. The technical report is based on the scrutiny of a large number of complex scientific articles. Therefore, while striving for objectivity, the conclusions drawn by the 8 task force members reflect what these individual physicians perceived as trustworthy evidence. Seen from the outside, cultural bias reflecting the normality of nontherapeutic male circumcision in the United States seems obvious, and the report's conclusions are different from those reached by physicians in other parts of the Western world, including Europe, Canada, and Australia. In this commentary, a different view is presented by non-US-based physicians and representatives of general medical associations and societies for pediatrics, pediatric surgery, and pediatric urology in Northern Europe. To these authors, only 1 of the arguments put forward by the American Academy of Pediatrics has some theoretical relevance in relation to infant male circumcision; namely, the possible protection against urinary tract infections in infant boys, which can easily be treated with antibiotics without tissue loss. The other claimed health benefits, including protection against HIV/AIDS, genital herpes, genital warts, and penile cancer, are questionable, weak, and likely to have little public health relevance in a Western context, and they do not represent compelling reasons for surgery before boys are old enough to decide for themselves.

Childhood obesity and co-morbid problems: effects of Epstein's family-based behavioural treatment in an Icelandic sample

OBJECTIVE

This study assessed the effects of Epstein's family-based behavioural treatment in a clinical sample of obese children in Iceland. Also, it explored whether co-morbid concerns affect treatment outcome.

METHODS

Eighty-four obese children [mean body-mass-index standard-deviation-scores (BMI-SDS) = 3.11, aged 7.5-13.6 years] and a participating parent initiated treatment in response to a school-based screening. Sixty-one families completed treatment and were followed for 1 year post treatment. Measurements included height, weight, reports of psychological well-being (Strengths and Difficulties Questionnaire, Multidimensional Anxiety Scale for Children, Children's Depression Inventory, Piers-Harris Self Concept Scale, Social Skills Rating System) and academic competencies.

RESULTS

Among treatment completers a large effect size was obtained for change in BMI-SDS during treatment (mean difference = -0.40, SD = 0.29). Psychological well-being improved and treatment effects were maintained at 1-year follow-up. At baseline, 69% of the children presented with one or more co-morbid concerns. Children who scored above cut-off for concern on parent-reported hyperactivity (Strengths and Difficulties Questionnaire subscale T-score ≥ 65) reduced their BMI-SDS less during treatment than children with lower hyperactivity scores whereas children who scored in the clinical range for social anxiety (Multidimensional Anxiety Scale for Children subscale T-score ≥ 65) reduced their BMI-SDS significantly more than children with lower social anxiety scores. The social anxiety effect was still present at 1-year follow-up, but not the hyperactivity effect (P > 0.05). No differential response was shown for children with higher depression scores, lower self-concept or low academic competencies.

CONCLUSIONS

Epstein's family-based behavioural treatment produced promising effects in both the short and the longer term in a clinical sample of Icelandic children with substantial rates of co-morbid concerns. Co-morbid problems affect outcome and tailoring treatment to address co-morbid concerns might improve outcomes for certain subgroups.

The role of parental motivation in family-based treatment for childhood obesity

This study investigated the role of parental motivation (importance, confidence and readiness) for predicting dropout and outcome from family-based behavioral treatment for childhood obesity. Parent and child demographics, adherence to treatment, and weight loss parameters were also explored as potential predictors. Eighty-four obese children (BMI-standard deviation scores (SDS) >2.14) and a participating parent with each child started treatment consisting of 12 weeks of group and individual treatment sessions (24 sessions total) delivered over a period of 18 weeks. Sixty-one families (73%) completed treatment and attended follow-up at 1 year after treatment. Child session attendance and completion of self-monitoring records served as measures of adherence. In regression analyses, parent reports (pretreatment) of confidence for doing well in treatment was the strongest predictor of treatment completion (P = 0.003) as well as early treatment response (weight loss at week 5) (P = 0.003). This variable remained a significant predictor of child weight loss at post-treatment (P = 0.014), but was not associated with child outcome at 1-year follow-up (P > 0.05). The only significant predictor of child weight loss at that point was child baseline weight (P = 0.001). However, pretreatment parent ratings of importance of and readiness for treatment did not predict dropout or weight loss at any point. The results underscore the importance of addressing parental motivation, specifically parental confidence for changing lifestyle related behaviors, early in the treatment process. Doing so may reduce treatment dropout and enhance treatment outcome.

