The trajectory of depression and anxiety among children and adolescents over two years of the COVID-19 pandemic.

Longitudinal research examining children's mental health (MH) over the course of the COVID-19 pandemic is scarce. We examined trajectories of depression and anxiety over two pandemic years among children with and without MH disorders. Parents and children 2-18 years completed surveys at seven timepoints (April 2020 to June 2022). Parents completed validated measures of depression and anxiety for children 8-18 years, and validated measures of emotional/behavioural symptoms for children 2-7 years old; children ≥10 years completed validated measures of depression and anxiety. Latent growth curve analysis determined depression and anxiety trajectories, accounting for demographics, child and parent MH. Data were available on 1315 unique children (1259 parent-reports; 550 child-reports). Trajectories were stable across the study period, however individual variation in trajectories was statistically significant. Of included covariates, only initial symptom level predicted symptom trajectories. Among participants with pre-COVID data, a significant increase in depression symptoms relative to pre-pandemic levels was observed; children and adolescents experienced elevated and sustained levels of depression and anxiety during the two-year period. Findings have direct policy implications in the prioritization and of maintenance of educational, recreational, and social activities with added MH supports in the face of future events.

Physicians' perspectives on COVID-19 vaccinations for children: a qualitative exploration in Ontario, Canada.

OBJECTIVES: Parents' decisions to vaccinate their children against COVID-19 are complex and often informed by discussions with primary care physicians. However, little is known about physicians' perspectives on COVID-19 vaccinations for children or their experiences counselling parents in their decision-making. We explored physicians' experiences providing COVID-19 vaccination recommendations to parents and their reflections on the contextual factors that shaped these experiences. DESIGN: We conducted an interpretive qualitative study using in-depth interviews. We analyzed the data using reflexive thematic analysis and a socioecological framework. SETTING: This study involved primary care practices associated with The Applied Research Group for Kids (TARGet Kids!) primary care research network in the Greater Toronto Area, Ontario, Canada. PARTICIPANTS: Participants were 10 primary care physicians, including family physicians, paediatricians and paediatric subspecialists. RESULTS: Participants discussed elements at the individual level (their identity, role, and knowledge), the interpersonal level (their relationships with families, responsiveness to parents' concerns, and efforts to build trust) and structural level (contextual factors related to the evolving COVID-19 climate, health system pandemic response, and constraints on care delivery) that influenced their experiences providing recommendations to parents. Our findings illustrated that physicians' interactions with families were shaped by a confluence of their own perspectives, their responses to parents' perspectives, and the evolving landscape of the broader pandemic. CONCLUSIONS: Our study underscores the social and relational nature of vaccination decision-making and highlights the multiple influences on primary care physicians' experiences providing COVID-19 vaccination recommendations to parents. Our findings offer suggestions for future COVID-19 vaccination programmes for children. Delivery of new COVID-19 vaccinations for children may be well suited within primary care offices, where trusting relationships are established, but physicians need support in staying knowledgeable about emerging information, communicating available evidence to parents to inform their decision-making and dedicating time for vaccination counselling.

Long-Term Cardiovascular Outcomes in Children and Adolescents With Hypertension.

