The effect of early growth patterns and lung function on the development of childhood asthma: a population based study.

BACKGROUND: Infant weight gain is associated with lower lung function and a higher risk of childhood asthma. Detailed individual childhood growth patterns might be better predictors of childhood respiratory morbidity than the difference between two weight and height measurements. We assessed the associations of early childhood growth patterns with lung function and asthma at the age of 10 years and whether the child's current body mass index (BMI) influenced any association. METHODS: We derived peak height and weight growth velocity, BMI at adiposity peak, and age at adiposity peak from longitudinally measured weight and height data in the first 3 years of life of 4435 children enrolled in a population-based prospective cohort study. At 10 years of age, spirometry was performed and current asthma was assessed by questionnaire. Spirometry outcomes included forced vital capacity (FVC), forced expiratory volume in 1 s (FEV1), FEV1/FVC ratio, and forced expiratory flow after exhaling 75% of vital capacity (FEF75). RESULTS: Greater peak weight velocity was associated with higher FVC but lower FEV1/FVC and FEF75. Greater BMI at adiposity peak was associated with higher FVC and FEV1 but lower FEV1/FVC and FEF75. Greater age at adiposity peak was associated with higher FVC, FEV1, FEV1/FVC and FEF75, particularly in children with a small size at birth, and lower odds of current asthma in boys. The child's current BMI only explained the associations of peak weight velocity and BMI at adiposity peak with FVC and FEV1. Peak height velocity was not consistently associated with impaired lung function or asthma. CONCLUSION: Peak weight velocity and BMI at adiposity peak were associated with reduced airway patency in relation to lung volume, whereas age at adiposity peak was associated with higher lung function parameters and lower risk of asthma at 10 years, particularly in boys.

Early Infant Growth Velocity Patterns and Cardiovascular and Metabolic Outcomes in Childhood.

OBJECTIVE: To evaluate the impact of infant growth on childhood health by examining the associations of detailed longitudinal infant weight velocity patterns with childhood cardiovascular and metabolic outcomes. STUDY DESIGN: In a population-based prospective cohort study of 4649 children, we used repeated growth measurements at age 0-3 years to derive peak weight velocity (PWV), age at adiposity peak (AGEAP), and body mass index at adiposity peak (BMIAP). At age 6 years, we measured blood pressure, left ventricular mass, and cholesterol, triglyceride, and insulin concentrations and defined children with clusters of risk factors. We assessed associations using 2 multivariable linear regression models. RESULTS: A 1-SDS-higher infant PWV was associated with higher diastolic blood pressure (0.05 SDS; 95% CI, 0.02-0.09) and lower left ventricular mass (-0.05 SDS; 95% CI, -0.09 to -0.01), independent of body size. A 1-SDS-higher BMIAP was associated with higher systolic (0.12; 95% CI, 0.09-0.16) and diastolic (0.05; 95% CI, 0.01-0.08) blood pressure, but these associations were explained by childhood BMI. We did not observe any associations of PWV, BMIAP, and AGEAP with cholesterol and insulin concentrations. Higher PWV and AGEAP were associated with elevated risk of clustering of cardiovascular risk factors in childhood (P < .05). CONCLUSION: Infant weight velocity patterns are associated with cardiovascular outcomes. Further studies are needed to explore the associations with metabolic outcomes and long-term consequences.

Association of light-to-moderate alcohol drinking in pregnancy with preterm birth and birth weight: elucidating bias by pooling data from nine European cohorts.

Women who drink light-to-moderately during pregnancy have been observed to have lower risk of unfavourable pregnancy outcomes than abstainers. This has been suggested to be a result of bias. In a pooled sample, including 193 747 live-born singletons from nine European cohorts, we examined the associations between light-to-moderate drinking and preterm birth, birth weight, and small-for-gestational age in term born children (term SGA). To address potential sources of bias, we compared the associations from the total sample with a sub-sample restricted to first-time pregnant women who conceived within six months of trying, and examined whether the associations varied across calendar time. In the total sample, drinking up to around six drinks per week as compared to abstaining was associated with lower risk of preterm birth, whereas no significant associations were found for birth weight or term SGA. Drinking six or more drinks per week was associated with lower birth weight and higher risk of term SGA, but no increased risk of preterm birth. The analyses restricted to women without reproductive experience revealed similar results. Before 2000 approximately half of pregnant women drank alcohol. This decreased to 39% in 2000-2004, and 14% in 2005-2011. Before 2000, every additional drink was associated with reduced mean birth weight, whereas in 2005-2011, the mean birth weight increased with increasing intake. The period-specific associations between low-to-moderate drinking and birth weight, which also were observed for term SGA, are indicative of bias. It is impossible to distinguish if the bias is attributable to unmeasured confounding, which change over time or cohort heterogeneity.