Asthma and allergy patterns over 18 years after severe RSV bronchiolitis in the first year of life

BACKGROUND

An increased prevalence of asthma/recurrent wheeze (RW), clinical allergy and allergic sensitisation up to age 13&emsp14;years has previously been reported in subjects hospitalised with respiratory syncytial virus (RSV) bronchiolitis in their first year of life compared with matched controls. A study was undertaken to examine whether these features persist into early adulthood, to report longitudinal wheeze and allergy patterns, and to see how large and small airway function relates to RSV infection and asthma.

METHODS

Follow-up at age 18 years was performed in 46 of 47 subjects with RSV and 92 of 93 controls. Assessments included questionnaire, clinical examination, skin prick tests, serum IgE antibodies to inhaled allergens, blood eosinophils, fraction of exhaled nitric oxide (FeNO), spirometry, multiple breath washout (lung clearance index, LCI) and dry air hyperventilation challenge.

RESULTS

Increased prevalence of asthma/RW (39% vs 9%), clinical allergy (43% vs 17%) and sensitisation to perennial allergens (41% vs 14%) were present at age 18 in the RSV cohort compared with controls. Persistent/relapsing wheeze associated with early allergic sensitisation predominated in the RSV cohort compared with controls (30% vs 1%). Spirometric function was reduced in subjects with RSV with or without current asthma, but not in asthmatic controls. LCI was linked only to current asthma, airway hyperresponsiveness and FeNO.

CONCLUSIONS

Severe early RSV bronchiolitis is associated with an increased prevalence of allergic asthma persisting into early adulthood. Small airway dysfunction (LCI) is related to current asthma and airway inflammation but not to RSV bronchiolitis. Reduced spirometry after RSV may reflect airway remodelling.

Decrease in adiponectin levels correlates to growth response in growth hormone-treated children

BACKGROUND/AIMS

Adiponectin is secreted by adipose tissue and circulates in human plasma at high levels. Decreased adiponectin levels are associated with insulin resistance and obesity. The aim of this study was to investigate whether changes in serum adiponectin levels are related to the growth response, insulin levels and insulin resistance during growth hormone (GH) treatment.

METHODS

The study included 94 short prepubertal children (19 girls and 75 boys). The mean age at the start of daily GH injections was 9.04 +/- 2.38 years. Adiponectin levels in serum were measured using an ELISA.

RESULTS

At baseline, adiponectin correlated with the first-year growth response (r = 0.26, p = 0.012). Adiponectin decreased significantly after 1 week, 3 months and 1 year from 14.5 +/- 5.71 to 13.1 +/- 5.22 (p < 0.0001), 10.3 +/- 4.82 (p < 0.0001) and 12.5 +/- 5.34 microg/ml (p < 0.0001), respectively. There were significant correlations between the first-year growth response and the decrease in adiponectin levels after 3 months and 1 year (r = -0.38, p < 0.0001 and r = -0.47, p < 0.0001, respectively). No correlations between adiponectin, insulin and the homeostasis model assessment of insulin resistance were seen.

CONCLUSIONS

GH treatment in prepubertal children decreases serum adiponectin levels, and the decrease is correlated to the growth response. No correlations between adiponectin and insulin levels or insulin resistance were found.

[Childhood type 1 diabetes in Iceland; evaluation of quality of treatment]

INTRODUCTION

The importance of adequate metabolic control in Type 1 DM has been repeatedly demonstrated in recent years. The care of diabetic children and adolescents in Iceland is centralized to one unit. The aim of the study was to analyze the quality of treatment and acute complications of Icelandic children with Type 1 diabetes.

METHODOLOGY

The total number of diabetic children in paediatric care was 98. A cross-sectional survey was done for the period March 15th to July 14th, 2004. The results for the patient last visit to the diabetes clinic were recorded. HbA1c levels (DCA 2000) and number of severe hypoglycaemic episodes, were evaluated.

RESULTS

The number of visits to the clinic during the 4 month interval were 83 (43 boys, 40 girls), mean age 13.3+/-3.78 years. Mean value of HbA1c in the cross-sectional survey was 8.16+/-1.31%. No difference in HbA1c was found between girls and boys. HbA1c increased with age in girls (p<0.01). Ten children experienced a total of 12 severe hypoglycaemic events during the period (43.4/100 patient years).

CONCLUSION

Overall the metabolic control in children and adolescents with IDDM in Iceland is satisfactory compared to internationally published results. It is important to focus attention on children with inadequate metabolic control, especially adolescent girls, and children experiencing serious hypoglycaemic episodes.

