Reconstructed Lost Native American Populations from Eastern Brazil Are Shaped by Differential Jê/Tupi Ancestry

After the colonization of the Americas by Europeans and the consequent Trans-Atlantic Slave Trade, most Native American populations in eastern Brazil disappeared or went through an admixture process that configured a population composed of three main genetic components: the European, the sub-Saharan African, and the Native American. The study of the Native American genetic history is challenged by the lack of availability of genome-wide samples from Native American populations, the technical difficulties to develop ancient DNA studies, and the low proportions of the Native American component in the admixed Brazilian populations (on average 7%). We analyzed genome-wide data of 5,825 individuals from three locations of eastern Brazil: Salvador (North-East), Bambui (South-East), and Pelotas (South) and we reconstructed populations that emulate the Native American groups that were living in the 16th century around the sampling locations. This genetic reconstruction was performed after local ancestry analysis of the admixed Brazilian populations, through the rearrangement of the Native American haplotypes into reconstructed individuals with full Native American ancestry (51 reconstructed individuals in Salvador, 45 in Bambui, and 197 in Pelotas). We compared the reconstructed populations with nonadmixed Native American populations from other regions of Brazil through haplotype-based methods. Our results reveal a population structure shaped by the dichotomy of Tupi-/Jê-speaking ancestry related groups. We also show evidence of a decrease of the diversity of nonadmixed Native American groups after the European contact, in contrast with the reconstructed populations, suggesting a reservoir of the Native American genetic diversity within the admixed Brazilian population.

Changes in Infant and Neonatal Mortality and Associated Factors in Eight Cohorts from Three Brazilian Cities

Stillbirth (SBR), perinatal (PMR), neonatal (NMR) and infant mortality rates (IMR) are declining in Brazil and the factors associated with these falls are still being investigated. The objective of the present study was to assess changes in SBR, PMR, NMR and IMR over time and to determine the factors associated with changes in NMR and IMR in eight Brazilian cohorts. All cohorts are population-based (Ribeirão Preto in 1978/79, 1994 and 2010; Pelotas in 1982, 1993 and 2004; and São Luís in 1997/98 and 2010). Were included data on 41440 children. All indicators were decreased, except in the city of Pelotas, from 1993 to 2004, and except SBR in São Luís. Sociodemographic variables seem to be able to explain reductions of NMR and IMR in Ribeirão Preto, from 1978/79 to 1994, and in São Luís. In Ribeirão Preto, from 1994 to 2010 declines in NMR and IMR seem to be explained by reductions in intrauterine growth restriction (IUGR). Newborn’s gestational age had diminished in all cohorts, preventing even greater reductions of NMR and IMR. Improved sociodemographic variables and reduction of IUGR, seem to be able to explain part of the decrease observed. NMR and IMR could have been reduced even more, were it not for the worsening in gestational age distribution.

Prenatal and birth predictors of objectively measured physical activity and sedentary time in three population-based birth cohorts in Brazil

Physical inactivity is a global pandemic with no signs of improvement. Prolonged sitting time is an emerging risk factor that exacerbates the health consequences of physical inactivity. Both behaviours are influenced by various individual and environmental factors but it remains unknown whether early-life exposures “program” these behaviours in later life. The current evidence is limited by a small number of studies which were primarily conducted in high-income countries, and a narrow range of early-life variables examined. Using data from three population-based Brazilian birth cohorts (analytical samples: n = 2740 for 1982 cohort, aged 30 years; n = 3592 for 1993 cohort, aged 18; n = 2603 for 2004 cohort, aged 6), we show that being female and higher family socioeconomic status at birth are strong and consistent predictors of lower physical activity and higher sedentary time from childhood to adulthood. Meanwhile, higher birth weight and lower birth order may also predict lower physical activity and higher sedentary time. Our findings are distinct from evidence from high-income countries, suggesting the importance of broader socioeconomic context in determining individual’s activity patterns through the life- course. Such evidence is essential for understanding the biological etiology and socioeconomic context of physical activity and sedentary behaviour at an early stage in life.

The Genomic Impact of European Colonization of the Americas

The human genetic diversity of the Americas has been affected by several events of gene flow that have continued since the colonial era and the Atlantic slave trade. Moreover, multiple waves of migration followed by local admixture occurred in the last two centuries, the impact of which has been largely unexplored. Here, we compiled a genome-wide dataset of ∼12,000 individuals from twelve American countries and ∼6,000 individuals from worldwide populations and applied haplotype-based methods to investigate how historical movements from outside the New World affected (1) the genetic structure, (2) the admixture profile, (3) the demographic history, and (4) sex-biased gene-flow dynamics of the Americas. We revealed a high degree of complexity underlying the genetic contribution of European and African populations in North and South America, from both geographic and temporal perspectives, identifying previously unreported sources related to Italy, the Middle East, and to specific regions of Africa.

Early menarche and blood pressure in adulthood: systematic review and meta-analysis

Background

It has been reported that early menarche is associated with high blood pressure and hypertension. However, some studies have failed to observe such association. We carried out a systematic review and meta-analysis on the association of early menarche with hypertension and high blood pressure in adulthood.

Methods

PUBMED, SciELO, Scopus and LILACS databases were searched. Studies that evaluated the association of early menarche with hypertension or high blood pressure, among women aged 20 years or more were included. Random effects models were used to pool the estimates. Meta-regression was used to evaluate the contribution of different co-variables to heterogeneity.

Results

We identified 17 studies with 18 estimates on the association of early menarche with hypertension and high blood pressure. The odds of hypertension/high blood pressure was higher among women with early menarche [pooled (OR):1.25; 95% confidence interval (CI): 1.17-1.34; P < 0.001]. In the meta-regression analysis, studies evaluating 1500 subjects or more had a higher pooled OR [1.27; 95%CI (1.19;1.36)] than those with less participants. Although funnel plots showed some asymmetry, Egger tests were not statistically significant. Therefore, it is unlikely that the observed association was to publication bias.

Conclusions

Early menarche is associated with hypertension among adult woman.

Trends and inequalities in maternal and child health in a Brazilian city: methodology and sociodemographic description of four population-based birth cohort studies, 1982-2015

Background

Few low-middle-income countries have data from comparable birth cohort studies spanning over time. We report on the methods used by the Pelotas cohorts (1982, 1993, 2004 and 2015) and describe time trends in sociodemographic characteristics of the participant families.

Methods

During the four study years, all maternity hospitals in the city were visited daily, and all urban women giving birth were enrolled. Data on socioeconomic and demographic characteristics were collected using standardized questionnaires, including data on maternal and paternal skin colour, age and schooling, maternal marital status, family income and household characteristics. The analyses included comparisons of time trends and of socioeconomic and ethnic group inequalities.

Results

Despite a near 50% increase in the city’s population between 1982 and 2015, the total number of births declined from 6011 to 4387. The proportion of mothers aged ≥35 years increased from 9.9% to 14.8%, and average maternal schooling from 6.5 [standard deviation (SD) 4.2] to 10.1 (SD 4.0) years. Treated water was available in 95.3% of households in 1982 and 99.3% in 2015. Three-quarters of the families had a refrigerator in 1982, compared with 98.3% in 2015. Absolute income-related inequalities in maternal schooling, household crowding, household appliances and access to treated water were markedly reduced between 1982 and 2015. Maternal skin colour was associated with inequalities in age at childbearing and schooling, as well as with household characteristics.

Conclusions

During the 33-year period, there were positive changes in social and environmental determinants of health, including income, education, fertility and characteristics of the home environment. Socioeconomic inequality was also reduced.

Hospital admissions in the first year of life: inequalities over three decades in a southern Brazilian city

BACKGROUND

Hospital admissions in infancy are declining in several countries. We describe admissions to neonatal intensive care units (NICU) and other hospitalizations over a 33-year period in the Brazilian city of Pelotas.

METHODS

We analysed data from four population-based birth cohorts launched in 1982, 1993, 2004 and 2015, each including all hospital births in the calendar year. NICU and other hospital admissions during infancy were reported by the mothers in the perinatal interview and at the 12-month visit, respectively. We describe these outcomes by sex of the child, family income and maternal skin colour.

