Associations of Abnormal Maternal Glucose Regulation in Pregnancy with Offspring Adiposity, Insulin Resistance, and Adipokine Markers During Childhood and Adolescence.

OBJECTIVE: To examine the associations of abnormal maternal glucose regulation in pregnancy with offspring adiposity, insulin resistance, adipokine, and inflammatory markers during childhood and adolescence. STUDY DESIGN: Project Viva is a prospective prebirth cohort (n = 2128 live births) initiated from 1999 through 2002 in Eastern Massachusetts, US. During the second trimester of pregnancy, clinicians used 2-step oral glucose challenge testing to screen for gestational diabetes mellitus. In the offspring, we measured anthropometry, insulin resistance, adipokines, lipids, and inflammatory markers in mid-childhood (n = 1107), early adolescence (n = 1027), and mid-adolescence (n = 693). We used multivariable linear regression models and generalized estimating equations adjusted for child age and sex, and for maternal age, race/ethnicity, education, parity, and smoking during pregnancy; we further adjusted for prepregnancy body mass index (BMI). RESULTS: In mid-adolescence (17.1 [0.8] years of age), offspring of mothers with gestational diabetes mellitus (n = 27) had a higher BMI z-score (ß; 95% Cl; 0.41 SD; 0.00, 0.82), sum of skinfolds (8.15 mm; 2.48, 13.82), homeostatic model assessment for insulin resistance (0.81 units; 0.13, 1.50), leptin z-score (0.40 SD; 0.01, 0.78), and leptin/adiponectin ratio z-score (0.51 SD; CI 0.09, 0.93) compared with offspring of mothers with normoglycemia (multivariable-adjusted models). The associations with BMI, homeostatic model assessment for insulin resistance, and adiponectin seemed stronger in mid-adolescence compared with earlier time points. The associations were attenuated toward the null after adjustment for maternal prepregnancy BMI. CONCLUSION: Exposure to gestational diabetes mellitus is associated with higher adiposity, insulin resistance, and altered adipokines in mid-adolescence. Our findings suggest that the peripubertal period could be a key time for the emergence of prenatally programmed metabolic abnormalities.

Metabolomic signatures for blood pressure from early to late adolescence: findings from a U.S. cohort.

INTRODUCTION: Metabolite signatures for blood pressure (BP) may reveal biomarkers, elucidate pathogenesis, and provide prevention targets for high BP. Knowledge regarding metabolites associated with BP in adolescence remains limited. OBJECTIVES: Investigate the associations between metabolites and adolescent BP, both cross-sectionally (in early and late adolescence) and prospectively (from early to late adolescence). METHODS: Participants are from the Project Viva prospective cohort. During the early (median: 12.8 years; N = 556) and late (median: 17.4 years; N = 501) adolescence visits, we conducted untargeted plasma metabolomic profiling and measured systolic (SBP) and diastolic BP (DBP). We used linear regression to identify metabolites cross-sectionally associated with BP at each time point, and to assess prospective associations of changes in metabolite levels from early to late adolescence with late adolescence BP. We used Weighted Gene Correlation Network Analysis and Spearman's partial correlation to identify metabolite clusters associated with BP at each time point. RESULTS: In the linear models, higher androgenic steroid levels were consistently associated with higher SBP and DBP in early and late adolescence. A cluster of 59 metabolites, mainly composed of androgenic steroids, correlated with higher SBP and DBP in early adolescence. A cluster primarily composed of fatty acid lipids was marginally associated with higher SBP in females in late adolescence. Multiple metabolites, including those in the creatine and purine metabolism sub-pathways, were associated with higher SBP and DBP both cross-sectionally and prospectively. CONCLUSION: Our results shed light on the potential metabolic processes and pathophysiology underlying high BP in adolescents.

Association of the Life's Essential 8 cardiovascular health score with periodontitis among US adults.

AIM: To investigate whether cardiovascular health (CVH) is associated with periodontitis. MATERIALS AND METHODS: We used data from the 2009 to 2014 National Health and Nutrition Examination Survey. We quantified CVH using Life's Essential 8, which includes four health behaviours (diet, smoking, physical activity and sleep) and four health factors (body mass index, blood cholesterol, glucose and pressure). We categorized scores as low (0-49), moderate (50-79) and high (80-100). We calculated subscores of health behaviours and factors and categorized them as low, moderate and high. We used logistic regression to assess the association of CVH with periodontitis, adjusting for age, gender, race/ethnicity, education, poverty index, marital status and health insurance. We computed odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: This study included 9296 adults ≥30 years old. Multivariable-adjusted models showed that subjects with moderate (OR, 0.62; 95% CI: 0.52-0.74) or high (OR, 0.43; 95% CI: 0.33-0.57) CVH had significantly lower odds of periodontitis compared to those with low CVH. These results were consistent in the health behaviours model, but the estimates in the health factors model were not significant. CONCLUSIONS: Improving CVH may help prevent periodontitis. Longitudinal studies are needed to confirm our findings.

