Cohort Profile Update: The 1982 Pelotas (Brazil) Birth Cohort Study

Lessons from 13 years of accelerometry measurements in five Brazilian cohorts: methodological aspects

This study describes key methodological decisions and their justifications for accelerometer data collection, processing, and cleaning/analysis in Pelotas (Rio Grande do Sul State, Brazil) cohorts, exemplifying how research using sensor monitors could be carried out in a middle-income country context. This is a descriptive methodological study using raw accelerometer data from five Brazilian population-based cohorts with 32,963 individuals. Data collection (pre-processing decisions), processing (choosing requirements to run the analysis), and post-processing decisions (data cleaning) are described in detail. Pre-processing includes choosing the device brand/model, placement of the device, algorithms/thresholds, and the number of days participants were required to wear the devices. Processing activities involve applying thresholds/algorithms to the data. Finally, post-processing includes data cleaning. The minimum number of days to be validated to correctly estimate weekly averages was specific to age and measurement. By summarizing and describing the methodological decisions and analysis protocol, we hope to contribute to the design and analysis of accelerometer data in future studies in similar research contexts.

Trans-ancestry genome-wide association study of childhood body mass index identifies novel loci and age-specific effects

Over the past 30 years, obesity prevalence has markedly increased globally, including among children. Although genome-wide association studies (GWASs) have identified over 1,000 genetic loci associated with obesity-related traits in adults, the genetic architecture of childhood obesity is less well characterized. Moreover, most childhood obesity GWASs have been restricted to severely obese children, in relatively small sample sizes, and in primarily European-ancestry populations. To identify genetic loci associated with early-childhood body mass index (BMI), we performed GWAS of BMI Z scores in eight ancestrally diverse cohorts: ZOE 2.0 cohort, the Santiago Longitudinal Study (SLS), the Vanderbilt University BioVU biobank, the Geisinger MyCode Health Initiative biobank, Study of Latino (SOL) Youth, Pelotas (Brazil) Birth Cohort, Cameron County Hispanic Cohort (CCHC), and Viva La Familia cohort. We subsequently performed inverse-variance-weighted fixed-effect meta-analysis of these results with previously published GWAS summary statistics of BMI Z scores of children in the Early Growth Genetics (EGG) Consortium and the Norwegian Mother and Child Cohort (MoBa), constituting a final total of 84,804 individuals. We identified 39 genome-wide significant loci associated with childhood BMI, including three putatively novel loci (EFNA5 and DTWD2, RP11-2N5.1 on chromosome 5, and LSM14A on chromosome 19). We also observed a dynamic nature of genetic loci-BMI associations across the life course, with distinct effects across childhood and adulthood, highlighting possible critical periods for early-childhood interventions. These findings strengthen calls for larger population-based studies of children across age strata and across diverse populations.

Breastfeeding and cardiometabolic risk factors in adulthood: results from the Pelotas (Brazil) birth cohort, 1982

Using data from a birth cohort study, we evaluated the long-term association between breastfeeding and metabolic cardiovascular risk factors at 30 years old. In 1982, the 5,914 live births in maternity hospitals in Pelotas, Rio Grande do Sul State, Brazil, were examined and the mothers were interviewed. Since then, these participants have been prospectively followed. The cohort members were interviewed at 30 years old and information on blood pressure, carotid intima-media thickness, pulse wave velocity, random blood glucose, and blood lipids were obtained. Simple and multiple linear regressions were used. In the crude and adjusted analyses, duration of breastfeeding did not show any clear association with mean arterial pressure, carotid intima-media thickness, and pulse wave velocity. Likewise, total and non-HDL cholesterol and blood glucose were not related to infant feeding. Regarding HDL cholesterol, it was positively related to predominant breastfeeding duration in the crude analysis, but the association disappeared after controlling for confounding variables. Concisely, our findings suggest that there is no association between duration of breastfeeding and cardiometabolic risk factors in adulthood. Despite that, promotion and support of breastfeeding must be reinforced due to its well-known benefits, such as reduction of infant and child mortality and human capital development.

Chronic Offending and Its Relation to Homicide in a Large, Prospective Brazilian Birth Cohort

BACKGROUND

Many studies have found that a small group of chronic offenders is responsible for the majority of crimes and tend to be particularly violent. However, there is a major lack of evidence on chronic offending in low- and middle-income countries; understanding these patterns is especially important in settings with very high levels of serious violence, such as Brazil.

AIMS

To identify the extent that crime is concentrated in chronic offenders and linked to violence and homicide in a Brazilian cohort.

METHODS

The 1982 Pelotas Birth Cohort includes 5623 participants followed from birth in 1982 with complete crime records up to age 30. Chronic offenders were defined as individuals who committed five or more offences and, in aggregate, over 50% of all crimes. Key offending characteristics including age of onset, violent and homicide offending, and incarceration rates were compared across three different offender groups (one-timers, below-chronic and chronic offenders).

RESULTS

Approximately 27% of participants had a record for at least one crime by age 30, and 5% were chronic offenders. Chronic offenders were responsible for 57% of all crimes, 54% of violent crimes and 68% of homicides. Chronic offenders exhibited more severe patterns of offending on all characteristics examined compared to non-chronic offenders. Homicides committed by chronic offenders were more likely to involve firearms than those by non-chronic offenders.

DISCUSSION

This is the first study to analyse chronic offending within a large prospective cohort in a low- and middle-income country. Chronic offending patterns in this Brazilian setting resemble those in high-income country studies and are highly related to homicides.

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.

Gender Gap for Accelerometry-Based Physical Activity Across Different Age Groups in 5 Brazilian Cohort Studies

OBJECTIVES

This study aims to evaluate the gender inequalities in accelerometer-based physical activity (PA) across different age groups using data from 5 Pelotas (Brazil) cohorts.

METHODS

The data come from 4 birth cohort studies, covering all live births in the urban area of Pelotas for each respective year (1982, 1993, 2004, and 2015), and the Como vai? cohort study focusing on 60 years and above. Raw accelerometry data were collected on the nondominant wrist using GENEActive/ActiGraph devices and processed with the GGIR package. Overall PA was calculated at ages 1, 2, 4, 6, 11, 15, 18, 23, 30, and 60+ years, while moderate to vigorous PA was calculated from 6 years onward. Absolute (difference) and relative (ratio) gender inequalities were calculated and intersectionality between gender and wealth was also evaluated.

RESULTS

The sample sizes per cohort ranged from 965 to 3462 participants. The mean absolute gender gap was 19.3 minutes (95% confidence interval, 12.7-25.9), with the widest gap at 18 years (32.9 min; 95% confidence interval, 30.1-35.7) for moderate to vigorous PA. The highest relative inequality was found in older adults (ratio 2.0; 95% confidence interval, 1.92-2.08). Our intersectionality results showed that the poorest men being the most active group, accumulating around 60 minutes more moderate to vigorous PA per day compared with the wealthiest women at age 18.

CONCLUSIONS

Men were more physically active than women in all ages evaluated. PA gender inequalities start at an early age and intensify in transition periods of life. Relative inequalities were marked among older adults.

Differential effect of social mobility on tooth loss by race in adulthood: 1982 Pelotas Birth Cohort Study

OBJECTIVES

To examine the association between social mobility and tooth loss in adults from the 1982 Pelotas Birth Cohort Study and whether race modifies this association.

METHODS

The Oral Health Study used data from 541 individuals who were followed up to 31 years of age. Social mobility, composed of the participants' socioeconomic position (SEP) at birth and at age 30, was categorized as never poor, upwardly mobile, downwardly mobile and always poor. The outcome was the prevalence of at least one tooth lost due to dental caries when the participants were examined at 31 years of age. The effect modifier was race (Black/Brown versus white people). Log-binomial regression models were used to estimate crude and sex-adjusted prevalence ratios (PR) and to determine whether the association varied with race. Statistical interactions were tested using an additive scale.

RESULTS

The prevalence of any tooth loss was 50.8% (n = 274). In social mobility groups, the prevalence of at least one tooth lost in the never-poor group was about 31% points higher for Black/Brown (68.2%) than for white people (37.4%). Antagonistic findings were found for the interaction between race and social mobility (Sinergy Index = 0.48; 95% CI 0.24, 0.99; and relative excess of risk due to the interaction = -1.38; 95% CI -2.34, -0.42), suggesting that the observed joint effect of race and social mobility on tooth loss was lower than the expected sum of these factors. The estimates for Black/Brown people were smaller for those who were always poor during their lives, relative to their white counterparts.