RESULTS

In 1982, NICUs did not exist in the city; admissions into NICUs increased from 2.7% of all newborns in 1993 to 6.7% in 2015, and admission rates were similar in all income groups. Hospitalizations during the first year of life fell by 29%, from 23.7% in 1982 to 16.8% in 2015, and diarrhoea admissions fell by 95.2%. Pneumonia admissions fell by 46.3% from 1993 to 2015 (no data available for 1982). Admissions due to perinatal causes increased during the period. In the poorest income quintile, total admissions fell by 33% (from 35.7% to 23.9%), but in the richest quintile these remained stable at around 10%, leading to a reduction in inequalities. Over the whole period, children born to women with black or brown skin were 30% more likely to be admitted than those of white-skinned mothers.

CONCLUSIONS

Whereas NICU admissions increased, total admissions in the first year of life declined by nearly one-third. Socioeconomic disparities were reduced, but important gaps remain.

Stillbirth, newborn and infant mortality: trends and inequalities in four population-based birth cohorts in Pelotas, Brazil, 1982-2015

BACKGROUND

Infant-mortality rates have been declining in many low- and middle-income countries, including Brazil. Information on causes of death and on socio-economic inequalities is scarce.

METHODS

Four birth cohorts were carried out in the city of Pelotas in 1982, 1993, 2004 and 2015, each including all hospital births in the calendar year. Surveillance in hospitals and vital registries, accompanied by interviews with doctors and families, detected fetal and infant deaths and ascertained their causes. Late-fetal (stillbirth)-, neonatal- and post-neonatal-death rates were calculated.

RESULTS

All-cause and cause-specific death rates were reduced. During the study period, stillbirths fell by 47.8% (from 16.1 to 8.4 per 1000), neonatal mortality by 57.0% (from 20.1 to 8.7) and infant mortality by 62.0% (from 36.4 to 13.8). Perinatal causes were the leading causes of death in the four cohorts; deaths due to infectious diseases showed the largest reductions, with diarrhoea causing 25 deaths in 1982 and none in 2015. Late-fetal-, neonatal- and infant-mortality rates were higher for children born to Brown or Black women and to low-income women. Absolute socio-economic inequalities based on income-expressed in deaths per 1000 births-were reduced over time but relative inequalities-expressed as ratios of mortality rates-tended to remain stable.

CONCLUSION

The observed improvements are likely due to progress in social determinants of health and expansion of health care. In spite of progress, current levels remain substantially greater than those observed in high-income countries, and social and ethnic inequalities persist.

Breastfeeding exclusivity and duration: trends and inequalities in four population-based birth cohorts in Pelotas, Brazil, 1982-2015

Background

Brazil has made substantial improvements in the duration of breastfeeding. We use data from four population-based cohorts to examine how trends and inequalities in breastfeeding indicators changed over time in a Brazilian city.

Methods

Data from four birth cohorts, each including all births in a calendar year (1982, 1993, 2004 and 2015) in the city of Pelotas were used. Information on breastfeeding was collected when children were aged between 3 and 20 months. The prevalences of continued breastfeeding at 1 year of age and of exclusive breastfeeding at 3 months were calculated according to family income, maternal skin colour and sex.

Results

Prevalence of breastfeeding at 12 months increased from 16% to 41% in the 33-year period. The prevalence of exclusive breastfeeding at 3 months increased from 7% in 1993 to 45% in 2015. Increases in exclusive breastfeeding at 3 months were seen in all socioeconomic groups, but the 2015 rates remain highest (57.2%) among the women in the richest quintile, and lowest among those in the poorest quintile (34.6%). Black mothers were more likely to breastfeed at 12 months than Whites in the four cohorts. In the earlier cohorts, breastfeeding at 12 months was more common among the poor, but by 2015 these differences had disappeared.

Conclusions

There were important positive changes in breastfeeding practices during this period, but less than half of the children in 2015 were receiving the full benefits of breast milk. Improved breastfeeding practices are being adopted by high-income women to a greater extent than by poor women.

Maternal reproductive history: trends and inequalities in four population-based birth cohorts in Pelotas, Brazil, 1982-2015

Background

Brazil experienced important progress in maternal and child health in recent decades. We aimed at describing secular trends as well as socioeconomic and ethnic inequalities in reproductive history indicators (birth spacing, previous adverse perinatal outcome, parity and multiple births) over a 33-year span.

Methods

Four population-based birth cohort studies included all hospital births in 1982, 1993, 2004 and 2015 in Pelotas, Southern Brazil. Information on reproductive history was collected through interviews. Indicators were stratified by family income quintiles and skin colour. Absolute and relative measures of inequality were calculated.

Results

From 1982 to 2015, the proportion of primiparae increased from 39.2% to 49.6%, and median birth interval increased by 23.2 months. Poor women were more likely to report short intervals and higher parity, although reductions were observed in all income and ethnic groups. History of previous low birthweight was inversely related to income and increased by 7.7% points (pp) over time—more rapidly in the richest (12.1 pp) than in the poorest quintile (0.4 pp). Multiple births increased from 1.7% to 2.7%, with the highest increase observed among the richest quintile and for white women (220% and 70% increase, respectively). Absolute and relative income and ethnic-related inequalities for short birth intervals increased, whereas inequalities for previous low birthweight decreased over time.

Conclusions

In this 33-year period there were increases in birth intervals, multiple births and reports of previous low-birthweight infants. These trends may be explained by increased family planning coverage, assisted reproduction and a rise in preterm births, respectively. Our results show that socioeconomic and ethnic inequalities in health are dynamic and vary over time, within the same location.

Multiancestry Genome-Wide Association Study of Lipid Levels Incorporating Gene-Alcohol Interactions

A person's lipid profile is influenced by genetic variants and alcohol consumption, but the contribution of interactions between these exposures has not been studied. We therefore incorporated gene-alcohol interactions into a multiancestry genome-wide association study of levels of high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides. We included 45 studies in stage 1 (genome-wide discovery) and 66 studies in stage 2 (focused follow-up), for a total of 394,584 individuals from 5 ancestry groups. Analyses covered the period July 2014-November 2017. Genetic main effects and interaction effects were jointly assessed by means of a 2-degrees-of-freedom (df) test, and a 1-df test was used to assess the interaction effects alone. Variants at 495 loci were at least suggestively associated (P < 1 × 10-6) with lipid levels in stage 1 and were evaluated in stage 2, followed by combined analyses of stage 1 and stage 2. In the combined analysis of stages 1 and 2, a total of 147 independent loci were associated with lipid levels at P < 5 × 10-8 using 2-df tests, of which 18 were novel. No genome-wide-significant associations were found testing the interaction effect alone. The novel loci included several genes (proprotein convertase subtilisin/kexin type 5 (PCSK5), vascular endothelial growth factor B (VEGFB), and apolipoprotein B mRNA editing enzyme, catalytic polypeptide 1 (APOBEC1) complementation factor (A1CF)) that have a putative role in lipid metabolism on the basis of existing evidence from cellular and experimental models.

Is vigorous-intensity physical activity required for improving bone mass in adolescence? Findings from a Brazilian birth cohort

The association between moderate and vigorous physical activity throughout adolescence and areal bone density (aBMD) at 18 years of age was evaluated. Vigorous-intensity physical activity at 11, 15, and 18 years was associated with aBMD in early adulthood, especially in boys. Cross-sectional analyses showed a positive association between moderate physical activity and aBMD.

INTRODUCTION

To evaluate independent associations of moderate and vigorous physical activity (MPA, VPA) across adolescence with areal bone mineral density (aBMD).

METHODS

Physical activity (PA) was assessed at 11, 15, and 18 years of age by self-report and at 18 years by accelerometry in the 1993 Pelotas Birth Cohort Study. Time spent in MPA and VPA was determined using metabolic equivalents and specific cutoffs based on raw acceleration. Lumbar spine and femoral neck aBMD were measured by DXA at 18 years. Statistical analyses evaluated the association of MPA and VPA with aBMD, after adjusting for skin color, asset index, current height and age at menarche, and peak strain score (based on ground reaction forces of PA).

