Neonatal Outcomes After COVID-19 Vaccination in Pregnancy

Importance

Better knowledge about neonatal adverse events after COVID-19 vaccination during pregnancy could help address concerns about vaccine safety.

Objective

To evaluate the risks of neonatal adverse events after exposure to COVID-19 vaccination during pregnancy.

Design, Setting, and Participants

Population-based cohort study including all infants in Sweden and Norway born from June 2021 to January 2023. Unique personal identity numbers were used to link individual information from different national registers.

Exposure

Administration of any mRNA vaccine against COVID-19 during pregnancy, irrespective of previous vaccination, number of doses during pregnancy, or vaccine manufacturer.

Main Outcomes and Measures

Outcomes were neonatal conditions with bleeding/thrombosis or inflammation/infection; disorders of the central nervous system; circulatory, respiratory, or gastrointestinal problems; and neonatal mortality. Statistical methods included logistic regression adjusted for characteristics of the pregnant individuals, with additional restricted and stratified analyses.

Results

Of 196 470 newborn infants included (51.3% male, 93.8% born at term, 62.5% born in Sweden), 94 303 (48.0%) were exposed to COVID-19 vaccination during pregnancy. Exposed infants exhibited no increased odds of adverse neonatal outcomes, and they exhibited lower odds for neonatal nontraumatic intracranial hemorrhage (event rate, 1.7 vs 3.2/1000; adjusted odds ratio [aOR], 0.78 [95% CI, 0.61-0.99]), hypoxic-ischemic encephalopathy (1.8 vs 2.7/1000; aOR, 0.73 [95% CI, 0.55-0.96]), and neonatal mortality (0.9 vs 1.8/1000; aOR, 0.68 [95% CI, 0.50-0.91]). Subgroup analyses found a similar association between vaccination during pregnancy and lower neonatal mortality; subgroups were restricted to infants delivered by individuals unvaccinated before pregnancy, individuals vaccinated before pregnancy, individuals vaccinated after a general recommendation of vaccination during pregnancy was issued, and individuals without COVID-19 infection during pregnancy. Analyses restricted to term infants, singleton births, or infants without birth defects yielded similar results. Stratifying the analysis by vaccine manufacturer did not attenuate the association between vaccination and low neonatal mortality.

Conclusions and Relevance

In this large population-based study, vaccination of pregnant individuals with mRNA COVID-19 vaccines was not associated with increased risks of neonatal adverse events in their infants.

The influence of immigrant background and parental education on overweight and obesity in 8-year-old children in Norway

BACKGROUND

Little is known about the prevalence of overweight/obesity and socio-economic position (SEP) in children with immigrant background in Scandinavia. The purpose of this study is to examine the prevalence of overweight/obesity by immigrant background among children in Norway and to explore the role of SEP in explaining differences in weight status.

METHODS

Anthropometric data from 8,858 children (age 8.3 years) from the population-based Norwegian Childhood Growth Study were used. Information about immigrant background, country of origin, and parental education (used as an indicator of SEP) were provided by Statistics Norway. For children with immigrant background, regional background was determined based on country of origin. Prevalence ratios (PR) were estimated for overweight/obesity and weight-to-height-ratio (WHtR) ≥ 0.5 by immigration and regional background, using generalized estimating equation log-binominal models adjusting for sex, age, survey year (model 1), residential area, population density (model 2) and parental education (model 3).

RESULTS

Children with immigrant background had a higher prevalence of overweight/obesity and WHtR ≥ 0.5 than non-immigrant background children. Adjusted for parental education, children with an immigrant background from Southern and Eastern Europe, Asia except South-Asia, and Africa had a higher prevalence of overweight/obesity [PR: 1.37 (95% confidence interval (CI): 1.10-1.72), 1.28 (1.05-1.57), 1.47 (1.13-1.91), respectively] than children with a non-immigrant background. Children originating from Asia except South-Asia had a higher prevalence of WHtR ≥ 0.5 (PR: 1.64, CI: 1.25-2.15) compared to non-immigrant background children. The adjustment for parental education did not substantially change the results.

CONCLUSION

Children with immigrant background had higher prevalence of overweight/obesity than non-immigrant background children. The difference varied according to region of origin but not substantially according to parental education. There is a need for culturally acceptable preventative measures targeting the parents of immigrant background children.

Perceived barriers in family-based behavioural treatment of paediatric obesity - Results from the FABO study

BACKGROUND

To date, few studies have investigated perceived barriers among those who participate in and drop out of family-based behavioural treatment (FBT) for paediatric obesity. Examining experienced barriers during treatment, and their role in participation and completion of treatment has important implications for clinical practice.

OBJECTIVES

To compare perceived barriers to participating in a family-based behavioural social facilitation treatment (FBSFT) for obesity among families who completed and did not complete treatment.

METHODS

Data were analysed from 90 families of children and adolescents (mean (M) age = 12.8 years, standard deviation (SD) = 3.05) with severe obesity enrolled in a 17-session FBSFT program. After completing 12 sessions or at the time of dropout, parents and therapists completed the Barriers to Treatment Participation Scale (BTPS), a 5-point Likert scale (1 = never a problem, 5 = very often a problem) which includes four subscales: 1. Stressors and obstacles that compete with treatment, 2. Treatment demands and issues, 3. Perceived relevance of treatment, 4. Relationship with the therapist.

RESULTS

Families who did not complete treatment scored significantly higher on the BTPS subscales stressors and obstacles that compete with treatment (M = 2.03, SD = 0.53 vs. M = 1.70, SD = 0.42), p = 0.010 and perceived relevance of treatment (M = 2.27, SD = 0.48 vs. M = 1.80, SD = 0.50), p < 0.001 than families who completed treatment. No other significant differences between groups were observed.

CONCLUSION

Families are more likely to drop out of FBSFT when experiencing a high burden from life stressors or when treatment is not meeting the expectations and perceived needs of the family.

Deep phenotyping of pubertal development in Norwegian children: the Bergen Growth Study 2

BACKGROUND

The Bergen Growth Study 2 (BGS2) aims to characterise somatic and endocrine changes in healthy Norwegian children using a novel methodology.

SUBJECTS AND METHODS

A cross-sectional sample of 1285 children aged 6-16 years was examined in 2016 using novel objective ultrasound assessments of breast developmental stages and testicular volume in addition to the traditional Tanner pubertal stages. Blood samples allowed for measurements of pubertal hormones, endocrine disruptive chemicals, and genetic analyses.

RESULTS

Ultrasound staging of breast development in girls showed a high degree of agreement within and between observers, and ultrasound measurement of testicular volume in boys also showed small intra- and interobserver differences. The median age was 10.4 years for Tanner B2 (pubertal onset) and 12.7 years for menarche. Norwegian boys reached a pubertal testicular volume at a mean age of 11.7 years. Continuous reference curves for testicular volume and sex hormones were constructed using the LMS method.