Phenotypic dissection of bone mineral density reveals skeletal site specificity and facilitates the identification of novel loci in the genetic regulation of bone mass attainment.

Heritability of bone mineral density (BMD) varies across skeletal sites, reflecting different relative contributions of genetic and environmental influences. To quantify the degree to which common genetic variants tag and environmental factors influence BMD, at different sites, we estimated the genetic (rg) and residual (re) correlations between BMD measured at the upper limbs (UL-BMD), lower limbs (LL-BMD) and skull (SK-BMD), using total-body DXA scans of ∼ 4,890 participants recruited by the Avon Longitudinal Study of Parents and their Children (ALSPAC). Point estimates of rg indicated that appendicular sites have a greater proportion of shared genetic architecture (LL-/UL-BMD rg = 0.78) between them, than with the skull (UL-/SK-BMD rg = 0.58 and LL-/SK-BMD rg = 0.43). Likewise, the residual correlation between BMD at appendicular sites (r(e) = 0.55) was higher than the residual correlation between SK-BMD and BMD at appendicular sites (r(e) = 0.20-0.24). To explore the basis for the observed differences in rg and re, genome-wide association meta-analyses were performed (n ∼ 9,395), combining data from ALSPAC and the Generation R Study identifying 15 independent signals from 13 loci associated at genome-wide significant level across different skeletal regions. Results suggested that previously identified BMD-associated variants may exert site-specific effects (i.e. differ in the strength of their association and magnitude of effect across different skeletal sites). In particular, variants at CPED1 exerted a larger influence on SK-BMD and UL-BMD when compared to LL-BMD (P = 2.01 × 10(-37)), whilst variants at WNT16 influenced UL-BMD to a greater degree when compared to SK- and LL-BMD (P = 2.31 × 10(-14)). In addition, we report a novel association between RIN3 (previously associated with Paget's disease) and LL-BMD (rs754388: ß = 0.13, SE = 0.02, P = 1.4 × 10(-10)). Our results suggest that BMD at different skeletal sites is under a mixture of shared and specific genetic and environmental influences. Allowing for these differences by performing genome-wide association at different skeletal sites may help uncover new genetic influences on BMD.

Associations of genetic risk scores based on adult adiposity pathways with childhood growth and adiposity measures.

BACKGROUND: Results from genome-wide association studies (GWAS) identified many loci and biological pathways that influence adult body mass index (BMI). We aimed to identify if biological pathways related to adult BMI also affect infant growth and childhood adiposity measures. METHODS: We used data from a population-based prospective cohort study among 3,975 children with a mean age of 6 years. Genetic risk scores were constructed based on the 97 SNPs associated with adult BMI previously identified with GWAS and on 28 BMI related biological pathways based on subsets of these 97 SNPs. Outcomes were infant peak weight velocity, BMI at adiposity peak and age at adiposity peak, and childhood BMI, total fat mass percentage, android/gynoid fat ratio, and preperitoneal fat area. Analyses were performed using linear regression models. RESULTS: A higher overall adult BMI risk score was associated with infant BMI at adiposity peak and childhood BMI, total fat mass, android/gynoid fat ratio, and preperitoneal fat area (all p-values < 0.05). Analyses focused on specific biological pathways showed that the membrane proteins genetic risk score was associated with infant peak weight velocity, and the genetic risk scores related to neuronal developmental processes, hypothalamic processes, cyclicAMP, WNT-signaling, membrane proteins, monogenic obesity and/or energy homeostasis, glucose homeostasis, cell cycle, and muscle biology pathways were associated with childhood adiposity measures (all p-values <0.05). None of the pathways were associated with childhood preperitoneal fat area. CONCLUSIONS: A genetic risk score based on 97 SNPs related to adult BMI was associated with peak weight velocity during infancy and general and abdominal fat measurements at the age of 6 years. Risk scores based on genetic variants linked to specific biological pathways, including central nervous system and hypothalamic processes, influence body fat development from early life onwards.

