Generation XXI Birth Cohort Research Articles

Green and blue spaces residential exposure over childhood and multimorbidity in adolescence

Abstract Background Previous studies have explored associations of exposure to natural spaces with specific adverse health outcomes over childhood. However, knowledge is lacking on its effects on multimorbidity, defined as the co-occurrence of two or more diseases in the same individual. We aimed to assess the associations between exposure to green and blue spaces, at multiple time points and through trajectories over childhood, with multimorbidity in early adolescence. Methods In 2388 children from the Generation XXI birth cohort, we assessed, at birth, 4, 7 and 10 years, the residential greenness through the Normalized Difference Vegetation Index (NDVI), the distance from the child’s residence to the closest green and blue space, and the presence of green and blue space (>5,000m²) within 300m distance from the child’s residence. We identified, from birth to 10 years, longitudinal trajectories of exposure to green and blue spaces, using latent class mixed models. At 13 years, participants were classified as having 0, 1 or ≥ 2 cardiometabolic, respiratory and/or neurodevelopmental adverse health outcomes. Adjusted multinomial logistic regression models were used. Results The prevalence of multimorbidity at 13 years was 43%, with overweight/obesity (35%), allergies and asthma (30%), and dyslipidemia (26%) as the most common adverse health outcomes. We observed that the presence of green spaces > 5,000m² within a distance of 300m at birth, 4, 7, and 10 years was associated with lower odds of developing multimorbidity (Odds Ratio (OR) [95% CI] 0.55 [0.32-0.95]; 0.52 [0.32-0.84]; 0.51 [0.32-0.82]; 0.51 [0.32-0.80], respectively). No other significant associations were observed. Conclusions Green spaces around the child’s residence seem to have a protective effect on the development of multimorbidity at 13 years. These findings reinforce the importance of urban design, and the creation of green spaces close to residential areas to optimize health across childhood and adolescence. Key messages • The prevalence of multimorbidity at 13 years is high and worrying. • Increasing accessibility to green spaces might decrease the risk of multimorbidity in adolescence.

Prediction of overweight/obesity risk in adolescence using static and dynamic multi-exposure models

Abstract Background Studying the risk factors for obesity development and timely identification of individuals at increased risk are key for obesity prevention. We aimed to assess the associations of multiple prenatal, infancy and childhood exposures with overweight/obesity at 13 years (y) and develop static and dynamic multiple-exposure prediction models. Methods In 4232 mother-child pairs from the Generation XXI birth cohort, we assessed, during pregnancy/infancy and childhood, 55 sociodemographic factors, anthropometric measures, lifestyle behaviors, and clinical exposures related to the mother and the child and categorized body mass index z-scores as normal weight and overweight/obesity at 13y. Static models for pregnancy/infancy, 4, 7 and 10y, and a dynamic model were fitted using Elastic Net and logistic regression and were compared in terms of predictive performance. Results Mothers with lower educational level and household income, no partner, overweight/obesity before and after pregnancy, excessive gestational weight gain, pregnancy complications and who were smokers during pregnancy had children with a higher risk of overweight/obesity at 13y. Children with higher BMI during infancy, overweight/obesity during childhood, an early introduction of solid foods (before 4 months), a higher consumption of soft drinks at 4y and females had a higher risk of overweight/obesity at 13y. We observed the lowest predictive performance for the pregnancy/infancy model (prediction error of 36%) and the highest predictive performance for the 10y and dynamic models (prediction errors of 17%). Conclusions We identified the most important predictors of overweight/obesity in adolescence, most of them modifiable, and able to be targeted in prevention strategies. Predicting overweight/obesity risk in adolescence might be suboptimal if only considering pregnancy/infancy data and improves as closer to the age of the outcome, with no additional benefit in using a complex dynamic model. Key messages • Prevention of overweight/obesity should start during prenatal life. • Children at higher risk of overweight/obesity may be identified years earlier using prediction models in clinical practice.