Prediction of internalizing and externalizing symptoms in late childhood from attention-deficit/hyperactivity disorder symptoms in early childhood.

Limited analyses based on national samples have assessed whether early attention-deficit/hyperactivity disorder (ADHD) symptoms predict later internalizing and externalizing symptoms in youth and the influence of sex and pubertal timing on subsequent psychiatric symptoms. This study analyzed data (n = 2818) from the Environmental influences on Child Health Outcomes Program national cohort. Analyses used data from early childhood (mean age = 5.3 years) utilizing parent-reported ADHD symptoms to predict rates of internalizing and externalizing symptoms from late childhood/adolescence (mean age = 11.9 years). Within a subsample age at peak height velocity (APHV) acted as a proxy to assess pubertal timing from early childhood (mean age = 5.4 years) to adolescence (mean age = 12.3 years). Early-childhood ADHD symptoms predicted later psychiatric symptoms, including anxiety, depression, aggressive behavior, conduct problems, oppositional defiant disorder, and rule-breaking behavior. Earlier APHV was associated with increased Conduct Disorder symptoms from late childhood to adolescence for females only. A stronger relation between ADHD symptoms and later aggression was observed in females with earlier APHV, whereas this same pattern with aggression, conduct problems and depression was observed in males with later APHV. Clinicians should consider that both young girls and boys with elevated ADHD symptoms, particularly with off-set pubertal timing, may be at risk for later psychiatric symptoms.

Delaying high school start times impacts depressed mood among students: evidence from a natural experiment.

PURPOSE: Delaying high school start times prolongs weekday sleep. However, it is not clear if longer sleep reduces depression symptoms and if the impact of such policy change is the same across groups of adolescents. METHODS: We examined how gains in weekday sleep impact depression symptoms in 2,134 high school students (mean age 15.16 ± 0.35 years) from the Minneapolis metropolitan area. Leveraging a natural experiment design, we used the policy change to delay school start times as an instrument to estimate the effect of a sustained gain in weekday sleep on repeatedly measured Kandel-Davies depression symptoms. We also evaluated whether allocating the policy change to subgroups with expected benefit could improve the impact of the policy. RESULTS: Over 2 years, a sustained half-hour gain in weekday sleep expected as a result of the policy change to delay start times decreased depression symptoms by 0.78 points, 95%CI (-1.32,-0.28), or 15.6% of a standard deviation. The benefit was driven by a decrease in fatigue and sleep-related symptoms. While symptoms of low mood, hopelessness, and worry were not affected by the policy on average, older students with greater daily screen use and higher BMI experienced greater improvements in mood symptoms than would be expected on average, signaling heterogeneity. Nevertheless, universal implementation outperformed prescriptive strategies. CONCLUSION: High school start time delays are likely to universally decrease fatigue and overall depression symptoms in adolescents. Students who benefit most with respect to mood are older, spend more time on screens and have higher BMI.

Incidence rates of childhood asthma with recurrent exacerbations in the US Environmental influences on Child Health Outcomes (ECHO) program.

BACKGROUND: Descriptive epidemiological data on incidence rates (IRs) of asthma with recurrent exacerbations (ARE) are sparse. OBJECTIVES: This study hypothesized that IRs for ARE would vary by time, geography, age, and race and ethnicity, irrespective of parental asthma history. METHODS: The investigators leveraged data from 17,246 children born after 1990 enrolled in 59 US with 1 Puerto Rican cohort in the Environmental Influences on Child Health Outcomes (ECHO) consortium to estimate IRs for ARE. RESULTS: The overall crude IR for ARE was 6.07 per 1000 person-years (95% CI: 5.63-6.51) and was highest for children aged 2-4 years, for Hispanic Black and non-Hispanic Black children, and for those with a parental history of asthma. ARE IRs were higher for 2- to 4-year-olds in each race and ethnicity category and for both sexes. Multivariable analysis confirmed higher adjusted ARE IRs (aIRRs) for children born 2000-2009 compared with those born 1990-1999 and 2010-2017, 2-4 versus 10-19 years old (aIRR = 15.36; 95% CI: 12.09-19.52), and for males versus females (aIRR = 1.34; 95% CI 1.16-1.55). Black children (non-Hispanic and Hispanic) had higher rates than non-Hispanic White children (aIRR = 2.51; 95% CI 2.10-2.99; and aIRR = 2.04; 95% CI: 1.22-3.39, respectively). Children born in the Midwest, Northeast and South had higher rates than those born in the West (P < .01 for each comparison). Children with a parental history of asthma had rates nearly 3 times higher than those without such history (aIRR = 2.90; 95% CI: 2.43-3.46). CONCLUSIONS: Factors associated with time, geography, age, race and ethnicity, sex, and parental history appear to influence the inception of ARE among children and adolescents.