Exercise echocardiography reveals subclinical cardiac dysfunction in young adult survivors of childhood acute lymphoblastic leukemia

OBJECTIVE

Anthracyclines (AC) have contributed significantly to increased survival rate in acute lymphoblastic leukemia (ALL), although the use of these drugs is limited due to cardiotoxicity. The aim was to evaluate heart muscle function in asymptomatic adult survivors of ALL treated in early childhood in relation to the combined effects of AC and other potential cardiotoxic factors.

PROCEDURE

Twenty-three young adult ALL survivors who had all received treatment with median 120 (120-400) mg AC/m(2) before the onset of puberty were examined median 21 years after remission and compared with 12 healthy controls. Basal echocardiography including two-dimensional (2D) M-mode and Doppler examination was performed, followed by a maximal exercise stress test and stress echocardiography immediately after stress test and after 5 min recovery.

RESULTS

We found significant differences in systolic function between patients and controls at maximal exercise despite absence of reported symptoms from the patients. The most marked difference was in ejection fraction at stress 59.5% (32.6-81.1) and 77.3% (66.2-85.3), respectively (P < 0.00006). Ten out of 23 patients reduced their ejection fraction at stress compared with at rest; this was not found in any of the controls. Cardiovascular risk factors such as GH deficiency and a high proportion of trunk fat did not have an impact on cardiac function.

CONCLUSIONS

With very long follow up in a homogenous cohort of ALL survivors, we found subclinical cardiac dysfunction with exercise stress echocardiography even after low doses of AC.

Bone mineral density and bone turnover in young adult survivors of childhood acute lymphoblastic leukaemia

OBJECTIVE

Treatment for childhood leukaemia induces many risk factors for development of decreased bone mineral density (BMD). Physical activity is also known to affect BMD. The aim was to study BMD and markers of bone turnover in a well-defined group of survivors of acute lymphoblastic leukaemia (ALL) who had all reached final height as well as peak bone mass, taking both previous treatment and physical activity into consideration.

DESIGN

All patients treated for ALL before the onset of puberty in the region of western Sweden, between 1973 and 1985, in first remission were included. Thirty-five out of forty-seven patients aged 20-32 years participated. Nineteen patients had received cranial radiotherapy, and the median follow-up time was 20 years.

METHODS

BMD was assessed using dual-energy X-ray absorptiometry (DEXA). Serum concentrations of markers of bone turnover were analysed. Physical performance was measured using a performance exercise capacity stress test.

RESULTS

BMD was slightly reduced in lumbar spine (-0.4 SD), but not in femoral neck or total body. BMD in femoral neck was correlated to physical performance and dose of corticosteroid, but no correlation was found with spontaneous growth hormone (GH) secretion. Markers of bone turnover were also correlated to physical performance, but not to GH secretion.

CONCLUSIONS

Physical fitness seems to be the most important factor in developing and preserving normal bone mineral density in ALL patients. We propose that lifestyle education promoting physical activity is encouraged from an early point in time for these patients.

Body composition in young adult survivors of childhood acute lymphoblastic leukaemia

OBJECTIVE

Obesity is frequently reported in patients treated for childhood leukaemia. Obesity, particularly abdominal obesity, is one of the main characteristics of the metabolic syndrome and a risk factor for cardiovascular disease and non-insulin-dependent diabetes mellitus (NIDDM).

DESIGN

All patients treated for acute lymphoblastic leukaemia (ALL) before the onset of puberty in the region of western Sweden, between 1973 and 1985, and in first remission, were included. 35 out of 47 patients aged 20-32 years participated. 19 patients had received cranial radiotherapy, and the median follow-up time was 20 years. The focus of this report was to study body composition and signs of the metabolic syndrome and correlate the findings to spontaneous growth hormone (GH) secretion.

METHODS

Body composition was assessed using dual-energy X-ray absorbtiometry (DEXA). We analyzed serum concentrations of insulin, glucose, leptin and lipids.

RESULTS

No patient was obese according to World Health Organization criteria (body mass index, BMI > or = 30 kg/m2) but one-third were overweight (BMI 25-29.9 kg/m2). The maximal GH peak during 24 h (GHmax) was correlated to percentage of total body fat (r = -0.42; P = 0.017), trunk fat (r = -0.5; P = 0.005) and fat-free mass (r = 0.42; P = 0.017). GHmax was also correlated to s-triglycerides (r = -0.54; P = 0.001), low-density lipoprotein-cholesterol (r = -0.382; P = 0.024) and high-density lipoprotein-cholesterol (r = 0.45; P = 0.007).

CONCLUSIONS

We found little effect on BMI but an increased percentage of total body fat, especially trunk fat, and a tendency for an unfavourable lipid profile in adult survivors of childhood leukaemia. These findings were related to low endogenous GH secretion due to cranial irradiation.