RESULTS

Lumbar spine and femoral neck aBMD were available for 3947 (49.9% of boys) and 3960 (49.6% of boys) individuals, respectively. Time spent in MPA at 11 and 15 years was not associated with aBMD. VPA at all time points was positively related to both lumbar spine and femoral neck aBMD in boys. Results were consistent for objectively measured VPA. Girls who achieved 75+ minutes/week of VPA in at least two follow-ups showed higher aBMD at 18 years of age. Boys who reached 75+ minutes/week of VPA at all follow-ups had on average 0.117 g/cm² (95% CI: 0.090; 0.144) higher femoral neck aBMD than those who never achieved this threshold.

CONCLUSIONS

Self-reported VPA but not MPA throughout adolescence was associated with aBMD. Recommendation for PA in young people should consider the importance of VPA.

Multi-ancestry genome-wide gene-smoking interaction study of 387,272 individuals identifies new loci associated with serum lipids

The concentrations of high- and low-density-lipoprotein cholesterol and triglycerides are influenced by smoking, but it is unknown whether genetic associations with lipids may be modified by smoking. We conducted a multi-ancestry genome-wide gene-smoking interaction study in 133,805 individuals with follow-up in an additional 253,467 individuals. Combined meta-analyses identified 13 new loci associated with lipids, some of which were detected only because association differed by smoking status. Additionally, we demonstrate the importance of including diverse populations, particularly in studies of interactions with lifestyle factors, where genomic and lifestyle differences by ancestry may contribute to novel findings.

Infant nutrition and growth: trends and inequalities in four population-based birth cohorts in Pelotas, Brazil, 1982-2015

BACKGROUND

Levels of child undernutrition have declined in many middle-income countries, whereas overweight and obesity have increased. We describe time trends in nutritional indicators at age 1 year in the 1982, 1993, 2004 and 2015 Pelotas (Brazil) Birth Cohorts.

METHODS

Each study included all children born in the urban area of the city, with over 4 200 births in each cohort. Children were measured at approximately 12 months of age. Anthropometric indicators were calculated according to World Health Organization Growth Standards. Stunting and wasting were defined as <-2 Z scores for length for age and weight for length, and overweight as >2 Z scores for weight for length. Prevalence was stratified by sex, maternal skin colour and family income.

RESULTS

The prevalence of stunting declined by 53% (from 8.3% to 3.9%) from 1982 to 2015. Wasting prevalence remained stable at low levels (1.8% in 1982 and 1.7% in 2015), whereas overweight increased by 88% (6.5% to 12.2%). Undernutrition was more common among boys, those born to mothers with brown or black skin colour and in the poorest quintile of families. Socioeconomic inequalities in undernutrition decreased markedly over time. Overweight was markedly more common among the rich in 1982, but fast increase among the poor eliminated socioeconomic differences by 2015, when all groups showed similar prevalence.

CONCLUSIONS

Our results confirm the rapid nutrition transition in Brazil, with marked reduction in levels and inequalities in undernutrition in parallel with a rapid increase in overweight, which became the main nutritional problem for children.

Low birthweight and preterm birth: trends and inequalities in four population-based birth cohorts in Pelotas, Brazil, 1982-2015

BACKGROUND

Despite positive changes in most maternal risk factors in Brazil, previous studies did not show reductions in preterm birth and low birthweight. We analysed trends and inequalities in these outcomes over a 33-year period in a Brazilian city.

METHODS

Four population-based birth cohort studies were carried out in the city of Pelotas in 1982, 1993, 2004 and 2015, with samples ranging from 4231 to 5914 liveborn children. Low birthweight (LBW) was defined as <2500 g, and preterm birth as less than 37 weeks of gestation. Information was collected on family income, maternal skin colour and other risk factors for low birthweight. Multivariable linear regression was used to estimate the contribution of risk factors to time trends in birthweight.

RESULTS

Preterm births increased from 5.8% (1982) to 13.8% (2015), and LBW prevalence increased from 9.0% to 10.1%, being higher for boys and for children born to mothers with low income and brown or black skin colour. Mean birthweight remained stable, around 3200 g, but increased from 3058 to 3146 g in the poorest quintile and decreased from 3307 to 3227 g in the richest quintile. After adjustment for risk factors for LBW, mean birthweight was estimated to have declined by 160 g over 1982-2015 (reductions of 103 g in the poorest and 213 g in the richest quintiles).

CONCLUSIONS

Data from four birth cohorts show that preterm births increased markedly. Mean birthweights remained stable over a 33-year period. Increased prevalence of preterm and early term births, associated with high levels of obstetric interventions, has offset the expected improvements due to reduction in risk factors for low birthweight.

Antenatal care and caesarean sections: trends and inequalities in four population-based birth cohorts in Pelotas, Brazil, 1982-2015

BACKGROUND

Antenatal care and correctly indicated caesarean section can positively impact on health outcomes of the mother and newborn. Our objective was to describe how coverage and inequalities for these interventions changed from 1982 to 2015 in Pelotas, Brazil.

METHODS

Using perinatal data from the 1982, 1993, 2004 and 2015 Pelotas birth cohorts, we assessed antenatal care coverage and caesarean section rates over time. Antenatal care indicators included the median number of visits, the prevalence of mothers attending at least six visits and the proportion who started antenatal care in the first trimester of pregnancy and attended at least six visits. We described these outcomes according to income quintiles and maternal skin colour, to identify inequalities. We described overall, private sector and public sector caesarean section rates. Differences in prevalence were tested using chi-square testing and median differences using Kruskal-Wallis testing.

RESULTS

From 1982 to 2015, the median number of antenatal care visits and the prevalence of mothers attending at least six visits increased in all income quintiles and skin colour groups. Inequalities were reduced, but not eliminated. The overall proportion of caesarean births increased from 27.6% in 1982 to 65.1% in 2015, when 93.9% of the births in the private sector were by caesarean section. Absolute income-related inequalities in caesarean sections increased over time.

CONCLUSIONS

Special attention should be given to the antenatal care of poor and Black women in order to reduce inequalities. The explosive increase in caesarean sections requires radical changes in delivery care policies, in order to reverse the current trend.

Maternal anthropometry: trends and inequalities in four population-based birth cohorts in Pelotas, Brazil, 1982-2015

BACKGROUND

Pre-pregnancy nutritional status and weight gain during pregnancy have short- and long-term consequences for the health of women and children. This study was aimed at evaluating maternal height,- and overweight or obesity at the beginning of the pregnancy and gestational weight gain, according to socioeconomic status and maternal skin colour of mothers in Pelotas, a southern Brazilian city, in 1982, 1993, 2004 and 2015.

METHODS

In 1982, 1993, 2004 and 2015, the maternity hospitals in Pelotas were visited daily, all deliveries were identified and mothers who lived in the urban area of the city were interviewed. Maternal weight at the beginning of the pregnancy was self-reported by the mother or obtained from the antenatal card. Maternal height was collected from the maternity records or measured by the research team. Overweight or obesity was defined by a body mass index ≥25 kg/m2. Gestational weight gain was evaluated according to the Institute of Medicine guidelines.

RESULTS

In the four cohorts, we evaluated 19 931 women. From 1982 to 2015, the prevalence of overweight or obesity at the beginning of the pregnancy increased from 22.1% to 47.0% and height increased by an average of 5.2 cm, whereas gestational weight gain did not change. Socioeconomic status was positively associated with maternal height, and the difference between the poorest and the wealthiest decreased. Overweight or obesity was lower among those mothers in the extreme categories of family income.

CONCLUSIONS

Over the 33-year span, mothers were taller at the beginning of the pregnancy, but the prevalence of overweight or obesity more than doubled.

Association of breastfeeding, maternal anthropometry and body composition in women at 30 years of age

This study aimed at assessing the association of breastfeeding with maternal body mass index (BMI), waist circumference, fat mass index, fat free mass index, android/gynoid fat ratio and bone mineral density. In 1982, the maternity hospitals in Pelotas, Rio Grande do Sul State, Brazil, were daily visited and all live births were identified and examined. These subjects underwent follow-up for several times. At 30 years of age, the participants were interviewed and examined. Parous women provided information on parity and duration of breastfeeding. Multiple linear regression was used in the multivariate analysis, controlling for genomic ancestry, family income, schooling and smoking at 2004-2005. After controlling for confounding factors, breastfeeding was inversely associated with BMI and fat mass index, whereas breastfeeding per live birth was negatively associated with BMI, waist circumference and fat mass index. Women who had had a child in the last 5 years and had breastfed, showed lower BMI (β = -2.12, 95%CI: -4.2; -0.1), waist circumference (β = -4.46, 95%CI: -8.3; -0.6) and fat mass index (β = -1.79, 95%CI: -3.3; -0.3), whereas no association was observed among those whose last childbirth was > 5 years, but the p-value for the tests of interaction were > 0.05. Our findings suggest that breastfeeding is associated with lower BMI and other adiposity measures, mostly in the first years after delivery. Besides that, it has no negative impact on bone mineral density.