Neighborhood Conditions and Resources in Mid-Childhood and Dampness and Pests at Home in Adolescence.

OBJECTIVE: To examine prospectively associations of neighborhood opportunity with the presence of dampness or pests in the home environment during early adolescence. STUDY DESIGN: We geocoded residential addresses from 831 children (mean age 7.9 years, 2007-2011) in the Project Viva cohort. We linked each address with census tract-level Child Opportunity Index scores, which capture neighborhood conditions and resources influencing child heath including educational, health, environmental, and socioeconomic factors. Our primary outcome was presence of dampness or pests in the home in early adolescence (mean age 13.2 years, 2013-2016). Secondary outcomes included current asthma and lung function testing results. Mixed-effects regression models estimated longitudinal associations of Child Opportunity Index scores with outcomes, adjusting for individual and family sociodemographics. RESULTS: Children residing in neighborhoods with greater overall opportunity were less likely to live in homes with dampness or pests approximately 5 years later (aOR 0.85 per 20-unit increase in Child Opportunity Index percentile rank, 95% CI 0.73-0.998). We observed no significant associations in adjusted models of overall neighborhood opportunity with current asthma or lung function. Lower school poverty or single-parent households and greater access to healthy food or economic resource index were associated with lower odds of a home environment with dampness or pests. CONCLUSIONS: More favorable neighborhood conditions in mid-childhood were associated with lower likelihood of living in a home with dampness or pests in the early adolescence.

Growth Velocities Across Distinct Early Life Windows and Child Cognition: Insights from a Contemporary US Cohort.

OBJECTIVE: To evaluate the relative importance of overall and period-specific postnatal growth and their interaction with fetal growth on cognition in a generally well-nourished population. STUDY DESIGN: We included 1052 children from Project Viva, a prospective cohort in Boston, Massachusetts. Using linear spline mixed-effects models, we modeled length/height and body mass index (BMI) trajectories from birth to 7 years and estimated standardized overall (0-7 years) and period-specific growth velocities ie, early infancy (0-4 months), late infancy (4-15 months), toddlerhood (15-37 months), and early childhood (37-84 months). We investigated associations of growth velocities as well as their interactions with birthweight-for-gestational age on mid-childhood (mean age: 7.9 years) IQ, visual memory and learning, and visual motor ability. RESULTS: Greater overall height velocity was associated with modestly higher design memory score, (adjusted ß [95% CI] 0.19 [-0.01,0.38] P = .057])points per SD increase but lower verbal IQ (-0.88 [-1.76,0.00] P = .051). Greater early infancy height velocity was associated with higher visual motor score (1.92 [0.67,3.18]). Greater overall BMI velocity was associated with lower verbal IQ (-0.71 [-1.52,0.11] P = .090). Greater late infancy BMI velocity was associated with lower verbal IQ (-1.21 [-2.07,-0.34]), design memory score (-0.22 [-0.42,-0.03)], but higher picture memory score (0.22 [0.01,0.43]). Greater early infancy height velocity (-1.5 SD vs 1.5 SD) was associated with higher nonverbal IQ (margins [95% CI] 102.6 [98.9106.3] vs 108.2 [104.9111.6]) among small-for-gestational age infants (P-interaction = 0.04). CONCLUSIONS: Among generally well-nourished children, there might not be clear cognitive gains with faster linear growth except for those with lower birthweight-for-gestational age, revealing the potential importance of early infancy compensatory growth.

Non-essential and essential trace element mixtures and kidney function in early pregnancy - A cross-sectional analysis in project viva.