CONCLUSIONS

The findings suggest a higher prevalence of at least one tooth lost among people in the downward mobile SEP group and Black/Brown people. Greater racial inequity was found among Black/Brown people who had never experienced episodes of poverty, with Black/Brown people having a greater prevalence of at least one tooth lost than their white counterparts.

The importance of birth cohort studies to low and middle income countries

In order to discern the causes of the health and developmental problems of children, and thence develop preventative strategies, longitudinal cohort studies offer major advantages. They can monitor the consequences of exposure to physical and psychological events and thence identify antecedents of various disorders. We describe the historical background to the development in the UK of this study design, and the uptake of longitudinal birth cohorts in low- and middle-income countries (LMICs), using the cohorts in Jamaica, South Africa and Brazil as exemplars. We describe the benefits of such studies and show how undertaking longitudinal cohort studies can have major health and financial benefits to the populations concerned. Additionally, the paper outlines the advantages of collaboration between studies and the pooling of data.

JA KIDS - Jamaica's second national birth cohort study: aims and methods

Birth cohort studies across the world have yielded information that has been used to inform policy and programme decisions that have improved the health and well-being of populations. A few such studies have been conducted in low- and middle-income countries due to funding, methodological and other challenges. This paper briefly reviews the methods of comprehensive birth cohort studies with extensive follow-up of participants through the life course conducted in low- and middle-income countries. It then reviews the first Jamaican birth cohort study of 1986 and discusses the methodological advances in implementing JA KIDS, the second Jamaican birth cohort study conducted in 2011. The aims and methods of JA KIDS are described in detail.

Life-course influences of poverty on violence and homicide: 30-year Brazilian birth cohort study

BACKGROUND

Homicide is the leading cause of death among young people in Latin America, one of the world's most violent regions. Poverty is widely considered a key cause of violence, but theories suggest different effects of poverty, depending on when it is experienced in the life-course. Longitudinal studies of violence are scarce in Latin America, and very few prospective data are available worldwide to test different life-course influences on homicide.

METHODS

In a prospective birth cohort study following 5914 children born in southern Brazil, we examined the role of poverty at birth, in early childhood, and in early adulthood on violence and homicide perpetration, in criminal records up to age 30 years. A novel Structured Life Course Modelling Approach was used to test competing life-course hypotheses about 'sensitive periods', 'accumulation of risk', and 'downward mobility' regarding the influence of poverty on violence and homicide.

RESULTS

Cumulative poverty and poverty in early adulthood were the most important influences on violence and homicide perpetration. This supports the hypothesis that early adulthood is a sensitive period for the influence of poverty on lethal and non-lethal violence. Results were replicable using different definitions of poverty and an alternative outcome of self-reported fights.

CONCLUSION

Cumulative poverty from childhood to adulthood was an important driver of violence and homicide in this population. However, poverty experienced in early adulthood was especially influential, suggesting the importance of proximal mechanisms for violence in this context, such as unemployment, organized crime, drug trafficking, and ineffective policing and justice systems.

Association between breast feeding and food consumption according to the degree of processing in Brazil: a cohort study

BACKGROUND

The benefits of breast feeding may be associated with better formation of eating habits beyond childhood. This study was designed to verify the association between breast feeding and food consumption according to the degree of processing in four Brazilian birth cohorts.

METHODS

The duration of exclusive, predominant and total breast feeding was evaluated. The analysis of the energy contribution of fresh or minimally processed foods (FMPF) and ultra-processed foods (UPF) in the diet was evaluated during childhood (13-36 months), adolescence (11-18 years) and adulthood (22, 23 and 30 years).

RESULTS

Those who were predominantly breastfed for less than 4 months had a higher UPF consumption (β 3.14, 95% CI 0.82 to 5.47) and a lower FMPF consumption (β -3.47, 95% CI -5.91 to -1.02) at age 22 years in the 1993 cohort. Exclusive breast feeding (EBF) for less than 6 months was associated with increased UPF consumption (β 1.75, 95% CI 0.25 to 3.24) and reduced FMPF consumption (β -1.49, 95% CI -2.93 to -0.04) at age 11 years in the 2004 cohort. In this same cohort, total breast feeding for less than 12 months was associated with increased UPF consumption (β 1.12, 95% CI 0.24 to 2.19) and decreased FMPF consumption (β -1.13, 95% CI -2 .07 to -0.19). Children who did not receive EBF for 6 months showed an increase in the energy contribution of UPF (β 2.36, 95% CI 0.53 to 4.18) and a decrease in FMPF (β -2.33, 95% CI -4 .19 to -0.48) in the diet at 13-36 months in the 2010 cohort. In this cohort, children who were breastfed for less than 12 months in total had higher UPF consumption (β 2.16, 95% CI 0.81 to 3.51) and lower FMPF consumption (β -1.79, 95% CI -3.09 to -0.48).

CONCLUSION

Exposure to breast feeding is associated with lower UPF consumption and higher FMPF consumption in childhood, adolescence and adulthood.

Breastfeeding moderates the association of maternal pre-pregnancy nutritional status with offspring body composition at 30 years

Maternal pre-pregnancy body mass index is positively associated with offspring obesity, even at adulthood, whereas breastfeeding decreases the risk of obesity. The present study was aimed at assessing whether breastfeeding moderates the association of maternal pre-pregnancy body mass index with offspring body composition at adulthood, using data from 3439 subjects enrolled in a southern Brazilian birth cohort. At 30 years of age, maternal pre-pregnancy body mass index was positively associated with offspring prevalence of obesity, abdominal obesity, as well as body mass index and fat and lean mass index. Breastfeeding moderated the association of maternal pre-pregnancy obesity with offspring adiposity at 30 years of age. For those breastfed<6 months, body mass index was 4.13 kg/m2 (95% confidence interval: 2.98; 5.28) higher among offspring of obese mothers, in relation to offspring of normal weight mothers, whereas among those breastfed≥6 months the magnitude of the difference was small [2.95 kg/m2 (95% confidence interval: 1.17; 4.73)], p-value for interaction = 0.03. Concerning obesity, among those who had been breastfed < 6 months, the prevalence of obesity was 2.56 (95% confidence interval: 1.98; 3.31) times higher among offspring of obese mothers. On the other hand, among those who were breastfed ≥ 6 months, the prevalence of obesity was 1.82 (95% confidence interval: 1.09; 3.04) times higher among offspring of obese mothers. Therefore, among overweight mothers breastfeeding for more than 6 months should be supported, as it may mitigate the consequences of maternal overweight on offspring body composition.

[Association between birth conditions and bone mineral density in adults from the 1982 and 1993 birth cohorts in Pelotas, Rio Grande do Sul State, Brazil]

This study assessed the association of birth weight, gestational age, and intrauterine growth with bone mineral density (BMD) at 22 and 30 years of age in the 1982 and 1993 birth cohorts in Pelotas, Rio Grande do Sul State, Brazil. BMD was measured by dual-energy X-ray absorptiometry (DXA) and the association was assessed using analysis of variance. Multiple linear regression was used to control for confounding factors: sex; household income at birth; maternal smoking during pregnancy; maternal schooling; maternal ethnicity/skin color; and pre-pregnancy body mass index. The study tested whether body fat in adulthood was a mediator of the association analyzed, using the G-computation Formula. A total of 6,803 participants from the 1982 and 1993 cohorts were evaluated at 30 and 22 years of age, respectively. Birth weight was associated with BMD at all sites, with a greater difference at the femoral neck. Individuals born weighing less than 2,000g had on average -0.036g/cm2 (95%CI: -0.064; -0.008) of BMD in the femoral neck than individuals weighing more than 3,500g. Individuals with an intrauterine growth z-score at least 1.28 standard deviation below the mean had an average of -0.013g/cm2 (95%CI: -0.024; -0.002) of BMD in the lumbar spine compared with individuals with an above-average z-score. The mediation analysis showed that body fat in adulthood did not mediate the association. Birth conditions have been associated with BMD in adulthood and the identification of early factors related to bone loss is essential due to the demographic inversion that has been taking place in low- and middle-income countries.

The politicizing clinic: insights on 'the social' for mental health policy and practice

PURPOSE

In this paper, we explore how Brazilian socially sensitive therapy can respond to care-users' desire to change the social and political forces shaping their lives. We use this case to demonstrate the limits of the "social determinants of health" agenda which, when operationalized, tends to leave questions of lasting structural change aside.