Severe respiratory syncytial virus bronchiolitis in infancy and asthma and allergy at age 13

We have prospectively studied wheezing disorder and allergy in 47 children hospitalized with respiratory syncytial virus (RSV) bronchiolitis in infancy and 93 matched control subjects. Subjects with at least three episodes of wheezing were defined as recurrent wheezers and as having asthma if the episodes were doctor verified. Here we report the outcome at age 13 years in 46/47 children with RSV and 92/93 control subjects. Wheezing disorder and clinical allergy were estimated using a questionnaire. Skin prick tests were performed and serum IgE antibodies measured. Spirometry was undertaken at rest, after dry air challenge, and after beta2-agonist inhalation. The occurrence of symptoms over the previous 12 months was significantly higher in the RSV group than among the control subjects, 43% versus 8% for asthma/recurrent wheezing and 39% versus 15% for allergic rhinoconjunctivitis. Sensitization to common inhaled allergens was more frequent in the RSV group than in the control subjects, judged by skin prick tests (50% versus 28%; p = 0.022), or by serum IgE antibodies (45% versus 26%; p = 0.038). Compared with the control subjects, the RSV group showed mild airway obstruction both at rest and after bronchodilation, and had slightly more reactive airways. RSV bronchiolitis in infancy severe enough to cause hospitalization is a risk factor for allergic asthma in early adolescence.

Young adult survivors of childhood acute lymphoblastic leukemia: spontaneous GH secretion in relation to CNS radiation

BACKGROUND

Young adults who are long-term survivors of acute lymphoblastic leukaemia (ALL) in early childhood usually do well and do not have to go to regular medical checkups. Many of these survivors did receive prophylactic cranial radiotherapy during their oncological treatment. The effect of cranial irradiation on the hypothalamus is considered to be progressive. Therefore, late effects, such as reduced growth hormone (GH) secretion, may remain undetected until adulthood.

PROCEDURE

Records from all patients treated for ALL before the onset of puberty in the region of West Sweden, between 1 January 1973 and 31 December 1985 were included, provided they were in first remission with a minimum follow-up time of 15 years, and a minimum age of 20. These criteria were met by 47 young adults aged 20-32 years, of whom 35 agreed to participate. We studied spontaneous GH secretion over 24 hr, IGF-I and IGFBP-3, final height and BMI. The patients had been treated according to three consecutive Swedish childhood leukaemia group protocols. The median follow-up time was 20 years, and 19 of the patients had been treated with cranial irradiation (CRT+), 16 had not (CRT-).

RESULTS

CRT+ patients had significantly lower maximal peaks of GH than CRT- patients. Fifty percent of the CRT+ patients had a GH(max) below the cut-off level (3.3 microg/l), for GH treatment. CRT- patients all had GH(max) levels considered within the normal range. Final height of all the patients, except one CRT+ women, was in the range of expected midparental height, the median loss in final height in the CRT+ patients was 0.8 standard deviation (SD). No patient in this study was obese by definition (BMI <30 kg/m(2)). IGF-I and IGFBP-3 concentrations did not correlate to variations in spontaneous GH secretion in these patients.

CONCLUSIONS

In spite of the little effect on final height, we found impaired spontaneous GH secretion in 79% of young adults 20-32 years of age, and GH deficiency (GHD) in 47% after low-dose cranial irradiation in early childhood. The consequences of this low-GH secretion need to be investigated.

Standard and low-dose IGF-I generation tests and spontaneous growth hormone secretion in children with idiopathic short stature

OBJECTIVE

Abnormalities in the GH-IGF-I axis, consistent with GH insensitivity (GHI), have been reported in some patients with idiopathic short stature (ISS). The standard IGF-I generation test (IGFGT) has not demonstrated mild GHI in subjects with ISS. The aim of this study was to investigate the GH-IGF-I axis in ISS by performing standard and novel low-dose IGFGTs together with determination of spontaneous GH secretion.

PATIENTS AND METHODS

Twenty-one (17 male) prepubertal children with ISS, mean age 8.3 years (4.5-12.2), mean height -3.48 SD (-5.40 to -1.79), mean peak GH to provocation with glucagon/clonidine 32.3 mU/l (14.1-66.0) were studied. Serum IGF-I and IGFBP-3 levels were measured during standard (GH 0.033 mg/kg/day x 4) and low (GH 0.011 mg/kg/day x 4) dose IGFGTs at 0, 12, 36 and 84 h. The low-dose IGFGT was performed in seven naive GH-deficient patients (4 male), mean age 8.5 years (range 4.1-11.1). Determination of spontaneous 24-h GH secretion was performed in the 21 ISS patients.