Importance: Hypertension affects 6% of all children, and its prevalence is increasing. Childhood hypertension tracks into adulthood and is associated with subclinical cardiovascular disease; however, there is a lack of evidence linking childhood hypertension to cardiovascular outcomes, which may contribute to underdiagnosis and undertreatment. Objective: To determine the long-term associated risk of major adverse cardiac events (MACE) among children diagnosed with hypertension. Design, Setting, and Participants: This was a population-based, retrospective, matched cohort study conducted from 1996 to 2022. The study included all children (aged 3-18 years) alive in Ontario, Canada, from 1996 to 2021, who were identified using provincial administrative health databases. Children with prior kidney replacement therapy were excluded. Exposure: Incident hypertension diagnosis, identified by validated case definitions using diagnostic and physician billing claims. Each case was matched with 5 controls without hypertension by age, sex, birth weight, maternal gestational hypertension, prior comorbidities (chronic kidney disease, diabetes, cardiovascular surgery), and a propensity score for hypertension. Main Outcomes and Measures: The primary outcome was MACE (a composite of cardiovascular death, stroke, hospitalization for myocardial infarction or unstable angina, or coronary intervention). Time to MACE was evaluated using the Kaplan-Meier method and Cox proportional hazards regression. Results: A total of 25 605 children (median [IQR] age, 15 [11-17] years; 14 743 male [57.6%]) with hypertension were matched to 128 025 controls without hypertension. Baseline covariates were balanced after propensity score matching, and prior comorbidities were uncommon (hypertension vs control cohort: malignancy, 1451 [5.7%] vs 7908 [6.2%]; congenital heart disease, 1089 [4.3%] vs 5408 [4.2%]; diabetes, 482 [1.9%] vs 2410 [1.9%]). During a median (IQR) of 13.6 (7.8-19.5) years of follow-up, incidence of MACE was 4.6 per 1000 person-years in children with hypertension vs 2.2 per 1000 person-years in controls (hazard ratio, 2.1; 95% CI, 1.9-2.2). Children with hypertension were at higher associated risk of stroke, hospitalization for myocardial infarction or unstable angina, coronary intervention, and congestive heart failure, but not cardiovascular death, compared with nonhypertensive controls. Conclusions and Relevance: Children diagnosed with hypertension had a higher associated long-term risk of MACE compared with controls without hypertension. Improved detection, follow-up, and control of pediatric hypertension may reduce the risk of adult cardiovascular disease.

Haemoglobin thresholds to define anaemia from age 6 months to 65 years: estimates from international data sources.

BACKGROUND: Detection of anaemia is crucial for clinical medicine and public health. Current WHO anaemia definitions are based on statistical thresholds (fifth centiles) set more than 50 years ago. We sought to establish evidence for the statistical haemoglobin thresholds for anaemia that can be applied globally and inform WHO and clinical guidelines. METHODS: In this analysis we identified international data sources from populations in the USA, England, Australia, China, the Netherlands, Canada, Ecuador, and Bangladesh with sufficient clinical and laboratory information collected between 1998 and 2020 to obtain a healthy reference sample. Individuals with clinical or biochemical evidence of a condition that could reduce haemoglobin concentrations were excluded. We estimated haemoglobin thresholds (ie, 5th centiles) for children aged 6-23 months, 24-59 months, 5-11 years, and 12-17 years, and adults aged 18-65 years (including during pregnancy) for individual datasets and pooled across data sources. We also collated findings from three large-scale genetic studies to summarise genetic variants affecting haemoglobin concentrations in different ancestral populations. FINDINGS: We identified eight data sources comprising 18 individual datasets that were eligible for inclusion in the analysis. In pooled analyses, the haemoglobin fifth centile was 104·4 g/L (90% CI 103·5-105·3) in 924 children aged 6-23 months, 110·2 g/L (109·5-110·9) in 1874 children aged 24-59 months, and 114·4 g/L (113·6-115·2) in 1839 children aged 5-11 years. Values diverged by sex in adolescents and adults. In pooled analyses, the fifth centile was 122·2 g/L (90% CI 121·3-123·1) in 1741 female adolescents aged 12-17 years and 128·2 g/L (126·4-130·0) in 1103 male adolescents aged 12-17 years. In pooled analyses of adults aged 18-65 years, the fifth centile was 119·7 g/L (90% CI 119·1-120·3) in 3640 non-pregnant females and 134·9 g/L (134·2-135·6) in 2377 males. Fifth centiles in pregnancy were 110·3 g/L (90% CI 109·5-111·0) in the first trimester (n=772) and 105·9 g/L (104·0-107·7) in the second trimester (n=111), with insufficient data for analysis in the third trimester. There were insufficient data for adults older than 65 years. We did not identify ancestry-specific high prevalence of non-clinically relevant genetic variants that influence haemoglobin concentrations. INTERPRETATION: Our results enable global harmonisation of clinical and public health haemoglobin thresholds for diagnosis of anaemia. Haemoglobin thresholds are similar between sexes until adolescence, after which males have higher thresholds than females. We did not find any evidence that thresholds should differ between people of differering ancestries. FUNDING: World Health Organization and the Bill & Melinda Gates Foundation.