Early childhood growth patterns and school-age respiratory resistance, fractional exhaled nitric oxide and asthma.

BACKGROUND: Greater infant weight gain is associated with lower lung function and increased risk of childhood asthma. The role of early childhood peak growth patterns is unclear. We assessed the associations of individually derived early childhood peak growth patterns with respiratory resistance, fractional exhaled nitric oxide, wheezing patterns, and asthma until school-age. METHODS: We performed a population-based prospective cohort study among 5364 children. Repeated growth measurements between 0 and 3 years of age were used to derive standard deviation scores (s.d.s) of peak height and weight velocities (PHV and PWV, respectively), and body mass index (BMI) and age at adiposity peak. Respiratory resistance and fractional exhaled nitric oxide were measured at 6 years of age. Wheezing patterns and asthma were prospectively assessed by annual questionnaires. We also assessed whether any association was explained by childhood weight status. RESULTS: Greater PHV was associated with lower respiratory resistance [Z-score (95% CI): -0.03 (-0.04, -0.01) per s.d.s increase] (n = 3382). Greater PWV and BMI at adiposity peak were associated with increased risks of early wheezing [relative risk ratio (95% CI): 1.11 (1.06, 1.16), 1.26 (1.11, 1.43), respectively] and persistent wheezing [relative risk ratio (95% CI): 1.09 (1.03, 1.16), 1.37 (1.17, 1.60), respectively] (n = 3189 and n = 3005, respectively). Childhood weight status partly explained these associations. No other associations were observed. CONCLUSIONS: PWV and BMI at adiposity peak are critical for lung developmental and risk of school-age wheezing. Follow-up studies at older ages are needed to elucidate whether these effects persist at later ages.

The Generation R Study: design and cohort update 2017.

The Generation R Study is a population-based prospective cohort study from fetal life until adulthood. The study is designed to identify early environmental and genetic causes and causal pathways leading to normal and abnormal growth, development and health from fetal life, childhood and young adulthood. This multidisciplinary study focuses on several health outcomes including behaviour and cognition, body composition, eye development, growth, hearing, heart and vascular development, infectious disease and immunity, oral health and facial growth, respiratory health, allergy and skin disorders of children and their parents. Main exposures of interest include environmental, endocrine, genomic (genetic, epigenetic, microbiome), lifestyle related, nutritional and socio-demographic determinants. In total, 9778 mothers with a delivery date from April 2002 until January 2006 were enrolled in the study. Response at baseline was 61%, and general follow-up rates until the age of 10 years were around 80%. Data collection in children and their parents includes questionnaires, interviews, detailed physical and ultrasound examinations, behavioural observations, lung function, Magnetic Resonance Imaging and biological sampling. Genome and epigenome wide association screens are available. Eventually, results from the Generation R Study contribute to the development of strategies for optimizing health and healthcare for pregnant women and children.

Meta-analysis of genome-wide scans for total body BMD in children and adults reveals allelic heterogeneity and age-specific effects at the WNT16 locus.

To identify genetic loci influencing bone accrual, we performed a genome-wide association scan for total-body bone mineral density (TB-BMD) variation in 2,660 children of different ethnicities. We discovered variants in 7q31.31 associated with BMD measurements, with the lowest P = 4.1 × 10(-11) observed for rs917727 with minor allele frequency of 0.37. We sought replication for all SNPs located ± 500 kb from rs917727 in 11,052 additional individuals from five independent studies including children and adults, together with de novo genotyping of rs3801387 (in perfect linkage disequilibrium (LD) with rs917727) in 1,014 mothers of children from the discovery cohort. The top signal mapping in the surroundings of WNT16 was replicated across studies with a meta-analysis P = 2.6 × 10(-31) and an effect size explaining between 0.6%-1.8% of TB-BMD variance. Conditional analyses on this signal revealed a secondary signal for total body BMD (P = 1.42 × 10(-10)) for rs4609139 and mapping to C7orf58. We also examined the genomic region for association with skull BMD to test if the associations were independent of skeletal loading. We identified two signals influencing skull BMD variation, including rs917727 (P = 1.9 × 10(-16)) and rs7801723 (P = 8.9 × 10(-28)), also mapping to C7orf58 (r(2) = 0.50 with rs4609139). Wnt16 knockout (KO) mice with reduced total body BMD and gene expression profiles in human bone biopsies support a role of C7orf58 and WNT16 on the BMD phenotypes observed at the human population level. In summary, we detected two independent signals influencing total body and skull BMD variation in children and adults, thus demonstrating the presence of allelic heterogeneity at the WNT16 locus. One of the skull BMD signals mapping to C7orf58 is mostly driven by children, suggesting temporal determination on peak bone mass acquisition. Our life-course approach postulates that these genetic effects influencing peak bone mass accrual may impact the risk of osteoporosis later in life.