CONCLUSIONS

Ultrasound-based assessments of puberty provided novel references for breast developmental stages and enabled the measurement of testicular volume on a continuous scale. Endocrine z-scores allowed for an intuitive interpretation of changing hormonal levels during puberty on a quantitative scale, which, in turn, provides opportunities for further analysis of pubertal development using machine-learning approaches.

Trends in the prevalence of breastfeeding up to 6 months of age using structured data from routine child healthcare visits

AIM

The Norwegian Action Plan for a Healthier Diet (2017-2021) set the target that 25% of infants should be exclusively breastfed for 6 months by 2022. Our aim was to determine trends in the prevalence and duration of breastfeeding in the municipality of Bergen.

METHODS

Data on breastfeeding status in 2010-2018 were extracted from a standardised electronic medical record kept by public child health centres and recorded as exclusive, partial or none, at 6 weeks and 6 months of age.

RESULTS

We found that 28,503 and 26,735 infants attended the 6-week and 6-month consultations, respectively. The prevalence of any breastfeeding was 92.0% at 6 weeks and 78.0% at 6 months with no trend over time between 2010 and 2018. The prevalence of exclusive breastfeeding at 6 weeks was 73.9% and stable over time, but it declined at 6 months, from 28.1% in 2010 to 11.1% in 2014 and remained stable thereafter.

CONCLUSION

During 2010-2018, the prevalence of any and exclusive breastfeeding at 6 weeks and any breastfeeding at 6 months was stable. Exclusive breastfeeding at 6 months declined halfway through the study period, to a stable, but low, prevalence of 11.1% by 2014.

Changes in life expectancy and disease burden in Norway, 1990–2019: an analysis of the Global Burden of Disease Study 2019

Background

Methods

Findings

Interpretation

Funding

Family-based treatment of children with severe obesity in a public healthcare setting: Results from a randomized controlled trial

To compare the effectiveness of family-based behavioural social facilitation treatment (FBSFT) versus treatment as usual (TAU) in children with severe obesity. Parallel-design, nonblinded, randomized controlled trial conducted at a Norwegian obesity outpatient clinic. Children aged 6-18 years referred to the clinic between 2014 and 2018 were invited to participate. Participants were randomly allocated using sequentially numbered, opaqued, sealed envelopes. FBSFT (n = 59) entailed 17 sessions of structured cognitive behavioural treatment, TAU (n = 55) entailed standard lifestyle counselling sessions every third month for 1 year. Primary outcomes included changes in body mass index standard deviation score (BMI SDS) and percentage above the International Obesity Task Force cut-off for overweight (%IOTF-25). Secondary outcomes included changes in sleep, physical activity, and eating behaviour. From pre- to posttreatment there was a statistically significant difference in change in both BMI SDS (0.19 units, 95% confidence interval [CI]: 0.10-0.28, p < .001) and %IOTF-25 (5.48%, 95%CI: 2.74-8.22, p < .001) between FBSFT and TAU groups. FBSFT participants achieved significant reductions in mean BMI SDS (0.16 units, (95%CI: -0.22 to -0.10, p < .001) and %IOTF-25 (6.53%, 95% CI: -8.45 to -4.60, p < .001), whereas in TAU nonsignificant changes were observed in BMI SDS (0.03 units, 95% CI: -0.03 to 0.09, p = .30) and %IOTF-25 (-1.04%, 95% CI: -2.99 to -0.90, p = .29). More FBSFT participants (31.5%) had clinically meaningful BMI SDS reductions of ≥0.25 from pre- to posttreatment than in TAU (13.0%, p = .021). Regarding secondary outcomes, only changes in sleep timing differed significantly between groups. FBSFT improved weight-related outcomes compared to TAU.

Characterization of the genetic architecture of infant and early childhood body mass index

Early childhood obesity is a growing global concern; however, the role of common genetic variation on infant and child weight development is unclear. Here, we identify 46 loci associated with early childhood body mass index at specific ages, matching different child growth phases, and representing four major trajectory patterns. We perform genome-wide association studies across 12 time points from birth to 8 years in 28,681 children and their parents (27,088 mothers and 26,239 fathers) in the Norwegian Mother, Father and Child Cohort Study. Monogenic obesity genes are overrepresented near identified loci, and several complex association signals near LEPR, GLP1R, PCSK1 and KLF14 point towards a major influence for common variation affecting the leptin-melanocortin system in early life, providing a link to putative treatment strategies. We also demonstrate how different polygenic risk scores transition from birth to adult profiles through early child growth. In conclusion, our results offer a fine-grained characterization of a changing genetic landscape sustaining early childhood growth.

A nationwide school fruit and vegetable policy and childhood and adolescent overweight: A quasi-natural experimental study

BACKGROUND

School free fruit and vegetable (FFV) policies are used to promote healthy dietary habits and tackle obesity; however, our understanding of their effects on weight outcomes is limited. We assess the effect of a nationwide FFV policy on childhood and adolescent weight status and explore heterogeneity by sex and socioeconomic position.

METHODS AND FINDINGS

This study used a quasi-natural experimental design. Between 2007 and 2014, Norwegian combined schools (grades 1-10, age 6 to 16 years) were obligated to provide FFVs while elementary schools (grades 1-7) were not. We used 4 nationwide studies (n = 11,215 children) from the Norwegian Growth Cohort with longitudinal or cross-sectional anthropometric data up to age 8.5 and 13 years to capture variation in FFV exposure. Outcomes were body mass index standard deviation score (BMISDS), overweight and obesity (OW/OB), waist circumference (WC), and weight to height ratio (WtHR) at age 8.5 years, and BMISDS and OW/OB at age 13 years. Analyses included longitudinal models of the pre- and post-exposure trajectories to estimate the policy effect. The participation rate in each cohort was >80%, and in most analyses <4% were excluded due to missing data. Estimates were adjusted for region, population density, and parental education. In pooled models additionally adjusted for pre-exposure BMISDS, there was little evidence of any benefit or unintended consequence from 1-2.5 years of exposure to the FFV policy on BMISDS, OW/OB, WC, or WtHR in either sex. For example, boys exposed to the FFV policy had a 0.05 higher BMISDS (95% CI: -0.04, 0.14), a 1.20-fold higher odds of OW/OB (95% CI: 0.86, 1.66) and a 0.3 cm bigger WC (95% CI: -0.3, 0.8); while exposed girls had a 0.04 higher BMISDS (95% CI: -0.04, 0.13), a 1.03 fold higher odds of OW/OB (95% CI: 0.75, 1.39), and a 0-cm difference in WC (95% CI: -0.6, 0.6). There was evidence of heterogeneity in the policy effect estimates at 8.5 years across cohorts and socioeconomic position; however, these results were inconsistent with other comparisons. Analysis at age 13 years, after 4 years of policy exposure, also showed little evidence of an effect on BMISDS or OW/OB. The main limitations of this study are the potential for residual confounding and exposure misclassification, despite efforts to minimize their impact on conclusions.