Some trace elements are established nephrotoxicants, yet their associations with kidney function remain understudied in the context of pregnancy, a time of substantial change in kidney physiology and function. We aimed to estimate the individual and joint associations of trace element mixtures with maternal kidney function during the 1st trimester of pregnancy (mean 9.7 gestational weeks). 1040 women from Project Viva contributed blood samples which were assessed for erythrocyte non-essential [arsenic (As), cadmium (Cd), cesium (Cs), mercury (Hg), lead (Pb)] and essential [barium (Ba), magnesium (Mg), manganese (Mn), selenium (Se), and Zinc (Zn)] trace elements, and plasma creatinine for kidney function. We estimated glomerular filtration rate using the Chronic Kidney Disease Epidemiology Collaboration (eGFRCKD-EPI) equation without race-adjustment factors. We examined associations of eGFRCKD-EPI with individual trace elements using multivariable linear regression and their mixtures using quantile-based g-computation, adjusting for sociodemographics, pregnancy characteristics, and diet. Participants in our study were predominantly White (75%), college graduates (72%), and had household income >$70,000/year (63%). After adjusting for covariates, higher Pb (ß -3.51 ml/min/1.73 m2; 95% CI -5.83, -1.18) concentrations were associated with lower eGFRCKD-EPI, while higher Mg (ß 10.53 ml/min/1.73 m2; 95% CI 5.35, 15.71), Se (ß 5.56 ml/min/1.73 m2; 95% CI 0.82, 10.31), and Zn (ß 5.88 ml/min/1.73 m2; 95% CI 0.51, 11.26) concentrations were associated with higher eGFRCKD-EPI. In mixture analyses, higher non-essential trace elements mixture concentration was associated with reduced eGFRCKD-EPI (Ψ -1.03 ml/min/1.73 m2; 95% CI: 1.92, -0.14). Conversely, higher essential trace elements mixture concentration was associated with higher eGFR (Ψ 1.42; 95% CI: 0.48, 2.37). Exposure to trace elements in early pregnancy may influence women's kidney function although reverse causation cannot be eliminated in this cross-sectional analysis. These findings have important implications for long-term cardiovascular and postpartum kidney health that warrant additional studies.

Associations of maternal non-nutritive sweetener intake during pregnancy with offspring body mass index and body fat from birth to adolescence.

BACKGROUND/OBJECTIVE: The evidence that maternal non-nutritive sweetener (NNS) intake during pregnancy increases childhood obesity risk is conflicting. A potential reason for this is that all prior studies examined childhood body mass index (BMI) at only one timepoint and at different ages. We examined the extent to which NNS intake during pregnancy is associated with offspring BMI z-score and body fat longitudinally from birth to 18 years. SUBJECTS: A total of 1683 children from Project Viva, a prospective pre-birth cohort, were recruited from 1999 to 2002 in Massachusetts. METHODS: We assessed maternal NNS intake in the first and second trimesters of pregnancy using a semiquantitative food frequency questionnaire. Our outcomes were offspring BMI z-score, (at birth, infancy (median 6.3 months), early childhood (3.2 years), mid-childhood (7.7 years), and early adolescence (12.9 years)), sum of skinfolds (SS), fat mass index (FMI) measured by dual x-ray absorptiometry, and BMI z-score trajectory from birth to 18 years. We adjusted models for maternal pre-pregnancy BMI, age, race/ethnicity, education, parity, pre-pregnancy physical activity, smoking, and paternal BMI and education. RESULTS: A total of 70% of mothers were white and pre-pregnancy BMI was 24.6 ± 5.2 kg/m2. The highest quartile of NNS intake (Q4: 0.98 ± 0.91 servings/day) was associated with higher BMI z-score in infancy (ß 0.20 units; 95% CI 0.02, 0.38), early childhood (0.21; 0.05, 0.37), mid-childhood (0.21; 0.02, 0.40), and early adolescence (0.14; -0.07, 0.35) compared with Q1 intake (Q1: 0.00 ± 0.00 servings/day). Q4 was also associated with higher SS in early childhood (1.17 mm; 0.47, 1.88), mid-childhood (2.33 mm; 0.80, 3.87), and early adolescence (2.27 mm; -0.06, 4.60) and higher FMI in mid-childhood (0.26 kg/m2; -0.07, 0.59). Associations of maternal NNS intake with offspring BMI z-score became stronger with increasing age from 3 to 18 years (Pinteraction < 0.0001). CONCLUSIONS: Maternal NNS intake during pregnancy is associated with increased childhood BMI z-score and body fat from birth to teenage years. This is relevant given the escalating obesity epidemic, and popularity of NNS.