The Generation R Study: Biobank update 2015.

The Generation R Study is a population-based prospective cohort study from fetal life until adulthood. The study is designed to identify early environmental and genetic causes and causal pathways leading to normal and abnormal growth, development and health from fetal life, childhood and young adulthood. In total, 9,778 mothers were enrolled in the study. Data collection in children and their parents include questionnaires, interviews, detailed physical and ultrasound examinations, behavioural observations, Magnetic Resonance Imaging and biological samples. Efforts have been conducted for collecting biological samples including blood, hair, faeces, nasal swabs, saliva and urine samples and generating genomics data on DNA, RNA and microbiome. In this paper, we give an update of the collection, processing and storage of these biological samples and available measures. Together with detailed phenotype measurements, these biological samples provide a unique resource for epidemiological studies focused on environmental exposures, genetic and genomic determinants and their interactions in relation to growth, health and development from fetal life onwards.

Ethnic disparities in general and abdominal adiposity at school age: a multiethnic population-based cohort study in the Netherlands.

BACKGROUND/AIMS: Ethnic differences in obesity prevalence have been reported. We examined ethnic differences in general and abdominal fat distribution in school-age children and the influence of parental prepregnancy, pregnancy, and childhood factors on these differences. METHODS: We performed a multiethnic population-based prospective cohort study among 5,244 children with information about prepregnancy factors, pregnancy, and childhood factors. At the age of 6 years, the BMI, total fat mass, android/gynoid fat mass ratio, and preperitoneal fat mass were assessed via dual-energy X-ray absorptiometry and abdominal ultrasound. RESULTS: The overweight and obesity prevalences among Dutch children were 10.0 and 2.1%, respectively. Higher prevalences were observed among Cape Verdean (21.0 and 10.3%), Dutch Antillean (18.4 and 13.8%), Moroccan (20.6 and 7.7%), Surinamese-Creole (13.4 and 7.7%), Surinamese-Hindustani (12.3 and 6.2%), and Turkish (23.8 and 12.0%) children. In the models adjusted for age and sex only, Moroccan, Surinamese-Hindustani, and Turkish children had a higher total fat mass than Dutch children, whereas Surinamese-Creole children had a lower total fat mass. Compared to Dutch children, the android/gynoid fat mass ratio was higher in Moroccan, Surinamese-Hindustani, and Turkish children, whereas the preperitoneal fat mass was higher among Dutch Antillean, Moroccan, Surinamese-Hindustani, and Turkish children (all p < 0.05). Prepregnancy factors explained up to 73% of these differences. In addition to prepregnancy factors, pregnancy factors explained up to 34% of the differences. Childhood factors did not significantly explain these associations. CONCLUSIONS: All ethnic minority groups had higher risks of overweight and obesity than Dutch children. Moroccan, Surinamese-Hindustani, and Turkish children also had an adverse body fat profile. Prepregnancy and pregnancy might be critical periods for preventive strategies focused on the reduction of ethnic disparities in childhood adiposity.

Gestational vitamin D deficiency and autism spectrum disorder.