CONCLUSIONS

In this study we observed little evidence that the Norwegian nationwide FFV policy had any notable beneficial effect or unintended consequence on weight status among Norwegian children and adolescents.

Global, regional, and national mortality among young people aged 10-24 years, 1950-2019: a systematic analysis for the Global Burden of Disease Study 2019

BACKGROUND

Documentation of patterns and long-term trends in mortality in young people, which reflect huge changes in demographic and social determinants of adolescent health, enables identification of global investment priorities for this age group. We aimed to analyse data on the number of deaths, years of life lost, and mortality rates by sex and age group in people aged 10-24 years in 204 countries and territories from 1950 to 2019 by use of estimates from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019.

METHODS

We report trends in estimated total numbers of deaths and mortality rate per 100 000 population in young people aged 10-24 years by age group (10-14 years, 15-19 years, and 20-24 years) and sex in 204 countries and territories between 1950 and 2019 for all causes, and between 1980 and 2019 by cause of death. We analyse variation in outcomes by region, age group, and sex, and compare annual rate of change in mortality in young people aged 10-24 years with that in children aged 0-9 years from 1990 to 2019. We then analyse the association between mortality in people aged 10-24 years and socioeconomic development using the GBD Socio-demographic Index (SDI), a composite measure based on average national educational attainment in people older than 15 years, total fertility rate in people younger than 25 years, and income per capita. We assess the association between SDI and all-cause mortality in 2019, and analyse the ratio of observed to expected mortality by SDI using the most recent available data release (2017).

FINDINGS

In 2019 there were 1·49 million deaths (95% uncertainty interval 1·39-1·59) worldwide in people aged 10-24 years, of which 61% occurred in males. 32·7% of all adolescent deaths were due to transport injuries, unintentional injuries, or interpersonal violence and conflict; 32·1% were due to communicable, nutritional, or maternal causes; 27·0% were due to non-communicable diseases; and 8·2% were due to self-harm. Since 1950, deaths in this age group decreased by 30·0% in females and 15·3% in males, and sex-based differences in mortality rate have widened in most regions of the world. Geographical variation has also increased, particularly in people aged 10-14 years. Since 1980, communicable and maternal causes of death have decreased sharply as a proportion of total deaths in most GBD super-regions, but remain some of the most common causes in sub-Saharan Africa and south Asia, where more than half of all adolescent deaths occur. Annual percentage decrease in all-cause mortality rate since 1990 in adolescents aged 15-19 years was 1·3% in males and 1·6% in females, almost half that of males aged 1-4 years (2·4%), and around a third less than in females aged 1-4 years (2·5%). The proportion of global deaths in people aged 0-24 years that occurred in people aged 10-24 years more than doubled between 1950 and 2019, from 9·5% to 21·6%.

INTERPRETATION

Variation in adolescent mortality between countries and by sex is widening, driven by poor progress in reducing deaths in males and older adolescents. Improving global adolescent mortality will require action to address the specific vulnerabilities of this age group, which are being overlooked. Furthermore, indirect effects of the COVID-19 pandemic are likely to jeopardise efforts to improve health outcomes including mortality in young people aged 10-24 years. There is an urgent need to respond to the changing global burden of adolescent mortality, address inequities where they occur, and improve the availability and quality of primary mortality data in this age group.

FUNDING

Bill & Melinda Gates Foundation.

Pregnancy and risk of COVID-19: a Norwegian registry-linkage study

Objective

To compare the risk of acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection and contact with specialist healthcare services for coronavirus disease 2019 (COVID‐19) between pregnant and non‐pregnant women.

Population or sample

All women ages 15–45 living in Norway on 1 March 2020 (n = 1 033 699).

Methods

We linked information from the national birth, patient, communicable diseases and education databases using unique national identifiers.

Main outcome measure

We estimated hazard ratios (HR) among pregnant compared to non‐pregnant women of having a positive test for SARS‐CoV‐2, a diagnosis of COVID‐19 in specialist healthcare, or hospitalisation with COVID‐19 using Cox regression. Multivariable analyses adjusted for age, marital status, education, income, country of birth and underlying medical conditions.

Results

Pregnant women were not more likely to be tested for or to a have a positive SARS‐CoV‐2 test (adjusted HR 0.99; 95% CI 0.92–1.07). Pregnant women had higher risk of hospitalisation with COVID‐19 (HR 4.70, 95% CI 3.51–6.30) and any type of specialist care for COVID‐19 (HR 3.46, 95% CI 2.89–4.14). Pregnant women born outside Scandinavia were less likely to be tested, and at higher risk of a positive test (HR 2.37, 95% CI 2.51–8.87). Compared with pregnant Scandinavian‐born women, pregnant women with minority background had a higher risk of hospitalisation with COVID‐19 (HR 4.72, 95% CI 2.51–8.87).

Conclusion

Pregnant women were not more likely to be infected with SARS‐CoV‐2. Still, pregnant women with COVID‐19, especially those born outside of Scandinavia, were more likely to be hospitalised.

Tweetable abstract

Pregnant women are at increased risk of hospitalisation for COVID‐19.

Pregnant women are at increased risk of hospitalisation for COVID‐19.

Overweight, obesity, and thinness among a nationally representative sample of Norwegian adolescents and changes from childhood: Associations with sex, region, and population density

Objective

To estimate the prevalence of overweight, obesity, and thinness among Norwegian 13-year-olds and the changes from childhood (age 8 years) to adolescence (age 13 years); and to explore associations with sex, region, and population density from childhood to adolescence.

Design

We used longitudinal, anthropometric data collected by school health nurses conducted in Norway. Weight status was classified according to the International Obesity Task Force cut-offs for overweight, obesity, and thinness, and according to mean body mass index (kg/m²).

Participants

The Norwegian Youth Growth Study, consisting of a nationally representative sample of Norwegian 13-year-olds (n = 1852; 50.7% girls), which is a part of The Norwegian Growth Cohort.

Results

Among 13-year-old Norwegians, the prevalence of overweight (including obesity), obesity, and thinness was 15.8%, 2.5%, and 7.3%, respectively. There was little evidence that these had changed from 8 to 13 years. From 8 to 13 years, the odds of obesity was highest in the Northern region of Norway compared to the South-East (odds ratio (OR): 3.78 (95% confidence interval (CI): 1.13, 12.65; p = 0.036) and in rural areas (OR: 4.76 (95% CI: 1.52, 14.90; p = 0.027). Over the same age period, girls had a trend towards a higher odds of thinness compared to boys (OR: 1.65 (95% CI: 0.98, 2.78; p = 0.057).