The Role of Childhood Asthma in Obesity Development: A Nationwide US Multicohort Study.

RATIONALE: Asthma and obesity often co-occur. It has been hypothesized that asthma may contribute to childhood obesity onset. OBJECTIVES: To determine if childhood asthma is associated with incident obesity and examine the role of asthma medication in this association. METHODS: We studied 8,716 children between ages 6 and 18.5 years who were nonobese at study entry participating in 18 US cohorts of the Environmental influences on Child Health Outcomes program (among 7,299 children with complete covariate data mean [SD] study entry age = 7.2 [1.6] years and follow up = 5.3 [3.1] years). MEASUREMENTS AND MAIN RESULTS: We defined asthma based on caregiver report of provider diagnosis. Incident obesity was defined as the first documented body mass index ≥95th percentile for age and sex following asthma status ascertainment. Over the study period, 26% of children had an asthma diagnosis and 11% developed obesity. Cox proportional hazards models with sex-specific baseline hazards were fitted to assess the association of asthma diagnosis with obesity incidence. Children with asthma had a 23% (95% confidence intervals [CI] = 4, 44) higher risk for subsequently developing obesity compared with those without asthma. A novel mediation analysis was also conducted to decompose the total asthma effect on obesity into pathways mediated and not mediated by asthma medication use. Use of asthma medication attenuated the total estimated effect of asthma on obesity by 64% (excess hazard ratios = 0.64; 95% CI = -1.05, -0.23). CONCLUSIONS: This nationwide study supports the hypothesis that childhood asthma is associated with later risk of obesity. Asthma medication may reduce this association and merits further investigation as a potential strategy for obesity prevention among children with asthma.

Cesarean delivery and metabolic health and inflammation biomarkers during mid-childhood and early adolescence.

BACKGROUND: We assessed differences in plasma levels of metabolic health and inflammation biomarkers during mid-childhood and early adolescence between children born by cesarean section vs. vaginal delivery. METHODS: Mother-child pairs (N = 942) enrolled during pregnancy in obstetric practices and child follow-up started at birth. Risk biomarkers were assessed in blood samples collected at the mild-childhood (median = 7 years) and early adolescence (median = 13 years) in-person visits. RESULTS: Two hundred and six children (22%) were born by cesarean section. There were no significant differences in biomarker levels between children born by cesarean and children born vaginally in mid-childhood. However, adolescents born by cesarean section had significantly lower adiponectin [% difference (95% confidence interval (CI)) = -11.3 (-18.1, -4.0) µg/mL] compared to vaginal delivery. We also found some suggestion of higher insulin resistance [insulin levels % difference (95% CI) = 11.5 (-0.40, 25.0) µU/mL and HOMA-IR (homeostatic model assessment of insulin resistance) % difference (95% CI) = 9.1 (-2.30, 21.8) U] in adolescents born by cesarean section compared to those born vaginally. CONCLUSIONS: We found suggestive evidence that adolescents born by cesarean section show differences in certain metabolic health biomarkers relative to adolescents born by vaginal delivery. Further studies are needed to reevaluate these associations since the clinical significance of these differences is unclear. IMPACT: Multiple studies show that children born by cesarean section are at higher risk of obesity compared to those born vaginally. It is unclear yet to what extent this elevated risk may extend to a more adverse profile of biomarkers of metabolic health and inflammation. Adolescents born by cesarean section show small differences in adiponectin and insulin relative to adolescents born by vaginal delivery. Adolescents born by cesarean section may be at higher risk to a more adverse profile of biomarkers of metabolic health and inflammation, but the clinical significance of these differences is uncertain.

Applications of conceptual models from lifecourse epidemiology in ecology and evolutionary biology.

In ecology and evolutionary biology (EEB), the study of developmental plasticity seeks to understand ontogenetic processes underlying the phenotypes upon which natural selection acts. A central challenge to this inquiry is ascertaining a causal effect of the exposure on the manifestation of later-life phenotype due to the time elapsed between the two events. The exposure is a potential cause of the outcome-i.e. an environmental stimulus or experience. The later phenotype might be a behaviour, physiological condition, morphology or life-history trait. The latency period between the exposure and outcome complicates causal inference due to the inevitable occurrence of additional events that may affect the relationship of interest. Here, we describe six distinct but non-mutually exclusive conceptual models from the field of lifecourse epidemiology and discuss their applications to EEB research. The models include Critical Period with No Later Modifiers, Critical Period with Later Modifiers, Accumulation of Risk with Independent Risk Exposures, Accumulation of Risk with Risk Clustering, Accumulation of Risk with Chains of Risk and Accumulation of Risk with Trigger Effect. These models, which have been widely used to test causal hypotheses regarding the early origins of adult-onset disease in humans, are directly relevant to research on developmental plasticity in EEB.

