Early exposure to cannabis and bipolar disorder incidence: Findings from a 22-year birth cohort study in Brazil.

BACKGROUND AND OBJECTIVES: Bipolar disorder is a chronic condition affecting millions of people worldwide. Currently, there is some evidence to suggest that cannabis use during adolescence may be an environmental risk factor for its onset, however inconsistencies have been observed across the literature. Considering this, we aimed to assess whether early lifetime cannabis is associated with subsequent bipolar disorder in young adults between 18 and 22 years of age. METHODS: Using data from the 1993 Pelotas (Brazil) birth cohort (n = 5249), cannabis exposure was examined at age 18 by self-report, and bipolar disorder diagnosis was measured at age 22 using the Mini International Neuropsychiatric Interview (MINI). In order to control the analysis, we considered socioeconomic status index, sex, skin color, physical abuse by parents and lifetime cocaine use. RESULTS: A total of 3781 individuals were evaluated in 2015 aged 22 years, of whom 87 were diagnosed with the bipolar disorder onset after the age of 18. Lifetime cannabis use predicted bipolar disorder onset at 22 years old (OR 1.82, 95% CI [1.10, 2.93]), and the effect remained after adjusting for socioeconomic status, sex, skin color, and physical abuse by parents (OR 2.00, 95% CI [1.20, 3.25]). However, this association was attenuated to statistically non-significant after further adjustment for all available covariates, including lifetime cocaine use (OR 1.79, 95% CI [0.95, 3.19]). We also found similar results for early cocaine use, where the association with bipolar disorder onset did not maintain significance in the multivariate model (OR 1.35, 95% CI [0.62, 2.86]). Otherwise, when we considered cannabis or cocaine lifetime use as a unique feature, our findings showed that the adolescent exposure to cannabis or cocaine increased the odds by 1.95 times of developing bipolar disorder at 22 years age, even when controlling for all other study variables (OR 2.14, 95% CI [1.30, 3.47]). Finally, our models suggest that cocaine use may potentially exert a major influence on the effect of lifetime cannabis use on bipolar disorder onset, and that physical abuse by parents and sex may modify the effect of cannabis use for later bipolar disorder onset. CONCLUSION: Based on our findings, early cannabis exposure predicted bipolar disorder onset in young adults, but this association was confounded by cocaine use. Contrary to schizophrenia, cannabis as a sole exposure was not associated with bipolar disorder onset after adjusting for control variables.

Investigating changes in IQ scores over a decade in Brazil: factors at play.

PURPOSE: This study aimed to determine whether the factors underlying potential differences between two birth cohorts, born in 1982 and 1993, influence the changes in IQ over time. METHODS: Data from two Brazilian birth cohorts were used (1993 and 1982 Pelotas Birth Cohorts). The IQ scores were assessed using the WAIS-III test. RESULTS: Results showed that women born in 1993 had a higher average IQ score than those born in 1982, but no difference was found among men. The increase in IQ scores was only limited to participants from families with an income ranging from 1.1 to 3 times the minimum wage at the time of birth. The mean IQ score of participants born to mothers below the age of 20 remained stable over time, but increase for participants whose mothers were 20 years of age or older at the time of birth. CONCLUSIONS: This study emphasizes the importance of considering socio-economic and demographic factors when examining differences in IQ scores over time. Further research is needed to understand the underlying mechanisms of these findings.

Effects of early-life poverty on health and human capital in children and adolescents: analyses of national surveys and birth cohort studies in LMICs.

The survival and nutrition of children and, to a lesser extent, adolescents have improved substantially in the past two decades. Improvements have been linked to the delivery of effective biomedical, behavioural, and environmental interventions; however, large disparities exist between and within countries. Using data from 95 national surveys in low-income and middle-income countries (LMICs), we analyse how strongly the health, nutrition, and cognitive development of children and adolescents are related to early-life poverty. Additionally, using data from six large, long-running birth cohorts in LMICs, we show how early-life poverty can have a lasting effect on health and human capital throughout the life course. We emphasise the importance of implementing multisectoral anti-poverty policies and programmes to complement specific health and nutrition interventions delivered at an individual level, particularly at a time when COVID-19 continues to disrupt economic, health, and educational gains achieved in the recent past.