Associations of Mitochondrial and Nuclear Mitochondrial Variants and Genes with Seven Metabolic Traits

Mitochondria (MT), the major site of cellular energy production, are under dual genetic control by 37 mitochondrial DNA (mtDNA) genes and numerous nuclear genes (MT-nDNA). In the CHARGEmtDNA+ Consortium, we studied genetic associations of mtDNA and MT-nDNA associations with body mass index (BMI), waist-hip-ratio (WHR), glucose, insulin, HOMA-B, HOMA-IR, and HbA1c. This 45-cohort collaboration comprised 70,775 (insulin) to 170,202 (BMI) pan-ancestry individuals. Validation and imputation of mtDNA variants was followed by single-variant and gene-based association testing. We report two significant common variants, one in MT-ATP6 associated (p ≤ 5E-04) with WHR and one in the D-loop with glucose. Five rare variants in MT-ATP6, MT-ND5, and MT-ND6 associated with BMI, WHR, or insulin. Gene-based meta-analysis identified MT-ND3 associated with BMI (p ≤ 1E-03). We considered 2,282 MT-nDNA candidate gene associations compiled from online summary results for our traits (20 unique studies with 31 dataset consortia's genome-wide associations [GWASs]). Of these, 109 genes associated (p ≤ 1E-06) with at least 1 of our 7 traits. We assessed regulatory features of variants in the 109 genes, cis- and trans-gene expression regulation, and performed enrichment and protein-protein interactions analyses. Of the identified mtDNA and MT-nDNA genes, 79 associated with adipose measures, 49 with glucose/insulin, 13 with risk for type 2 diabetes, and 18 with cardiovascular disease, indicating for pleiotropic effects with health implications. Additionally, 21 genes related to cholesterol, suggesting additional important roles for the genes identified. Our results suggest that mtDNA and MT-nDNA genes and variants reported make important contributions to glucose and insulin metabolism, adipocyte regulation, diabetes, and cardiovascular disease.

Avaliação da atenção pré-natal ofertada às mulheres indígenas no Brasil: achados do Primeiro Inquérito Nacional de Saúde e Nutrição dos Povos Indígenas

Resumo: Este estudo avalia a atenção pré-natal de mulheres indígenas com idades entre 14-49 anos, com filhos menores de 60 meses no Brasil. O Primeiro Inquérito Nacional de Saúde e Nutrição dos Povos Indígenas avaliou 3.967 mulheres que atendiam a tais requisitos, sendo 41,3% da Região Norte; 21,2% do Centro-oeste; 22,2% do Nordeste; e 15% do Sul/Sudeste. O pré-natal foi ofertado a 3.437 (86,6%) delas. A Região Norte registrou a maior proporção de mulheres que não fizeram pré-natal. A cobertura alcançada foi de 90,4%, mas somente cerca de 30% iniciaram o pré-natal no 1º trimestre e apenas 60% das elegíveis foram vacinadas contra difteria e tétano. Somente 16% das gestantes indígenas realizaram 7 ou mais consultas de pré-natal. Ter acesso a pelo menos um cuidado clínico-obstétrico foi observado em cerca de 97% dos registros, exceto exame de mamas (63%). Foi baixa a solicitação de exames (glicemia 53,6%, urina 53%, hemograma 56,9%, citologia oncótica 12,9%, teste de sífilis 57,6%, sorologia para HIV 44,2%, hepatite B 53,6%, rubéola 21,4% e toxoplasmose 32,6%) e prescrição de sulfato ferroso (44,1%). No conjunto, a proporção de solicitações de exames laboratoriais preconizados não ultrapassou 53%. Os percentuais de realização das ações do pré-natal das indígenas são mais baixos que os encontrados para mulheres não indígenas no conjunto do território nacional, e até mesmo para as residentes em regiões de elevada vulnerabilidade social e baixa cobertura assistencial como a Amazônia Legal e o Nordeste. Os resultados reafirmam a persistência de desigualdades étnico-raciais que comprometem a saúde e o bem-estar de mães indígenas.

Adolescent parenthood associated with adverse socio-economic outcomes at age 30 years in women and men of the Pelotas, Brazil: 1982 Birth Cohort Study

OBJECTIVE

To investigate the potential long-term effects of adolescent parenthood on completed education and income.

DESIGN

Population-based birth cohort study.

SETTING

All live births in 1982, whose mothers lived in the urban area of Pelotas, southern Brazil.

SAMPLE

A total of 3701 participants: 1914 women and 1787 men at age 30 years.

METHODS

Questionnaires were completed by the mothers in the early phases of this study, and by the cohort members in adolescence and adulthood. Linear regression models and G-computation were used in the analyses.

MAIN OUTCOME MEASURES

Educational attainment and income at age 30 years.

RESULTS

In women, adolescent parenthood was associated with lower attained education compared with women without adolescent maternity: by -2.8 years [95% confidence interval (CI) -3.2 to -2.3] if their first birth was at age 16-19, and by -4.4 years (-5.5 to -3.3) at age 11-15. These effects were greater among women who had three or more children. Women with adolescent parenthood also had 49 or 33% lower income at age 30 if their first child was born when aged 16-19 or 11-15, respectively. In men, the adverse effect of adolescent parenthood on education appeared to be mediated by a higher number of children and there was no effect of adolescent paternity on income at age 30 years.

CONCLUSION

These findings suggest lasting socio-economic disadvantages of adolescent parenthood, with larger effects being apparent in women than in men.

TWEETABLE ABSTRACT

Adolescent parenthood has an adverse effect on educational attainment later in life, and on household income among women.

Obesity-induced hypoadiponectinaemia: the opposite influences of central and peripheral fat compartments

Background and Aims

The substantial reduction in adiponectin concentration among obese individuals seems to depend on fat distribution and is a marker of metabolic and adipose tissue dysfunction. We aimed to: (i) address whether abdominal fat from different compartments (visceral, deep subcutaneous abdominal and superficial subcutaneous abdominal) and gluteofemoral fat are independently associated with blood adiponectin concentration; and (ii) investigate whether abdominal (proxied by waist circumference) and gluteofemoral fat (proxied by hip circumference) accumulation causally determine blood adiponectin concentration.

Methods

To investigate the independent association of abdominal and gluteofemoral fat with adiponectin concentration, we used multivariable regression and data from 30-year-old adults from the 1982 Pelotas Birth Cohort (n = 2,743). To assess the causal role of abdominal and gluteofemoral fat accumulation on adiponectin concentration, we used Mendelian randomization and data from two consortia of genome-wide association studies-the GIANT (n > 210 000) and ADIPOGen consortia (n = 29 347).

Results

In the multivariable regression analysis, all abdominal fat depots were negatively associated with adiponectin concentration, specially visceral abdominal fat [men: β = -0.24 standard unit of log adiponectin per standard unit increase in abdominal fat; 95% confidence interval (CI) = -0.31, -0.18; P = 8*10-13; women: β = -0.31; 95% CI = -0.36, -0.25; P = 7*10-27), whereas gluteofemoral fat was positively associated with adiponectin concentration (men: β = 0.13 standard unit of log adiponectin per standard unit increase in gluteofemoral fat; 95% CI = 0.03, 0.22; P = 0.008; women: β = 0.24; 95% CI = 0.17, 0.31; P = 7*10-11). In the Mendelian randomization analysis, genetically-predicted waist circumference was inversely related to blood adiponectin concentration (β = -0.27 standard unit of log adiponectin per standard unit increase in waist circumference; 95% CI = -0.36, -0.19; P = 2*10-11), whereas genetically-predicted hip circumference was positively associated with blood adiponectin concentration (β = 0.17 standard unit of log adiponectin per standard unit increase in hip circumference; 95% CI = 0.11, 0.24; P = 1*10-7).