Association between bisphenol A exposure and cardiometabolic outcomes: a longitudinal approach

Abstract Background Increased cardiometabolic risk is associated with abnormalities in blood biomarkers profile and adiposity measurements. Some substances found in the food matrix or the environment, called endocrine-disrupting chemicals, may impair cardiometabolic health in the yearly and later stages of life. Bisphenol A (BPA) is a food contaminant that migrates from food contact materials and may act as an endocrine disruptor, negatively affecting human health. The present work aims to assess the longitudinal association between BPA exposure and cardiometabolic outcomes. Methods Data from the four waves of the Portuguese population-based birth cohort Generation XXI were used (n = 3138). Dietary data were collected by 3-d food diaries, using the FoodEx2 classification system to describe the reported foods. BPA daily exposure was estimated using a random forest model, combining dietary information with urinary BPA measured in 24-h urine from a subsample, used to predict the remaining sample’s BPA exposure. The generalised least squares model was used to test the associations between BPA and cardiometabolic outcomes. Results Blood insulin and HOMA-IR presented a significant longitudinal association with BPA daily exposure after adjustment for important variables and energy (0.06 SD(0.03, 0.09); 0.05 SD(0.02, 0.08) respectively). The same findings were observed for fat mass and waist circumference (0.03 SD(0.01, 0.06); 0.06 SD(0.04, 0.08), respectively). For z-BMI, a significant cross-sectional and longitudinal association was found (0.03 SD(0.01, 0.04); 0.02 SD(0.00, 0.04), respectively). Conclusions This was the first study assessing the association between BPA exposure and health outcomes from childhood to adolescence. We found an association between BPA exposure and an increased blood insulin level, insulin resistance, fat mass percentage, waist circumference and z-score of body mass index. Our results point to the need to reduce exposure to BPA in the early stages of life. Key messages • BPA exposure was estimated using direct and indirect methods. • BPA can impair cardiometabolic outcomes from the early stages of life, such as higher blood insulin level, insulin resistance, fat mass, waist circumference, and body mass index.

Differences in the work-family experience of mothers and fathers of a southern European country

Abstract Background The intense childrearing years often coincide with the heightened work demands and responsibilities of the career-building years. We aimed to evaluate the association between family-life stage and men’s and women’s experience of work and private demands, and the conflict between these demands. Methods We evaluated 3532 mothers and 731 fathers as part of the Portuguese population-based birth cohort Generation XXI (2018-2020). Data on family-life stage (exposure), work demands, private demands, and work-to-family conflict (outcomes) were retrieved at the 13-year follow-up wave, as well as data on sociodemographic and household characteristics. Family-life stage was operationalized according to the age of the youngest child: stage 1 (≤5 years), stage 2 (6-11 years), and stage 3 (≥12 years). Ordinal logistic regression models were used to estimate associations. Results Men reported more frequently long working hours, while women spent more time on household and child-related tasks. After adjustment for parents’ and household characteristics, mothers and fathers with younger children were more likely to report spending more time on child-related tasks (ORmothers = 1.83; 95%CI 1.44, 2.33; ORfathers = 2.36; 95%CI 1.41, 3.94), compared to those with older children. Fathers with younger children were also more likely to report spending more time on household tasks (OR = 2.20; 95%CI 1.30, 3.73 for routine tasks and OR = 1.75; 95%CI 1.03, 2.97 for sporadic tasks). Mothers exhibited a significant association between family-life stage and time-based work-to-family conflict when they had younger children (OR = 1.24; 95% CI 1.05, 1.47 for family-life stage 2 and OR = 1.28; 95% CI 1.00, 1.63 for family-life stage 1). Conclusions Both fathers and mothers with young children experienced increased private demands, but only mothers experienced work-to-family conflict. This reveals that family and working arrangements remain marked by a gendered pattern against women.

The trajectories of free sugar intake during childhood, their main sources and its association with socio-economic factors: generation XXI birth cohort.

The study aimed to describe trajectories of free sugar (FS) intake, its main sources and the associations with socio-economic status (SES) in Portuguese children/adolescents evaluated at 4, 7, 10 and 13 years of age from Generation XXI birth-cohort. Dietary intake was assessed through 3-day food diaries (n 5268). Added sugar intake was estimated following a systematic methodology, and FS was based on the WHO definition. A mixed-effects model with linear and quadratic terms for time was used to estimate FS trajectories and its association with SES, adjusting for children's sex, age, BMI and SES. The FS mean intake (g/day) was 37, 47, 51 and 48 at 4, 7, 10 and 13 years, respectively. FS intake increased 4·6 g/year (CI 95 %: 4·20, 5·04), but velocity decreased by 0·3 g/year2 until 13 years. At all ages, the main food source was sweets. Some item's consumption declined (sweets 25-21 % and yoghurts 22-7 %) as children grew older. Inversely, soft drink intake increased (9-18 %). Boys and children from younger mothers had higher FS intake, whereas higher maternal-SES was associated with lower children's FS intake: occupational status (β = -3·5; 95 % CI: -4·97, -1·94), years of education (β = -3·7; 95 % CI: -4·93, -2·40) and household income (β = -4·9; 95 % CI: -6·50, -3·27). The FS trajectories were similar by SES categories but different by obesity status (interaction term β = -1·04; CI 95 % (-1·50, -0·59)). An increasing FS trajectory during childhood is mainly driven by an increasing intake of soft drinks and nectars. The FS trajectory pattern did not change according to SES categories, but children's FS intake was always higher when their mothers had a lower SES.