Quality of vital event data for infant mortality estimation in prospective, population-based studies: an analysis of secondary data from Asia, Africa, and Latin America.

INTRODUCTION: Infant and neonatal mortality estimates are typically derived from retrospective birth histories collected through surveys in countries with unreliable civil registration and vital statistics systems. Yet such data are subject to biases, including under-reporting of deaths and age misreporting, which impact mortality estimates. Prospective population-based cohort studies are an underutilized data source for mortality estimation that may offer strengths that avoid biases. METHODS: We conducted a secondary analysis of data from the Child Health Epidemiology Reference Group, including 11 population-based pregnancy or birth cohort studies, to evaluate the appropriateness of vital event data for mortality estimation. Analyses were descriptive, summarizing study designs, populations, protocols, and internal checks to assess their impact on data quality. We calculated infant and neonatal morality rates and compared patterns with Demographic and Health Survey (DHS) data. RESULTS: Studies yielded 71,760 pregnant women and 85,095 live births. Specific field protocols, especially pregnancy enrollment, limited exclusion criteria, and frequent follow-up visits after delivery, led to higher birth outcome ascertainment and fewer missing deaths. Most studies had low follow-up loss in pregnancy and the first month with little evidence of date heaping. Among studies in Asia and Latin America, neonatal mortality rates (NMR) were similar to DHS, while several studies in Sub-Saharan Africa had lower NMRs than DHS. Infant mortality varied by study and region between sources. CONCLUSIONS: Prospective, population-based cohort studies following rigorous protocols can yield high-quality vital event data to improve characterization of detailed mortality patterns of infants in low- and middle-income countries, especially in the early neonatal period where mortality risk is highest and changes rapidly.

Maternal smoking during pregnancy and birthweight on the third generation: results from two birth cohort studies.

The purpose of this research is to investigate whether grandmother's smoking during pregnancy reduces the grandchildren's birthweight and whether maternal smoking during pregnancy modified this association. We also evaluated the effect of duration and intensity of smoking. This study included data from three generations from two birth cohorts carried out in Pelotas, a southern Brazilian city: women enrolled in the perinatal study in the 1982 and 1993 cohorts (G1); daughters (G2) of those G1 mothers who were followed to adulthood; and first children (G3) born from G2 women. Information on maternal smoking during pregnancy was obtained from women (G1) shortly after delivery of the two cohorts and from G2 in the follow-up in adulthood of the 1993 cohort. Mothers (G2) reported G3 birthweight during the follow-up visit at adulthood. Multiple linear regression was used to obtain effect measures adjusted for confounders. The study included 1602 grandmothers (G1), mothers (G2), and grandchildren (G3). Prevalence of maternal (G1) smoking during pregnancy was 43% and mean G3 birthweight was 3118.9 g (SD: 608.8). Grandmother's smoking in the pregnancy was not associated with grandchild's birthweight. However, offspring of both G1 and G2 smokers had lower mean birthweight than those whose mother and grandmother did not smoke (adjusted ß: - 223.05; 95% CI: - 415.16, - 32.76). CONCLUSION: No significant association was observed between grandmother's smoking in the pregnancy and grandchild's birthweight. But it seems that grandmother's smoking in pregnancy has an effect on grandchild's birthweight when the mother also smoked in the pregnancy. . WHAT IS KNOWN: • Most studies on the association of maternal tobacco smoking in pregnancy with offspring birthweight have been restricted to two generations, and an inverse association is well known. WHAT IS NEW: • Besides to investigate whether grandmother's smoking during pregnancy reduces the grandchildren's birthweight, we examined whether this association varied according to maternal smoking during pregnancy.

Child maltreatment associates with violent victimization in young adulthood: a Brazilian birth cohort study.