Association of factors with childhood asthma and allergic diseases using latent class analysis.

We hypothesize that children characterized by deprived factors have poorer health outcomes. We aim to identify clustering of determinants and estimate risk of early childhood diseases. This 1993-2019 longitudinal cohort study combines three Canadian pediatric cohorts and their families. Mothers and children are clustered using latent class analysis (LCA) by 16 indicators in three domains (maternal and newborn; socioeconomic status [SES] and neighbourhood; environmental exposures). Hazard ratios (HR) of childhood asthma, allergic rhinitis (AR), and eczema are quantified with Cox proportional hazard (PH) regression. Rate ratios (RR) of children's health services use (HSU) are estimated with Poisson regression. Here we report the inclusion of 15,724 mother-child pairs; our LCA identifies four mother-clusters. Classes 1 and 2 mothers are older (30-40 s), non-immigrants with university education, living in high SES neighbourhoods; Class 2 mothers have poorer air quality and less greenspace. Classes 3 and 4 mothers are younger (20-30 s), likely an immigrant/refugee, with high school-to-college education, living in lower SES neighborhoods with poorer air quality and less greenspace. Children's outcomes differ by Class, in comparison to Class 1. Classes 3 and 4 children have higher risks of asthma (HR 1.24, 95% CI 1.11-1.37 and HR 1.39, 95% CI 1.22-1.59, respectively), and similar higher risks of AR and eczema. Children with AR in Class 3 have 20% higher all-cause physician visits (RR = 1.20, 95% CI 1.10-1.30) and those with eczema have 18% higher all-cause emergency department visits (RR = 1.18, 95% CI 1.09-1.28) and 14% higher all-cause physician visits (RR = 1.14, 95% CI 1.09-1.19). Multifactorial-LCA mother-clusters may characterize associations of children's health outcomes and care, adjusting for interrelationships.

The mediation effect of breastfeeding duration on the relationship between maternal preconception BMI and childhood nutritional risk.

BACKGROUND: Higher maternal preconception body mass index (BMI) is associated with lower breastfeeding duration, which may contribute to the development of poor child eating behaviours and dietary intake patterns (components of nutritional risk). A higher maternal preconception BMI has been found to be associated with higher child nutritional risk. This study aimed to determine whether breastfeeding duration mediated the association between maternal preconception BMI and child nutritional risk. METHODS: In this longitudinal cohort study, children ages 18 months to 5 years were recruited from The Applied Research Group for Kids (TARGet Kids!) in Canada. The primary outcome was child nutritional risk, using The NutriSTEP®, a validated, parent-reported questionnaire. Statistical mediation analysis was performed to assess whether total duration of any breastfeeding mediated the association between maternal preconception BMI and child nutritional risk. RESULTS: This study included 4733 children with 8611 NutriSTEP® observations. The mean (SD) maternal preconception BMI was 23.6 (4.4) and the mean (SD) breastfeeding duration was 12.4 (8.0) months. Each 1-unit higher maternal preconception BMI was associated with a 0.081 unit higher nutritional risk (95% CI (0.051, 0.112); p < 0.001) (total effect), where 0.011(95% CI (0.006, 0.016); p < 0.001) of that total effect or 13.18% (95% CI: 7.13, 21.25) was mediated through breastfeeding duration. CONCLUSION: Total breastfeeding duration showed to mediate part of the association between maternal preconception BMI and child nutritional risk. Interventions to support breastfeeding in those with higher maternal preconception BMI should be evaluated for their potential effect in reducing nutritional risk in young children.

Evaluation of an automated matching system of children and families to virtual mental health resources during COVID-19.