Are the EAT-Lancet dietary recommendations associated with cardiometabolic health? – Insights from the Generation XXI cohort from childhood into early adolescence

BackgroundThe prospective effect of healthy and planetary diets on cardiometabolic health at young ages remains unclear. ObjectivesThis study aims to investigate the prospective associations between adherence to the EAT-Lancet dietary recommendations at age 7 and the prevalence of obesity and Metabolic Syndrome (MetS) at 7, 10, and 13 y old. MethodsParticipants are children from the Generation XXI birth cohort who completed 3-d food diaries at age 7, with complete data in variables of interest (n = 3564). Adherence to the EAT-Lancet dietary recommendations was evaluated using the World Index for Sustainability and Health (WISH); a higher score indicates a healthier and environmentally sustainable diet. At 7, 10, and 13 y, anthropometrics (weight, height, and waist circumference), blood pressure, serum-fasting triglycerides, high-density lipoprotein cholesterol, and glucose were measured. Obesity and MetS prevalence were determined by the World Health Organization and the International Diabetes Federation criteria, respectively. Adjusted custom binomial log-linear models were used to calculate prevalence ratios (PR) and the respective 95% confidence intervals (95% CI) (covariates: mother’s age, education, prepregnancy body mass index (BMI), gestational diabetes, child’s sex, age, Tanner stage, sports practice and total grams of the remaining food). ResultsFrom 7 to 13 y, obesity decreased from 14.1% to 9.3% and MetS increased from 1.0% to 5.1%. Higher WISH scores at 7 y were associated with a lower prevalence of obesity, measured by both BMI (≥97th percentile: PR = 0.912; 95% CI: 0.839, 0.991; PR = 0.882; 95% CI: 0.79, 0.938, respectively at 10 and 13 y) and waist circumference (≥90th percentile: PR = 0.899; 95% CI: 0.830, 0.974; PR = 0.858; 95% CI: 0.782, 0.942, respectively at 10 and 13 y). For each 10-point increase in the WISH, a reduction of 16% in MetS prevalence at 13 y was observed (PR = 0.837; 95% CI: 0.732, 0.957). No significant effects were found at younger ages. ConclusionsAdherence to the EAT-Lancet diet from an early age may help reduce cardiometabolic risk in early adolescence.

Association between calcium intake from different food sources during childhood and cardiometabolic risk on adolescence: The Generation XXI birth cohort.

Calcium intake has been associated with lower adiposity, but few studies explored the longitudinal relation of calcium from different sources and cardiometabolic markers in young population. Prospectively estimate the association between dairy and non-dairy calcium intake at 4, 7, and 10 years (y) of age and cardiometabolic risk at 13 y. The sample included 4017 participants from the Generation XXI birth cohort. Dietary data were collected from a 3-day food diary. Cardiometabolic clusters at 13 y were estimated by a probabilistic Gaussian mixture model (z-score of waist circumference [WC], HOMA-IR; HDL cholesterol, triglycerides, and systolic blood pressure [BP]). Multivariable linear and logistic regression models were used to estimate associations. Calcium intake (/100 mg), after adjustment for confounders, was negatively and significantly associated with body mass index (BMI) (β = -0.02, 95% CI: -0.04; -0.01), WC (cm) (β = -0.23, 95% CI: -0.36; -0.11), and diastolic BP (mmHg) (β = -0.14, 95% CI: -0.26; -0.03). After additional adjustment for total energy intake, associations lose statistical significance. Calcium intake from milk at 7 y was inversely associated with WC (β = -0.25, 95% CI: -0.48; -0.03) and from yogurt at 10 y was associated with higher BMI (β = 0.08, 95% CI: 0.03; 0.13) and WC (β = 0.54, 95% CI: 0.12; 0.96). Calcium from vegetables at 4, 7, 10 y reduces later cardiometabolic risk (OR = 0.71; OR = 0.84; OR = 0.98, respectively). This study supports a protective effect of calcium on adolescents' cardiometabolic health, especially from vegetables.