RESULTS

Basal IGF-I and IGFBP-3 standard deviation scores (SDS) in ISS patients were -1.39 (-2.4-1.16) and -0.45 (-1.13-0.38), respectively, IGF-I being lower than IGFBP-3 (P < 0.0001). IGF-I increased in the standard IGFGT at 12 h (P < 0.005), 36 h (P < 0.001) and 84 h (P < 0.001); maximal increment 1.54 (-0.32-3.48), and in the low-dose test at 12 h (P < 0.005), 36 h (P < 0.001) and 84 h (P < 0.005); maximal increment 0.53 (0.08 to -1.23). IGFBP-3 SDS increased in the standard IGFGT at 36 h (P < 0.01) and 84 h (P < 0.001); maximal increment 0.72 (-0.44-1.96), and in the low-dose test at 84 h (P < 0.005); maximal increment 0.33 (-0.08-0.87). Five/19 patients with an IGF-I response > 2 x coefficient of variation (CV) of assay in the standard test failed to respond in the low-dose test, suggestive of mild GHI. In GH-deficient patients, IGF-I increased at each time point (P < 0.05) and IGFBP-3 at 36 h (P < 0.05). Mean GH secretion, expressed in SDS, compared with 66 normal stature controls was: basal GH -0.48 (-0.84-0.93), height of GH peaks compared with zero -0.36 (-1.26-1.51) (both P < 0.05), total GH secretion -0.76 (-1.22-0.42), total GH secretion above baseline -0.67 (-1.21-0.94) (both P < 0.01).

CONCLUSIONS

In children with ISS, basal IGF-I and IGFBP-3 SDS values were below the mean, IGF-I showing a greater response in both IGFGTs. In the standard IGFGT, the IGF-I increase at 36 h was equal to that at 84 h. The low-dose IGFGT, in combination with the standard test, may identify patients with mild GHI.

Short-term gluten challenge in children with coeliac disease does not impair spontaneous growth hormone secretion

BACKGROUND

Growth retardation in children with coeliac disease has been attributed to impaired growth hormone (GH) secretion observed in stimulation tests.

OBJECTIVE

This study aimed at investigating the possible change in spontaneous GH secretion during a standardised gluten challenge.

PATIENTS

Twelve children with previous enteropathy suggesting coeliac disease and a normal pre-challenge biopsy on a gluten-free diet were included; eight of them completed all parts of the study, including repeated 24-h GH sampling.

METHODS

At the start and the end of a 5-6 weeks standardised gluten challenge, blood was drawn at a constant rate for 24 h and collected for GH analysis at 20-min intervals. The graph of plotted GH values was analysed by means of a computer program (PULSAR).

RESULTS

No significant changes were seen in the measures of maximum GH peak, baseline GH values, area under the curve over the baseline (AUCb), the number of GH peaks or mean GH concentration. GH secretion rate (GHt) increased slightly. None of the characteristics of the 24-h profile was significantly correlated to the change of IGF-I.

CONCLUSION

No impaired GH secretion was found. Thus, we speculate that decreased growth rate in celiac disease may not be primarily caused by changes in GH secretion. Instead it may be caused by changed peripheral sensitivity to GH.

Body composition, as assessed by bioelectrical impedance spectroscopy and dual-energy X-ray absorptiometry, in a healthy paediatric population

The aim of this study was to determine the level of agreement between body composition measurements by dual-energy X-ray absorptiometry (DXA), single-frequency bioelectrical impedance analysis (BIA) and multifrequency bioelectrical impedance spectroscopy (BIS). Fat-free mass (FFM), body fat mass and body fatness (percentage fat) were measured by DXA, BIA and BIS in 61 healthy children (37M, 24F, aged 10.9-13.9 y). Estimates of FFM, body fat mass and body fatness were highly correlated (r = 0.73-0.96, p < 0.0001) between the different methods. However, a Bland-Altman comparison showed wide limits of agreement between the methods. The mean differences between methods for FFM ranged from -2.31 +/- 7.76 kg to 0.48 +/- 7.58 kg. Mean differences for body fat mass ranged from 0.16 +/- 5.06 kg to 2.95 +/- 5.65 kg and for body fatness from -2.3 +/- 7.8% to 0.8 +/- 9.3%. Calculations of body composition with BIS were not superior to BIA. However, BIA overestimated fat mass in lean, subjects and underestimated fat mass in overweight subjects more than BIS, compared with DXA.