BACKGROUND: Maltreatment in childhood may leave people vulnerable to further experiences of violence and more severe effects of stress later in life. Longitudinal studies of risk for violent victimisation after maltreatment are lacking in low- and middle-income countries. The objective of this study was to quantify the risk for violent victimization in the family and community in young adulthood following experiences of childhood maltreatment (experiences of physical, emotional and sexual abuse and neglect) up to age 15 years in an urban Brazilian population. METHODS: 3246 participants in a prospective, population-based birth cohort study in Pelotas, Rio Grande do Sul, Brazil, were assessed at birth, 15 and 22 years. Sociodemographic factors were reported by mothers at birth and adolescents at age 15 years. Maltreatment and violent victimisation were self-reported in confidential questionnaires at 15 and 22, respectively. Multinomial logistic regression analyses estimated the association between having experienced any maltreatment and later experiences of family and community violence in young adulthood (no adult violence, violence only in the family context, only in the community, or both violence in the family and community), adjusting for sociodemographic factors. RESULTS: 39% of females and 27% of males reported any maltreatment up to age 15 years. At 22 years, rates of past year violence in the family or community were 17.6% for females and 20.2% for males. Maltreatment was strongly associated with community violence (Females: OR = 2.96, CI = 1.83-4.80; Males: OR = 2.01, 95%CI = 1.01-4.00) and its co-occurrence with family violence (Females: OR = 2.33, 95%CI = 1.34-4.04; Males: OR = 3.20, 95%CI = 1.82-5.65) in young adulthood, after adjustment for background sociodemographic factors. CONCLUSION: Childhood maltreatment is an important risk factor for later violent victimisation in both the family and community context. The effects of repeated trauma through the life-course needs research and clinical attention.

ADHD in childhood predicts BMI and body composition measurements over time in a population-based birth cohort.

BACKGROUND/OBJECTIVES: Obesity has been reported as an attention-deficit hyperactivity disorder (ADHD) comorbidity. So far, few studies have aimed to explore the potential causal relationship between ADHD and obesity, as well as used other measures of body composition like fat-free mass (FFM) and fat mass (FM) as measures of obesity. This study aimed to test the association between ADHD and body composition (body mass index [BMI] and others) and to evaluate the potential causal relationship with obesity. SUBJECTS/METHODS: Data from the 1993 Pelotas (Brazil) birth cohort at age 11-, 15-, 18-, and 22-year follow-up was used. We performed a cross-lagged panel model (CLPM) analysis between ADHD symptoms and BMI to explore the causal relationship between both traits. Finally, we tested whether ADHD, inattention, and hyperactivity symptom scales were associated with BMI, FM, and FFM at 22 years. RESULTS: In the CLPM, higher ADHD scores at age 11 predicted higher BMI at age 15 (ß = 0.055, 95% CI [0.037; 0.073]). ADHD symptoms at age 11 was also associated with a decrease in the FFM (ß = -0.16, 95% CI [-0.28; -0.05]), and an increase in the BMI (ß = 0.17, 95% CI [0.10; 0.23]) and FM (ß = 0.17, 95% CI [0.06; 0.29]) at 22 years. At 22 years of age, ADHD was associated with FFM and FM. Moreover, an increase in BMI was observed with an increase in several symptoms of ADHD in general (ß = 0.06, 95% CI [0.004; 0.12]), and hyperactivity symptoms (ß = 0.15, 95% CI [0.05; 0.25]). CONCLUSION: ADHD at 11 years predicted a higher BMI at 15 years, and body fat composition in adulthood, suggesting higher scores on ADHD symptoms in early life may be a critical point for body composition in early adulthood. The hyperactivity symptoms may play an important role in the BMI increase.

Maternal smoking during pregnancy and intelligence quotient of offspring aged 18 and 30 years: Evidence from two birth cohorts in southern Brazil.