METHODS

We report on mixed methods ethnographic and epidemiological results from the 1982 Pelotas (Brazil) birth cohort study, a prospective study of 5914 children. Ethnographic analysis explored the cyclical relationship between schooling, mental health care, conceptualizations of mental distress, social and political engagement, and experiences with diverse forms of discrimination. Epidemiological bivariate and multivariate analyses examined differences in socio-political participation and the reporting of discrimination at different time-points for participants who used therapy with those who did not. Effect modification analysis tested the hypothesis that the socially empowering effects of therapy were greater for marginalized and minoritized youth.

RESULTS

Most young people living in situations of precarity experienced therapy, particularly when based in schools, to be a blame-inducing process. A more fulfilling and impactful therapeutic experience took shape when young people were able to shift the focus away from symptom reduction and behavioral management toward narrative life analyses, social debate, and political agency. Use of socially sensitive therapy was statistically associated with increased political participation and reporting of discrimination after controlling for confounders. The empowering effects of therapy were greater for those with less formal education and family income, but not for young people who identified as black, brown, or non-white.

CONCLUSION

The findings underscore the importance of considering agency, sociality, and politics when theorizing "the social" in clinical practice, and health and social policy.

Maximising the potential of Chinese birth cohort studies: a systematic review of mother-baby cohorts in mainland China

OBJECTIVES

There is now a growing interest in early-life influences on adult diseases in China. A number of birth cohorts have been established. This systematic review provided a better understanding of the development of mother-baby cohorts in China.

STUDY DESIGN

Systematic review.

METHODS

We conducted a systematic review for research or profile papers in English/Chinese that reported data from mother-baby cohorts in mainland China, with ≥1y follow-up after birth. We identified 315 papers, corresponding to 31 cohorts from 19 provinces/megacities.

RESULTS

All cohorts started in 1999-2017 (21 after 2010) and were set up with broad objectives or specific scientific focus. The baseline sample size varied, from <500 to >300,000 mothers. A majority of cohorts were initiated during pregnancy and followed children to <10y, only six to adolescence and none into adulthood. These cohorts mostly collected samples from mothers and babies, in addition to using interviews/questionnaires to collect information about pregnancy, birth and child health. Most cohorts were recruited from a single province/city. The large western region was understudied.

CONCLUSIONS

Mother-baby cohorts have developed rapidly in China, but usually with a short follow-up duration. Extending the follow-up of children and developing cross-cohort collaboration will increase the diversity, size and coverage of the sample, allow studying early influences on life-course health and identify targets for early intervention in the Chinese population.

[Birth conditions and attention deficit/hyperactivity disorders (ADHD) in adults in the Pelotas (Brazil) birth cohorts of 1982 and 1993]

This study evaluates the association of birth conditions with attention deficit/hyperactivity disorders (ADHD) in adults using data from two birth cohorts in the city of Pelotas Rio Grande do Sul State, Brazil. In 1982 and 1993 all births in the city were identified and have been prospectively monitored. In the follow-ups at 30 and 22 years of the 1982 (n = 3,574) and 1993 (n = 3,780) cohorts, respectively, participants were examined, and trained psychologists applied the Mini-International Neuropsychiatric Interview (M.I.N.I.). Those individuals who met the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) diagnostic criteria were defined as positive for ADHD. Poisson regression with robust variance adjustment was used to estimate the prevalence ratio (PR) adjusted for sex, maternal skin color, family income, maternal age, maternal schooling during pregnancy, maternal marital status, parity, and maternal smoking during pregnancy. The prevalence of adult ADHD was 4.4% and 4.5% in the 1982 and 1993 cohorts, respectively. The prevalence of ADHD was higher in those born with lower weight, but no linear trend was observed, and those born with weight between 3,000 and 3,499 grams (PR = 1.40; 95%CI: 1.05-1.86) had the highest risk. For gestational age, we observed an inversely proportional relationship for the presence of ADHD: preterm infants had a 33% higher risk (95%CI: 0.90-1.96) of being considered as having ADHD than those born at 39 or more weeks, but as the confidence interval included nullity, this association may have occurred at random. These results indicate that birth weight and gestational age may be associated with adult ADHD.

Prospective Association of Occupational and Leisure-Time Physical Activity With Cardiovascular Risk Factors in Early Adulthood: Findings From Pelotas (Brazil) 1982 Birth Cohort

BACKGROUND

The benefits of physical activity in health outcomes are well established. However, recent evidence suggests that benefits may differ by domain and population. Thus, we aimed to investigate the prospective association of occupational (OPA) and leisure-time physical activity (LTPA) with cardiovascular risk factors.

METHODS

In 1982, the maternity hospitals of Pelotas were visited daily; those live births whose families lived in urban areas were evaluated, and their mothers were later interviewed (n = 5914). In the 2004/5 follow-up (23 y old), both OPA and LTPA were measured in 4295 participants using their respective sections of the International Physical Activity Questionnaire. In the 2012 follow-up (30 y old), the following cardiovascular risk factors were collected: high-density lipoprotein (in milligrams per deciliter), low-density lipoprotein (in milligrams per deciliter), triglycerides (in milligrams per deciliter), glucose (in milligrams per deciliter), and blood pressure (in millimeters of mercury). Multivariable linear regressions were performed to evaluate associations between OPA and LTPA with these specific cardiovascular risk factors.

RESULTS

In total, 3241 participants were analyzed. Our main findings suggest that there was no association between OPA and LTPA with high- and low-density lipoprotein. There were inverse associations between OPA and lower levels of triglycerides among males (β = -0.002; 95% confidence interval, -0.003 to -0.000) and positive associations between LTPA and higher levels of diastolic blood pressure among females (β = 0.111; 95% confidence interval, 0.005-0.216).

CONCLUSION

In conclusion, our findings suggest that there was no association, or association with limited clinical relevance, of OPA and LTPA with cardiovascular risk factors in early adulthood.

Performance of Body Fat Percentage, Fat Mass Index and Body Mass Index for Detecting Cardiometabolic Outcomes in Brazilian Adults

Obesity is a recognized risk factor for the development of cardiometabolic outcomes. Therefore, it is essential to evaluate anthropometric and body composition indicators used for its diagnosis. This study aimed to assess the diagnostic performance of body fat percentage (BF%), fat mass index (FMI) and body mass index (BMI) for detecting cardiometabolic outcomes in adults. A cross-sectional study was conducted involving adults at 30 years of age from Pelotas, RS (n = 3517) and at 37-39 years from Ribeirão Preto, SP (n = 1696). Receiver operating characteristic (ROC) curves were used to determine the cut-off points for predicting cardiometabolic risk factors, including altered blood pressure, blood glucose, triglycerides, total cholesterol, low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDDL-c), C-reactive protein and glycated hemoglobin. The cut-off points of BF% ranged from 25.2 to 27.8 in men and from 37.4 to 39.7 in women at 30 years, and from 26.1 to 27.8 in men and from 38.5 to 42.2 in women at 37-39 years. For FMI (kg/m2), the cut-off points ranged from 6.3 to 7.5 in men and from 9.5 to 10.8 in women at 30 years, and from 7.3 to 7.8 in men and from 10.2 to 12.2 in women at 37-39 years. The BMI cut-off points (kg/m2) ranged from 26.3 to 27.3 in men and from 25.4 to 27.2 in women at 30 years, and from 28.3 to 29.0 in men and from 27.2 to 29.6 in women at 37-39 years. The areas under the curve were similar for the three indicators, ranging from 0.523 to 0.746. BMI showed a performance similar to that of the body fat-based indicators in identifying cardiometabolic outcomes. The cut-off points of the three indicators showed acceptable discriminatory power in subjects with cardiometabolic risk factors.

Birth conditions nutritional status in childhood associated with cardiometabolic risk factors at 30 years of age: a cohort study

This study aimed to assess the association of birth conditions, nutritional status, and childhood growth with cardiometabolic risk factors at 30 years of age. We also evaluated whether body mass index (BMI) at 30 years mediated the association of weight gain in childhood with cardiometabolic risk factors. This is a prospective cohort study that included all live births in 1982 in hospitals in the city of Pelotas, Rio Grande do Sul State, Brazil, whose families lived in the urban area. Mothers were interviewed at birth, and participants were followed at different ages. For our analyses, we used data on weight and height collected at birth, 2 and 4 years and cardiovascular risk factors at 30 years. Multiple linear regressions were performed to obtain adjusted coefficients and G-formula for mediation analysis. Relative weight gain in childhood, despite the age, was positively related to mean arterial pressure, whereas relative weight gain in late childhood was positively associated with carotid intima-media thickness, pulse wave velocity, triglycerides, non-HDL cholesterol, plasma glucose, and C-reactive protein. BMI in adulthood captured the total effect of relative weight gain in the period between 2 and 4 years on carotid intima-media thickness, triglycerides, non-HDL cholesterol, and C-reactive protein. Our findings reinforce the evidence that rapid relative weight gain after 2 years of age may have long-term consequences on the risk of metabolic and cardiovascular disorders.