CONCLUSION

The methods used provided estimates of FFM, body fat mass and body fatness that were highly correlated in a population of healthy children. However, the large limits of agreement derived from the Bland-Altman procedure suggest that the methods should not be used interchangeably.

Spontaneous growth hormone secretory characteristics in children with partial growth hormone insensitivity

OBJECTIVE

To investigate the characteristics of spontaneous GH secretion in four male children with short stature due to partial GH insensitivity. Their molecular defect consists of inclusion of a mutant intronic pseudoexon in the region of the GH receptor involved in homodimerization.

SUBJECTS

The subjects were two pairs of brothers who were first cousins, aged 10.4-14.2 years, heights -3.3 to -5.6 SDS, from a consanguineous Pakistani family. Basal serum IGF-I levels were extremely low (20-29 mg/l; NR > 50), with absent or minimal response to human recombinant GH (hGH) stimulation. Serum IGFBP-3 SDS levels were also low (-2.9 to -8.9). GH binding protein (GHBP) levels were normal (28.1-51.7%).

METHODS

Spontaneous GH secretion was studied by intermittent (20 min) venous sampling from 2000 to 0800 h. The secretion profiles were analysed using the Pulsar programme and compared to data from a reference population of 76 prepubertal Swedish children [median age 10.7 years, median height -1.1 SDS (-2.0 to 1.4)] according to Swedish growth standards.

RESULTS

Median (range) Pulsar-derived values in the four patients and controls were, respectively: GHmax (mU/l) 276.6 (178.7-325.8) and 27.2 (13.1-94.9), mean GH (mU/l) 64.5 (41.9-77.8) and 5.8 (3.2-20.6), baseline (mU/l) 12.3 (11.7-20.1) and 1.1 (0.2-6.1), AUCb (mU/l x 24 h) 1210 (684-1555) and 112.5 (60.6-316.4), i.e. all parameters of GH secretion in the four patients were markedly elevated compared with the control population.

CONCLUSIONS

Spontaneous GH secretion is elevated in partial GH insensitivity. This investigation could be of diagnostic value in children with short stature.

Enhanced IL-4 responses in children with a history of respiratory syncytial virus bronchiolitis in infancy

Infants who recover from respiratory syncytial virus (RSV)-induced bronchiolitis are at high risk of developing asthma and recurrent wheezing. It is not known whether severe RSV infection itself causes persistent effects or is a marker of a "wheezy" predisposition. To determine the long-term immunological correlates of infantile bronchiolitis, interleukin (IL)-4 and interferon (IFN)-gamma responses to a panel of antigens were studied in a well-characterised cohort of 7-8-yr-old children with a history of severe RSV bronchiolitis in infancy. Peripheral blood lymphocytes from 37 children who were hospitalised with RSV bronchiolitis in infancy and from 69 age-, sex- and location-matched controls were stimulated in vitro with RSV, house-dust mite, birch and cat antigens. Cellular proliferation, and enzyme-linked immunoSPOT IFN-gamma and IL-4 production were measured. IL-4 producing T-cells responding to RSV and cat antigens were significantly more frequent in exbronchiolitics. Other responses (including the IFN-gamma response to RSV) were equally strong in exbronchiolitics and controls. Respiratory syncytial virus infection primes memory T-cells that make interferon-gamma, but virus and aeroallergen-specific and interleukin-4 producing T-cells are also frequently primed in bronchiolitics. Respiratory syncytial virus bronchiolitis in infancy may increase the risk of allergic sensitisation by providing a local interleukin-4-rich environment, in which airborne allergens are first encountered.

Currently used growth-promoting treatment of children results in normal bone mass and density. A prospective trial of discontinuing growth hormone treatment in adolescents

BACKGROUND AND AIMS

The need for continued GH replacement in patients with childhood-onset GH deficiency (GHD) into adulthood has been recognized. The consequences of discontinuing GH treatment on bone mineralization in adolescent patients with GHD and short stature were examined over a period of 2 years.

PATIENTS

Forty adolescents (aged 16-21 years) treated with GH for more than 3 years and 16 closely matched healthy controls were studied. After a baseline visit, GH treatment was discontinued. The patients were then re-examined with the same protocol after 1 and 2 years. Twenty-one patients had continuing severe GHD into adulthood, while 19 patients were regarded as having sufficient endogenous GH secretion (GHS).