Maternal smoking during pregnancy causes several harmful effects, including deficits in the intelligence quotient (IQ), a measure associated with academic achievements and higher socioeconomic position. We aimed to measure the association between maternal smoking during pregnancy and offspring's IQ in two birth cohorts from Pelotas, Brazil. Data from the 1982 and 1993 birth cohorts were analyzed. Smoking during pregnancy was ascertained at the perinatal follow-up, and IQ was measured at 30 years (1982) and 18 years (1993). Simple and multiple linear regressions were used for crude and adjusted analysis. Mediation analysis was performed using birth weight and breastfeeding as possible mediators. Data analysis was conducted in 2020. There were 3611 and 4050 participants from the 1982 and 1993 cohorts, respectively. After adjustment for potential confounders, the inverse association between smoking during pregnancy and children's IQ remained significant in both cohorts. Offspring of mothers who smoked during pregnancy had an average of 1.32 less IQ points (95%CI: -2.23, -0.242) in the 1982 cohort, and an average of 1.66 less IQ points (95%CI: -2.42, -0.90) in the 1993 cohort. Neither cohort showed association with paternal smoking (negative controls) after adjustment. Breastfeeding's mediated effects accounted for 26.2% and 23.9% of the association in the 1982 and 1993 cohorts, respectively, while birth weight's accounted for 6.8% and 30.1%, respectively; indirect effects were not significant. The inverse association between maternal smoking and IQ and the lack of association with paternal smoking reinforces our findings of a negative association between exposure and outcome.

Wheezing trajectories from childhood to adulthood in a population-based cohort.

BACKGROUND: Wheezing may lead to asthma and reduced pulmonary function in later life. The study aims to identify wheezing trajectories and investigate their relation with pulmonary function and asthma-related outcomes at 22 years of age. METHODS: Individuals from a population-based cohort in Brazil (1993 Pelotas Birth Cohort) with post-bronchodilator pulmonary function data at 22 years (3350) were included in the study. From parentally reported (4 and 11 years) and self-reported (15, 18 and 22 years) history of wheezing in the last 12 months, we used a group-based trajectory modelling approach to derive wheezing trajectories. RESULTS: Four trajectories were identified: never/infrequent, transient-early, late-onset and persistent wheeze. After adjustments, wheezing trajectories remained associated with lower post-bronchodilator values of pulmonary function. Individuals in the persistent wheeze trajectory had a markedly poorer pulmonary function and also showed greater odds of asthma-related outcomes compared to other trajectories groups. Those following this trajectory had on average -109 ml (95% CI: -188; -35), -1.80 percentage points (95% CI: -2.73; -0.87) and -316 ml/s (95% CI: -482; -150) lower FEV1, FEV1/FVC ratio and FEF25-75% respectively; higher odds of self-reported medical diagnosis of allergy (OR 6.18; 95% CI: 3.59; 10.61) and asthma (OR 12.88; 95% CI: 8.91; 18.61) and asthma medication use (OR 9.42; 95% CI: 5.27; 16.87) compared to the never/infrequent group. CONCLUSIONS: Wheezing trajectories, especially the persistent wheeze trajectory, were related to lower pulmonary function values and increased risk of asthma and allergy diagnosis in early adulthood.

Prevalence of ideal cardiovascular health in young adults: A birth cohort from southern Brazil.

BACKGROUND: Ideal cardiovascular health (ICH) aims at primordial prevention of cardiovascular diseases in the population. However, there is a lack of research describing ICH in youth from middle-income countries. The aims of this study were to describe the prevalence of ICH at 18- and 22-year-old and to investigate the influence of socioeconomic status. METHODS: The sample consisted of participants from the Pelotas 1993 birth-cohort followed-up at 18- (n = 4,106) and 22-year-old (n = 3,810). Ideal metrics were created for diet, smoking, body mass index, physical activity, blood pressure, total cholesterol, and blood glucose. The presence of 4 or more ideal metrics was defined as ICH. Socioeconomic status was obtained using wealth quintiles calculated with factor analysis based on analysis based on the ownership of household and education. The impact of socioeconomic status on ICH metrics was statistically measured using the slope index of inequality. RESULTS: The prevalence of ICH was 84.5% (95% confidence interval [CI] = 82.7-86.2%) and 84.1% (82.3-85.8%) at 18-year-old and decreased to 61.1% (58.4-63.7%) and 68.7% (66.2-71.2%) at 22-years old, for male and female, respectively. Socioeconomic status influenced ICH and its components differently in males and females. Wealthiest females had ICH prevalence 19 percentage points (pp) (11-27 pp) higher compared to the poorest, whereas poorest males had ICH prevalence 12 pp (1-21 pp) higher compared to the wealthiest. Longitudinal decreases in ICH components were mostly present in the poorest females. CONCLUSIONS: In middle-income countries, the prevalence of ICH is high at 18-year-old and decreases in a 4-year follow-up. Socioeconomic status influences differently individuals' ICH between sexes. Efforts are needed to maintain ICH in youth and different strategies may be required between the social status.