Consumption of ultra-processed foods and IL-6 in two cohorts from high- and middle-income countries

This study evaluated the association between ultra-processed foods (UPF) on serum IL-6 and to investigate the mediation role of adiposity. Participants were 524 adults from the EPITeen Cohort (Porto, Portugal) and 2888 participants from the 1982 Pelotas Birth Cohort (Pelotas, Brazil). Dietary intake was collected using FFQ when participants were 21 years of age in the EPITeen and 23 years in the Pelotas Cohort. Serum IL-6 and body fat mass were evaluated when participants were 27 and 30 years old in the EPITeen and Pelotas, respectively. Generalised linear models were fitted to test main associations. Mediation of body fat mass was estimated using G-computation. After adjustment for socio-economic and behaviour variables, among females from the EPITeen, the concentration of IL-6 (pg/ml) increased with increasing intake of UPF from 1·31 (95 % CI 0·95, 1·82) in the first UPF quartile to 2·20 (95 % CI 1·60, 3·01) and 2·64 (95 % CI 1·89, 3·69) for the third and fourth UPF quartiles, respectively. A similar result was found among males in the Pelotas Cohort, IL-6 increased from 1·40 (95 % CI 1·32, 1·49) in the first UPF quartile to 1·50 (95 % CI 1·41, 1·59) and 1·59 (95 % CI 1·49, 1·70) in the two highest UPF quartiles. The P-value for the linear trend was < 0·01 in both findings. The indirect effect through fat mass was NS. Our findings suggest that the consumption of UPF was associated with an increase in IL-6 concentration; however, this association was not explained by adiposity.

Impact of tooth mineral tissues genes on dental caries: a birth-cohort study

OBJECTIVE

We aimed to investigate whether Single Nucleotide Polymorphisms present in the genes of tooth mineral tissues influence dental caries trajectory across the life course, and if there is an epistatic (gene-gene) interaction between these SNPs.

METHODS

A representative sample of all 5,914 births from the 1982 Pelotas birth cohort study was prospectively investigated. Dental caries trajectory across the life course was assessed at 15(n=888), 24(n=720), and 31 years old(n=539). Group-based trajectory modelling was used to identify distinct subgroups of individuals whose caries measurements followed a similar pattern over time. Genetic material was collected, and individuals were genotyped [rs4970957(TUFT1), rs1711437(MMP20), rs1784418(MMP20), rs2252070(MMP13), rs243847(MMP2), rs2303466(DLX3), rs11656951(DLX3), rs7501477(TIMP2), rs388286(BMP7), and rs5997096(TFIP11)]. Analyzes were performed for allele and genotype using logistic regression and generalized multifactor dimensionality reduction for epistatic interactions.

RESULTS

The analyses included 678 individuals, those with allele C (OR=0.74, CI95%[0.59-0.92]), genotype CC in the additive effect (OR=0.52, CI95%[0.31-0.89]), and the genotype TC/CC in dominant effect (OR=0.72, CI95%[0.53-0.98]) on the rs243847(MMP2) were associated with low caries trajectory. Individuals with the allele T (OR=0.79, CI95%[0.64-0.98]) and the genotype TC/CC in dominant effect (OR=0.66, CI95%[0.47-0.95]) on the rs5997096(TFIP11) were associated with low caries trajectory. Positive epistatic interactions were observed involving two (MMP2 and BMP7; p=0.006) and three (TUFT1, MMP2, and TFIP11; p<0.001) loci and high caries trajectory.

CONCLUSIONS

Some SNPs present in the genes of tooth mineral tissues were associated with caries trajectory and epistatic interactions increasing the network of SNPs involved in individual caries experience.

CLINICAL SIGNIFICANCE

Single nucleotide polymorphisms in the pathway of tooth mineral tissues genes may contribute significantly to the individual caries experience across the life course.

When a birth cohort grows up: challenges and opportunities in longitudinal developmental origins of health and disease (DOHaD) research

High-quality evidence from prospective longitudinal studies in humans is essential to testing hypotheses related to the developmental origins of health and disease. In this paper, the authors draw upon their own experiences leading birth cohorts with longitudinal follow-up into adulthood to describe specific challenges and lessons learned. Challenges are substantial and grow over time. Long-term funding is essential for study operations and critical to retaining study staff, who develop relationships with participants and hold important institutional knowledge and technical skill sets. To maintain contact, we recommend that cohorts apply multiple strategies for tracking and obtain as much high-quality contact information as possible before the child's 18th birthday. To maximize engagement, we suggest that cohorts offer flexibility in visit timing, length, location, frequency, and type. Data collection may entail multiple modalities, even at a single collection timepoint, including measures that are self-reported, research-measured, and administrative with a mix of remote and in-person collection. Many topics highly relevant for adolescent and young adult health and well-being are considered to be private in nature, and their assessment requires sensitivity. To motivate ongoing participation, cohorts must work to understand participant barriers and motivators, share scientific findings, and provide appropriate compensation for participation. It is essential for cohorts to strive for broad representation including individuals from higher risk populations, not only among the participants but also the staff. Successful longitudinal follow-up of a study population ultimately requires flexibility, adaptability, appropriate incentives, and opportunities for feedback from participants.

Sweet Taste Receptor Gene and Caries Trajectory in the Life Course

This study aims to investigate whether the trajectory of dental caries in the life course is associated with rs307355 (TAS1R3) and rs35874116 (TAS1R2) and if there is an epistatic association between rs307355 (TAS1R3) and rs35874116 (TAS1R2). A representative sample of all 5,914 births from the 1982 Pelotas birth cohort was prospectively investigated, and the decayed, missing, and filled teeth (DMF-T) components were assessed at ages 15 (n = 888), 24 (n = 720), and 31 (n = 539) y. Group-based trajectory modeling was used to identify groups with similar trajectories of DMF-T components in the life course. Genetic material was collected, and rs307355 (TAS1R3) and rs35874116 (TAS1R2) were genotyped. Ethnicity was evaluated using ADMIXTURE. Generalized multifactor dimensionality reduction software was used to investigate epistatic interactions. Considering rs307355 (TAS1R3) in the additive effect, the genotype TT was associated with the high decayed trajectory group (odds ratio [OR] = 4.52; 95% confidence interval [CI], 1.15-17.74) and the high missing trajectory group (OR = 3.35; 95% CI, 1.09-10.26). In the dominant effect, the genotype CT/TT was associated with the high decayed trajectory group (OR = 1.64; 95% CI, 1.14-2.35). Allele T was associated with an increased odds of 64% (OR = 1.64; 95% CI, 1.20-2.25) for the decayed component and 41% (OR = 1.41; 95% CI, 1.04-1.92) for the missing component. No associations were observed between rs307355 (TAS1R3) and the filled component. rs35874116 (TAS1R2) was not associated with DMF-T components. Positive epistatic interactions were observed involving rs307355 (TAS1R3) and rs35874116 (TAS1R2) with the decayed component (OR = 1.72; 95% CI, 1.04-2.84). Thus, rs307355 (TAS1R3) genotypes and alleles seem positively associated with the trajectory of decayed and missing components in the life course. Epistatic interaction between rs307355 and rs35874116 may increase the decayed caries trajectory.

Growth patterns in childhood and adolescence and adult body composition: a pooled analysis of birth cohort studies from five low and middle-income countries (COHORTS collaboration)

OBJECTIVE

We examined associations among serial measures of linear growth and relative weight with adult body composition.

DESIGN

Secondary data analysis of prospective birth cohort studies.

SETTINGS

Six birth cohorts from Brazil, Guatemala, India, the Philippines and South Africa.

PARTICIPANTS

4173 individuals followed from birth to ages 22-46 years with complete and valid weight and height at birth, infancy, childhood and adolescence, and body composition in adult life.

EXPOSURES

Birth weight and conditional size (standardised residuals of height representing linear growth and of relative weight representing weight increments independent of linear size) in infancy, childhood and adolescence.

PRIMARY OUTCOME MEASURES

Body mass index, fat mass index (FMI), fat-free mass index (FFMI), fat mass/fat-free mass ratio (FM/FFM), and waist circumference in young and mid-adulthood.