Conclusions

In Norway, the prevalence of overweight, obesity, and thinness among 13-year-olds seem to be established by age 8 years. The prevalence of obesity was higher in the North and in rural areas. The results indicate the continued need for early prevention and treatment, and targeted interventions to certain areas.

Growth in children conceived by ART

STUDY QUESTION

Is the growth pattern of children conceived by ART different compared to naturally conceived children.

SUMMARY ANSWER

Both ART and underlying parental subfertility may contribute to differences in early childhood growth between children conceived with and without the use of ART.

WHAT IS KNOWN ALREADY

Children conceived by ART weigh less and are shorter at the time of delivery. The extent to which differences in growth according to mode of conception persist during childhood, and the role of underlying parental subfertility, remains unclear.

STUDY DESIGN, SIZE, DURATION

We conducted a prospective study population-based study. We studied 81 461 children participating in the Norwegian Mother, Father and Child Cohort Study (MoBa) and 544 113 adolescents screened for military conscription.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Conception by ART as registered in the Medical Birth Registry. We compared maternally reported length/height and weight among children in MoBa from mid-pregnancy to age 7 according to mode of conception using mixed-effects linear regression. Differences in self-reported height and weight at 17 years of age at screening for military conscription were assessed with linear regression.

MAIN RESULTS AND THE ROLE OF CHANCE

At birth, children conceived by ART were shorter (boys −0.3 cm; 95% CI, −0.5 to −0.1), girls −0.4 cm; 95% CI, −0.5 to −0.3) and lighter (boys −113 grams; 95% CI, −201 to −25, girls −107 grams; 95% CI, −197 to −17). After birth, children conceived by ART grew more rapidly, achieving both greater height and weight at age 3. Children conceived by ART had a greater height up to age 7, but did not have a greater height or weight by age 17. Naturally conceived children of parents taking longer time to conceive had growth patterns similar to ART children. Children born after frozen embryo transfer had larger ultrasound measures and were longer and heavier the first 2 years than those born after fresh embryo transfer.

LIMITATIONS, REASONS FOR CAUTIONS

Selection bias could have been introduced due to the modest participation rate in the MoBa cohort. Our reliance on self-reported measures of length/height and weight could have introduced measurement error.

WIDER IMPLICATIONS OF THE FINDINGS

: Our findings provide reassurance that offspring conceived by ART are not different in height, weight or BMI from naturally conceived once they reach adolescence.

STUDY FUNDING/COMPETING INTEREST(S)

Research Council of Norway; Medical Research Council; National Institute of Environmental Health Sciences. The authors have no competing interest.

TRIAL REGISTRATION NUMBER

N/A.

Low BMI, but not high BMI, influences the timing of puberty in boys

BACKGROUND

Previous studies investigating the association between weight status and onset of puberty in boys have been equivocal. It is currently unclear to what extent weight class influences puberty onset and progression.

OBJECTIVES

To explore the relationship between degree of sexual maturation and anthropometric measures in Norwegian boys.

METHODS

The following endpoints were collected in a Norwegian cross-sectional study of 324 healthy boys aged 9-16: ultrasound-determined testicular volume (USTV), total serum testosterone, Tanner pubic hair stage, height, weight, waist circumference (WC), subscapular skinfolds (SSF), and body fat percentage (%BF). Testicular volume-for-age z-scores were used to classify "early," "average," or "late" maturing boys. Ordinal logistic regression analyses with a proportional odds model were applied to analyze the association between anthropometric variables and age-adjusted degree of pubertal development, with results expressed as age-adjusted odds ratios (AOR). Cumulative incidence curves for reaching pubertal milestones were stratified by BMI.

RESULTS

Boys with a low BMI for age (BMI_z  < -1) were less likely to have reached a pubertal testicular volume (USTV ≥ 2.7 mL) or a pubertal serum level of testosterone (≥0.5 nmol/L) compared to normal weight boys (AOR 0.3, p = 0.038, AOR 0.3, p = 0.026, respectively), and entered puberty on average with a delay of approximately eight months. Boys with high BMI for age (BMI_z  > 1) exhibited a comparable timing as normal weight boys. The same was found for WC. Pubertal markers were not associated with SSF or %BF.

CONCLUSION

By examining the association between puberty and weight status classified as low, average, or high, we found that a low BMI or WC for age were associated with a less advanced pubertal development and delayed timing of puberty in boys. No significant association was observed for a high BMI or WC. Moreover, no significant effects of SSF or %BF were observed. A low weight status should also be considered when assessing pubertal development in boys.

Beyond sleep duration: Sleep timing as a risk factor for childhood obesity

BACKGROUND

Ample evidence attests to the relationship between short sleep duration, sleep problems and childhood obesity. However, few studies have examined the association between sleep timing and obesity in children.

OBJECTIVES

To investigate how sleep duration, problems and timing relate to obesity and obesogenic behaviours in children.

METHODS

Eighty-five children (58.8% girls) with severe obesity and mean (SD) age of 12.1 (2.9) years, were matched by age and sex with peers with normal weight (n = 85,12.0 [2.8] years). Sleep and moderate-to-vigorous physical activity (MVPA) were measured via accelerometer for seven consecutive days. Children self-reported emotional eating on the Dutch eating behavior questionnaire. Parents reported children's screen time and sleep problems.

RESULTS

Children with severe obesity had significantly later mean mid-sleep time, overall (36 minutes later, P < .001), on school nights (36 minutes later, P < .001) and weekend nights (39 minutes later, P = .002) compared to children with normal weight. Children with obesity had more sleep problems (P = .030), but no differences emerged in sleep duration or social jetlag. After adjusting for demographic factors, mid-sleep time was positively related to screen time (P = .030). Mid-sleep time and sleep duration were inversely related to time in MVPA (Ps ≤ .041). There were no other significant associations between the sleep variables and the obesogenic behaviours.

CONCLUSIONS

Later sleep timing was related to obesogenic behaviours in children and may represent an obesity risk factor.

Hormone References for Ultrasound Breast Staging and Endocrine Profiling to Detect Female Onset of Puberty

CONTEXT

Application of ultrasound (US) to evaluate attainment and morphology of glandular tissue provides a new rationale for evaluating onset and progression of female puberty, but currently no hormone references complement this method. Furthermore, previous studies have not explored the predictive value of endocrine profiling to determine female puberty onset.

OBJECTIVE

To integrate US breast staging with hypothalamic-pituitary-gonadal hormone references and test the predictive value of an endocrine profile to determine thelarche.

DESIGN SETTING AND PARTICIPANTS

Cross-sectional sample of 601 healthy Norwegian girls, ages 6 to 16 years.

MAIN OUTCOME MEASURES

Clinical and ultrasound breast evaluations were performed for all included girls. Blood samples were analyzed by immunoassay and ultrasensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) to quantify estradiol (E2) and estrone (E1) from the subpicomolar range.