RESULTS

At baseline, there were no differences between the groups in total bone mineral content (BMC) or bone mineral density (BMD). After 2 years without GH treatment, BMC increased similarly in the GHD and GHS groups. BMC of the lumbar spine (L2-L4) increased only in the GHD group. Lumbar spine BMD increased in the GHD and the GHS groups. No changes were observed in the femoral neck region. Biochemical measurements showed that carboxy-terminal cross-linked telopeptide of type I collagen (ICTP) and bone specific alkaline phosphates (ALP) were higher in the GHD and GHS groups at baseline compared with controls. Osteocalcin, carboxy-terminal propeptide of type I procollagen (PICP), ICTP and ALP decreased during the 2 years off treatment in both the GHD and GHS groups. PICP was also lower after 2 years in the GHD group compared with both the GHS group and controls.

CONCLUSIONS

After discontinuation of GH therapy in adolescents at or near final height, there was a continued increase in BMC and BMD both for adolescents with growth hormone deficiency and for those classified as growth hormone sufficient. These groups did not differ from controls at baseline or after 2 years. In the growth hormone deficiency group, biochemical markers for bone formation decreased to levels below those in the growth hormone sufficient and healthy control groups. Although the number of patients and controls in this study were small, the results indicate that the present treatment of Swedish GH-deficient children to final height results in normal BMD.

The decrease of IGF-I, IGF-binding protein-3 and bone alkaline phosphatase isoforms during gluten challenge correlates with small intestinal inflammation in children with coeliac disease

OBJECTIVE

In children with coeliac disease, the ingestion of gluten causes small intestinal inflammation and a clinical picture of malabsorption, weight reduction and short stature. Decreased alkaline phosphatase (ALP) during gluten challenge was found in a previous study. ALP is a marker of bone formation and ALP activities are correlated with growth velocity. The aim of this study was to characterise the previously observed decrease of total ALP by investigating three specific bone ALP isoforms (bone/intestinal, B1 and B2) and three specific liver ALP isoforms (L1, L2 and L3) and, moreover, to correlate these ALP isoforms with other growth factors and growth markers. In addition, we also studied the association with possible weight changes, small intestinal mucosa inflammation, sex, age and gluten dose during gluten challenge.

MATERIALS AND METHODS

Bone and liver ALP isoforms, IGF-I, IGF-binding protein (IGFBP)-3 and serum cross-linked carboxy-terminal telopeptide of type I collagen (ICTP) were measured together with change in weight and small intestinal mucosa histopathology in 54 children with earlier enteropathy who participated in a 4-week gluten challenge.

RESULTS

We observed a decreased total ALP activity after 4 weeks of gluten challenge, 7.8+/-1.8 to 6.5+/-1.7 microkat/l (means +/- s.d.), which was mainly due to a reduction of the bone ALP isoforms. The sum of all three bone ALP isoforms decreased from 6.3+/-1.7 to 5.1+/-1.6 microkat/l. The decreased activities of the bone ALP isoforms correlated with the observed reductions of IGF-I (r=0.74, P<0.001), IGFBP-3 (r=0.51, P<0.001) and ICTP (r=0.57, P<0.001). The decrease of the growth factors and growth markers correlated with weight reduction, but when influences from the change in weight were adjusted for, the partial correlation of the small intestinal mucosa inflammation was significant for IGF-I (r=-0.56, P<0.001) and IGFBP-3 (r=-0.55, P<0.001).

CONCLUSION

The decrease of total ALP was due to a reduction of bone ALP. The decrease of IGF-I and IGFBP-3 was independently correlated with weight change and small intestinal inflammation.

Respiratory syncytial virus bronchiolitis in infancy is an important risk factor for asthma and allergy at age 7

We previously reported an increased risk for bronchial obstructive disease and allergic sensitization up to age 3 in 47 children hospitalized with a respiratory syncytial virus (RSV) bronchiolitis in infancy compared with 93 matched control subjects recruited during infancy. The aims of the present study were to evaluate the occurrences of bronchial obstructive disease and allergic sensitization in these children at age 7(1)/ (2). All 140 children reported for the follow-up, which included physical examination, skin prick tests, and serum IgE tests for common food and inhaled allergens. The cumulative prevalence of asthma was 30% in the RSV group and 3% in the control group (p < 0.001), and the cumulative prevalence of "any wheezing" was 68% and 34%, respectively (p < 0.001). Asthma during the year prior to follow-up was seen in 23% of the RSV children and 2% in the control subjects (p < 0.001). Allergic sensitization was found in 41% of the RSV children and 22% of the control subjects (p = 0.039). Multivariate evaluation of possible risk factors for asthma and sensitization using a stepwise logistic statistical procedure for all 140 children showed that RSV bronchiolitis had the highest independent risk ratio for asthma (OR: 12.7, 95% CI 3.4 to 47.1) and a significantly elevated independent risk ratio for allergic sensitization (OR: 2.4, 95% CI 1.1 to 5.5). In conclusion, RSV bronchiolitis in infancy severe enough to cause hospitalization was highly associatied with the development of asthma and allergic sensitization up to age 7(1)/ (2). The results support the theory that the RSV influences the mechanisms involved in the development of asthma and allergy in children.