BACKGROUND: Children and their families often face obstacles in accessing mental health (MH) services. The purpose of this study was to develop and pilot test an electronic matching process to match children with virtual MH resources and increase access to treatment for children and their families during COVID-19. METHODS: Within a large observational child cohort, a random sample of 292 families with children ages 6-12 years were invited to participate. Latent profile analysis indicated five MH profiles using parent-reported symptom scores from validated depression, anxiety, hyperactivity, and inattention measures: (1) Average Symptoms, (2) Low Symptoms, (3) High Symptoms, (4) Internalizing, and (5) Externalizing. Children were matched with virtual MH resources according to their profile; parents received surveys at Time 1 (matching process explanation), Time 2 (match delivery) and Time 3 (resource uptake). Data on demographics, parent MH history, and process interest were collected. RESULTS: 128/292 families (44%) completed surveys at Time 1, 80/128 families (63%) at Time 2, and a final 67/80 families (84%) at Time 3, yielding an overall uptake of 67/292 (23%). Families of European-descent and those with children assigned to the Low Symptoms profile were most likely to express interest in the process. No other factors were associated with continued interest or uptake of the electronic matching process. Most participating parents were satisfied with the process. CONCLUSIONS: The electronic matching process delivered virtual MH resources to families in a time-efficient manner. Further research examining the effectiveness of electronically matched resources in improving children's MH symptoms is needed.

Consumption of 100% Fruit Juice and Body Weight in Children and Adults: A Systematic Review and Meta-Analysis.

Importance: Concerns have been raised that frequent consumption of 100% fruit juice may promote weight gain. Current evidence on fruit juice and weight gain has yielded mixed findings from both observational studies and clinical trials. Objective: To synthesize the available evidence on 100% fruit juice consumption and body weight in children and adults. Data Sources: MEDLINE, Embase, and Cochrane databases were searched through May 18, 2023. Study Selection: Prospective cohort studies of at least 6 months and randomized clinical trials (RCTs) of at least 2 weeks assessing the association of 100% fruit juice with body weight change in children and adults were included. In the trials, fruit juices were compared with noncaloric controls. Data Extraction and Synthesis: Data were pooled using random-effects models and presented as ß coefficients with 95% CIs for cohort studies and mean differences (MDs) with 95% CIs for RCTs. Main Outcomes and Measures: Change in body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) was assessed in children and change in body weight in adults. Results: A total of 42 eligible studies were included in this analysis, including 17 among children (17 cohorts; 0 RCTs; 45 851 children; median [IQR] age, 8 [1-15] years) and 25 among adults (6 cohorts; 19 RCTs; 268 095 adults; median [IQR] age among cohort studies, 48 [41-61] years; median [IQR] age among RCTs, 42 [25-59]). Among cohort studies in children, each additional serving per day of 100% fruit juice was associated with a 0.03 (95% CI, 0.01-0.05) higher BMI change. Among cohort studies in adults, studies that did not adjust for energy showed greater body weight gain (0.21 kg; 95% CI, 0.15-0.27 kg) than studies that did adjust for energy intake (-0.08 kg; 95% CI, -0.11 to -0.05 kg; P for meta-regression <.001). RCTs in adults found no significant association of assignment to 100% fruit juice with body weight but the CI was wide (MD, -0.53 kg; 95% CI, -1.55 to 0.48 kg). Conclusion and Relevance: Based on the available evidence from prospective cohort studies, in this systematic review and meta-analysis, 1 serving per day of 100% fruit juice was associated with BMI gain among children. Findings in adults found a significant association among studies unadjusted for total energy, suggesting potential mediation by calories. Further trials of 100% fruit juice and body weight are desirable. Our findings support guidance to limit consumption of fruit juice to prevent intake of excess calories and weight gain.

Maternal postnatal depressive symptoms and early achievement of developmental milestones in infants and young children: A meta-analysis.