RESULTS

References for E2, E1, luteinizing hormone, follicle-stimulating hormone, and sex hormone-binding globulin were constructed in relation to chronological age, Tanner stages, and US breast stages. An endocrine profile index score derived from principal component analysis of these analytes was a better marker of puberty onset than age or any individual hormone, with receiver-operating characteristic area under the curve 0.91 (P < 0.001). Ultrasound detection of nonpalpable glandular tissue in 14 out of 264 (5.3%) girls with clinically prepubertal presentation was associated with significantly higher median serum levels of E2 (12.5 vs 4.9 pmol/L; P < 0.05) and a distinct endocrine profile (arbitrary units; P < 0.001).

CONCLUSIONS

We provide the first hormone references for use with US breast staging and demonstrate the application of endocrine profiling to improve detection of female puberty onset.

Reference data for testicular volume measured with ultrasound and pubic hair in Norwegian boys are comparable with Northern European populations

AIM

To estimate references for testicular volume measured with ultrasound and Tanner stages of pubic hair in Norwegian boys, and to compare the timing of puberty with data from similar populations.

METHODS

Testicular volume was derived from ultrasound measurements of testicular volume in a cross-sectional study of 514 healthy boys. A continuous testicular volume for age reference curve was estimated with the LMS method. Tanner stages for pubic hair were clinically assessed in 452 boys. Age references for pubertal milestones were estimated with probit regression.

RESULTS

Puberty onset, defined by an ultrasound testicular volume of 2.7 mL, equivalent to an orchidometer volume of 4 mL, occurred at a mean (SD) age of 11.7 (1.1) years. The reference range was 9.7 (3rd) to 13.7 years (97th percentile). Pubic hair (Tanner stage 2) appeared on average at 11.8 (1.2) years with a corresponding reference range of 9.5-14.1 years.

CONCLUSION

The references for testicular volume measured with ultrasound are continuous in age and allow for the quantification of pubertal development. The age distribution of reaching pubertal milestones was comparable with data from other Northern European countries.

Testicular Ultrasound to Stratify Hormone References in a Cross-Sectional Norwegian Study of Male Puberty

CONTEXT

Testicular growth represents the best clinical variable to evaluate male puberty, but current pediatric hormone references are based on chronological age and subjective assessments of discrete puberty development stages. Determination of testicular volume (TV) by ultrasound provides a novel approach to assess puberty progression and stratify hormone reference intervals.

OBJECTIVE

The objective of this article is to establish references for serum testosterone and key hormones of the male pituitary-gonadal signaling pathway in relation to TV determined by ultrasound.

DESIGN, SETTING, AND PARTICIPANTS

Blood samples from 414 healthy Norwegian boys between ages 6 and 16 years were included from the cross-sectional "Bergen Growth Study 2." Participants underwent testicular ultrasound and clinical assessments, and serum samples were analyzed by liquid chromatography tandem-mass spectrometry and immunoassays.

MAIN OUTCOME MEASURES

We present references for circulating levels of total testosterone, luteinizing hormone, follicle-stimulating hormone, and sex hormone-binding globulin in relation to TV, chronological age, and Tanner pubic hair stages.

RESULTS

In pubertal boys, TV accounted for more variance in serum testosterone levels than chronological age (Spearman r = 0.753, P < .001 vs r = 0.692, P < .001, respectively). Continuous centile references demonstrate the association between TV and hormone levels during puberty. Hormone reference intervals were stratified by TV during the pubertal transition.

CONCLUSIONS

Objective ultrasound assessments of TV and stratification of hormone references increase the diagnostic value of traditional references based on chronological age or subjective staging of male puberty.

Larger head circumference in Icelandic children 0-4 years of age compared to the World Health Organization and Swedish growth charts

AIM

The World Health Organization (WHO) published universal growth standards for children below five year of age in 2006. Traditionally, Swedish growth references have been used to monitor growth of children in Iceland, but it is not yet known how they compare with these reference charts.

METHODS

A total of 2128 longitudinal measurements of length or height, 2132 of weight and 2126 of head circumference between birth and four years of age were collected in 1996-2000 from 199 healthy children (53% boys) recruited at Landspitali University Hospital. Measurements were converted to z-scores using the WHO growth standards and Swedish growth references for further analysis with mixed-effects models.

RESULTS

Length or height, weight and in particular head circumference largely exceeded the WHO standards, with average z-scores that fluctuated between 0.5 and 1.5. Likewise, the proportion of children with a z-score larger than 2 SD increased about 10-fold. Icelandic children were longer and heavier than their Swedish peers during the first six months of life, but differences were less pronounced thereafter.

CONCLUSION

The growth of Icelandic children deviated significantly from the WHO growth standards. Although more comparable to the Swedish references, significant differences were found, suggesting that a national growth reference would be more appropriate.

References for Ultrasound Staging of Breast Maturation, Tanner Breast Staging, Pubic Hair, and Menarche in Norwegian Girls

CONTEXT

Discriminating adipose and glandular tissue is challenging when clinically assessing breast development. Ultrasound facilitates staging of pubertal breast maturation (US B), but has not been systematically compared to Tanner breast (Tanner B) staging, and no normative data have been reported.

OBJECTIVE

To present normative references for US B along with references for Tanner B, pubic hair (PH), and menarche.

DESIGN, SETTING, AND PARTICIPANTS

A cross-sectional sample of 703 healthy girls aged 6 to 16 years were examined.

MAIN OUTCOME MEASURES

Breast development was determined with US B and Tanner B staging. Tanner PH and menarcheal status were recorded. The age distributions of entry in US B, Tanner B, and PH stages and menarche were estimated with generalized linear and generalized additive models with a probit link. Method agreement was tested with weighted Cohen's kappa.

RESULTS

The median (±2SD) ages for thelarche, US B2 and Tanner B2, were 10.2 (7.7, 12.8) and 10.4 (8.0, 12.7) years. The median (±2SD) ages at Tanner PH2 and menarche were 10.9 (8.5, 13.3) and 12.7 (11.0, 16.2) years. Cohen's kappa of agreement (95% confidence interval) between US B and Tanner B was 0.87 (0.85-0.88). When the methods disagreed, US B was usually more advanced.

CONCLUSION

Thelarche occurred at a slightly younger age when assessed with ultrasound compared to clinical Tanner staging, although the 2 methods had a very good agreement when determining pubertal breast maturation. A significant decrease of 2.8 months in age at menarche was observed during the past decade in Norwegian girls.

Norwegian children and adolescents in blended families are at risk of larger one-year BMI increments

AIM

To study how sociodemographic factors and family structure associate with baseline BMI z-scores (BMIz) and BMIz change in 767 Norwegian children aged 6-15 years.

METHODS

Baseline BMIz and 1-year BMIz increments in children from the Bergen Growth Study were analysed with linear and logistic regression, according to sociodemographic factors and family structure. A blended family was defined as including a step-parent and/or half-sibling.

