Adolescent Growth and Development

To investigate the cross-sectional association between sleep problems (the exposure) and headaches (the outcome) among 15-year-olds from the Pelotas 2004 Birth Cohort, a population-based study in the south of Brazil.

The occurrence of headaches was obtained through the question: “Do you usually suffer headaches?” and the ICHD-3 criteria were used to classify as: tension-type headache, headache with characteristics of migraine with or without aura, or other. Regarding sleep, the weekly frequency in the last month of insomnia and bad dreams/nightmares, and self-reported sleep quality were investigated. Unadjusted and adjusted prevalence ratios (PR) with 95% confidence intervals were calculated using Poisson regression with robust variance.

A total of 1916 adolescents were analyzed. The prevalence of headaches was 51.6% (69.0% in females and 34.8% in males): 31.8% (39.7% vs. 24.1%) reported tension-type headache; 14.7% (21.9% vs. 7.8%), headaches with characteristics of migraines without aura; 3.6%, headaches with characteristics of migraines with aura; and 1.5% (5.1% vs. 2.3%), other types. Adolescents with insomnia ≥3 times/week presented higher probability of headaches (PR = 1.54; 95%CI 1.23–1.93), compared with those with no problems falling asleep or maintaining sleep. Among those who classified their sleep as poor/very poor, the probability of headaches was 33% higher (PR = 1.33; 95%CI 1.13–1.57) than among those who classified their sleep as very good.

Headaches were highly prevalent among the adolescents and were related to sleep problems even after allowing for several confounders.

Stress is associated with weight changes, yet how level and sources of stress relate to this association is poorly understood. This mixed methods study examined associations between adolescent stress at the COVID-19 pandemic onset and standardized BMI (BMIz) over a three-month period. Methods: Participants (N = 197, mean age 13.66 ± 1.43 years, 85% Hispanic, 56% female) were recruited from a charter school in Texas to participate in a healthy lifestyle intervention during physical education class. We calculated BMIz using height and weight measurements taken December 2019 and the week of COVID-19 school closures in March 2020. We measured stress in March 2020 with the 4-item Perceived Stress Scale. We ran a multiple linear regression model controlling for baseline BMIz (December 2019), age, sex, intervention condition, and assessed the interaction between baseline BMIz and PSS-4 score on BMIz change.

Overall, our sample had an average PSS-4 score of seven and mean BMIz decrease of 0.04 over the three-month period. We observed a significant interaction between PSS-4 score and baseline BMIz. At lower baseline BMIz scores, higher PSS-4 scores were associated with decreases in BMIz over time. There was no significant association at higher baseline BMIz scores. COVID-19 pandemic-related concerns and school performance were the two primary stressors reported.

The relation between stress and weight changes differed based on starting weight status. Future interventions should consider the influence of external stressors on intervention adherence and outcomes.

Biomarker concentrations of metals are associated with neurodevelopment, and these associations may be modified by nutritional status (e.g., iron deficiency). No prior study on associations of metal mixtures with neurodevelopment has assessed effect modification by iron status.

We aimed to quantify associations of an industry-relevant metal mixture with verbal learning and memory among adolescents, and to investigate the modifying role of iron status on those associations.

We used cross-sectional data from 383 Italian adolescents (10–14 years) living in proximity to ferroalloy industry. Verbal learning and memory was assessed using the California Verbal Learning Test for Children (CVLT-C), and metals were quantified in hair (manganese, copper, chromium) or blood (lead) using inductively coupled plasma mass spectrometry. Serum ferritin, a proxy for iron status, was measured using immunoassays. Covariate-adjusted associations of the metal mixture with CVLT subtests were estimated using Bayesian Kernel Machine Regression, and modification of the mixture associations by ferritin was examined.

Compared to the 50th percentile of the metal mixture, the 90th percentile was associated with a 0.12 standard deviation [SD] (95% CI = −0.27, 0.50), 0.16 SD (95% CI = −0.11, 0.44), and 0.11 SD (95% CI = −0.20, 0.43) increase in the number of words recalled for trial 5, long delay free, and long delay cued recall, respectively. For an increase from its 25th to 75th percentiles, copper was beneficially associated the recall trials when other metals were fixed at their 50th percentiles (for example, trial 5 recall: β = 0.31, 95% CI = 0.14, 0.48). The association between copper and trial 5 recall was stronger at the 75th percentile of ferritin, compared to the 25th or 50th percentiles.

In this metal mixture, copper was beneficially associated with neurodevelopment, which was more apparent at higher ferritin concentrations. These findings suggest that metal associations with neurodevelopment may depend on iron status, which has important public health implications.