Conclusions

These results support the hypotheses that there is a complex interplay between body fat distribution and circulating adiponectin concentration, and that whereas obesity-induced hypoadiponectinaemia seems to be primarily attributed to abdominal fat accumulation, gluteofemoral fat accumulation is likely to exert a protective effect.

Comparative Models of Biological and Social Pathways to Predict Child Growth through Age 2 Years from Birth Cohorts in Brazil, India, the Philippines, and South Africa

Background

Early growth faltering accounts for one-third of child deaths, and adversely impacts the health and human capital of surviving children. Social as well as biological factors contribute to growth faltering, but their relative strength and interrelations in different contexts have not been fully described.

Objective

The aim of this study was to use structural equation modelling to explore social and biological multidetermination of child height at age 2 y in longitudinal data from 4 birth cohort studies in low- and middle-income countries.

Methods

We analyzed data from 13,824 participants in birth cohort studies in Brazil, India, the Philippines, and South Africa. We used exploratory structural equation models, with height-for-age at 24 mo as the outcome to derive factors, and path analysis to estimate relations among a wide set of social and biological variables common to the 4 sites.

Results

The prevalence of stunting at 24 mo ranged from 14.0% in Brazil to 67.7% in the Philippines. Maternal height and birthweight were strongly predictive of height-for-age at 24 mo in all 4 sites (all P values <0.001). Three social-environmental factors, which we characterized as "child circumstances," "family socioeconomic status," and "community facilities," were identified in all sites. Each social-environmental factor was also strongly predictive of height-for-age at 24 mo (all P values <0.001), with some relations partly mediated through birthweight. The biological pathways accounted for 59% of the total explained variance and the social-environmental pathways accounted for 41%. The resulting path coefficients were broadly similar across the 4 sites.

Conclusions

Early child growth faltering is determined by both biological and social factors. Maternal height, itself a marker of intergenerational deprivation, strongly influences child height at 2 y, including indirect effects through birthweight and social factors. However, concurrent social factors, many of which are modifiable, directly and indirectly contribute to child growth. This study highlights opportunities for interventions that address both biological and social determinants over the long and short term.

A Genome-Wide Association Study in Hispanics/Latinos Identifies Novel Signals for Lung Function. The Hispanic Community Health Study/Study of Latinos

RATIONALE

Lung function and chronic obstructive pulmonary disease (COPD) are heritable traits. Genome-wide association studies (GWAS) have identified numerous pulmonary function and COPD loci, primarily in cohorts of European ancestry.

OBJECTIVES

Perform a GWAS of COPD phenotypes in Hispanic/Latino populations to identify loci not previously detected in European populations.

METHODS

GWAS of lung function and COPD in Hispanic/Latino participants from a population-based cohort. We performed replication studies of novel loci in independent studies.

MEASUREMENTS AND MAIN RESULTS

Among 11,822 Hispanic/Latino participants, we identified eight novel signals; three replicated in independent populations of European Ancestry. A novel locus for FEV1 in ZSWIM7 (rs4791658; P = 4.99 × 10-9) replicated. A rare variant (minor allele frequency = 0.002) in HAL (rs145174011) was associated with FEV1/FVC (P = 9.59 × 10-9) in a region previously identified for COPD-related phenotypes; it remained significant in conditional analyses but did not replicate. Admixture mapping identified a novel region, with a variant in AGMO (rs41331850), associated with Amerindian ancestry and FEV1, which replicated. A novel locus for FEV1 identified among ever smokers (rs291231; P = 1.92 × 10-8) approached statistical significance for replication in admixed populations of African ancestry, and a novel SNP for COPD in PDZD2 (rs7709630; P = 1.56 × 10-8) regionally replicated. In addition, loci previously identified for lung function in European samples were associated in Hispanic/Latino participants in the Hispanic Community Health Study/Study of Latinos at the genome-wide significance level.

CONCLUSIONS

We identified novel signals for lung function and COPD in a Hispanic/Latino cohort. Including admixed populations when performing genetic studies may identify variants contributing to genetic etiologies of COPD.

Novel genetic associations for blood pressure identified via gene-alcohol interaction in up to 570K individuals across multiple ancestries

Heavy alcohol consumption is an established risk factor for hypertension; the mechanism by which alcohol consumption impact blood pressure (BP) regulation remains unknown. We hypothesized that a genome-wide association study accounting for gene-alcohol consumption interaction for BP might identify additional BP loci and contribute to the understanding of alcohol-related BP regulation. We conducted a large two-stage investigation incorporating joint testing of main genetic effects and single nucleotide variant (SNV)-alcohol consumption interactions. In Stage 1, genome-wide discovery meta-analyses in ≈131K individuals across several ancestry groups yielded 3,514 SNVs (245 loci) with suggestive evidence of association (P < 1.0 x 10-5). In Stage 2, these SNVs were tested for independent external replication in ≈440K individuals across multiple ancestries. We identified and replicated (at Bonferroni correction threshold) five novel BP loci (380 SNVs in 21 genes) and 49 previously reported BP loci (2,159 SNVs in 109 genes) in European ancestry, and in multi-ancestry meta-analyses (P < 5.0 x 10-8). For African ancestry samples, we detected 18 potentially novel BP loci (P < 5.0 x 10-8) in Stage 1 that warrant further replication. Additionally, correlated meta-analysis identified eight novel BP loci (11 genes). Several genes in these loci (e.g., PINX1, GATA4, BLK, FTO and GABBR2) have been previously reported to be associated with alcohol consumption. These findings provide insights into the role of alcohol consumption in the genetic architecture of hypertension.

EPIGEN-Brazil Initiative resources: a Latin American imputation panel and the Scientific Workflow

EPIGEN-Brazil is one of the largest Latin American initiatives at the interface of human genomics, public health, and computational biology. Here, we present two resources to address two challenges to the global dissemination of precision medicine and the development of the bioinformatics know-how to support it. To address the underrepresentation of non-European individuals in human genome diversity studies, we present the EPIGEN-5M+1KGP imputation panel—the fusion of the public 1000 Genomes Project (1KGP) Phase 3 imputation panel with haplotypes derived from the EPIGEN-5M data set (a product of the genotyping of 4.3 million SNPs in 265 admixed individuals from the EPIGEN-Brazil Initiative). When we imputed a target SNPs data set (6487 admixed individuals genotyped for 2.2 million SNPs from the EPIGEN-Brazil project) with the EPIGEN-5M+1KGP panel, we gained 140,452 more SNPs in total than when using the 1KGP Phase 3 panel alone and 788,873 additional high confidence SNPs (info score ≥ 0.8). Thus, the major effect of the inclusion of the EPIGEN-5M data set in this new imputation panel is not only to gain more SNPs but also to improve the quality of imputation. To address the lack of transparency and reproducibility of bioinformatics protocols, we present a conceptual Scientific Workflow in the form of a website that models the scientific process (by including publications, flowcharts, masterscripts, documents, and bioinformatics protocols), making it accessible and interactive. Its applicability is shown in the context of the development of our EPIGEN-5M+1KGP imputation panel. The Scientific Workflow also serves as a repository of bioinformatics resources.

Contributions of mean and shape of blood pressure distribution to worldwide trends and variations in raised blood pressure: a pooled analysis of 1018 population-based measurement studies with 88.6 million participants

BACKGROUND

Change in the prevalence of raised blood pressure could be due to both shifts in the entire distribution of blood pressure (representing the combined effects of public health interventions and secular trends) and changes in its high-blood-pressure tail (representing successful clinical interventions to control blood pressure in the hypertensive population). Our aim was to quantify the contributions of these two phenomena to the worldwide trends in the prevalence of raised blood pressure.

METHODS

We pooled 1018 population-based studies with blood pressure measurements on 88.6 million participants from 1985 to 2016. We first calculated mean systolic blood pressure (SBP), mean diastolic blood pressure (DBP) and prevalence of raised blood pressure by sex and 10-year age group from 20-29 years to 70-79 years in each study, taking into account complex survey design and survey sample weights, where relevant. We used a linear mixed effect model to quantify the association between (probit-transformed) prevalence of raised blood pressure and age-group- and sex-specific mean blood pressure. We calculated the contributions of change in mean SBP and DBP, and of change in the prevalence-mean association, to the change in prevalence of raised blood pressure.