Socioeconomic and household framework influences in school-aged children's eating habits: Understanding the parental roles

Maternal influences on children's diet have been widely studied, while paternal and household frameworks require further research. This study aimed to evaluate how individual, socioeconomic and household characteristics at birth and 7 years (y) impact children's fruit and vegetable (FV) and energy-dense foods (EDF) intake at 10y, distinguishing maternal and paternal effects. The sample included 2750 children evaluated at 7 and 10y in the Portuguese birth cohort Generation XXI. The children's food intake was assessed through a Food Frequency Questionnaire at both ages, where 4 food groups were defined: FV, ‘Sweet foods’, ‘Salty snacks’, and ‘Soft drinks’. The associations between food intake at 7y, parents' and children's characteristics, and food intake at 10y were evaluated via binary logistic regression models. Offspring of older mothers with higher age and education, who live with siblings and had higher family income were likelier to have 5 servings of FV daily at 10y. Children eating 5 portions/day of FV at 7y had higher odds of keeping this pattern at 10y. Higher maternal age and education, and father's education decreased the odds of having soft drinks daily at 10y. Higher family income was linked with lower odds of weekly salty snacks and daily sweet foods at 10y. In conclusion, parental education, maternal age, living with siblings, and higher family income influenced children's FV and EDF intake at 10y. Mothers' effects appear to impact children's food intake more than fathers'.

Prevalence, characteristics, and impact of spinal and lower limb recurrent pain at age 13

Objectives: To compare spinal and lower limb pain in adolescents regarding prevalence, characteristics, causes, and impact. Methods: A descriptive cross-sectional study was conducted in 13-year-old adolescents (female n=2210; male n=2353) from the Portuguese Generation XXI birth cohort. Data were collected between 2018 and 2020 through personal interviews by applying the Luebeck Pain Questionnaire. The pain features examined in each anatomical location (back and lower limb) were recurrence, duration, frequency, intensity, perceived causes, and impact on school and leisure activities. Frequencies and the Chi-square test were used. Results: Questionnaires from 4563 adolescents were analysed, 57.9% had pain in the last three months (main pain in the spine: 11.6%; main pain in the lower limb: 29.0%). Of those, 69.4% and 62.4% reported recurrent pain in the spine and lower limb, respectively. Recurrent pain was more frequent in girls than in boys (spine: 80.0%; 57.0%; lower limb: 70.4%; 58.1% respectively). Pain lasted more than three months in most adolescents (spine: about 60%; lower limb: above 50%); frequency was similarly high in both regions and both sexes (girls: 47.0%; boys: 45.7% in the spine; girls: 45.7%; boys: 40.3% in the lower limb); intensity was rated as high by girls (spine: 45.5%; lower limb: 47.3%) and moderate by boys (spine: 42.0%; lower limb: 41.0%). The leading causes of pain were daily living activities, both for the spine (girls: 65.9%; boys: 76.5%) and the lower limb (girls: 62.2%; boys: 72.1%). Psychosocial causes were the second most common cause of spinal pain (girls: 25.0%; boys: 21.0%). Other causes of lower limb pain were traumatic (girls: 25.5%; boys: 16.6%) and physical factors (girls: 20.7%; boys: 23.8%). Absences from school (girls: 11.7%; boys: 4.8%) and restrictions of leisure activities (girls: 20.7%; boys: 25.2%) were more related to pain in the lower limb. Conclusion: More than half of the adolescents reported spinal or lower limb recurrent pain, which presents a higher frequency, higher intensity, and longer duration in the spine. However, lower limb pain led to more concurrent limitations.

Association between bisphenol A exposure and cardiometabolic outcomes: A longitudinal approach

Increased cardiometabolic risk is associated with abnormalities in blood biomarkers profile and adiposity measurements. Some substances found in the food matrix and the environment, called endocrine-disrupting chemicals, may impair cardiometabolic health in the early and later stages of life. Bisphenol A (BPA) is a food contaminant that migrates from food contact materials and may act as an endocrine disruptor, negatively affecting human health. The present work aims to longitudinally assess the association between BPA exposure and cardiometabolic outcomes, considering data from Portuguese population-based birth cohort Generation XXI. Blood insulin (0.06stdβ; 95 %CI:0.03,0.09) and insulin resistance (0.05stdβ; 95 %CI:0.02,0.08) presented a significant longitudinal association with BPA daily exposure after adjustment for important variables and energy. The same findings were observed for fat mass (0.03stdβ; 95 %CI 0.01,0.06) and waist circumference (0.06stdβ; 95 %CI:0.04,0.08). For z-BMI, a significant cross-sectional (0.03stdβ; 95 %CI:0.01,0.04) and longitudinal (0.02stdβ; 95 %CI:0.00,0.04) association was found. This was the first study assessing the association between BPA exposure and health outcomes from childhood to adolescence. We found an association between BPA exposure and increased blood insulin level, insulin resistance, fat mass percentage, waist circumference and z-BMI. Our results point to the need to reduce exposure to BPA in the early stages of life.