Breastfeeding may benefit cardiometabolic health of children exposed to increased gestational glycemia in utero.

PURPOSE: There is altered breastmilk composition among mothers with gestational diabetes and conflicting evidence on whether breastfeeding is beneficial or detrimental to their offspring's cardiometabolic health. We aimed to investigate associations between breastfeeding and offspring's cardiometabolic health across the range of gestational glycemia. METHODS: We included 827 naturally conceived, term singletons from a prospective mother-child cohort. We measured gestational (26-28 weeks) fasting plasma glucose (FPG) and 2-h plasma glucose (2 hPG) after an oral glucose tolerance test as continuous variables. Participants were classified into 2 breastfeeding categories (high/intermediate vs. low) according to their breastfeeding duration and exclusivity. Main outcome measures included magnetic resonance imaging (MRI)-measured abdominal fat, intramyocellular lipids (IMCL), and liver fat, quantitative magnetic resonance (QMR)-measured body fat mass, blood pressure, blood lipids, and insulin resistance at 6 years old (all continuous variables). We evaluated if gestational glycemia (FPG and 2 hPG) modified the association of breastfeeding with offspring outcomes after adjusting for confounders using a multiple linear regression model that included a 'gestational glycemia × breastfeeding' interaction term. RESULTS: With increasing gestational FPG, high/intermediate (vs. low) breastfeeding was associated with lower levels of IMCL (p-interaction = 0.047), liver fat (p-interaction = 0.033), and triglycerides (p-interaction = 0.007), after adjusting for confounders. Specifically, at 2 standard deviations above the mean gestational FPG level, high/intermediate (vs. low) breastfeeding was linked to lower adjusted mean IMCL [0.39% of water signal (0.29, 0.50) vs. 0.54% of water signal (0.46, 0.62)], liver fat [0.39% by weight (0.20, 0.58) vs. 0.72% by weight (0.59, 0.85)], and triglycerides [0.62 mmol/L (0.51, 0.72) vs. 0.86 mmol/L (0.75, 0.97)]. 2 hPG did not significantly modify the association between breastfeeding and childhood cardiometabolic risk. CONCLUSION: Our findings suggest breastfeeding may confer protection against adverse fat partitioning and higher triglyceride concentration among children exposed to increased glycemia in utero.

Associations of Healthy Infant Feeding Practices and Early Childhood Adiposity in the Rise & SHINE Cohort.

We studied healthy infant feeding practices among 308 mother-infant pairs, including exclusive breastmilk, satiety cues, complementary food introduction, sugary beverage intake, and bottle use in bed. We examined associations of individual and cumulative infant feeding practices through 12 months of age with body mass index (BMI) z -score at 2 years. Exclusive breastmilk and avoidance of bottle use in bed were associated with lower BMI z -score (ß -0.29 units; 95% CI, -0.56, -0.02 units and ß -0.32 units; 95% CI, -0.57, -0.07, respectively), when accounting for maternal pre-pregnancy BMI, household income, infant sex, race, and ethnicity. Adherence to 4--5 practices, compared to ≤ 2 practices, was associated with lower BMI z -score (ß -0.84 units; 95% CI, -1.35, -0.34 units). Adherence to healthy infant feeding practices may reduce risk of excessive adiposity in early childhood. Targeting multiple infant feeding practices may be a more effective way to prevent childhood adiposity.

Separating Algorithms From Questions and Causal Inference With Unmeasured Exposures: An Application to Birth Cohort Studies of Early Body Mass Index Rebound.

Observational studies reporting on adjusted associations between childhood body mass index (BMI; weight (kg)/height (m)2) rebound and subsequent cardiometabolic outcomes have often not paid explicit attention to causal inference, including definition of a target causal effect and assumptions for unbiased estimation of that effect. Using data from 649 children in a Boston, Massachusetts-area cohort recruited in 1999-2002, we considered effects of stochastic interventions on a chosen subset of modifiable yet unmeasured exposures expected to be associated with early (

Association of mode of delivery with offspring pubertal development in Project Viva: a prospective pre-birth cohort study in the USA.

