First-Borns Carry a Higher Metabolic Risk in Early Adulthood: Evidence from a Prospective Cohort Study

Background: Birth order has been associated with early growth variability and subsequent increased adiposity, but the consequent effects of increased fat mass on metabolic risk during adulthood have not been assessed. We aimed to quantify the metabolic risk in young adulthood of being first-born relative to those born second or subsequently.Methodology and Principal Findings: Body composition and metabolic risk were assessed in 2,249 men, aged 17-19 years, from a birth cohort in southern Brazil. Metabolic risk was assessed using a composite z-score integrating standardized measurements of blood pressure, total cholesterol, high density lipoprotein, triglycerides and fat mass. First-borns had lower birth weight z-score (Delta = -0.25, 95%CI -0.35, -0.15, p<0.001) but showed greater weight gain during infancy (change in weight z-score from birth to 20 months: Delta = 0.39, 95%CI 0.28-0.50, P<0.0001) and had greater mean height (Delta = 1.2 cm, 95%CI: 0.7-1.6, p<0.0001) and weight (Delta = 0.34 kg, 95%CI: 0.13-0.55, p<0.002) at 43 months. This greater weight and height tracked into early adulthood, with first-borns being significantly taller, heavier and with significantly higher fat mass than later-borns. The metabolic risk z-score was significantly higher in first-borns.Conclusions/Significance: First-born status is associated with significantly elevated adiposity and metabolic risk in young adult men in Brazil. Our results, linking cardiovascular risk with life history variables, suggest that metabolic risk may be associated with the worldwide trend to smaller family size and it may interact with changes in behavioural or environmental risk factors

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

UNLABELLED: 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.Authors also acknowledge the MRC Epidemiology PA Programme for assisting with analyses and support of activity monitors funding bodies Medical Research Council and Research Council of Norway

Late weaning and maternal closeness, associated with advanced motor and visual maturation, reinforce autonomy in healthy, 2-year-old children.

We studied neurodevelopmental outcomes and behaviours in healthy 2-year old children (N = 1306) from Brazil, India, Italy, Kenya and the UK participating in the INTERGROWTH-21st Project. There was a positive independent relationship of duration of exclusive breastfeeding (EBF) and age at weaning with gross motor development, vision and autonomic physical activities, most evident if children were exclusively breastfed for ≥7 months or weaned at ≥7 months. There was no association with cognition, language or behaviour. Children exclusively breastfed from birth to 6 months had, in a dose-effect pattern, adjusting for confounding factors, higher scores for "emotional reactivity". The positive effect of EBF and age at weaning on gross motor, running and climbing scores was strongest among children with the highest scores in maternal closeness proxy indicators. EBF, late weaning and maternal closeness, associated with advanced motor and vision maturation, independently influence autonomous behaviours in healthy children

Role of Adiponectin in Coronary Heart Disease Risk: A Mendelian Randomization Study

RATIONALE: Hypoadiponectinemia correlates with several coronary heart disease (CHD) risk factors. However, it is unknown whether adiponectin is causally implicated in CHD pathogenesis. OBJECTIVE: We aimed to investigate the causal effect of adiponectin on CHD risk. METHODS AND RESULTS: We undertook a Mendelian randomization study using data from genome-wide association studies consortia. We used the ADIPOGen consortium to identify genetic variants that could be used as instrumental variables for the effect of adiponectin. Data on the association of these genetic variants with CHD risk were obtained from CARDIoGRAM (22 233 CHD cases and 64 762 controls of European ancestry) and from CARDIoGRAMplusC4D Metabochip (63 746 cases and 130 681 controls; ≈ 91% of European ancestry) consortia. Data on the association of genetic variants with adiponectin levels and with CHD were combined to estimate the influence of blood adiponectin on CHD risk. In the conservative approach (restricted to using variants within the adiponectin gene as instrumental variables), each 1 U increase in log blood adiponectin concentration was associated with an odds ratio for CHD of 0.83 (95% confidence interval, 0.68–1.01) in CARDIoGRAM and 0.97 (95% confidence interval, 0.84–1.12) in CARDIoGRAMplusC4D Metabochip. Findings from the liberal approach (including variants in any locus across the genome) indicated a protective effect of adiponectin that was attenuated to the null after adjustment for known CHD predictors. CONCLUSIONS: Overall, our findings do not support a causal role of adiponectin levels in CHD pathogenesis