RESULTS

In pooled analyses, a higher birth weight and relative weight gains in infancy, childhood and adolescence were positively associated with all adult outcomes. Relative weight gains in childhood and adolescence were the strongest predictors of adult body composition (β (95% CI) among men: FMI (childhood: 0.41 (0.26 to 0.55); adolescence: 0.39 (0.27 to 0.50)), FFMI (childhood: 0.50 (0.34 to 0.66); adolescence: 0.43 (0.32 to 0.55)), FM/FFM (childhood: 0.31 (0.16 to 0.47); adolescence: 0.31 (0.19 to 0.43))). Among women, similar patterns were observed, but, effect sizes in adolescence were slightly stronger than in childhood. Conditional height in infancy was positively associated with FMI (men: 0.08 (0.03 to 0.14); women: 0.11 (0.07 to 0.16)). Conditional height in childhood was positively but weakly associated with women's adiposity. Site-specific and sex-stratified analyses showed consistency in the direction of estimates, although there were differences in their magnitude.

CONCLUSIONS

Prenatal and postnatal relative weight gains were positive predictors of larger body size and increased adiposity in adulthood. A faster linear growth in infancy was a significant but weak predictor of higher adult adiposity.

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 β: - 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.

Prevalence of tooth wear and associated factors: A birth cohort study

OBJECTIVES

To investigate the prevalence of tooth wear and associated factors in adults from the 1982 Pelotas Birth Cohort.

METHODS

A subsample of the 5,914 individuals from the 1982 Pelotas Birth Cohort was randomly selected to be interviewed and clinically examined at the age of 31. Tooth wear was evaluated using a simplified version of the Tooth Wear Index (TWI), considering the absence or presence of tooth wear in dentin of first molars and anterior teeth (incisors and canines). Independent variables were socioeconomic, demographic, unhealthy behavior, and mental health. Crude and adjusted Poisson regression models were employed. A significant level of P ≤ 0.05 was adopted.

RESULTS

A total of 537 individuals were evaluated. A tooth wear prevalence of 61.6% was observed. Females presented a statistically significant lower tooth wear in dentin prevalence ratio (PR) compared to males in the adjusted analysis (PR 0.76; 95% CI: 0.67-0.86). Acid beverage consumption (PR 1.22; 95% CI: 1.01-1.49) and consumption of alcoholic beverages (PR 1.19; 95% CI: 1.04-1.35) were positively associated with tooth wear.

CONCLUSION

Almost 2/3 of the surveyed individuals presented tooth wear in dentin. Being a male, higher consumption of alcohol and acidic beverages were factors associated with tooth wear.

CLINICAL SIGNIFICANCE

There was a high prevalence of tooth wear in dentin in the adult population. Data has also shown the etiological complexity of tooth wear, reinforcing the importance of an early diagnosis and the establishment of preventive measures to decrease the potentially hazardous effect of tooth wear over time.

Physical activity in birth cohorts of three Brazilian cities (Ribeirão Preto, Pelotas, and São Luís): A cross-sectional study

OBJECTIVE

To describe the prevalence of physical activity among subjects from birth cohorts of three cities located in different regions of Brazil according to sociodemographic characteristics and sex, comparing the relationships within and between cohorts.

METHODS

Cross-sectional study involving 12,724 adolescents and young adults who participated in five birth cohorts: Ribeirão Preto [1978/79 (37/39 years old in 2016) and 1994 (22 years in 2016)]; Pelotas [1982 (30 years in 2012) and 1993 (22 years in 2015)], and São Luís [1997/98 (18/19 years in 2016)]. Leisure-time physical activity was evaluated with questionnaires (insufficiently active: <150 min/week and active: ≥150 min/week) and moderate and vigorous physical activity (MVPA) was objectively measured by accelerometry. Those, in each city, were evaluated accordingly to skin color, socioeconomic classification, and study/work activities.

RESULTS

The prevalence of leisure-time physical activity ranged from 29.2% at 30 years old in Pelotas to 54.6% among adolescents from São Luís. The prevalence of leisure-time physical activity was higher among younger people (54.6% in São Luís 1997), while the same was not observed for total physical activity. MVPA (3rd tercile) was higher in the cohorts from Pelotas and São Luís. The prevalence of leisure-time physical activity and MVPA was higher in men. The data showed that the variation in physical activity was associated with sex and sociodemographic conditions in all cohorts.

CONCLUSION

Sociodemographic characteristics should be considered when promoting leisure-time physical activity and actions aimed at young people, and adults who are more socioeconomically vulnerable should be encouraged.

Periodontitis Is Associated with Consumption of Processed and Ultra-Processed Foods: Findings from a Population-Based Study

The association between periodontitis and lifestyle factors has been widely investigated. However, an association between periodontitis and dietary patterns has not been explored. Therefore, this study investigated the association between periodontitis and food consumption among a Southern Brazil population. Data from the 1982 Pelotas Birth Cohort were used (n = 537). The exposure, periodontitis, was clinically measured and classified using the AAP/CDC system, then two latent variables were defined: ‘initial’ and ‘moderate/severe’ periodontitis. The consumption of in natura, processed, and ultra-processed foods (NOVA classification) was the outcome and measured in calories using the food frequency questionnaire (FFQ). Confounders were sex, maternal education, smoking status, xerostomia, and halitosis. Data were analyzed by structural equation modeling. ‘Initial’ periodontitis was associated with a higher consumption of in natura food (standardized coefficient (SC) 0.102; p-value = 0.040), versus processed (SC 0.078; p-value = 0.129) and ultra-processed (SC 0.043; p-value = 0.400) foods. ‘Moderate/severe’ periodontitis was associated with higher consumption of ultra-processed foods (SC 0.108; p-value = 0.024), versus processed (SC 0.093; p-value = 0.053) and in natura (SC 0.014; p-value = 0.762) foods. ‘Moderate/severe’ periodontitis appears to be associated with the consumption of processed and ultra-processed foods.

Prospective association between ultra-processed food consumption and incidence of elevated symptoms of common mental disorders

BACKGROUND

Our aim was to investigate the association between ultra-processed food (UPF) consumption and the incidence of elevated symptoms of common mental disorders (CMD) in two Brazilian birth cohorts.

METHODS

We analyzed data from the 1993 (n = 3130) and 1982 (n = 3165) Pelotas Birth Cohorts. In the 1993 cohort, the 18y wave provided the first wave data and the 22y wave the second wave data. In the 1982 cohort, the first and the second waves data came from the 22y and the 30y waves, respectively. The self-reporting questionnaire (SRQ-20) was used to assess CMD symptoms and determine the incidence of elevated symptoms of CMD over time. UPF consumption was assessed using food frequency questionnaires, and it was expressed as % of the total energy and % of g/d intake and coded into quartiles according to sex. Poisson and Cox regression models were used to estimate the association between UPF consumption and incidence of elevated symptoms of CMD.

RESULTS

There were no associations between first wave quartiles of UPF consumption and incidence of elevated symptoms of CMD (quartiles based on % of total energy:Q2: HR = 1.15, 95%CI: 0.93-1.42; Q3 = 0.91, 0.73-1.14; Q4 = 0.97, 0.77-1.21. Quartiles based on % of g/d: Q2 = 1.03, 0.83-1.27; Q3 = 1.05, 0.85-1.31; Q4 = 0.97, 0.78-1.21).

LIMITATIONS

Recall bias and only two time-points in each cohort study.

CONCLUSIONS

The consumption of ultra-processed food was not associated with the incidence of elevated CMD symptoms over time.

Robbery Victimization in Early Adulthood, and Depression and Anxiety at Age 30 Years: Results From the 1982 Pelotas (Brazil) Birth Cohort Study

Robbery is one of the most common urban crimes, but little is known about its relationship with mental disorders in young adults. This study aimed to assess the relationship between robbery victimization and Major Depressive Disorder (MDD), Generalized Anxiety Disorder (GAD) and comorbidity between MDD and GAD at 30 years of age. A birth cohort study has followed all children born in the city of Pelotas, southern Brazil, since 1982. At ages 23 and 30 years, participants were interviewed and asked about lifetime and recent experiences of robbery. Covariates were measured in interviews between birth and age 30 years. MDD and GAD were measured using the MINI-International Neuropsychiatric Interview. Adjusted prevalence ratio (aPR) and corresponding 95% confidence interval (CI) for associations between robbery and mental disorders were calculated using Poisson regression with robust standard error. Of 3,701 cohort members interviewed at age 30 years, 42% reported robbery victimization during their lifetime. Victimization across three periods (lifetime, past 10 years, past 12 months) was associated with increased occurrence of MDD, GAD, as well as the MDD and GAD comorbidity. The strongest associations were found to robbery occurring in the previous 12 months with the MDD and GAD comorbidity, both for burglary at home (aPR 2.52; 95% CI 1.52-4.22) or community family victimization (aPR 2.10; 95% CI 1.34-3.27). These findings highlight the importance of community violence for mental health in young adulthood, and the need for public policies to prevent violence as well as support services for victims to mitigate its adverse health consequences.