Screening for social determinants of health, including maternal depression, is a recommended pediatric practice. However, the magnitude of association between maternal and child screening tools remains to be determined. The current study evaluated the association between maternal postnatal depressive symptoms and child developmental milestones, as well as moderators of these associations. A comprehensive search strategy was carried out in four databases (MEDLINE, EMBASE, APA PsycINFO, and Cochrane Central Register of Controlled Trials) from database inception to September 2022. Studies that examine postnatal depressive symptoms and associations with infant and early child (<6 years) achievement of developmental milestones were included. Data were extracted by two independent coders and a random-effects meta-analysis was used to estimate pooled effect sizes and test for moderators. A total of 38 non-overlapping studies (95,897 participants), all focused on maternal postnatal depression, met inclusion criteria. The pooled effect size for the association between postnatal depressive symptoms and early achievement of infant and child developmental milestones (N = 38; r = -.12; 95% CI = -.18, -.06) was small in magnitude. Child age at maternal depression measurement was a moderator, whereby effect sizes became greater for older children. Despite small effects, maternal postnatal depressive symptoms should be included in screening during routine well-child visits to enhance child development outcomes.

El examinar los determinantes sociales de la salud, incluyendo la depresión materna, es una práctica pediátrica recomendada. Sin embargo, la magnitud de la asociación entre las herramientas de examinación materna y del niño está por ser determinada. El presente estudio evaluó la asociación entre los síntomas depresivos postnatales maternos y los momentos cruciales en el desarrollo del niño, así como su papel de moderadores de estas asociaciones. Una estrategia de investigación comprensiva se llevó a cabo en cuatro bancos de datos (MEDLINE, EMBASE, APA PsycINFO, y el Registro Central Cochrane para Ensayos Controlados) desde el inicio del banco de datos hasta septiembre de 2022. Se incluyeron los estudios que examinan los síntomas depresivos postnatales y sus asociaciones con el alcance de logros de momentos cruciales del infante y del niño en su temprana niñez (<6 años). Se extrajeron los datos por medio de dos independientes codificadores y se usó un metaanálisis de efectos al azar para estimar los tamaños de efectos agrupados y examinarlos como moderadores. Un total de 38 estudios que no compartían la misma información (95,897 participantes), todos enfocados en la depresión materna postnatal, reunieron los criterios para ser incluidos. El tamaño de los efectos agrupados para la asociación entre los síntomas depresivos postnatales y el logro temprano de los momentos cruciales del infante y el niño (N = 38; r = -.12; 95% CI = -.18, -.06) fue pequeño en magnitud. La edad del niño en la medida de la depresión materna fue un moderador, por lo cual los tamaños de los efectos se hicieron mayores para los niños de mayor edad. A pesar de los pequeños efectos, los síntomas depresivos postnatales maternos deben ser incluidos en la examinación durante las visitas rutinarias de chequeos del bienestar del niño para mejorar los resultados del desarrollo del niño.

Le dépistage de déterminants sociaux de la santé, y compris la dépression maternelle, est une pratique pédiatrique recommandée. Cependant la magnitude du lien entre les outils de dépistage maternelle et de l'enfant reste indéterminée. Cette étude a évalué le lien entre les symptômes dépressifs postnatals maternels et les jalons du développement de l'enfant, ainsi que les modérateurs de ces liens. Une stratégie de recherche exhaustive a été adoptée pour quatre bases de données (MEDLINE, EMBASE, APA PsycINFO, et Cochrane Central Register of Controlled Trials) des débuts de la base de données jusqu'à septembre 2022. Les études examinant les symptômes dépressifs postnatals et les liens avec l'atteinte des jalons de développement du nourrisson et du petit enfant (<6 ans) ont été inclues. Les données ont été extraites par deux codeurs et une méta-analyse à effets aléatoires a été utilisée afin d'estimer les tailles et tests d'effet regroupées pour les modérateurs. Un total de 38 études ne se recoupant pas (95897 participantes), toutes focalisées sur la dépression maternelle postnatale, ont rempli les critères d'inclusion. La taille d'effet regroupé pour le lien entre les symptômes dépressifs postnatales et l'atteinte précoce des jalons de développement du nourrisson et de l'enfant (N = 38; r = -,12; 95% CI = -,18, -,06) était petite en magnitude. L'âge de l'enfant à la mesure de la dépression maternelle était un modérateur, où l'ampleur de l'effet était plus grande pour les enfants plus âgés. En dépit du peu d'ampleur les symptômes dépressifs postnatals maternels devraient être inclus dans le dépistage durant les visites de routine de santé de l'enfant afin d'améliorer les résultats sur le développement de l'enfant.