BACKGROUND: There is growing interest in linking vitamin D deficiency with autism spectrum disorders (ASDs). The association between vitamin D deficiency during gestation, a critical period in neurodevelopment, and ASD is not well understood. AIMS: To determine the association between gestational vitamin D status and ASD. METHOD: Based on a birth cohort (n=4334), we examined the association between 25-hydroxyvitamin D (25OHD), assessed from both maternal mid-gestation sera and neonatal sera, and ASD (defined by clinical records; n=68 cases). RESULTS: Individuals in the 25OHD-deficient group at mid-gestation had more than twofold increased risk of ASD (odds ratio (OR)=2.42, 95% confidence interval (CI) 1.09 to 5.07, P=0.03) compared with the sufficient group. The findings persisted in analyses including children of European ethnicity only. CONCLUSIONS: Mid-gestational vitamin D deficiency was associated with an increased risk of ASD. Because gestational vitamin D deficiency is readily preventable with safe, inexpensive and readily available supplementation, this risk factor warrants closer scrutiny. DECLARATION OF INTEREST: None. COPYRIGHT AND USAGE: © The Royal College of Psychiatrists 2017. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) license.

Prevalence and predictors of vitamin D deficiency based on maternal mid-gestation and neonatal cord bloods: The Generation R Study.

BACKGROUND: Population-based studies have confirmed that the prevalence of vitamin D deficiency is substantial in many societies, and is of particular concern in pregnant women. Vitamin D deficiency during pregnancy is associated with a wide range of adverse maternal and offspring health outcomes. To date, studies of vitamin D deficiency during pregnancy have focused on measurements at one or two time points in isolation. We examined both midgestation and cord blood 25 hydroxyvitamin D (25OHD) concentration and explored the prevalence and correlates of vitamin D deficiency in a large ethnically diverse cohort of pregnant women and their infants in the Netherlands. METHODS: This study was embedded in the Generation R Study, a population-based prospective cohort from fetal life onwards in Rotterdam, The Netherlands. Using a highly sensitive tandem mass spectroscopy-based assay, we measured 25OHD in 7256 midgestation samples (mean gestation 20.6 weeks) and 5023 neonatal cord blood samples (mean gestation 40.0 weeks). Using a conservative threshold of less than 25nmol/L to define vitamin D deficiency, we examined the prevalence and socio-demographic correlates of vitamin D deficiency in mothers and infants. We also derived a measure of vitamin D deficiency based on the two time points in order to explore persistent vitamin D deficiency in mother-infant pairs. RESULTS: The prevalence of vitamin D deficiency at midgestation was 26%, while in neonates 46% were deficient. 21% of the mother-infant pairs had persistent vitamin D deficiency (i.e., deficient in maternal and cord samples) and an additional 29% were vitamin D deficient in one of the two samples only. Persistent vitamin D deficiency was strongly associated with non-European ancestry and spring birth. CONCLUSIONS: A sizeable proportion of women and their neonatal offspring in the Generation R cohort were vitamin D deficient. In light of the large body of evidence linking vitamin D deficiency with adverse health outcomes for pregnant women and their offspring, our findings indicate a large unmet need in this population. In particular, women and infants from non-European ethnic background are at high risk of vitamin D deficiency.

Parental smoking during pregnancy, early growth, and risk of obesity in preschool children: the Generation R Study.

BACKGROUND: Maternal smoking during pregnancy seems to be associated with obesity in offspring. Not much is known about the specific critical exposure periods or underlying mechanisms for this association. OBJECTIVE: We assessed the associations of active maternal and paternal smoking during pregnancy with early growth characteristics and risks of overweight and obesity in preschool children. DESIGN: This study was a population-based, prospective cohort study from early fetal life until the age of 4 y in 5342 mothers and fathers and their children. Growth characteristics [head circumference, length, weight, and body mass index (BMI; in kg/m(2))] and overweight and obesity were repeatedly measured at the ages of 1, 2, 3, and 4 y. RESULTS: In comparison with children from nonsmoking mothers, children from mothers who continued smoking during pregnancy had persistently smaller head circumferences and heights until the age of 4 y, whereas their weights were lower only until the age of 3 mo. This smaller length and normal to higher weight led to an increased BMI [SD score difference: 0.11; 95% CI: 0.02, 0.20; P < 0.05)] and an increased risk of obesity (odds ratio: 1.61; 95% CI: 1.03, 2.53; P < 0.05) at the age of 4 y. In nonsmoking mothers, paternal smoking was not associated with postnatal growth characteristics or risk of obesity in offspring. Maternal smoking during pregnancy was associated with a higher BMI at the age of 4 y in children with a normal birth weight and in those who were small for gestational age at birth. CONCLUSION: Our findings suggest that direct intrauterine exposure to smoke until late pregnancy leads to different height and weight growth adaptations and increased risks of overweight and obesity in preschool children.