Association between Polygenic Risk Scores for ADHD and Asthma: A Birth Cohort Investigation

OBJECTIVE

Shared genetic mechanisms have been hypothesized to explain the comorbidity between ADHD and asthma. To evaluate their genetic overlap, we relied on data from the 1982 Pelotas birth cohort to test the association between polygenic risk scores (PRSs) for ADHD (ADHD-PRSs) and asthma, and PRSs for asthma (asthma-PRSs) and ADHD.

METHOD

We analyzed data collected at birth, 2, 22, and 30 years from 3,574 individuals.

RESULTS

Subjects with ADHD had increased risk of having asthma (OR 1.92, 95% CI 1.01-3.66). The association was stronger for females. Our results showed no evidence of association between ADHD-PRSs and asthma or asthma-PRSs and ADHD. However, an exploratory analysis suggested that adult ADHD might be genetically associated with asthma.

CONCLUSION

Our results do not support a shared genetic background between both conditions. Findings should be viewed in light of important limitations, particularly the sample size and the self-reported asthma diagnosis. Studies in larger datasets are required to better explore the genetic overlap between adult ADHD and asthma.

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.

Epidemiology of interleukin-6: the 30-year follow-up of the 1982 Pelotas (Brazil) birth cohort study

BACKGROUND

Cardiovascular diseases are the main cause of death globally. Interleukin-6 (IL-6) is a biomarker of cardiovascular risk.

AIM

To investigate factors associated with IL-6 concentration in serum, from early life up to 30 years of age.

SUBJECTS AND METHODS

In the 2012-2013 follow-up, IL-6 was measured in 2809 participants of the 1982 Pelotas Birth Cohort (1369 males). Multivariable linear regressions, stratified by sex, were performed to evaluate the associations of African ancestry, family income and maternal education at birth, monthly income and education at 30 years, smoking status, harmful alcohol intake, physical activity, and body composition with IL-6, considering a conceptual hierarchical framework.

RESULTS

Males with low educational levels and current smokers had the highest mean IL-6. Among females, African ancestry and low monthly income were associated with the highest mean values for the outcome. Physical activity had an inverse association with IL-6 concentration among females. A direct relationship was observed between the measures of adiposity on IL-6, in both sexes.

CONCLUSION

Body composition was the main predictor for the outcome evaluated in males and females. Thus, the avoidance of overweight remains an important strategy for the prevention and control of cardiovascular risk and biomarkers associated with these diseases.

Medication use in children from the 2015 Pelotas (Brazil) birth cohort aged between three months and four years

Medication use is an important part of the health process and prevalence of its use among infants can reach up to 65% in their first months of life. The excessive use of medication could lead to an increase in their potential harm, surpassing their benefits. Considering this, this study aimed to describe medication use in children aged 3, 12, 24, and 48 months. Standardized questionnaires were applied to assess patterns and covariables of medication use. Medication use was investigated as an outcome and defined as the receipt of any medication within 15 days before the interview. Prevalence of medication use and 95% confidence intervals (95%CI) were described using chi-squared tests. Prescription source and frequency of use were also reported, along with the most frequent medication in each follow-up. Medication use prevalence was 67.2% (95%CI: 65.8; 68.6), 68.2% (95%CI: 66.8; 69.6), 52.4% (95%CI: 50.9; 54.0), 47.2% (95%CI: 45.7; 48.8), at 3, 12, 24, and 48 months, respectively. We observed a decrease in the proportion of medically prescribed medications and an increase in self-medication over the years. Drugs for gastrointestinal disorders (A03), vitamins (A11), analgesics (N02), anti-inflammatories (M01), and nasal formulations (R01) were the most frequently used medications. We found that children under four years of age comprised over 50% of the total use of medications and self-medication. These results highlight the need to warn caregivers on the importance of proper professional examination and prescription before they administer medications to children.

Social and racial inequity in self-rated oral health in adults in Southern Brazil

This study aimed to estimate social and racial inequalities in self-rated oral health in adults from the Brazilian birth cohort study. This study belongs to 1982 Pelotas (Brazil) birth cohort study. Data from this study was collected for oral health conditions 31 years old (Oral Health Study). The outcome was self-rated oral health, dichotomized into positive (good/very good) and negative (regular/bad/very bad). Analyses were stratified by gender, racial/skin color groups, schooling level and income. For statistical analysis, the slope index of inequality (SII) and the concentration index (CIX) were used. The prevalence of negative self-rated oral health was 36.1%. Social inequalities were observed in self-rated oral health in both absolute and relative terms. A SII of -30.0 (95%CI: -43.6; -16.4) was observed for income, and -27.7 (95%CI: -41.9; -13.4) for schooling level. Both the individuals’ income and the schooling level had negative CIX (CIXincome -14.6 [95%CI: -21.2; -8.0] and CIXschooling level -14.1 [95%CI: -20.7; -7.5]). Furthermore, the prevalence of negative self-rated oral health in black/brown/indigenous individuals from the highest income/schooling level was comparable to prevalence of the outcome in the white individuals belonging to the lowest income/schooling levels. This study results demonstrate racial disparities in oral health regardless of income and schooling levels. Furthermore, a higher concentration of negative self-rated oral health was identified among the most socioeconomically vulnerable individuals. Our findings reinforce the presence of racial and socioeconomic inequalities in oral health.

Association between cesarean section and human capital in adulthood: 1982 and 1993 Pelotas birth cohorts, Rio Grande do Sul State, Brazil

This study aims to assess the association between mode of delivery and human capital among young adults enrolled in the 1982 and 1993 Pelotas birth cohorts, Rio Grande do Sul State, Brasil. In 1982 and 1993, the maternity hospitals of the municipality were daily visited, the births identified, and those live births, whose family lived in the urban area of Pelotas, were examined and their mothers interviewed. Information on mode of delivery, vaginal or cesarean, was provided by the mother in the perinatal study. Performance in intelligence tests achieved schooling and income were evaluated in the 30 years visit at the 1982 cohort. At the 1993 cohort, schooling and income were assessed at the 22 years visit, whereas IQ was evaluated at 18 years. Tobacco smoking in adulthood and type of school was used as negative outcomes to strength causal inference. Initially, cesarean section was positively associated with human capital at adulthood, with the exception of income in the 1993 cohort. After controlling for confounders, the magnitude of the associations was strongly reduced, and the regression coefficients were close to the null value. The negative outcome analysis showed that, after controlling for confounding variables, the mode of delivery was not associated with tobacco smoking and type of school. Suggesting that the variables included in the regression model to control for confounding, provided an adequate adjustment and it is unlikely that the results are due to residual confounding by socioeconomic status. On the other hand, considering the short- and long-term risks and the epidemic of cesarean sections, measures should be implemented to reduce its prevalence.

Non-carious cervical lesions (NCCLs) and associated factors: A multilevel analysis in a cohort study in southern Brazil

AIM

To investigate the prevalence of non-carious cervical lesions (NCCLs) and their association with individual and tooth-related factors in adults from the 1982 Pelotas Birth Cohort.

MATERIALS AND METHODS

Participants were interviewed and clinically examined at the age of 31. NCCL was defined as loss of dental tissue without bacterial involvement in the cervical region. Independent variables were the socioeconomic, demographic, behavioural, and clinical characteristics. Associations were tested using a multilevel Poisson regression model.

RESULTS

Five-hundred and thirty-nine participants were clinically examined, with a 26% prevalence of NCCLs, which were more prevalent in the maxilla (56.5%) and in premolars (72.9%). In the multilevel analysis, women presented lower prevalence than men [prevalence ratio (PR) 0.59 (0.48-0.73)]; those who reported smoking at both 22 and 30 years of age had more NCCLs than those who never smoked [PR 1.65 (1.31-2.07)]; and high-frequency brushers presented higher prevalence than low-frequency brushers [PR 1.26 (1.03-1.55)]. Gingival recession increased 10 times the prevalence of NCCLs [PR 10.03 (8.15-12.35)], while the presence of periodontal pockets (≥4 mm) reduced the prevalence of NCCLs [PR 0.43 (0.28-0.66)].

CONCLUSIONS

NCCLs were more prevalent in males, smokers, and those with higher frequency of toothbrushing. While the presence of periodontal pockets was associated with a lower prevalence of NCCLs, gingival recession was a strong clinical indicator for the presence of NCCLs.