RESULTS

In a fully adjusted regression model, baseline BMIz were only significantly associated with maternal BMI (b = 0.087, 95%CI 0.067, 0.107). Body Mass Index z-scores increments were larger in children living in a blended family (b = 0.060, 95%CI 0.006, 0.115), with a lower parental education (b = 0.127, 95%CI 0.029, 0.226) and with a higher maternal BMI (b = 0.008, 95%CI 0.001, 0.014). The odds for a large BMIz increment (>1 SD) were higher in children living in blended families (OR 1.82, 95%CI 1.16, 2.88) and with higher maternal BMI (OR 1.07, 95%CI 1.01, 1.13) and lower in 9-11-year-old children (OR 0.44, 95%CI 0.26, 0.77) compared with 12-15-year-olds.

CONCLUSION

Body Mass Index z-scores increments were more strongly associated with sociodemographic factors and living in a blended family than baseline BMIz values. BMI z-scores increments could be useful for identifying children at risk of becoming overweight or obese.

No significant associations between breastfeeding practices and overweight in 8-year-old children

AIM

The aim was to examine if breastfeeding practices were associated with body mass index (BMI) and risk of overweight or obesity in third grade (8 years) of elementary school.

METHODS

In a regional cohort, we related BMI z-scores and presence of overweight or obesity at 8 years of age with ever being breastfed and with duration of exclusive and partial breastfeeding after adjusting for potential confounders. Parents completed questionnaires on breastfeeding and sociodemographic and lifestyle factors at school entry, and public health nurses measured height and weight. For non-participants, the nurses anonymously reported these measurements together with sex and age.

RESULTS

90% of participants had been breastfed. In adjusted analyses, BMI z-scores were not significantly related to whether or not the child had been breastfed (P = .64), or to the duration of exclusive (P = .80) or partial breastfeeding (P = .94). Logistic regression also showed no significant association between breastfeeding measures and overweight or obesity.

CONCLUSION

This study on 8-year-old Norwegian children did not support a commonly held notion that breastfeeding reduces the risk of overweight or obesity.

Monitoring children and adolescents with severe obesity: body mass index (BMI), BMI z-score or percentage above the International Obesity Task Force overweight cut-off?

AIM

Body mass index (BMI) metrics are widely used as a proxy for adiposity in children with severe obesity. The BMI expressed as the percentage of a cut-off percentile for overweight or obesity has been proposed as a better alternative than BMI z-scores when monitoring children and adolescents with severe obesity.

METHODS

Annual changes in BMI, BMI z-score and the percentage above the International Obesity Task Force overweight cut-off (%IOTF-25) were compared with dual-energy X-ray absorptiometry (DXA) derived body fat (%BF-DXA) in 59 children and adolescents with severe obesity.

RESULTS

The change in %BF-DXA was correlated with the change in %IOTF-25 (r = 0.68) and BMI (r = 0.70), and somewhat less with the BMI z-score (r = 0.57). Cohen's Kappa statistic to detect an increase or decrease in %BF-DXA was fair for %IOTF-25 (κ = 0.25; p = 0.04) and BMI (κ = 0.33; p = 0.01), but not for the BMI z-score (κ = 0.08; p = 0.5). The change in BMI was positively biased due to a natural increase with age.

CONCLUSION

Changes in the BMI metrics included in the study are associated differently with changes in %BF-DXA. The BMI z-score is widely used to monitor changes in adiposity in children and adolescents with severe obesity, but the %IOTF-25 might be a better alternative.

Sex-related change in BMI of 15- to 16-year-old Norwegian girls in cross-sectional studies in 2002 and 2017

Background

The prevalence of overweight and obesity (OWOB) has stabilized in some countries, but a portion of children with high body mass index (BMI) may have become heavier. This study aimed to describe the distributions of BMI and the point prevalence of OWOB in Norwegian adolescents in 2002 and 2017.

Methods

A cross-sectional study involving 15- to 16-year-old adolescents in Oppland, Norway, was undertaken in 2002 and 2017. We calculated their BMI, BMI z-scores (BMIz), and the prevalence of OWOB.

Results

The mean BMI increased from 20.7 to 21.4 (p < 0.001) for girls but remained unchanged at 21.5 vs 21.4 (p = 0.80) for boys. The prevalence of OWOB increased from 9 to 14% among girls (difference 5, 95% CI: 2, 8) and from 17 to 20% among boys (difference 3, 95% CI: − 1, 6%). The BMI density plots revealed similar shapes at both time points for both sexes, but the distribution for girls shifted to the right from 2002 to 2017.

Conclusion

Contrary to previous knowledge, we found that the increase in OWOB presented a uniform shift in the entire BMI distribution for 15–16-year-old Norwegian girls and was not due to a larger shift in a specific subpopulation in the upper percentiles.

PAPSS2-related brachyolmia: Clinical and radiological phenotype in 18 new cases

Brachyolmia is a skeletal dysplasia characterized by short spine-short stature, platyspondyly, and minor long bone abnormalities. We describe 18 patients, from different ethnic backgrounds and ages ranging from infancy to 19 years, with the autosomal recessive form, associated with PAPSS2. The main clinical features include disproportionate short stature with short spine associated with variable symptoms of pain, stiffness, and spinal deformity. Eight patients presented prenatally with short femora, whereas later in childhood their short-spine phenotype emerged. We observed the same pattern of changing skeletal proportion in other patients. The radiological findings included platyspondyly, irregular end plates of the elongated vertebral bodies, narrow disc spaces and short over-faced pedicles. In the limbs, there was mild shortening of femoral necks and tibiae in some patients, whereas others had minor epiphyseal or metaphyseal changes. In all patients, exome and Sanger sequencing identified homozygous or compound heterozygous PAPSS2 variants, including c.809G>A, common to white European patients. Bi-parental inheritance was established where possible. Low serum DHEAS, but not overt androgen excess was identified. Our study indicates that autosomal recessive brachyolmia occurs across continents and may be under-recognized in infancy. This condition should be considered in the differential diagnosis of short femora presenting in the second trimester.

Intrauterine metformin exposure and offspring cardiometabolic risk factors (PedMet study): a 5-10 year follow-up of the PregMet randomised controlled trial

BACKGROUND

Metformin is increasingly used to treat gestational diabetes and type 2 diabetes in pregnancy, and in attempts to improve pregnancy outcomes in polycystic ovary syndrome and obesity. It passes across the placenta with possible long-term consequences for the offspring. We previously explored the effect of metformin, given to women with polycystic ovary syndrome during pregnancy, on children's growth up to 4 years of age. In this 5-10 year follow-up, we examined the cardiometabolic risk factors in these children.