Association of adverse childhood experiences with dietary patterns of school-age children: evidence from the birth cohort Generation XXI

BackgroundAdverse Childhood Experiences (ACEs) have been associated with health-risk behaviors and several chronic diseases in adulthood. However, the relationship between exposure to ACEs and dietary patterns at school age is unknown. ObjectivesTo investigate the association between ACEs and dietary patterns of 10-year-olds. MethodsThe study included 5034 children from the Generation XXI cohort, recruited in 2005/2006 in Porto, Portugal. ACEs were assessed through a self-administered questionnaire covering the first 10 years (y) of life, quantified and grouped into 5 dimensions: “abuse,” “school problems,” “death/severe disease,” “life changes,” and “household dysfunction.” Dietary patterns were identified by latent class analysis using data collected with a validated food frequency questionnaire. Five dietary patterns were studied: “low consumption,” “energy-dense foods,” “snacking,” “intermediate consumption,” and “healthier” (used as reference). Multinomial regression analyses were conducted, adjusted for the child’s sex, household income, family structure, and mother’s age [odds ratio (OR) and 99% confidence intervals (CIs)]. ResultsMost children were exposed to ≥1 ACE (96%), and ∼27% had reported 6 or more ACEs throughout life. Those reporting 4–5 and ≥6 ACEs were more likely to follow the “Energy-dense foods” dietary pattern compared with those with no ACEs (OR: 2.41; 99% CI: 1.00, 5.77 and OR: 2.65; 99% CI: 1.10, 6.39, respectively). Children exposed to “abuse” in the first 10 y showed 28% higher odds of following the “low consumption” dietary pattern when compared to children with no reported ACEs and using the “healthier” dietary pattern as a reference (OR: 1.28; 99% CI: 1.00, 1.63). ConclusionsExposure to ACEs was associated with less healthy dietary patterns in school-aged children. Results suggest a cumulative effect of the adverse experiences resulting in a dietary pattern higher in energy-dense foods. Children with ACEs reported under the dimension of “abuse” seemed to have reduced food consumption.

Sleep duration is associated with appetitive traits in school-age years – results from the Generation XXI birth cohort

Sleep may influence appetite regulation through physiological and neurocognitive pathways. However, the association between sleep and appetite in childhood has been scarcely reported, particularly using a prospective design. We aimed to test associations between sleep duration at 7 years of age (y) and appetitive traits at both 7 and 10 y. Participants are from the population-based birth cohort Generation XXI (Porto, Portugal), at 7 (n = 2437) and 10 y (n = 1938) follow-ups. Data on sleep was gathered at 7 y and, considering bedtime and get-up time, total mean sleep duration was calculated and further categorized according to the 10th and 90th percentiles. Appetitive traits were assessed at 7 and 10 y using the parent-reported Children's Eating Behaviour Questionnaire. Associations were tested through Generalized Linear Models (co-variates: child's sex; maternal age, education and pre-pregnancy body mass index at 7 y). At 10 y, associations were further adjusted for the respective appetitive trait at 7 y. Children slept a mean of 10.2 h/night, and 13% and 9% slept ≤9.5 and ≥ 11.0 h/night at 7 y, respectively. For each additional hour in sleep duration, children scored 0.078 (99%CI: −0.145; −0.011) lower on Food Responsiveness, 0.065 (99%CI: −0.129; −0.002) lower on Emotional Undereating and 0.096 (99%CI: −0.161; −0.032) lower on Food Fussiness. Lastly, children sleeping ≤9.5 h/night scored higher on Food Responsiveness (β = 0.145 99%CI: 0.020; 0.271); while those sleeping ≥11.0 h/night scored lower on Food Fussiness (β = −0.255 99%CI: −0.370; −0.079). No significant prospective associations were found. In conclusion, in 7 y children, sleep duration was cross-sectionally associated with lower scores on food approach (Food Responsiveness) and avoidant traits (Emotional Undereating and Food Fussiness). However, the magnitude of the associations was small and further studies are warranted.