Serum leptin levels correlate with growth hormone secretion and body fat in children

The aim of this study was to investigate the relationship among GH secretion, leptin concentrations, and body composition measured with x-ray absorptiometry (DXA) in children. In total, 71 children were investigated, 51 males and 20 females. Their mean chronological age was 10.8 yr (range, 6.2-17.7 ys), and their mean height (SD) was -2.1 (0.63) SD scores. Their mean weight for height SD scores (WH(SDS)) was 0.2 (1.18). Body composition was investigated using DXA. Blood samples were taken for analysis of leptin, insulin-like growth factor I (IGF-I), IGF-binding protein-3, and 24-h GH secretion. A positive correlation was found between leptin and total body fat (r = 0.83; P < 0.0001) and when fat was expressed as a percentage of body weight (r = 0.86; P < 0.0001). There were significant (P < 0.0001) relationships between leptin and WH(SDS) (r = 0.45) and between leptin and body mass index (r = 0.69). A significant gender difference in leptin levels was found, but this disappeared after adjustment for body fat, as measured by DXA. There were significant (P < 0.001) inverse correlations between leptin and the AUCb for GH (r = -0.41), leptin, and GHmax (r = -0.38), where AUCb is the area under the curve above the calculated baseline, and GHmax is the maximum peak during the 24-h GH profile (percent fat and AUCb for GH, r = -0.43; percent fat and GHmax, r = -0.39). In a multiple stepwise forward regression analysis with leptin as the dependent variable, the percent trunk fat accounted for 77.7% of the leptin variation. With AUCb for GH as the dependent variable, the percent trunk fat accounted for 20.3% of the variation. With GHmax as the dependent variable, the percent trunk fat accounted for 18.8% of the variation, IGF-binding protein-3 for another 8.5%, and the percentage of fat from arms and legs for another 4.4%. We demonstrated a strong positive correlation between leptin levels and body fat, a significant negative correlation between leptin levels and GH secretion, and a significant negative correlation between body fat and GH secretion. We have also shown that specific regional fat depots have different relationships with leptin and particular markers of GH secretion.

Changes in body composition and leptin levels during growth hormone (GH) treatment in short children with various GH secretory capacities

OBJECTIVE

The aim of this study was to follow changes in body composition, estimated by dual-energy X-ray absorptiometry (DXA), in relation to changes in leptin during the first year of GH therapy in order to test the hypothesis that leptin is a metabolic signal involved in the regulation of GH secretion in children.

DESIGN AND METHODS

In total, 33 prepubertal children were investigated. Their mean (S.D.) chronological age at the start of GH treatment was 11.5 (1.6) years, and their mean height was -2.33 (0.38) S.D. scores (SDS). GH was administered subcutaneously at a daily dose of 0.1 (n=26) or 0.2 (n=7) IU/kg body weight. Ten children were in the Swedish National Registry for children with GH deficiency, and twenty-three children were involved in trials of GH treatment for idiopathic short stature. Spontaneous 24-h GH secretion was studied in 32 of the children. In the 24-h GH profiles, the maximum level of GH was determined and the secretion rate estimated by deconvolution analysis (GHt). Serum leptin levels were measured at the start of GH treatment and after 10 and 30 days and 3, 6 and 12 months of treatment. Body composition measurements, by DXA, were performed at baseline and 12 months after the onset of GH treatment.

RESULTS

After 12 months of GH treatment, mean height increased from -2.33 to -1.73 SDS and total body fat decreased significantly by 3.0 (3.3)%. Serum leptin levels were decreased significantly at all time points studied compared with baseline. There was a significant correlation between the change in total body fat and the change in serum leptin levels during the 12 months of GH treatment, whereas the leptin concentration per unit fat mass did not change. In a multiple stepwise linear regression analysis with 12 month change in leptin levels as the dependent variable, the percentage change in fat over 12 months, the baseline fat mass (%) of body mass and GHt accounted for 24.0%, 11.5% and 12.2% of the variability respectively.

CONCLUSIONS

There are significant correlations between changes in leptin and fat and endogenous GH secretion in short children with various GH secretory capacities. Leptin may be the messenger by which the adipose tissue affects hypothalamic regulation of GH secretion.