The neurodevelopmental nature of attention-deficit hyperactivity disorder in adults.

BACKGROUND: Population studies have suggested that most adults with attention-deficit hyperactivity disorder (ADHD) did not have the disorder in childhood, challenging the neurodevelopmental conceptualisation of ADHD. Arbitrary definitions of age at onset and lack of defined trajectories were accounted for the findings. AIMS: The objective of this study was to assess the proportion of individuals presenting with either a neurodevelopmental trajectory or late-onset disorder, and to assess risk factors associated with them. METHOD: Data of 4676 individuals from the 1993 Pelotas birth cohort at 11, 15, 18 and 22 years of age were used. Polythetic and latent class mixed model analyses were performed to define ADHD trajectories from childhood to adulthood, and characterise the neurodevelopmental or late-onset courses. Regression models were applied to assess factors associated with different trajectories. RESULTS: Classical polythetic analyses showed that 67% of those with ADHD at 22 years of age had a neurodevelopmental course of the disorder. Latent class mixed model analysis indicated that 78% of adults with ADHD had a trajectory of persistent symptoms, more common in males. The remaining adults with ADHD had an ascending symptom trajectory that occurred after puberty, with late-onset ADHD associated with female gender and higher IQ. CONCLUSIONS: Both polythetic and latent trajectories analyses provided empirical evidence supporting that the large majority of adults with ADHD had a neurodevelopmental disorder.

Sleep duration trajectories from adolescence to emerging adulthood: Findings from a population-based birth cohort.

This study aimed to describe longitudinal trajectories of sleep duration, among adolescents and adults from the Pelotas (Brazil) 1993 Birth Cohort, as well as characterize different trajectories groups according to socioeconomic, demographic and behavior characteristics. Sleep duration, hours per day (from Monday to Friday), bedtime and wake-up time were self-reported by participants at ages 11, 18 and 22 years. Covariables included socioeconomic, demographic, health and behavior characteristics. Trajectory analysis was performed using a semi-parametric, group-based modelling approach. Prevalence and 95% confidence interval were obtained to describe covariables and sleep trajectory groups. Chi-square test was employed in statistical analysis and all analyses were stratified by sex. A total of 3.395 individuals were included in the analysis. In both sexes, bedtime became later across years, while wake-up time presented little variation. Differences according sex were more pronounced from 18 years onwards. Three trajectories of sleep duration from 11 to 22 years were identified for males: "increase and maintenance" (3.4%), "fast reduction and maintenance" (45.0%) and "constant reduction" (51.6%). While in females the trajectories identified were: "increase and decrease" (2.4%), "fast reduction and maintenance" (25.6%) and "constant reduction" (72.0%). Men and women who belong to trajectories with longer sleep durations were more likely to present higher percentages of some risk behaviors and poor socioeconomic condition. Our results have provided longitudinal information regarding sleep duration trajectories in a medium-sized city in Brazil, aiming at filling an existing gap in literature from low- and middle-income countries.

Influence of maternal pre-pregnancy nutritional status on offspring anthropometric measurements and body composition in three Brazilian Birth Cohorts.

OBJECTIVE: We aimed at evaluating the association of maternal pre-pregnancy nutritional status with offspring anthropometry and body composition. We also evaluated whether these associations were modified by gender, diet and physical activity and mediated by birth weight. DESIGN: Birth cohort study. SETTING: Waist circumference was measured with an inextensible tape, and fat and lean mass were measured using dual-energy X-ray absorptiometry. Multiple linear regression was used to adjust for possible confounders and allele score of BMI. We carried out mediation analysis using G-formula. PARTICIPANTS: In 1982, 1993 and 2004, all maternity hospitals in Pelotas (South Brazil) were visited daily and all live births whose families lived in the urban area of the city were evaluated. These subjects have been followed up at different ages. RESULTS: Offspring of obese mothers had on average higher BMI, waist circumference and fat mass index than those of normal weight mothers, and these differences were higher among daughters. The magnitudes of the association were similar in the cohorts, except for height, where the association pattern was not clear. In the 1982 cohort, further adjustment for a BMI allele score had no material influence on the magnitude of the associations. Mediation analyses showed that birth weight captured part of this association. CONCLUSIONS: Our findings suggest that maternal pre-pregnancy nutritional status is positively associated with offspring BMI and adiposity in offspring. And this association is higher among daughters whose mother was overweight or obese and, birth weight explains part of this association.