RESULTS

In 2005-16, at the same level of population mean SBP and DBP, men and women in South Asia and in Central Asia, the Middle East and North Africa would have the highest prevalence of raised blood pressure, and men and women in the high-income Asia Pacific and high-income Western regions would have the lowest. In most region-sex-age groups where the prevalence of raised blood pressure declined, one half or more of the decline was due to the decline in mean blood pressure. Where prevalence of raised blood pressure has increased, the change was entirely driven by increasing mean blood pressure, offset partly by the change in the prevalence-mean association.

CONCLUSIONS

Change in mean blood pressure is the main driver of the worldwide change in the prevalence of raised blood pressure, but change in the high-blood-pressure tail of the distribution has also contributed to the change in prevalence, especially in older age groups.

Impact of stressful life events on central adiposity in the Pelotas Birth Cohort

OBJECTIVE:

To investigate how stressful life events and social support relate to central adiposity in Southern Brazil.

METHODS:

Data included information from 802 participants in the 1982 Pelotas Birth Cohort that was collect in 2004-2005 and 2006. Stratifying by sex, we studied self-reported stressful life events during the year before 2004-2005 in relation to change in waist circumference between 2004-2005 and 2006 and waist-to-hip ratio in 2006, using both bivariate and multivariate linear regression models.

RESULTS:

In adjusted models, the experience of stressful life events during the year before 2004-2005 predicted a change in waist circumference in 2006 in men and a change in both waist-to-hip ratio in 2006 and waist circumference between 2004-2005 and 2006 in women. Men who experienced two or more stressful events had on average a one centimeter increase in their waist circumference between 2004-2005 and 2006 (β = 0.97, 95%CI 0.02-1.92), compared to those reporting no stressful events. For women, those who had one and those who had two or more stressful life events had over a 1 cm increase in their waist circumference from 2004-2005 to 2006 (β = 1.37, 95%CI 0.17-2.54; β = 1.26, 95%CI 0.11-2.40, respectively), compared to those who did not experience any stressful event. For both sexes, social support level was not significantly related to either waist-to-hip ratio or change in waist circumference, and it did not modify the association between stress and central adiposity.

CONCLUSIONS:

The experience of more than one stressful life event was associated with distinct indicators of central adiposity for men versus women.

Breastfeeding and neurodevelopmental outcomes

PURPOSE OF REVIEW

Breastfeeding has clear short-term benefits for child survival. Concerning its long-term consequences, it has been reported that subjects who had been breastfed would have a better performance in intelligence tests. In this review, we perused the recently published studies on the association of breastfeeding with developmental outcomes.

RECENT FINDINGS

A meta-analysis published in 2015 reported that intelligence quotient (IQ) was 3.44 points (95% confidence interval: 2.30; 4.58) higher among subjects who had been breastfed, and this association was observed even among those studies that controlled for maternal IQ. In the present review, we identified two studies that reported that duration of breastfeeding was positively associated with IQ in childhood, whereas another study reported that cognitive score at 67.9 years of age was higher among those subjects who had been breastfed for at least 6 months. Furthermore, two studies reported that the small gain in IQ was associated with higher school achievement and income in adulthood. Concerning the possible mechanisms for the effect of breastfeeding on development, children who had been breastfed showed greater gray matter volume in the left and right parietal and left temporal lobes and more activation in the right frontal and temporal lobes for perception tasks, whereas for the language task, the activation was higher in the left temporal lobe. Moreover, it has been reported that subcortical gray matter volume mediated the association between breastfeeding and IQ.

SUMMARY

The new studies identified in the review reinforce the evidence that breastfeeding has long-term consequences on performance in intelligence tests. In addition, this association between breastfeeding and development has long-term consequences on human capital, increasing earning ability.

Genetic structure of pharmacogenetic biomarkers in Brazil inferred from a systematic review and population-based cohorts: a RIBEF/EPIGEN-Brazil initiative

We present allele frequencies involving 39 pharmacogenetic biomarkers studied in Brazil, and their distribution on self-reported race/color categories that: (1) involve a mix of perceptions about ancestry, morphological traits, and cultural/identity issues, being social constructs pervasively used in Brazilian society and medical studies; (2) are associated with disparities in access to health services, as well as in their representation in genetic studies, and (3), as we report here, explain a larger portion of the variance of pharmaco-allele frequencies than geography. We integrated a systematic review of studies on healthy volunteers (years 1968-2017) and the analysis of allele frequencies on three population-based cohorts from northeast, southeast, and south, the most populated regions of Brazil. Cross-validation of results from these both approaches suggest that, despite methodological heterogeneity of the 120 studies conducted on 51,747 healthy volunteers, allele frequencies estimates from systematic review are reliable. We report differences in allele frequencies between color categories that persist despite the homogenizing effect of >500 years of admixture. Among clinically relevant variants: CYP2C9*2 (null), CYP3A5*3 (defective), SLCO1B1-rs4149056(C), and VKORC1-rs9923231(A) are more frequent in Whites than in Blacks. Brazilian Native Americans show lower frequencies of CYP2C9*2, CYP2C19*17 (increased activity), and higher of SLCO1B1-rs4149056(C) than other Brazilian populations. We present the most current and informative database of pharmaco-allele frequencies in Brazilian healthy volunteers.

Effect of life-course family income trajectories on periodontitis: Birth cohort study

AIMS

To quantify the impact of life course income trajectories on periodontitis in adulthood.

MATERIALS AND METHODS

Data from the 1982 Pelotas Birth Cohort Study, Brazil, were used. Information on family income was collected at birth and ages 15, 19, 23 and 30 years. Group-based trajectory modelling was used to identify income trajectories. Periodontal measures were assessed through clinical examination at age 31. Log-Poisson regression models were used to estimate prevalence ratios (PRs) of any and moderate/severe periodontitis, as outcomes.

RESULTS

Prevalence of any periodontitis and moderate/severe periodontitis was 37.3% and 14.3% (n = 539). Income trajectories were associated with prevalence of moderate/severe periodontitis. Adjusted PR in participants in low and variable income trajectory was 2.1 times higher than in participants in stable high-income trajectory. The unadjusted association between income trajectories and prevalence of any periodontitis was explained by the inclusion of behavioural and clinical variables in the model.

CONCLUSIONS

Low and variable life course income increased the prevalence of moderate/severe periodontitis at age 31 years. The findings may inform programmes in identifying and targeting potentially at-risk groups during the life course to prevent periodontitis.

Is there a causal effect of parity on body composition: a birth cohort study

BACKGROUND

Non-communicable diseases are the leading cause of death, worldwide. Obesity is one of the factors that is associated with the development of such diseases. The role of reproductive factors on women body composition has been evaluated, but the findings are controversial. This study was aimed at assessing the association of parity with body composition among women.

METHODS

In 1982, the maternity hospital of Pelotas, a southern Brazilian city, were visited daily and all deliveries were identified. Those livebirths whose family lived in the urban area of the city have been prospectively followed (n = 5914). In 2012-13, we tried to follow the whole cohort, the subjects were interviewed and examined. We evaluated the association of parity with the following body composition variables: body mass index, waist circumference and fat mass %. Estimates were adjusted for family income, skin color, maternal schooling, occupational status, alcohol, smoking, physical activity, and consumption of processed and ultraprocessed foods. All these analyses were replicated among the cohort men as a comparison. We also assessed whether duration of breastfeeding moderated the association.

RESULTS

In the 2012-13 visit, 3701 subjects were evaluated (mean age of 30.2 years). In the present analysis, we included 1620 women and 1653 men. 33% of women were nulliparous and 48% of men were without children. Even after controlling for confounding, parous women had a BMI 0.96 kg/m² (95% CI: 0.30; 1.62) higher than nulliparous and for men the regression coefficient was 0.79 kg/m² (95% CI: 0.29; 1.29). Waist circumference was also higher among parous women. Among men, the association was not linear and the regression coefficients were lower than that observed among women [3.41 cm (95% CI: -0.91; 7.73) among men and 4.83 cm (95% CI: 2.43; 7.24) among women with more than 3 children when compared with those without children], but this difference was not statistically significant (interaction p value = 0.58). Fat mass % was not associated with parity. Breastfeeding did not modify the association between parity and body composition.