METHODS

This is a follow-up of children from the PregMet study, a double-blind, randomised controlled trial comparing metformin with placebo in polycystic ovary syndrome pregnancies. In the PregMet study, between Feb 4, 2005, and Jan 27, 2009, 257 pregnant women aged 18-45 years with polycystic ovary syndrome according to the Rotterdam criteria were included with 274 singleton pregnancies at 5-12 weeks of gestation at 11 study centres in Norway. 17 women participated twice. Pregnant women were randomised to metformin (2000 mg/day) or placebo from inclusion in the first trimester to birth. Randomisation was stratified according to metformin use at conception. In this follow-up, the primary endpoint was body-mass index (BMI) in the offspring at 5-10 years of age assessed by the standard deviation score (Z score). The primary endpoint was analysed with independent sample t tests. ClinicalTrials.gov number NCT00159536.

FINDINGS

Of the 255 invited children from the PregMet study, 141 (55%) consented to participate and were included between April 29, 2014, and July 12, 2016. Maternal baseline characteristics in the first trimester were similar between groups. Children in the metformin group had a higher BMI Z score than those in the placebo group (difference in means=0·41, 95% CI 0·03-0·78, p=0·03).

INTERPRETATION

The increased BMI in metformin-exposed children might indicate a potential risk of inferior cardiometabolic health. Implications for adult health cannot be excluded.

FUNDING

The Research Council of Norway, Novo Nordisk Foundation, St Olavs University Hospital, and the Norwegian University of Science and Technology.

Effectiveness and safety of long-term treatment with sulfonylureas in patients with neonatal diabetes due to KCNJ11 mutations: an international cohort study

BACKGROUND

KCNJ11 mutations cause permanent neonatal diabetes through pancreatic ATP-sensitive potassium channel activation. 90% of patients successfully transfer from insulin to oral sulfonylureas with excellent initial glycaemic control; however, whether this control is maintained in the long term is unclear. Sulfonylurea failure is seen in about 44% of people with type 2 diabetes after 5 years of treatment. Therefore, we did a 10-year multicentre follow-up study of a large international cohort of patients with KCNJ11 permanent neonatal diabetes to address the key questions relating to long-term efficacy and safety of sulfonylureas in these patients.

METHODS

In this multicentre, international cohort study, all patients diagnosed with KCNJ11 permanent neonatal diabetes at five laboratories in Exeter (UK), Rome (Italy), Bergen (Norway), Paris (France), and Krakow (Poland), who transferred from insulin to oral sulfonylureas before Nov 30, 2006, were eligible for inclusion. Clinicians collected clinical characteristics and annual data relating to glycaemic control, sulfonylurea dose, severe hypoglycaemia, side-effects, diabetes complications, and growth. The main outcomes of interest were sulfonylurea failure, defined as permanent reintroduction of daily insulin, and metabolic control, specifically HbA_1c and sulfonylurea dose. Neurological features associated with KCNJ11 permanent neonatal diabetes were also assessed. This study is registered with ClinicalTrials.gov, number NCT02624817.

FINDINGS

90 patients were identified as being eligible for inclusion and 81 were enrolled in the study and provided long-term (>5·5 years cut-off) outcome data. Median follow-up duration for the whole cohort was 10·2 years (IQR 9·3-10·8). At most recent follow-up (between Dec 1, 2012, and Oct 4, 2016), 75 (93%) of 81 participants remained on sulfonylurea therapy alone. Excellent glycaemic control was maintained for patients for whom we had paired data on HbA_1c and sulfonylurea at all time points (ie, pre-transfer [for HbA_1c], year 1, and most recent follow-up; n=64)-median HbA_1c was 8·1% (IQR 7·2-9·2; 65·0 mmol/mol [55·2-77·1]) before transfer to sulfonylureas, 5·9% (5·4-6·5; 41·0 mmol/mol [35·5-47·5]; p<0·0001 vs pre-transfer) at 1 year, and 6·4% (5·9-7·3; 46·4 mmol/mol [41·0-56·3]; p<0·0001 vs year 1) at most recent follow-up (median 10·3 years [IQR 9·2-10·9]). In the same patients, median sulfonylurea dose at 1 year was 0·30 mg/kg per day (0·14-0·53) and at most recent follow-up visit was 0·23 mg/kg per day (0·12-0·41; p=0·03). No reports of severe hypoglycaemia were recorded in 809 patient-years of follow-up for the whole cohort (n=81). 11 (14%) patients reported mild, transient side-effects, but did not need to stop sulfonylurea therapy. Seven (9%) patients had microvascular complications; these patients had been taking insulin longer than those without complications (median age at transfer to sulfonylureas 20·5 years [IQR 10·5-24·0] vs 4·1 years [1·3-10·2]; p=0·0005). Initial improvement was noted following transfer to sulfonylureas in 18 (47%) of 38 patients with CNS features. After long-term therapy with sulfonylureas, CNS features were seen in 52 (64%) of 81 patients.

INTERPRETATION

High-dose sulfonylurea therapy is an appropriate treatment for patients with KCNJ11 permanent neonatal diabetes from diagnosis. This therapy is safe and highly effective, maintaining excellent glycaemic control for at least 10 years.

FUNDING

Wellcome Trust, Diabetes UK, Royal Society, European Research Council, Norwegian Research Council, Kristian Gerhard Jebsen Foundation, Western Norway Regional Health Authority, Southern and Eastern Norway Regional Health Authority, Italian Ministry of Health, Aide aux Jeunes Diabetiques, Societe Francophone du Diabete, Ipsen, Slovak Research and Development Agency, and Research and Development Operational Programme funded by the European Regional Development Fund.

Targeted next-generation sequencing reveals MODY in up to 6.5% of antibody-negative diabetes cases listed in the Norwegian Childhood Diabetes Registry

AIMS/HYPOTHESIS

MODY can be wrongly diagnosed as type 1 diabetes in children. We aimed to find the prevalence of MODY in a nationwide population-based registry of childhood diabetes.

METHODS

Using next-generation sequencing, we screened the HNF1A, HNF4A, HNF1B, GCK and INS genes in all 469 children (12.1%) negative for both GAD and IA-2 autoantibodies and 469 antibody-positive matched controls selected from the Norwegian Childhood Diabetes Registry (3882 children). Variants were classified using clinical diagnostic criteria for pathogenicity ranging from class 1 (neutral) to class 5 (pathogenic).

RESULTS

We identified 58 rare exonic and splice variants in cases and controls. Among antibody-negative patients, 6.5% had genetic variants of classes 3-5 (vs 2.4% in controls; p = 0.002). For the stricter classification (classes 4 and 5), the corresponding number was 4.1% (vs 0.2% in controls; p = 1.6 × 10^-5). HNF1A showed the strongest enrichment of class 3-5 variants, with 3.9% among antibody-negative patients (vs 0.4% in controls; p = 0.0002). Antibody-negative carriers of variants in class 3 had a similar phenotype to those carrying variants in classes 4 and 5.