Uric acid is independent and inversely associated to glomerular filtration rate in young adult Brazilian individuals.

BACKGROUND AND AIMS: Uric acid, the end-product of human purine metabolism, is associated with hypertension, diabetes and obesity. It has also been independently associated with the onset of chronic kidney disease in several populations. In this study, the association between serum uric acid (SUA) level and estimated glomerular filtration rate (eGFR) was investigated in healthy individuals belonging to two Brazilian birth cohorts. METHODS AND RESULTS: Data from 3541 to 3482 individuals, aged 30 and 22-years old, respectively, was included. eGFR was calculated using Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation based on creatinine measurement. Regression analyses were sex-stratified due to interaction between SUA and sex (p < 0.001) and adjusted for perinatal, cardiometabolic and behavioral variables. We observed an inverse association between eGFR and SUA even after adjustment. In the highest tertile (3rd) of SUA, the eGFR coefficients at 30-years were-0.21 (95%CI -0.24;-0.18) for men and -0.20 (95%CI -0.23; -0.17) for women; at 22-years, were -0.09 (95%CI -0.12;-0.05) for men and -0.13 (95%CI -0.15; -0.10) for women. Higher differences among exponential means (95% CI) of eGFR between the 1st and the 3rd tertile of SUA were seen in older participants, being more pronounced in men. At 22-years, the highest difference was found in women. CONCLUSIONS: In young healthy individuals from a low-middle income country, SUA level was inversely associated with eGFR. Gender-related differences in eGFR according tertiles of SUA were higher in men at 30-years and in women at 22-years.

How different online recruitment methods impact on recruitment rates for the web-based coortesnaweb project: a randomised trial.

BACKGROUND: The number of web-based E-epidemiologic studies using online recruitment methods is increasing. However, the optimal online recruitment method in terms of maximizing recruitment rates is still unknown. Our aim was to compare the recruitment rates of three online recruitment methods and to describe how these rates differ according to individual's socioeconomic and demographic factors. METHODS: A total of 2394 members of the 1993 Pelotas birth cohort that provided an e-mail address, a Facebook name, and a WhatsApp number during a face-to-face follow-up were randomly allocated to be recruited by e-mail, Facebook or WhatsApp (798 individuals per method). This was a parallel randomised trial applying a block randomisation (block size = 3). Between January and February 2018, we sent messages inviting them to register into the web-based coortesnaweb platform. Recruitment rates were calculated for each method, and stratified according to the individual's socioeconomic and demographic characteristics. We also analysed absolute and relative inequalities on recruitment according to schooling and socioeconomic position. RESULTS: Out of the 2394 individuals analysed, 642 registered into the platform. The overall recruitment rate was 26.8%. Recruitment rates for women were almost 10 percentage points higher compared to men. Facebook was the most effective recruitment method, as 30.6% of those invited through the social network were recruited. Recruitment rates of e-mail and WhatsApp were similar (recruitment rate = 24.9%). E-mail and Facebook were the most effective recruitment methods to invite highly educated and wealthier individuals. However, sending e-mails to recruit individuals also reflected in the highest inequalities according to schooling and socioeconomic position. In contrast, the lowest inequalities according to socioeconomic position were observed using Facebook. CONCLUSIONS: Facebook was the most effective online recruitment method, also achieving the most equitable sample in terms of schooling and socioeconomic position. The effectiveness of online recruitment methods depends on the characteristics of the sample. It is important to know the profile of the target sample in order to decide which online recruitment method to use. TRIAL REGISTRATION: Brazilian Registry of Clinical Trials, identifier: RBR-3dv7gc , retrospectively registered in 10 April 2018.