Role of occlusal factors on probable bruxism and orofacial pain: Data from the 1982 Pelotas birth cohort study

OBJECTIVES

This study aimed to explore the association between occlusal features and temporomandibular disorder (TMD) pain complaints and probable awake or sleep bruxism METHODS: Path analysis was used to estimate direct, indirect and total effects of occlusal features on probable bruxism and pain-related TMD in adults aged 31 years from the 1982 Pelotas Birth Cohort. A total of 539 cohort members had an oral examination in 2013. Occlusal features were assessed through the Dental Aesthetic Index (DAI), orofacial pain complaints through the TMD pain screener and probable bruxism based on self-reports in combination with clinical findings.

RESULTS

Malocclusions were found in 28.8% of the participants, while awake bruxism was reported in 35.2%, sleep bruxism in 15.2%, and pain-related TMD in 52.5% of the sample. Occlusion had no direct effect on either awake bruxism [standardized coefficient (SC) -0.002; p = 0.995] or pain-related TMD (SC -0.06; p = 0.115). Conversely, probable awake bruxism was associated with pain-related TMD (SC 0.35; p < 0.001). Similar results were found when sleep bruxism was set as the mediator of interest, as malocclusion did not directly affect sleep bruxism (SC 0.05; p= 0.220) nor pain-related TMD (SC -0.06; p = 0.167). A direct effect of sleep bruxism on pain-related TMD was observed with an SC of 0.16 (p < 0.001).

CONCLUSION

Our findings suggested that malocclusion during adulthood did not directly influence probable awake or sleep bruxism nor TMD pain complaints. Instead, probable awake and sleep bruxism was associated with TMD pain complaints.

CLINICAL SIGNIFICANCE

Malocclusion did not impact the presence of bruxism nor TMD complaints in adulthood, but awake and sleep bruxism were associated with TMD pain complaints. The significance of malocclusion should be reconsidered in contemporary dentistry and oral rehabilitation.

Clinical and self-reported oral conditions and quality of life in the 1982 Pelotas birth cohort

AIM

To investigate and compare the effects of clinical and self-perceived oral conditions on oral health-related quality of life (OHRQoL) among young adults.

MATERIALS AND METHODS

Adults enrolled in the 1982 Pelotas birth cohort were included in this study. OHRQoL was assessed by the Oral Health Impact Profile-14 (OHIP-14) instrument. Clinical parameters such as dental caries, periodontitis, aesthetics, and occlusal characteristics, and tongue coating were collected through clinical evaluation, while dental anxiety and halitosis were self-reported. Direct and indirect effects of clinical and self-perceived oral conditions on OHRQoL were assessed using structural equation modelling.

RESULTS

Five-hundred and thirty-nine individuals participated in this study. Dental caries (β = 0.12) and periodontitis (β = 0.11) were directly and indirectly (via halitosis, β = 0.05 for periodontitis only) associated with greater OHIP-14 scores, while the other clinical conditions did not influence the OHIP-14 scores. Dental anxiety and halitosis were also associated with higher OHIP-14 scores (β = 0.31 and β = 0.27, respectively).

CONCLUSIONS

This study found a positive association between clinically diagnosed and self-reported oral conditions and OHRQoL; however, the self-reported conditions had a higher impact on OHRQoL.

High prevalence of symptoms among Brazilian subjects with antibodies against SARS-CoV-2

Since the beginning of the pandemic of COVID-19, there has been a widespread assumption that most infected persons are asymptomatic. Using data from the recent wave of the EPICOVID19 study, a nationwide household-based survey including 133 cities from all states of Brazil, we estimated the proportion of people with and without antibodies for SARS-CoV-2 who were asymptomatic, which symptoms were most frequently reported, number of symptoms and the association with socio-demographic characteristics. We tested 33,205 subjects using a rapid antibody test previously validated. Information was collected before participants received the test result. Out of 849 (2.7%) participants positive for SARS-CoV-2 antibodies, only 12.1% (95% CI 10.1-14.5) reported no symptoms, compared to 42.2% (95% CI 41.7-42.8) among those negative. The largest difference between the two groups was observed for changes in smell/taste (56.5% versus 9.1%, a 6.2-fold difference). Changes in smell/taste, fever and body aches were most likely to predict positive tests as suggested by recursive partitioning tree analysis. Among individuals without any of these three symptoms, only 0.8% tested positive, compared to 18.3% of those with both fever and changes in smell or taste. Most subjects with antibodies against SARS-CoV-2 are symptomatic, even though most present only mild symptoms.

Excess weight and obesity prevalence in the RPS Brazilian Birth Cohort Consortium (Ribeirão Preto, Pelotas and São Luís)

Our objective was to estimate the prevalence of excess weight and obesity, according to sex and income in the RPS Brazilian Birth Cohort Consortium (Ribeirão Preto, Pelotas, and São Luís). Participants in the Ribeirão Preto (1978/1979 and 1994), Pelotas (1982, 1993 and 2004) and São Luís (1997/1998) birth cohorts were included in different follow-ups from 7 years old onwards. Excess weight (overweight and obesity) were assessed by body mass index. The highest prevalences were observed in Ribeirão Preto (excess weight: 27.7% at 9-11 and 47.1% at 22-23 years; obesity: 8.6% at 9-11 and 19.8% at 22-23 years) while the smallest was in São Luís (excess weight: 5.4 to 7-9 and 17.2% at 18-19 years; obesity: 1.8% at 7-9 and 3.6% at 18-19 years). The younger the cohort, the greater the prevalence of excess weight and obesity when comparing similar age groups. Increases in obesity prevalence were greater than in excess weight prevalence. Women had lower excess weight prevalence in older cohorts and higher obesity prevalence in younger cohorts. Higher excess weight and obesity prevalence were observed in higher income children and adolescents, and in poorer adults. Differences in the prevalence of excess weight and obesity evidenced that individuals from younger cohorts are more exposed to this morbidity, as well as those who were born in the most developed city, low-income adults as well as children and adolescents belonging to families of the highest income tertile. Therefore, the results of this study indicate the need to prioritize actions aimed at younger individuals.

RPS Brazilian Birth Cohorts Consortium (Ribeirão Preto, Pelotas and São Luís): history, objectives and methods

This paper describes the history, objectives and methods used by the nine Brazilian cohorts of the RPS Brazilian Birth Cohorts Consortium (Ribeirão Preto, Pelotas and São Luís) Common thematic axes are identified and the objectives, baseline periods, follow-up stages and representativity of the population studied are presented. The Consortium includes three birth cohorts from Ribeirão Preto, São Paulo State (1978/1979, 1994 and 2010), four from Pelotas, Rio Grande do Sul State (1982, 1993, 2004 and 2015), and two from São Luís, Maranhão State (1997 and 2010). The cohorts cover three regions of Brazil, from three distinct states, with marked socioeconomic, cultural and infrastructure differences. The cohorts were started at birth, except for the most recent one in each municipality, where mothers were recruited during pregnancy. The instruments for data collection have been refined in order to approach different exposures during the early phases of life and their long-term influence on the health-disease process. The investigators of the nine cohorts carried out perinatal studies and later studied human capital, mental health, nutrition and precursor signs of noncommunicable diseases. A total of 17,636 liveborns were recruited in Ribeirão Preto, 19,669 in Pelotas, and 7,659 in São Luís. In the studies starting during pregnancy, 1,400 pregnant women were interviewed in Ribeirão Preto, 3,199 in Pelotas, and 1,447 in São Luís. Different strategies were employed to reduce losses to follow-up. This research network allows the analysis of the incidence of diseases and the establishment of possible causal relations that might explain the health outcomes of these populations in order to contribute to the development of governmental actions and health policies more consistent with reality.

Obesity and ADHD: Exploring the role of body composition, BMI polygenic risk score, and reward system genes

The association between obesity and attention-deficit hyperactivity disorder (ADHD) has been extensively reported in the literature. However, the potential mechanisms underlying this association are not completely understood. This study aimed to evaluate the association between body composition and ADHD and explore the possible genetic mechanisms involved. We used data from the 1982 Pelotas (Brazil) Birth Cohort at age 30-year follow-up (N = 3630). We first used logistic regression analysis to test whether body mass index (BMI), fat mass (FM), and fat-free mass (FFM) were associated with ADHD. We further tested the association between BMI polygenic risk score (BMI-PRS) and ADHD and the role of the genes upregulated in the reward system using a gene-set association approach. BMI (odds ratio [OR] = 1.05; 95% confidence interval [CI], 1.00-1.09; p = 0.038) and FM (OR = 1.04; 95% CI, 1.00-1.07; p = 0.043) were associated with ADHD. The BMI-PRS was associated with ADHD (using p-value threshold (P_T) = 0.4; OR = 1.65; 95% CI, 1.02-2.65) at a nominal level. In gene-set analysis, the reward system genes were associated with BMI in subjects with a high BMI-PRS score, considering P_T = 0.4 (p = 0.014). The results suggest that BMI genetic components, especially those genes related to the reward system, may be involved in this association.