CONCLUSIONS

Parity was positively associated with body mass index and waist circumference among women. However, similar results among men suggest that there is no causal effect of parity.

Life-Course Genome-wide Association Study Meta-analysis of Total Body BMD and Assessment of Age-Specific Effects

Bone mineral density (BMD) assessed by DXA is used to evaluate bone health. In children, total body (TB) measurements are commonly used; in older individuals, BMD at the lumbar spine (LS) and femoral neck (FN) is used to diagnose osteoporosis. To date, genetic variants in more than 60 loci have been identified as associated with BMD. To investigate the genetic determinants of TB-BMD variation along the life course and test for age-specific effects, we performed a meta-analysis of 30 genome-wide association studies (GWASs) of TB-BMD including 66,628 individuals overall and divided across five age strata, each spanning 15 years. We identified variants associated with TB-BMD at 80 loci, of which 36 have not been previously identified; overall, they explain approximately 10% of the TB-BMD variance when combining all age groups and influence the risk of fracture. Pathway and enrichment analysis of the association signals showed clustering within gene sets implicated in the regulation of cell growth and SMAD proteins, overexpressed in the musculoskeletal system, and enriched in enhancer and promoter regions. These findings reveal TB-BMD as a relevant trait for genetic studies of osteoporosis, enabling the identification of variants and pathways influencing different bone compartments. Only variants in ESR1 and close proximity to RANKL showed a clear effect dependency on age. This most likely indicates that the majority of genetic variants identified influence BMD early in life and that their effect can be captured throughout the life course.

Social inequalities in mental disorders and substance misuse in young adults : A birth cohort study in Southern Brazil

PURPOSE

To investigate the association between mental disorders and substance misuse at 30 years of age with gender, socioeconomic position at birth, and family income trajectories.

METHODS

The 1982 Pelotas Birth Cohort was used; all 5914 children born alive at hospital were originally enrolled (99.2% of all city births). In 2012, 3701 subjects were located and interviewed (68% retention rate). Mental disorders and substance misuse were assessed, and their prevalence analysed according to gender, socioeconomic status at birth, and four different income trajectories: always poor, never poor, poor at birth/non-poor at age 30, and non-poor at birth/poor at age 30.

RESULTS

While women presented higher prevalence of mental disorders, substance misuse was much more frequent among men. Individuals in the lowest income quintile at birth presented 2-5 times more mental disorders and substance misuse than those in the highest quintile. Young adults who were always poor or were not poor at birth but were poor at 30 years of age had a higher prevalence of mental disorders than the other groups.

CONCLUSIONS

The high rates of mental disorders and lifetime suicide attempts in young adults, especially those who were always poor or became poor after childhood, suggest that recent socioeconomic-related stressful situations may have a higher impact on the current mental health than events earlier in life. However, we could not identify at what specific ages socioeconomic changes were more important.

Worldwide trends in body-mass index, underweight, overweight, and obesity from 1975 to 2016: a pooled analysis of 2416 population-based measurement studies in 128·9 million children, adolescents, and adults

BACKGROUND

Underweight, overweight, and obesity in childhood and adolescence are associated with adverse health consequences throughout the life-course. Our aim was to estimate worldwide trends in mean body-mass index (BMI) and a comprehensive set of BMI categories that cover underweight to obesity in children and adolescents, and to compare trends with those of adults.

METHODS

We pooled 2416 population-based studies with measurements of height and weight on 128·9 million participants aged 5 years and older, including 31·5 million aged 5-19 years. We used a Bayesian hierarchical model to estimate trends from 1975 to 2016 in 200 countries for mean BMI and for prevalence of BMI in the following categories for children and adolescents aged 5-19 years: more than 2 SD below the median of the WHO growth reference for children and adolescents (referred to as moderate and severe underweight hereafter), 2 SD to more than 1 SD below the median (mild underweight), 1 SD below the median to 1 SD above the median (healthy weight), more than 1 SD to 2 SD above the median (overweight but not obese), and more than 2 SD above the median (obesity).

FINDINGS

Regional change in age-standardised mean BMI in girls from 1975 to 2016 ranged from virtually no change (-0·01 kg/m2 per decade; 95% credible interval -0·42 to 0·39, posterior probability [PP] of the observed decrease being a true decrease=0·5098) in eastern Europe to an increase of 1·00 kg/m2 per decade (0·69-1·35, PP>0·9999) in central Latin America and an increase of 0·95 kg/m2 per decade (0·64-1·25, PP>0·9999) in Polynesia and Micronesia. The range for boys was from a non-significant increase of 0·09 kg/m2 per decade (-0·33 to 0·49, PP=0·6926) in eastern Europe to an increase of 0·77 kg/m2 per decade (0·50-1·06, PP>0·9999) in Polynesia and Micronesia. Trends in mean BMI have recently flattened in northwestern Europe and the high-income English-speaking and Asia-Pacific regions for both sexes, southwestern Europe for boys, and central and Andean Latin America for girls. By contrast, the rise in BMI has accelerated in east and south Asia for both sexes, and southeast Asia for boys. Global age-standardised prevalence of obesity increased from 0·7% (0·4-1·2) in 1975 to 5·6% (4·8-6·5) in 2016 in girls, and from 0·9% (0·5-1·3) in 1975 to 7·8% (6·7-9·1) in 2016 in boys; the prevalence of moderate and severe underweight decreased from 9·2% (6·0-12·9) in 1975 to 8·4% (6·8-10·1) in 2016 in girls and from 14·8% (10·4-19·5) in 1975 to 12·4% (10·3-14·5) in 2016 in boys. Prevalence of moderate and severe underweight was highest in India, at 22·7% (16·7-29·6) among girls and 30·7% (23·5-38·0) among boys. Prevalence of obesity was more than 30% in girls in Nauru, the Cook Islands, and Palau; and boys in the Cook Islands, Nauru, Palau, Niue, and American Samoa in 2016. Prevalence of obesity was about 20% or more in several countries in Polynesia and Micronesia, the Middle East and north Africa, the Caribbean, and the USA. In 2016, 75 (44-117) million girls and 117 (70-178) million boys worldwide were moderately or severely underweight. In the same year, 50 (24-89) million girls and 74 (39-125) million boys worldwide were obese.

INTERPRETATION

The rising trends in children's and adolescents' BMI have plateaued in many high-income countries, albeit at high levels, but have accelerated in parts of Asia, with trends no longer correlated with those of adults.

FUNDING

Wellcome Trust, AstraZeneca Young Health Programme.

Does objectively measured physical activity modify the association between early weight gain and fat mass in young adulthood?

Background

Substantial evidence suggests that weight gain in early life is associated with increased adiposity and other metabolic disorders later in life. It is, however, unknown whether physical activity (PA) may modify these associations. We aimed to examine whether objectively measured PA at 30 years modified the associations between conditional weight gain in infancy (0–2 y) and childhood (2–4 y) with fat mass index (FMI) and visceral abdominal fat measured at age 30 years.

Methods

Prospective birth cohort study in Pelotas, Brazil, including 1874 participants with weight data at birth, two and four years of age, and measures of FMI, visceral abdominal fat and PA at a mean age of 30.2 years. At age 30, time spent (min/day) in moderate-to-vigorous physical activity (MVPA) was measured objectively using a wrist-worn accelerometer worn for four to seven consecutive days.. Multiple linear regression analyses was performed to assess the associations between conditional weight gain and outcome variables at 30 years, adjusting for covariates. We examined whether PA modified the association between conditional weight gain and the outcomes of interest by introducing an interaction term (conditional weight gain × PA) in the models.

Results

Conditional weight gain in infancy and childhood were both positively associated with later FMI (infancy weight gain: β = 0.68, 95% CI: 0.48, 0.88; P < 0.001; childhood weight gain: β = 0.91, 95% CI: 0.70, 1.11; P < 0.001). A formal test for interaction suggested that MVPA at 30 years of age modified the association between childhood relative weight gain and later FMI (β = −0.006, 95% CI: -0.011, −0.001; P = 0.029), suggesting stronger associations between weight gain and FMI in those with lower levels of MVPA. Conditional weight gain in childhood was also positively associated with visceral abdominal fat (β = 0.24, 95% CI: 0.15, 0424, P < 0.001). There was no evidence for a modification of the latter association after adjustment for physical activity.