Association of risk behaviours, socio-economic characteristics and academic progress in adolescents: an analysis of the 1993 birth cohort in Pelotas, Brazil.

To analyze how socio-economic factors and behavioural characteristics are related to the failure of academic progress. Data of the 1993 Birth Cohort of the city of Pelotas, Brazil, were analyzed using four follow-up waves. As a measure of the failure of academic progress, we used indicators of the age-grade gap. We analyzed the association of demographic, socio-economic, and behavioural characteristics. Factors associated with failure of academic progress were assessed through logistic regression. There are a higher odds of the age-grade gap when the adolescent is not white, man, of low socio-economic status, whose parents have low schooling and living in large families. In relation to risk behaviours, alcohol and tobacco consumption represent higher odds of the age-grade gap at age 18. The results show that socio-economic factors and behavioural characteristics are important predictors of academic progress. Public policies that seek to promote education should be targeted at the most vulnerable groups, decreasing the observed inequalities.

Association between interleukin-6, C-reactive protein and adiponectin with adiposity: Findings from the 1993 pelotas (Brazil) birth cohort at 18 and 22 years.

BACKGROUND: Most of the literature has shown a direct association between adiposity, interleukin-6 (IL-6) and C-reactive protein (CRP), and an inverse association with adiponectin. The aim of this paper was to assess the association of obesity measurements and IL-6, CRP and adiponectin. METHODS: We performed cross-sectional/longitudinal analysis in the 1993 Birth Cohort in Brazil. Associations between IL-6 (pg/mL), CRP (mg/L) and adiponectin (µg/Ml) with body mass index (BMI), waist circumference (WC), percentage total fat mass (FM) (BODPOD) and trunk FM (DXA) were verified. Four trajectory variables were generated: (a) highest tertile/obesity according to BMI in both follow-ups; (b) highest tertile/obesity only at 18 years; (c) highest tertile/obesity only at 22 years; (d) not in the highest tertile/not obese at both ages. RESULTS: We found a direct association for IL-6 and CRP and an inverse association for adiponectin with measures of adiposity. For instance, for females, the highest mean IL-6 and CRP, respectively, was for those who had been in the obese category at 18-22 years (2.49; 3.75), in the highest tertile of WC (2.11; 3.08), in the highest % of FM (1.56; 3.30 l), and in the highest tertile of trunk FM (2.07; 3.26) (p < 0.001 for all these results in the adjusted analysis). Adiponectin showed an inverse association for the above variables, with lower mean values for males than females. CONCLUSION: There was a longitudinal and direct association between adiposity and IL-6 and CRP, and an inverse association with adiponectin at 22 years.

Lifelong robbery victimisation and mental disorders at age 18 years: Brazilian population-based study.

PURPOSE: Urban violence is a major problem in Brazil and may contribute to mental disorders among victims. The aim of this study was to assess the association between robbery victimisation and mental health disorders in late adolescence. METHODS: At age 18 years, 4106 participants in the 1993 Pelotas Birth Cohort Study were assessed. A questionnaire about history of robbery victimisation was administered, the Self-Report Questionnaire was used to screen for common mental disorders, and the Mini International Neuropsychiatric Interview was used to assess major depressive disorder and generalised anxiety disorder. Cross-sectional prevalence ratios between lifetime robbery victimisation and mental disorders were estimated using Poisson regression with robust standard errors, adjusting for socioeconomic variables measured at birth and violence in the home and maltreatment measured at age 15. RESULTS: There was a dose-response relationship between frequency of lifetime robberies and risk of mental disorders. Adolescents who had been robbed three or more times had twice the risk (PR 2.04; 95% CI 1.64-2.56) for common mental disorders, over four times the risk for depression (PR 4.59; 95% CI 2.60-8.12), and twice the risk for anxiety (PR 1.93; 95% CI 1.06-3.50), compared with non-victims, adjusting for covariates. Experiencing frequent robberies had greater impact on common mental disorders than experiencing an armed robbery. Population attributable fractions with regard to robbery were 9% for common mental disorders, 13% for depression, and 8% for anxiety. CONCLUSIONS: Robberies are associated with common mental disorders in late adolescence, independently of violence between family members. Reducing urban violence could significantly help in preventing common mental illnesses.