Prematurity and body composition at 6, 18, and 30 years of age: Pelotas (Brazil) 2004, 1993, and 1982 birth cohorts

Background

We aimed to investigate the association between preterm birth and body composition at 6, 18, and 30 years of age using data from three population-based birth cohort studies.

Methods

Gestational age (GA), defined by the date of the last menstrual period (categorized in ≤33, 34–36, and ≥ 37 weeks), was gathered in the first 24-h after delivery for all live births occurring in the city of Pelotas, Brazil, in 2004, 1993 and 1982. Body composition was assessed by air-displacement plethysmography. Outcomes included fat mass (FM, kg), percent FM (%FM), FM index (FMI, kg/m²), fat-free mass (FFM, kg); percent FFM (%FFM), FFM index (FFMI, kg/m²), body mass index (BMI, kg/m² at 18 years in the 1993 cohort and 30 years in the 1982 cohort), and BMI Z-score (at 6 years in the 2004 cohort). We further explored the association of birth weight for GA with body composition indicators and BMI. Crude and adjusted linear regressions provided beta coefficients with 95% confidence intervals (95%CI).

Results

A total of 3036, 3027, and 3369 participants, respectively, from the 2004, 1993, and 1982 cohorts were analyzed. At 6 years, preterm boys (born at 34–36 weeks) presented lower adjusted mean of FM (β = − 0.80 kg, − 1.45;-0.16, p = 0.046), %FM (β = − 2.39%, − 3.90;-0.88, p = 0.008), FMI (β = − 0.70 kg/m², − 1.13;-0.27, p = 0.004) as well as lower FFM (β = − 0.4 kg, − 0.77; − 0.12, p = 0.010) and FFMI (β = − 0.3 kg/m², − 0.46;-0.10, p < 0.001), and BMI Z-score (β = − 0.69,; − 0.99;-0.40, p < 0.001); but higher %FFM (β = 2.4%, 0.87;-3.90, p = 0.008), when compared to boys born at term (≥37). At 30 years, FM (15.7 kg, 0.25;31.1, p = 0.102) was higher among males born at ≤33 weeks. No association was observed for females from the three cohorts and for 18-year-old males. The association of birth weight for GA with body composition and BMI was not significant in any cohort. At 6 years, SGA boys had lower FFMI than boys AGA.

Conclusions

Our results suggest that preterm birth is associated with decreased body fat and fat-free mass in childhood but higher fat mass in adulthood. Nevertheless, results were only significant for males. SGA boys also showed lower FFMI.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10368-w.

Early age at menarche and metabolic cardiovascular risk factors: mediation by body composition in adulthood

Evidence suggests that early menarche increases cardiometabolic risk, and adiposity would be a possible mediator of this association. We assessed the association between age at menarche and metabolic cardiovascular risk factors and estimated the indirect effect of body composition in adulthood. In 1982, all hospital births in the city of Pelotas/Brazil, were identified and live births were examined and have been prospectively followed. At 30 years, information on age at menarche and metabolic cardiovascular risk factors was available for 1680 women. Mediation analysis was performed using G-computation to estimate the direct effect of age at menarche and the indirect effect of body composition. The prevalence of age at menarche < 12 years was 24.5% and was associated with higher mean diastolic blood pressure [β: 1.98; 95% CI: 0.56, 3.40], total cholesterol (β: 8.28; 95% CI: 2.67, 13.88), LDL-cholesterol (β: 6.53; 95% CI: 2.00, 11.07), triglycerides (β: 0.11; 95% CI: 0.03, 0.19). For diastolic blood pressure, total cholesterol, LDL-cholesterol, triglycerides, body composition assessed by fat mass index captured from 43.8 to 98.9% of the effect of early menarche, except to systolic blood pressure, HDL-cholesterol, C-reactive-protein. Suggesting that the effect of menarche age < 12 years on some metabolic cardiovascular risk factors is mediated partially by body composition in adulthood.

LRRK2 Gene Variants Associated With a Higher Risk for Alcohol Dependence in Multiethnic Populations

Background: Genetics influence the vulnerability to alcohol use disorders, and among the implicated genes, three previous studies have provided evidences for the involvement of LRRK2 in alcohol dependence (AD). LRRK2 expression is broadly dysregulated in postmortem brain from AD humans, as well as in the brain of mice with alcohol dependent-like behaviors and in a zebrafish model of alcohol preference. The aim of the present study was to evaluate the association of variants in the LRRK2 gene with AD in multiethnic populations from South and North America. Methods: Alcohol-screening questionnaires [such as CAGE and Alcohol Use Disorders Identification Test (AUDIT)] were used to determine individual risk of AD. Multivariate logistic regression analyses were done in three independent populations (898 individuals from Bambuí, Brazil; 3,015 individuals from Pelotas, Brazil; and 1,316 from the United States). Linkage disequilibrium and conditional analyses, as well as in silico functional analyses, were also conducted. Results: Four LRRK2 variants were significantly associated with AD in our discovery cohort (Bambuí): rs4768231, rs4767971, rs7307310, and rs1465527. Two of these variants (rs4768231 and rs4767971) were replicated in both Pelotas and US cohorts. The consistent association signal (at the LRRK2 locus) found in populations with different genetic backgrounds reinforces the relevance of our findings. Conclusion: Taken together, these results support the notion that genetic variants in the LRRK2 locus are risk factors for AD in humans.

Follow-Up de Nascidos Prematuros: Uma Revisão Sistemática da Literatura

Resumo Objetivou-se mapear estudos científicos sobre follow-up de prematuros na área da psicologia. Buscou-se no portal BVS artigos empíricos publicados até dezembro de 2017 pelos descritores prematur* AND follow up AND child AND psychology. A partir dos critérios adotados, analisou-se 48 artigos, nas categorias: faixa etária em que os prematuros foram avaliados; objetivos do estudo; tipo de avaliação realizada; e resultados encontrados. Destaca-se que a metade realizou o follow-up entre o nascimento e a adolescência, a maioria investigou o desenvolvimento neuropsicológico e encontrou associações entre a prematuridade, déficits cognitivos e psicológicos. Compreende-se que os estudos priorizam as repercussões no desenvolvimento de habilidades e competências, dando pouca atenção aos aspectos psíquicos e às interações criança-pais-ambiente.

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.

Mental disorders, comorbidities, and suicidality at 30 years of age in a Brazilian birth cohort

BACKGROUND

Studies on mental disorders prevalence and comorbidity, including suicidality, are scarce in low and middle-income settings. We aimed to describe the pattern of comorbidity between mental disorders and their association with suicidality.

METHODS

In 1982, all hospital deliveries in Pelotas (Southern Brazil) were identified (n = 5914) and have been prospectively followed. Participants were evaluated for the presence of common mental disorders (CMD) at the ages of 18-19, 23 and 30 years. In 2012-13 (30 years of age), trained psychologists evaluated 3657 individuals for disorders using the Mini International Neuropsychiatric Interview.

RESULTS

Prevalence of suicidal wishing, suicidal planning and lifetime suicidal attempt was 4.9%, 3.8% and 6.6%, respectively. Suicidal wishing was most strongly associated with having joint major depressive episode (MD) and lifetime suicidal attempt (OR = 26.4, 95%CI:13.9-50.4) with comorbid MD with mania/hypomania (OR = 21.2, 95%CI:6.93-65.1). Suicidal planning was most strongly associated with having joint MD and lifetime suicidal attempt (OR = 44.7, 95%CI:22.6-88.4), with comorbid MD and social anxiety disorder (OR = 30.6, 95%CI:13.0-72.0), and joint social anxiety disorder with lifetime suicidal attempt (OR = 26.3, 95%CI:8.33-82.7). Independently of other disorders, prospective and cross-sectional measures of CMD were associated with higher rates of suicidality.

LIMITATIONS

We do not have data on suicide deaths in follow-up and the diagnostic instrument used at 30 years of age was not used in all previous follow-up.

CONCLUSION

MD and social anxiety have independent and combined associations with suicidality, and also with they occur with lifetime suicidal attempt and other mental disorders.