Development of a healthy lifestyle assessment index for school-age children

INTRODUCTION: Assessing children's lifestyles is fundamental for developing policies that prevent the onset of non-communicable diseases. OBJECTIVES: To develop a short lifestyle index for school-age children (6 to 9 years old) and assess their lifestyle characterization. METHODOLOGY: The index was developed based on data from the 7-year follow-up of the birth cohort Generation XXI (n=4336 children), grouped into four domains: frequency of food consumption, eating behaviours, physical activity (including sedentary behaviours) and sleep duration. Cronbach alpha coefficient was obtained to assess the index internal consistency. Associations between sociodemographic characteristics, the physical environment of the house, and the index score were evaluated through linear regression models, obtaining beta coefficients and respective 95% confidence interval (95%CI). RESULTS: The final index included only two domains (food consumption and physical activity) with a Cronbach alpha of 0.52 and a mean score of 3.6 ± 2.8 (range: -5 to 10). Maternal age (β=1.066; 95%CI=1.045-1.087), years of education (β=1.216; 95%CI=1.186-1.246), having a house with a garden (β=1.630; 95%CI=1.304-2.037), internet access (β=1.524; 95%CI=1.086-2.139) and having a bicycle (β=1.710; 95%CI=1.086-2.694) were positively associated with a healthier lifestyle of the children. CONCLUSIONS: The index developed is a short instrument that can be used to evaluate school-age children’s overall lifestyle. Better maternal sociodemographic characteristics and a better house physical environment increase the likelihood of children having a healthier lifestyle.

Atopic dermatitis in early life and pain at 10years of age: An exploratory study.

Pain is a distinctive burden in atopic dermatitis and recognized as an important and highly prevalent symptom. It is unknown if the presence of atopic disease may sensitize children to adverse pain profiles in the long term. We aimed to assess the impact of early-life atopic dermatitis-like symptoms on pain at 10years of age. We used data from 1302 and 874 participants of the Generation XXI birth cohort evaluated at 6 and 15months, respectively, and 10years. Atopy-like symptoms since birth, including atopic dermatitis, were collected at ages 6 and 15months by interviewing parents. Pain history in the last 3months at age 10 was collected from parents and children using structured questionnaires. We computed relative risks (RR) and respective 95% confidence intervals of pain features at age 10 according to each atopic-like symptom at 6 and 15months. Children whose parents reported atopic dermatitis-like symptoms at 6months and at 15months had higher risk of reporting any pain (RR 1.75 [1.15-2.66]) and multisite pain, respectively (RR 1.67 [1.18-2.37]) at 10years of age. Conclusion: Atopic dermatitis symptoms in early life were associated with a higher risk of pain at age 10, suggesting that potential for sensitization during the first decade of life and highlighting the importance of improving the health care of children with atopic dermatitis is worth investigating. What is Known: • Atopic disorders have been associated with many non-atopic comorbidities, including chronic pain. • Pain and atopic dermatitis share common inflammatory pathways. Inflammation, injury to the skin from scratching, fissures, and intolerance to irritants related to atopic dermatitis can cause pain. What is New: • Atopic dermatitis in early life is linked to an increased likelihood of experiencing pain at the age of 10, which suggests that exploring the potential for sensitization is a worthwhile area of investigation. • Our proof-of-concept study highlights the potential benefit of studying management targets and improving itching and relieving skin pain as quickly as possible, avoiding potential long-term consequences of the sensitization process.

Longitudinal tracking of diet quality from childhood to adolescence: The Interplay of individual and sociodemographic factors

This study aimed to examine diet tracking from childhood to adolescence, using 4 time-points, and the influence of socioeconomic and individual characteristics in this transition. The sample included 6893 children from the Portuguese birth cohort Generation XXI with complete information on Food Frequency Questionnaire in at least one of the considered follow-ups. A Healthy Eating Index (HEI), previously developed to assess adherence to WHO's dietary recommendations, was applied at all ages (4, 7, 10 and 13y). The intraclass correlation coefficient (ICC) was used to analyse the tracking of diet quality. Linear mixed-effect models were performed to estimate the association of the child's socioeconomic and individual characteristics with the HEI score and respective trajectories over time. The overall diet quality decreased from childhood (22.2 ± 3.6 at 4y) to adolescence (18.2 ± 3.9 at 13y), with moderate tracking (ICC = 0.53), showing that children who start a healthy diet earlier might have a better diet quality as time goes by. Children of older mothers (β = 0.079, 95%CI = 0.061–0.097) and with higher education (β = 0.203, 95%CI = 0.178–0.229) and a higher household monthly income (β = 0.024,95%CI = 0.007–0.041) had a higher diet quality over time. Besides family characteristics, the child's sedentary activities (β = −0.009, 95%CI = −0.014–-0.003) negatively influence diet quality throughout life. In contrast, being a girl (β = −0.094, 95%CI = −0.132–-0.056) and having higher sleep duration (β = 0.039, 95%CI = 0.015–0.064) are associated with a higher diet quality over time. The presence of dietary tracking from childhood to adolescence implies that promoting healthy eating habits during the first years of life is crucial for a healthier diet quality during late childhood and early adolescence, focusing on maternal and individual child characteristics.