Are cytokines (IL-6, CRP and adiponectin) associated with bone mineral density in a young adult birth cohort?

BACKGROUND: Studies have shown that cytokines play a role in bone remodeling. METHODS: In 1993, all hospital births occurred in Pelotas (Brazil) were identified and a total of 5249 newborns were included in the present cohort. Sub-samples of this cohort were visited during childhood and all members were traced at 11, 15, 18 and 22 years old. At 18 and 22 years the following biomarkers were measured: IL-6, CRP and adiponectin (the last one in a sub-sample) and bone mineral density (BMD-mg/cm2) was evaluated at 22 years. Crude regression analysis as well as adjusted for confounders (birth weight, pregnancy maternal smoking, gestational age, skin color, schooling, income, smoking, alcohol, physical activity, medical diagnosis of asthma, diabetes and hypertension, BMI, height, calcium intake, corticosteroid use, age at menarche, insulin and testosterone) were performed between the three biomarkers and the whole-body, lumbar spine and femoral BMD. RESULTS: No statistical significant association was found between IL-6 and CRP with BMD, in males. Significant inverse association in the adjusted analysis, among females, was found for the highest tertiles of CRP at 22 y (beta - 15.2 mg/cm2; 95% CI: -25.4; - 4.9; p = 004), of CRP and IL-6 at 22 years (beta - 20.0 mg/cm2; 95% CI: -31.7; - 8.3; p = 0.003), and of IL-6 and CRP at both ages (beta - 20.3 mg/cm2; 95% CI: -38.0; - 2.5; p = 0.001) with total body BMD. Significant association, among males, was also found between the highest tertile of adiponectin at 22 y (beta - 23.3 mg/cm2; 95% CI: -35.5; - 11.1; p = < 001; beta - 22.5 mg/cm2; 95% CI: -42.9; - 2.2; p = 0.03; and beta - 31.8 mg/cm2; 95% CI: -55.5; - 9.1; p = 0.006) and total body, lumbar spine and femur neck BMD, respectively; and, among females, - 17.8 mg/cm2; 95% CI: -34.9; - 0.9; p = 0.033, with lumbar spine BMD. CONCLUSION: CRP at 22 years, in females, seems to be a marker for total body BMD; adiponectin at 22 years is also a marker for BMD at the three sites, in males, and for lumbar spine BMD, in females.

[Breastfeeding and externalizing behaviors in childhood and adolescence in a birth cohort]. / Amamentação e comportamentos externalizantes na infância e adolescência em uma coorte de nascimentos.

OBJECTIVE: To assess the association between breastfeeding duration and externalizing behaviors in childhood and adolescence. METHODS: Data from the 1993 Pelotas Birth Cohort was used. Information on breastfeeding was assessed at 12 months of age. Behavior was assessed at 4 years of age using the Child Behavior Checklist (CBCL), and at ages 11 and 15 years using the Strengths and Difficulties Questionnaire (SDQ), both administered to the mother or caretaker. Of 5 249 cohort participants, those with complete data on breastfeeding and externalizing behaviors were included: 630 children at 4 years of age, 1 277 adolescents at 11 years, and 1 199 at 15 years. Poisson regression with robust variance was used to assess the association between breastfeeding duration and externalizing behaviors. RESULTS: After adjustment for confounders, children who were breastfed for least 6 months had lower risk of hyperactivity (RR = 0.54; 95%CI: 0.32-0.91) at age 11 compared to those breastfed for less than 1 month. However, no association was observed between breastfeeding duration and externalizing behaviors at ages 4 and 15. CONCLUSIONS: Although breastfeeding for at least 6 months was inversely associated with hyperactivity at 11 years of age no association was observed at 4 and 15 years of age. Further longitudinal studies should focus on other aspects influencing externalizing behaviors, such as presence of the father in the family, domestic violence and abuse, and the quality of mother-child relationship.