STUDY QUESTION: Is cesarean delivery associated with earlier offspring pubertal development? SUMMARY ANSWER: We identified that boys born by cesarean delivery developed puberty earlier, evidenced by an earlier age at peak height velocity and earlier attainment of puberty score > 1, than boys born by vaginal delivery. WHAT IS KNOWN ALREADY: Cesarean delivery is posited to have long-term effects on health outcomes. However, few studies have examined whether mode of delivery is related to pubertal development. STUDY DESIGN, SIZE, DURATION: Prospective pre-birth cohort study consisting of 1485 mother-child pairs enrolled during pregnancy from obstetric practices and followed up until early adolescence (median age 12.9 years). Participant inclusion required data on mode of delivery and at least one measure of pubertal development. PARTICIPANTS/MATERIALS, SETTING, METHODS: Participants are children from the Project Viva study. We abstracted information on delivery mode from electronic medical records from children followed since birth (1999-2002) and examined the following markers of pubertal development: age at peak height velocity (APHV); age at menarche (girls only); parent-reported pubertal development score; and child-reported pictograph Tanner pubic hair staging. We used multivariable regression models to examine associations of delivery mode with these four pubertal indices, adjusting for the following confounders: demographic and socioeconomic factors; maternal height, pre-pregnancy BMI, total gestational weight gain, pregnancy conditions, parity, and maternal age at menarche; paternal height and BMI; gestational age at delivery and birthweight-for-gestational-age z-score. MAIN RESULTS AND THE ROLE OF CHANCE: In this study, 23.2% of children were born by cesarean delivery. Girls had an earlier APHV, had a higher pubertal score throughout childhood and in early adolescence, and were more likely to attain puberty score >1 and Tanner pubic hair Stage >1 earlier compared to boys. Mean (SD) age at menarche in girls was 12.4 (1.0) years. Boys born by cesarean delivery had significantly earlier APHV (ß -0.23 years; 95% CI -0.40, -0.05) and higher risk of earlier attainment of puberty score > 1 (hazard ratio 1.09; 95% CI 1.01, 1.19) than boys born by vaginal delivery, after adjusting for confounders. These associations were not mediated by pre-pubertal BMI and were similar for planned (no labor) and unplanned (labor) cesarean delivery. No associations were observed between delivery mode and time to attain Tanner pubic hair Stage > 1 in boys. In girls, mode of delivery was not associated with any of the measured pubertal development markers. LIMITATIONS, REASONS FOR CAUTION: This study used, as secondary outcomes, parent- and child-reported measures of pubertal development, which may be more prone to error and misclassification than information collected by trained observers or physicians during clinical examinations. The findings may also not be generalizable to populations from different settings, because all participants lived in one geographic area, were well educated, and had health care. WIDER IMPLICATIONS OF THE FINDINGS: Our findings provide support for cesarean delivery as a potential indicator of identifying children who are likely to experience earlier pubertal development; however, more studies are needed to confirm or refute these observations. STUDY FUNDING/COMPETING INTEREST(S): The project was funded by grants from the National Institutes of Health. The authors have no financial relationships or competing interests to disclose. TRIAL REGISTRATION NUMBER: N/A.

Childhood patterns of overweight and wheeze and subsequent risk of current asthma and obesity in adolescence.

BACKGROUND: Obesity and asthma in childhood often co-occur. Few studies have examined this relationship using repeated measures of body mass index (BMI) or asthma symptoms (such as wheeze). OBJECTIVE: We compared two analytic approaches for repeated measures data to investigate this relationship. METHODS: Our baseline sample consisted of 1277 children enrolled in a Boston-area cohort with BMI or wheeze at age 1 year and no missing covariates. We used latent class growth models (LCGM) and inverse probability weighting (IPW) of marginal structural models to examine the extent to which presence of overweight across childhood was associated with early adolescent current asthma, and conversely of repeated measures of wheeze across childhood with early adolescent obesity. RESULTS: Using LCGM, a "persistent" childhood overweight class (vs "never") was associated with higher risk of asthma in early adolescence (RR 1.9; 95% CI 1.1, 3.0), while "persistent" childhood wheeze (vs "never") was associated with higher risk of obesity in early adolescence (RR 2.7; 95% CI 1.0, 6.4) after adjusting for baseline covariates. An IPW analysis treating childhood overweight and wheeze as time-varying exposures and adjusting for baseline and time-varying covariates resulted in weaker and less precise associations of "persistent" (vs "never") overweight with adolescent asthma (RR 1.3; 95% CI 0.3, 3.0), and of "persistent" (vs "never") wheeze with adolescent obesity (RR 2.3; 95% CI 0.4, 5.3). CONCLUSION: Our point estimates from both approaches suggest an association between "persistent" childhood overweight and adolescent asthma, and between "persistent" childhood wheeze and adolescent obesity. LCGM results were stronger and more precise, whereas IPW results were less conclusive with wider 95% confidence intervals containing the null. The precision gained from LCGM may be at the expense of bias, and the use of both approaches helps to shed some light on this tradeoff.