Plant-Based Milk Consumption and Growth in Children 1-10 Years of Age.

BACKGROUND: The effects of plant-based milk consumption on the growth of children are unclear. OBJECTIVES: We aimed to evaluate the relationship between plant-based milk consumption and BMI in childhood. Secondary objectives were to examine the association with height and whether these relationships are mediated by dairy milk intake and modified by age or the type of plant-based milk consumed. METHODS: A prospective cohort study was conducted in healthy children aged 1-10 y through the TARGet Kids! primary care research network in Toronto, Canada. Linear mixed-effect modeling and logistic generalized estimating equations were used to evaluate the association between plant-based milk consumption (number of 250 mL cups/d) and BMI. A mediation analysis was conducted to examine whether dairy milk intake mediated these relationships. Effect modification by age and type of plant-based milk was explored. RESULTS: Among 7195 children (mean age: 3.1 y; 52.3% male), higher plant-based milk consumption was associated with lower BMI (P = 0.0002) and height (P = 0.005). No association was found with BMI categories. Lower dairy milk intake partially mediated these relationships. A child aged 5 y who consumed 3 cups of plant-based milk compared with 3 cups of dairy milk had a lower weight of 0.5 kg and lower height of 0.8 cm. Associations did not change over time and were similar for children who consumed soy milk compared with other plant-based milks. CONCLUSIONS: Plant-based milk consumption was associated with lower BMI and height, but both were within the normal range on average. Future longitudinal studies are needed to determine whether these associations persist over time.

Underweight in the first 2 years of life and nutrition risk in later childhood: a prospective cohort study.

BACKGROUND: Children with underweight in the first 2 years have lower body mass index z-score (zBMI) and height-for-age z-score (HAZ) in later childhood. It is not known if underweight in the first 2 years is associated with nutrition risk in later childhood. OBJECTIVE: (1) Determine the relationship between underweight (zBMI < -2) in the first 2 years and nutrition risk measured by the Nutrition Screening for Toddlers and Preschoolers (NutriSTEP) score from 18 months to 5 years. (2) Explore the relationship between underweight in the first 2 years and the NutriSTEP subscores for eating behaviours and dietary intake from 18 months to 5 years. METHODS: This was a prospective study, including healthy full-term children in Canada aged 0-5 years. zBMI was calculated using measured heights and weights and the WHO growth standards. NutriSTEP score was measured using a parent-completed survey and ranged from 0 to 68. Nutrition risk was defined as a score ≥21. Linear mixed effects models were used. RESULTS: Four thousand nine hundred twenty-nine children were included in this study. At enrolment, 51.9% of participants were male. The prevalence of underweight children was 8.8%. Underweight in the first 2 years was associated with higher NutriSTEP (0.79, 95% CI: 0.29,1.29), higher eating behaviour subscore (0.24, 95% CI: 0.03, 0.46) at 3 years and higher odds of nutrition risk (OR: 1.39, 95% CI: 1.07,1.82) at 5 years. CONCLUSIONS: Children with underweight in the first 2 years had higher nutrition risk in later childhood. Further research is needed to understand the factors which influence these relationships.

Association Between Family Income and Positive Developmental Screening Using the Infant Toddler Checklist at the 18-Month Health Supervision Visit.

OBJECTIVE: To examine the associations between several potential predictors (child biologic, social, and family factors) and a positive screen for developmental delay using the Infant Toddler Checklist (ITC) at the 18-month health supervision visit in primary care. METHODS: This was a cross-sectional study of healthy children attending an 18-month health supervision visit in primary care. Parents completed a standardized questionnaire, addressing child, social, and family characteristics, and the ITC. Logistic regression analyses were used to assess the associations between predictors and a positive ITC. RESULTS: Among 2188 participants (45.5% female; mean age, 18.2 months), 285 (13%) had a positive ITC and 1903 (87%) had a negative ITC. The aOR for a positive ITC for male compared with female sex was 2.15 (95% CI, 1.63-2.83; P < .001). The aOR for birthweight was 0.65 per 1 kg increase (95% CI, 0.53-0.80; P < .001). The aOR for a family income of <$40,000 compared with ≥$150,000 was 3.50 (95% CI, 2.22-5.53; P < .001), and the aOR for family income between $40,000-$79,999 compared with ≥$150,000 was 1.88 (95% CI, 1.26-2.80; P = .002). CONCLUSIONS: Screening positive on the ITC may identify children at risk for the double jeopardy of developmental delay and social disadvantage and allow clinicians to intervene through monitoring, referral, and resource navigation for both child development and social needs. TRIAL REGISTRATION: Clinicaltrials.gov (NCT01869530).