Conclusion

Conditional weight gain between 2 and 4 years of age is associated with increased FMI at age 30 years. However, higher levels of MVPA appear to attenuate this detrimental association.

Higher experience of caries and lower income trajectory influence the quality of restorations: A multilevel analysis in a birth cohort

OBJECTIVES

This study aimed to evaluate the quality of posterior restorations (amalgam or composite) placed in adults from a birth cohort and its association with clinical and socioeconomic determinants experienced during their life course.

METHODS

A representative sample (n=539) of all 5914 births occurring in Pelotas (Brazil) in 1982 was prospectively investigated. Quality of posterior restorations (satisfactory or unsatisfactory) was assessed at 31 yrs-old, using modified USPHS criteria. Trained and calibrated dentists performed clinical examination. Explanatory variables included demographic and socioeconomic, oral health and dental service utilization patterns during the life course. Tooth related variables (type of tooth, material, size of cavity) were also analyzed. Untreated caries and socioeconomic status were assessed by group-based trajectories analyses. Multilevel Regression models were used to determine factors associated with restoration outcomes.

RESULTS

In total 2123 restorations (53% composite) were evaluated of which 107 (5%) were assessed as failed. The main reasons for failure were tooth/restoration fracture (50.5%) and secondary caries (30.7%). Failures in posterior restorations showed a significant association with socioeconomic aspects (lower tertile of income at age 30 - prevalence ratio (PR) 2.21 [95% CI 1.19-4.09]), clinical variables (trajectory of higher untreated caries - PR 2.11 [95% CI 1.23-3.61]) and also with tooth-related factors (Restorations involving three or more surfaces - PR 5.51 [95% CI 3.30-9.19]) after adjustment for each other.

CONCLUSIONS

These findings suggest that, although tooth-related variables have an important role in restoration longevity, patient-related factors, such as socioeconomic variables and untreated caries are also associated with failure and should be taken into account when evaluating longevity of posterior restorations.

CLINICAL SIGNIFICANCE

This was the first study assessing long-term trajectory of untreated caries, showing an association between higher experience of caries during the life-course and unsatisfactory restorations. The findings suggest that individual related factors should be considered when planning treatment and in future research evaluating the longevity of dental restorations.

Genome-Wide Association Study of Blood Pressure Traits by Hispanic/Latino Background: the Hispanic Community Health Study/Study of Latinos

Hypertension prevalence varies between ethnic groups, possibly due to differences in genetic, environmental, and cultural determinants. Hispanic/Latino Americans are a diverse and understudied population. We performed a genome-wide association study (GWAS) of blood pressure (BP) traits in 12,278 participants from the Hispanics Community Health Study/Study of Latinos (HCHS/SOL). In the discovery phase we identified eight previously unreported BP loci. In the replication stage, we tested these loci in the 1982 Pelotas Birth Cohort Study of admixed Southern Brazilians, the COGENT-BP study of African descent, women of European descent from the Women Health Initiative (WHI), and a sample of European descent from the UK Biobank. No loci met the Bonferroni-adjusted level of statistical significance (0.0024). Two loci had marginal evidence of replication: rs78701042 (NGF) with diastolic BP (P = 0.008 in the 1982 Pelotas Birth Cohort Study), and rs7315692 (SLC5A8) with systolic BP (P = 0.007 in European ancestry replication). We investigated whether previously reported loci associated with BP in studies of European, African, and Asian ancestry generalize to Hispanics/Latinos. Overall, 26% of the known associations in studies of individuals of European and Chinese ancestries generalized, while only a single association previously discovered in a people of African descent generalized.

Short Stature Is Associated With Overweight but Not With High Energy Intake in Low-Income Quilombola Women

BACKGROUND

Population exposed to chronic undernutrition in early life seems to be more susceptible to obesity in adulthood due to the development of mechanisms that improve the efficiency of energy use. Therefore, these individuals have relatively reduced energy requirements (thrifty phenotype).

OBJECTIVE

To investigate, among women living on severe socioeconomic vulnerability, whether short stature, a marker for undernutrition in early life, is associated with excess body weight but not with a high energy intake.

METHODS

This cross-sectional study, carried out between July and November 2008, evaluated 1308 women from all (N = 39) Quilombola communities of Alagoas. Adequacy of energy intake was estimated by the ratio between energetic ingestion and the estimated energy requirement (EER).

RESULTS

The prevalence of short stature (≤ 154.8 cm) was 43.0% and 52.4% had excess body weight (body mass index ≥ 25 kg/m²), being that 33.1% were overweight and 19.3% obese. Excess body weight was higher among women with short stature (56.6% vs 49.2%; P = .008), even after adjusting for age, energy intake, and per capita income (prevalence ratio = 1.16; 95% confidence interval = 1.04; 1.28). The ratio of energy intake/EER was independent of women's stature.

CONCLUSION

Excess body weight among Quilombola women represents a serious health problem. Short stature was significantly associated with excess body weight but not with a high energy intake. "Thrifty phenotype" may be one of the plausible explanations for this finding.

Diet-Induced Overweight and Obesity and Periodontitis Risk: An Application of the Parametric G-Formula in the 1982 Pelotas Birth Cohort

We aimed to estimate hypothetical effects of habits (smoking, alcohol consumption, and fat and carbohydrates consumption) combined with diet-induced overweight/obesity on the risk of periodontitis. The risk of any periodontitis, moderate/severe periodontitis, and the combination of bleeding on probing (BOP) and clinical attachment loss (CAL) was estimated using the parametric g-formula in adults aged 31 years from the 1982 Pelotas Birth Cohort in Brazil. Individuals in this cohort have been followed since birth. Hypothetical conditions were set independently for each risk factor and in combination for the entire population. A total of 539 participants had oral examinations in 2013. The cumulative 31-year risk under no intervention was 33.3% for any periodontitis, 14.3%, for moderate/severe periodontitis, and 14.7%, for BOP and CAL. According to our statistical approach, diet-induced overweight/obesity increased the risk of all outcomes: 11% (overweight) and 22% (obesity) higher risk of periodontitis; 12% (overweight) and 27% (obesity) higher risk of moderate/severe periodontitis; 21% (overweight) and 57% (obesity) higher risk of CAL and BOP. When overweight/obesity was combined with other unhealthy habits, the risk was even greater. Our findings suggest that the combination of diet-induced obesity with other risk factors may increase the risk of periodontitis. Further research in the field is required to corroborate our study.

Caesarean section and adiposity at 6, 18 and 30 years of age: results from three Pelotas (Brazil) birth cohorts

Background

Association between caesarian section (C-section) and obesity is controversial and mostly based on body mass index (BMI), which has inherent limitations. Using direct estimates of body fat mass, we aimed to assess the association between C-section and adiposity using fat mass index and BMI z-score in three birth cohort studies from Pelotas, Brazil.

Methods

We measured weight, height and fat mass (using dual X-ray absorptiometry (DXA)) at ages 6, 18 and 30 years among participants in the 2004, 1993 and 1982 population-based Pelotas Birth Cohort Studies, respectively. We used multiple linear regression analysis to examine the crude and adjusted association between C-section and the body composition indicators. We also modelled height as an outcome to explore the presence of residual confounding.

Results

We observed that fat mass index and BMI z-score were strongly and positively associated with C-section in the crude analysis. However, when we adjusted for socioeconomic characteristics, maternal BMI, parity, age and smoking during pregnancy, effect estimates were attenuated towards the null, except for 30-year-old women. In those women from the 1982 cohort, C-section remained associated with fat mass index (β = 0.82; CI95% 0.32;1.32) and BMI z-score (β = 0.15; CI95% 0.03;0.28), even after adjusting for all potential confounders, suggesting an increase in fat mass index and BMI at 30 years among those born by C-section.

Conclusion

We found no consistent association of C-section with fat mass index measured by DXA and BMI z-score in individuals aged 6, 18 and 30 years, except for women in the latter group, which might be explained by residual confounding. Confounding by socioeconomic and maternal characteristics accounted for all the other associations.