Sleep timing behaviour, sleep duration and adherence to obesogenic dietary patterns from pre-school to school age: results from the Portuguese birth cohort Generation XXI.

In an obesogenic environment, short sleeping may increase opportunistic eating. The timing of sleep might also influence the drive to eat. This study investigated the prospective association of sleep timing and duration with diet in 5286 children from the Portuguese birth cohort Generation XXI, evaluated at 4 and 7 years of age. At 4 years, sleep duration was categorised into ≤10 and >10 h. Four sleep timing categories were generated based on the median split for sleep-onset and -offset times: 'Early Sleep-Early Wake'; 'Early Sleep-Late Wake'; 'Late Sleep-Early Wake'; 'Late Sleep-Late Wake'. At 7 years, diet was obtained by a food frequency questionnaire and three dietary patterns were included: 'Healthier', 'Energy-Dense Foods (EDF)' and 'Snacking'. The Healthy Eating Index was used to evaluate diet quality. Multinomial logistic regression models and generalised linear models were performed. Children who had a late sleep, independently of the time of waking up, had higher odds of following the 'EDF' pattern, compared with the 'Healthier'. Boys who had late sleep and/or late wake had also higher odds of following the 'Snacking' pattern and had poorer diet quality. In both sexes, a late sleep or late wake were associated with a lower diet quality, compared to the group 'Early Sleep-Early Wake', and independently of nap behaviour. In boys, shorter sleep duration was associated with a poorer diet. In conclusion, pre-schoolers with late bedtimes or wake-up times have worse dietary patterns and poorer diet quality at the age of 7 years, which seems to be independent of sleep duration.

Association between adverse childhood experiences and bodily pain in early adolescence.

We aimed to examine the relationship between lifetime exposure to adverse childhood experiences (ACEs) during the first decade of life and recent pain features reported in early adolescence. We conducted a prospective study using data from 4564 adolescent Generation XXI birth cohort participants recruited in 2005-2006. Adverse childhood experiences were reported by children at ages 10 and 13years using a 15-item questionnaire. Recent pain features (e.g., any pain, pain sites, recurrent pain intensity, and recurrent pain duration) were measured using structured questionnaires, including the Luebeck pain screening questionnaire at age 13. Using hierarchical binary and multinomial logistic regression analyses with progressive adjustments for confounders, we estimated the associations [adjused odds ratios (aOR) with their 95% confidence intervals (95% CI)] between exposure to ACEs at 10 and pain features at 13years. The study revealed a statistically significant association between exposure to ACEs reported at age 10 and any pain experienced at age 13 (OR=1.09; 95% CI [1.07, 1.12]). Even after accounting for the newly reported ACEs at age 13, the association with ACEs at age 10, remained significant (aOR=1.11 [95% CI, 1.08-1.14]). Consistent patterns were observed when the number of pain sites, recurrent pain intensity, or recurrent pain duration were used as outcome variables instead of any pain at age 13. Adverse childhood experiences occurring during the first decade of life predict the onset of pain features during early adolescence. Consequently, childhood exposure to adversity should be considered a pivotal initial exposure in a pathway leading to chronic pain later in life.