CONCLUSIONS/INTERPRETATION

This is the first study screening for MODY in all antibody-negative children in a nationwide population-based registry. Our results suggest that the prevalence of MODY in antibody-negative childhood diabetes may reach 6.5%. One-third of these MODY cases had not been recognised by clinicians. Since a precise diagnosis is important for treatment and genetic counselling, molecular screening of all antibody-negative children should be considered in routine diagnostics.

Maternal hormonal contraceptive use and offspring overweight or obesity

BACKGROUND/OBJECTIVES

Experiments in animal models have shown a positive association between in utero exposure to pharmacologic sex hormones and offspring obesity. The developmental effects of such hormones on human obesity are unknown.

SUBJECTS/METHODS

Using data from a large, prospective pregnancy cohort study (n=19 652), with linkage to a national prescription registry, we evaluated the association between use of hormonal contraceptives before and after conception (defined from dispensed prescription data and characterized by last date of use relative to conception, 12 to >4 months before (n=3392), 4 to >1 months before (n=2541), 1 to >0 months before (n=2997) and 0-12 weeks after (n=567)) in relation to offspring overweight or obesity at age 3 years.

RESULTS

We observed a weak, inverse association between early pregnancy use of a combination oral contraceptive and offspring overweight or obesity at age 3 (adjusted odds ratio (OR): 0.75, 95% confidence interval (CI): 0.53, 1.08) and a positive, but imprecise, association with use of a progestin-only oral contraceptive in early pregnancy (adjusted OR: 1.26, 95% CI: 0.79, 2.02). In general, no association was observed between the use of a hormonal contraceptive before conception and offspring overweight or obesity. A sensitivity analysis comparing combination oral contraceptive users in early pregnancy to other unplanned pregnancies without hormonal contraceptive use further strengthened the inverse association (adjusted OR: 0.70, 95% CI: 0.48, 1.02). Other sensitivity analyses were conducted to evaluate the robustness of the associations observed given varying assumptions.

CONCLUSIONS

Pharmacologic sex hormones in early pregnancy may be inversely or positively associated with offspring overweight or obesity at age 3, depending on the specific formulation used. The present study provides support for the potential for environmental sources of hormonally active agents to exert developmental effects.

High prevalence of overweight and obesity among 6-year-old children in Finnmark County, North Norway

AIM

The aim was to determine the prevalence of overweight and obesity among 6-year-old children in Finnmark, the northernmost county of Norway.

METHODS

This is a survey of 1774 children born during 1999 and 2000 from 18 of 19 child healthcare centres in Finnmark. Body mass index data extracted retrospectively in 2007 from health records at the age of 6 years were compared with international definitions of over- and underweight. The prevalence figures were further compared with socio-demographic figures on municipality level.

RESULTS

Overall, 19% of the children were classified as overweight or obese; 5% were classified as obese. The prevalence of overweight and obesity was higher among girls (22%) than among boys (16%) (p < 0.01). The prevalence of underweight was 8% among both girls and boys. Despite large variations in the prevalence of overweight and obesity between municipalities (9-35%), no association was found with municipality figures on socio-demographic factors.

CONCLUSION

In the northernmost county Finnmark, the prevalence of overweight including obesity among 6-year-old children was somewhat higher than in previous surveys from Norway, especially among girls.

Clinical spectrum of SIX3-associated mutations in holoprosencephaly: correlation between genotype, phenotype and function

BACKGROUND

Holoprosencephaly (HPE) is the most common structural malformation of the human forebrain. There are several important HPE mutational target genes, including the transcription factor SIX3, which encodes an early regulator of Shh, Wnt, Bmp and Nodal signalling expressed in the developing forebrain and eyes of all vertebrates.

OBJECTIVE

To characterise genetic and clinical findings in patients with SIX3 mutations.

METHODS

Patients with HPE and their family members were tested for mutations in HPE-associated genes and the genetic and clinical findings, including those for additional cases found in the literature, were analysed. The results were correlated with a mutation-specific functional assay in zebrafish.

RESULTS

In a cohort of patients (n = 800) with HPE, SIX3 mutations were found in 4.7% of probands and additional cases were found through testing of relatives. In total, 138 cases of HPE were identified, 59 of whom had not previously been clinically presented. Mutations in SIX3 result in more severe HPE than in other cases of non-chromosomal, non-syndromic HPE. An over-representation of severe HPE was found in patients whose mutations confer greater loss of function, as measured by the functional zebrafish assay. The gender ratio in this combined set of patients was 1.5:1 (F:M) and maternal inheritance was almost twice as common as paternal. About 14% of SIX3 mutations in probands occur de novo. There is a wide intrafamilial clinical range of features and classical penetrance is estimated to be at least 62%.

CONCLUSIONS

Our data suggest that SIX3 mutations result in relatively severe HPE and that there is a genotype-phenotype correlation, as shown by functional studies using animal models.

Lack of meiotic crossovers during oogenesis in an apparent 45,X Ullrich-Turner syndrome patient with three children

A woman with apparent 45,X Ullrich-Turner syndrome was ascertained after the birth of three girls, the last being growth retarded due to a del(X)(p22.11) of grand-paternal origin. In this woman no del(X)-chromosome was detectable in blood by FISH or PCR. Fibroblast cultures from four different biopsies of her skin varied from having 45,X only to mosaic 46,X,del(X) to 46,X,del(X) only. In one fibroblast culture, a few cells with two del(X) chromosomes were found, probably remnants of a paternal dicentric X that caused the condition. Her three daughters were born when she was 29, 31, and 39 years old, respectively, indicating that disomy for the distal half of Xp is not required for normal folliculogenesis. When studying the crossover pattern of her daughters' maternal X-chromosomes, it turned out that one daughter had an X that was exclusively grand-maternal, one daughter lacked crossovers on Xq, and one daughter lacked crossovers on Xp. This suggests that univalent X-chromosomes were present in the Ullrich-Turner patient's primordial egg cells, either because there was only a single X-chromosome present (a 45,X primary oocyte), or because the X-chromosome was a partially or completely unpaired in pachytene, indicating a problem with chromosome association and synapsis formation.

[Kawasaki disease in Iceland 1979-1997.]

Kawasaki disease is a multisystem inflammatory disease most commonly affecting young children. The first patient documented with the disease in Iceland was diagnosed in 1979. In this retrospective study we describe our experience with the disease in Iceland over 19 years. From 1979 to 1997 40 children were diagnosed with Kawasaki disease, i.e. an annual incidence of 8.5 per 100,000 children younger than five years of age. Male-female ratio was 2:1. The number of patients each year varied from none to seven. Coronary aneurisms were revealed in four of 30 patients (13%) undergoing 2D echocardiography. One patient died (2.5%) of cardiac complication (heart failure). Twenty-seven of 30 patients diagnosed after 1987 were treated with intravenous immunoglobulins. The incidence of Kawasaki disease in Iceland is comparable to what has been reported in the other Nordic countries.