Increasing nausea and vomiting of pregnancy is associated with sex-dependent differences in early childhood growth: the GUSTO mother-offspring cohort study.

BACKGROUND: Nausea and vomiting of pregnancy (NVP) is common and underlying mechanisms are poorly understood. Longer-term offspring outcomes are also not well documented. This study aimed to determine if NVP, even in milder forms, is associated with adverse pregnancy and childhood growth outcomes. METHODS: In the GUSTO prospective mother-offspring cohort, women with singleton pregnancies (n = 1172) recruited in first trimester responded to interviewer-administered questions at 26-28 weeks' gestation about earlier episodes of NVP since becoming pregnant. Pregnancy outcomes were obtained from medical records. Offspring height and weight measured at 15 time-points between birth to 72 months (m) were standardised for age and sex. RESULTS: 58.5% (n = 686) reported mild-moderate vomiting (mNVP), 10.5% (n = 123) severe vomiting (sNVP) and 5.7% (n = 67) severe vomiting with hospitalisation (shNVP). There was no difference in odds of gestational diabetes, hypertensive disorders of pregnancy, labour induction or caesarean section after adjustment for covariates. sNVP was associated with late preterm delivery [34+ 0-36+ 6 weeks', adjusted OR = 3.04 (95% CI 1.39,6.68)], without increased odds of neonatal unit admission. Compared with no NVP, boys born to mothers with sNVP were longer at birth [adjusted ß = 0.38 standard deviations (SDs) (95% CI 0.02,0.73)], remained taller [0.64 SDs (0.23,1.04) at 72 m] and heavier [0.57 SDs (0.05,1.08) at 60 m] without differences in BMI. Conversely, girls born to mothers with shNVP were lighter from 48 m [- 0.52 SDs (- 1.00, - 0.03)] onwards with lower BMI [- 0.61 SDs (- 1.12,-0.09)]. Conditional growth modelling revealed significant sex-divergence in weight-gain at birth-3 m, 6-9 m and 4-5 years. CONCLUSIONS: Severe NVP was associated with late preterm delivery, and both mild-moderate and severe NVP associated with sex-dependent differences in early childhood growth. Boys whose mothers had NVP were taller and heavier from birth with faster growth in the first year, whereas, girls had poorer weight gain and were lighter by 48 m. As even milder severities of NVP could have long-term impact on offspring growth, further research is needed to determine mechanisms involved and implications on future health. TRIAL REGISTRATION: Clinicaltrials.gov identifier NCT01174875 .

Growth During Infancy and Early Childhood and Its Association With Metabolic Risk Biomarkers at 11.5 Years of Age.

The evidence that fetal life and early infancy are "critical" or "sensitive" ages for later development of cardiometabolic disease is based on flawed methods for comparing different age periods. Moreover, most previous studies have limited their focus to weight gain, rather than growth in length/height or body mass index (weight (kg)/height (m)2). We undertook a secondary analysis of data from the Promotion of Breastfeeding Intervention Trial (1996-2010), a birth cohort study nested within a large cluster-randomized trial in the Republic of Belarus, that had repeated measurements of weight and length/height taken from birth to 11.5 years of age. We used mixed-effects linear models to analyze associations of changes in standardized weight, length/height, and body mass index during 5 age periods (conception to birth, birth to age 3 months, ages 3-12 months, ages 12 months-6.5 years, and ages 6.5-11.5 years) with fasting glucose, insulin, insulin resistance, ß-cell function, and adiponectin at age 11.5 years. We observed strong associations between the metabolic markers and all 3 growth measures, with the largest magnitudes being observed during the latest age period (ages 6.5-11.5 years) and negligible associations during gestation and the first year of life. Later age periods appear more "sensitive" than earlier periods to the adverse metabolic association with rapid growth in childhood.