Bisphenol A and cardiometabolic risk in adolescents: Data from the Generation XXI cohort

Background and aimsBisphenol A (BPA), an endocrine disruptor widely used in food contact materials, has been linked to a worse health profile. This study intends to estimate the association between BPA exposure and cardiometabolic patterns at adolescence. Methods and resultsData from the Portuguese population-based birth cohort Generation XXI at the age of 13 were used (n = 2386 providing 3-day food diaries and fasting blood samples). BPA exposure was measured in 24-h urine from a subsample (n = 206) and then predicted in all participants using a random forest method and considering dietary intake from diaries. Three cardiometabolic patterns were identified (normal, modified lipid profile and higher cardiometabolic risk) using a probabilistic Gaussian mixture model. Multinomial regression models were applied to associate BPA exposure (lower, medium, higher) and cardiometabolic patterns, adjusting for confounders. The median BPA exposure was 1532 ng/d, corresponding to 29.4 ng/kg/d. Adolescents higher exposed to BPA (compared to medium and lower levels) had higher BMI z-score (kg/m2) (0.68 vs. 0.39 and 0.52, respectively; p = 0.008), higher levels of body fat (kg) (16.3 vs. 13.8 and 14.6, respectively; p = 0.002), waist circumference (76.2 vs. 73.7 and 74.9, respectively; p = 0.026), insulinemia (ug/mL) (14.1 vs. 12.7 and 13.1, respectively; p = 0.039) and triglyceridemia (mg/dL) (72.7 vs. 66.1 and 66.5, respectively; p = 0.030). After adjustment, a significant association between higher BPA and a higher cardiometabolic risk pattern was observed (OR: 2.55; 95%CI: 1.41, 4.63). ConclusionHigher BPA exposure was associated with a higher cardiometabolic risk pattern in adolescents, evidencing the role of food contaminants in health.

Gender-related differences in cardiometabolic risk factors and oxidative stress among prepubertal children with obesity.

Gender-related differences in oxidative stress, nitric oxide bioavailability, and cardiometabolic risk factors were examined in a cross-sectional study involving 313 prepubertal children (8-9 years old) from the generation XXI birth-cohort. Anthropometric measurements, cardiometabolic variables, and redox markers were assessed, including plasma and urinary isoprostanes (P-Isop, U-Isop), plasma total antioxidant status (P-TAS), serum myeloperoxidase (MPO), plasma and urinary nitrates and nitrites (P-NOX, U-NOX), and urinary hydrogen peroxide (U-H2O2). Girls showed higher levels of total/non-HDL cholesterol, triglycerides, and insulin resistance (HOMA-IR) compared to boys. Notably, U-H2O2 values were lower in girls. When stratifying by body mass index (BMI) and gender, both girls and boys exhibited higher MPO concentration and U-Isop values. Uric acid concentration was higher in overweight and obese girls than in normal weight girls, while no significant differences were observed among boys across BMI categories. Furthermore, U-NOX values differed only in boys, with higher levels observed in overweight and obese individuals compared to those with normal weight. Multivariate analysis, adjusted for age and BMI z-score, demonstrated inverse associations between U-H2O2 and pulse wave velocity values, as well as between U-NOX and total or non-HDL cholesterol, exclusively in boys. In girls, a positive association between U-Isop and HOMA-IR values was observed. In conclusion, gender differentially impacts oxidative stress, nitric oxide bioavailability, and cardiometabolic risk factors in prepubertal children. Prepubertal girls appear more susceptible to oxidative stress-induced metabolic dysfunction, while in boys, elevated levels of redox and nitric oxide bioavailability markers seem to provide protection against arterial stiffness and lipid homeostasis.

Cardiovascular rhythmicity in overweight and obese children.

Obesity is thought to play a role in the disruption of cardiac rhythmicity in obese children, but this is mostly an unexplored field of investigation. We aimed to evaluate the impact of overweight and obesity on circadian and ultradian cardiovascular rhythmicity of prepubertal children, in comparison with normal weight counterparts. We performed a cross sectional study of 316 children, followed in the birth cohort Generation XXI (Portugal). Anthropometrics and 24-hour ambulatory blood pressure were measured and profiles were examined with Fourier analysis for circadian and ultradian blood pressure (BP) and heart rate (HR) rhythms. Overweight/obese children presented more frequently a non-dipping BP pattern than normal weight counterparts (31.5% vs. 21.6%, p = 0.047). The prevalence of 24-hour mean arterial pressure (MAP) and 8-hour HR rhythmicity was significantly lower in obese children (79.3% vs. 88.0%, p = 0.038 and 33.3% vs. 45.2%, p = 0.031, respectively). The prevalence of the remaining MAP and HR rhythmicity was similar in both groups. No differences were found in the median values of amplitudes and acrophases of MAP and HR rhythms. The alterations found in rhythmicity suggest that circadian and ultradian rhythmicity analysis might be sensitive in detecting early cardiovascular dysregulations, but future studies are needed to reinforce our findings and to better understand their long-term implications.