Association of birthweight with diabetes, hypertension, and ischemic heart disease in young adulthood: a retrospective cohort study.

Birthweight has been associated with diabetes in a reverse J-shape (highest risk at low birthweight and moderately high risk at high birthweight) and inversely associated with hypertension in adulthood with inconsistent evidence for cardiovascular disease. There is a lack of population-based studies examining the incidence of cardiometabolic outcomes in young adults born with low and high birthweights. To evaluate the association between birthweight and diabetes, hypertension, and ischemic heart disease (IHD) in young adulthood, we conducted a retrospective cohort study of 874,904 singletons born in Ontario, Canada, from 1994 to 2002, identified from population-based health administrative data. Separate Cox regression models examined birthweight in association with diabetes, hypertension, and IHD adjusting for confounders. Among adults 18-26 years, the diabetes incidence rate was 18.15 per 100,000 person-years, hypertension was 15.80 per 100,000 person-years, and IHD was 1.85 per 100,000 person-years. Adjusted hazard ratios (AHR) for the hazard of diabetes with low (<2500g) and high (>4000g), compared with normal (2500-4000g) birthweight, were 1.46 (95% CI 1.28, 1.68) and 1.09 (0.99, 1.21), respectively. AHR for hypertension with low and high birthweight were 1.34 (1.15, 1.56) and 0.86 (0.77, 0.97), respectively. AHR for IHD with low and high birthweight were 1.28 (0.80, 2.05) and 0.97 (0.71, 1.33), respectively. Overall, birthweight was associated with diabetes in young adults in a reverse J-shape and inversely with hypertension. There was insufficient evidence of an association with IHD. Further evidence is needed to understand the causal mechanisms between birthweight and cardiometabolic diseases in young adults.

Prospective cohort study of vitamin D and autism spectrum disorder diagnoses in early childhood.

Several studies have suggested an association between vitamin D in childhood and autism spectrum disorder. No prospective studies have evaluated whether lower vitamin D levels precede ASD diagnoses - a necessary condition for causality. The objective of this study was to prospectively evaluate whether vitamin D serum levels in early childhood was associated with incident physician diagnosed ASD. A prospective cohort study was conducted using data from preschool-aged children in the TARGet Kids! practice-based research network in Toronto, Canada, from June 2008 to July 2015. 25-hydroxyvitamin D concentration was measured through blood samples and vitamin D supplementation from parent report. Autism spectrum disorder diagnosis was determined from medical records at follow-up visits. Covariates included age, sex, family history of autism spectrum disorder, maternal ethnicity, and neighborhood household income. Unadjusted and adjusted relative risks and 95% confidence intervals were estimated using Poisson regression with a robust error variance. In this study, 3852 children were included. Autism spectrum disorder diagnosis was identified in 41 children (incidence = 1.1%) over the observation period (average follow-up time = 2.5 years). An association between 25-hydroxyvitamin D concentration and autism spectrum disorder was not identified in the unadjusted (relative risk = 1.04, 95% confidence interval: 0.97, 1.11 per 10 nmol/L increase in 25-hydroxyvitamin D concentration) or adjusted models (adjusted relative risk = 1.06; 95% confidence interval: 0.95, 1.18). An association between vitamin D supplementation in early childhood and autism spectrum disorder was also not identified (adjusted relative risk = 0.86, 95% confidence interval: 0.46, 1.62). Vitamin D in early childhood may not be associated with incident physician diagnoses of autism spectrum disorder.