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

$\textbf{Background and Aims:}$ 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. $\textbf{Methods:}$ 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). $\textbf{Results:}$ In the multivariable regression analysis, all abdominal fat depots were negatively associated with adiponectin concentration, specially visceral abdominal fat [men: $\beta$ = -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: $\beta$ = -0.31; 95% CI = -0.36, -0.25; $P$ = 7*10$^{-27}$), whereas gluteofemoral fat was positively associated with adiponectin concentration (men: $\beta$ = 0.13 standard unit of log adiponectin per standard unit increase in gluteofemoral fat; 95% CI = 0.03, 0.22; $P$ = 0.008; women: $\beta$ = 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 ($\beta$ = -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 ($\beta$ = 0.17 standard unit of log adiponectin per standard unit increase in hip circumference; 95% CI = 0.11, 0.24; $P$ = 1*10$^{-7}$). $\textbf{Conclusions:}$ 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.The study ‘Pelotas Birth Cohort, 1982’ is conducted by Postgraduate Program in Epidemiology at Universidade Federal de Pelotas with the collaboration of the Brazilian Public Health Association (ABRASCO). From 2004 to 2013, the Wellcome Trust supported the 1982 birth cohort study. The International Development Research Center, World Health Organization, Overseas Development Administration, European Union, National Support Program for Centers of Excellence (PRONEX), the Brazilian National Research Council (CNPq) and the Brazilian Ministry of Health supported previous phases of the study. M.C.B. receives financial support from the Brazilian National Research Council (CNPq) [144749/2014-9, 201498/2014-6 (Science Without Borders Program), and 163291/2015-2] and Coordenac¸~ao de Aperfeic¸oamento de Pessoal de Nıvel Superior (CAPES). K.K.O. is supported by the Medical Research Council [Unit Programme numbers MC_UU_12015/1 and MC_UU_12015/2]

An exploration of the experiences of mothers who breastfeed long-term: What are the issues and why does it matter?

Background: The World Health Organization (WHO) promotes breastfeeding for 2 years and beyond. Despite this, only 25% of women in the United Kingdom are breastfeeding at all by 6 months postpartum, with a minority of women breastfeeding beyond the first year. Those who do often report feeling ridiculed or alienated in their choice. Here, the aim was to examine the experiences of women who chose to breastfeed longer term and to seek insight into the ways they felt breastfeeding could be normalized past infancy. Subjects and Methods: The study combined two qualitative datasets that explored maternal attitudes and experiences toward longer-term breastfeeding. In Study 1 a combination of methods was used, including interviews, to explore the challenges, attitudes, and experiences faced by women who had breastfed for over 6 months postpartum. In Study 2, 1,319 mothers who were pregnant or had an infant 0-2 years old completed an open-ended questionnaire exploring their attitudes toward longer-term breastfeeding. Results: Mothers who had experience of longer-term breastfeeding described how they faced negative attitudes and criticism from others, including the perceptions that longer-term breastfeeding was comical, bizarre, and pointless. Mothers discussed ways in which longer-term breastfeeding could be normalized rather than promoted, targeting health professionals and society instead of encouraging mothers themselves. Key ideas included greater visual representation, increasing knowledge and removing stigma. Conclusions: Longer-term breastfeeding needs to be normalized to increase acceptance and in turn reduce the negative attitudes that mothers often face despite following WHO guidance. Greater support is needed from health professionals and in health policy. © Mary Ann Liebert, Inc

The relationship between breastfeeding and weight status in a national sample of Australian children and adolescents

<p>Abstract</p> <p>Background</p> <p>Breastfeeding has been shown consistently in observational studies to be protective of overweight and obesity in later life. This study aimed to investigate the association between breastfeeding duration and weight status in a national sample of Australian children and adolescents.</p> <p>Methods</p> <p>A secondary analysis of the 2007 Australian National Children's Nutrition and Physical Activity Survey data involving 2066, males and females aged 9 to 16 years from all Australian states and territories. The effect of breastfeeding duration on weight status was estimated using multivariate logistic regression analysis.</p> <p>Results</p> <p>Compared to those who were never breastfed, children breastfed for ≥6 months were significantly less likely to be overweight (adjusted odds ratio: 0.64, 95%CI: 0.45, 0.91) or obese (adjusted odds ratio: 0.51, 95%CI: 0.29, 0.90) in later childhood, after adjustment for maternal characteristics (age, education and ethnicity) and children's age, gender, mean energy intake, level of moderate and vigorous physical activity, screen time and sleep duration.</p> <p>Conclusions</p> <p>Breastfeeding for 6 or more months appears to be protective against later overweight and obesity in this population of Australian children. The beneficial short-term health outcomes of breastfeeding for the infant are well recognised and this study provides further observational evidence of a potential long-term health outcome and additional justification for the continued support and promotion of breastfeeding to six months and beyond.</p