Early origins of socioeconomic inequalities in chronic inflammation: Evaluating the contributions of low birth weight and short breastfeeding

Disparities in birth outcomes within the U.S. White population: Prevalence of low birth weight among immigrant mothers from the Middle East and North Africa

Immigration from the Middle East and North Africa (MENA) has diversified the U.S. non-Hispanic White population. Analyzing health disparities within this group is a complex task due to data limitations across most federal and state data collection systems. This study investigates disparities in the risk of giving birth to a low-birth-weight infant among foreign-born non-Hispanic White MENA and non-MENA mothers and by MENA mothers' nationality. This population-based study uses Restricted-Use Detail Natality Data from 2016 to 2019 accessed through the National Center for Health Statistics and provided by the Centers for Disease Control and Prevention. The study examines the risk of giving birth to a low-birth-weight infant (<2500g) among foreign-born non-Hispanic White mothers by MENA/non-MENA status as the primary independent variable of interest. Logistic regression models are used to control for social and demographic characteristics, medical risk factors, and measures of prenatal care adequacy. Results are presented as odds ratios. Among foreign-born non-Hispanic White mothers, 139,708 (32%) are classified as MENA and 296,093 (68%) as non-MENA. Results show that after controlling for social and demographic characteristics, medical factors, and measures of prenatal care adequacy, foreign-born non-Hispanic White MENA mothers have greater odds of giving birth to a low-birth-weight infant than their non-MENA counterparts (OR: 1.443, p-value <0.001). Increased immigration from the MENA region has contributed to changes in health profiles among foreign-born non-Hispanic White mothers. As this group grows, understanding the impact of immigration on the composition of the non-Hispanic White population, and consequently, racial disparities in the U.S., is crucial for researchers and policymakers.

Separating Scarring Effect and Selection of Early-Life Exposures With Genetic Data

Causal life course research examining consequences of early-life exposures has largely relied on associations between early-life environments and later-life outcomes using exogenous environmental shocks. Nonetheless, even with (quasi-)randomized early-life exposures, these associations may reflect not only causation ("scarring") but also selection (i.e., which members are included in data assessing later life). Investigating this selection and its impacts on estimated effects of early-life conditions has, however, often been ignored because of a lack of pre-exposure data. This study proposes an approach for assessing and correcting selection, separately from scarring, using genetic measurements. Because genetic measurements are determined at the time of conception, any associations with early-life exposures should be interpreted as selection. Using data from the UK Biobank, we find that in utero exposure to a higher area-level infant mortality rate is associated with genetic predispositions correlated with better educational attainment and health. These findings point to the direction and magnitude of selection from this exposure. Corrections for this selection in examinations of effects of exposure on later educational attainment suggest underestimates of 26-74%; effects on other life course outcomes also vary across selection correction methods.

Best for Whom? Heterogeneous Treatment Effects of Breastfeeding on Child Development

The slogan "Breast is Best" has been popularized by medical organizations and parenting networks to extoll the benefits of breastfeeding, yet the causal effects are widely debated. Our study contributes to the debate by examining whether breastfeeding has differential effects based on the propensity to breastfeed, which is also known as causal effect heterogeneity. Prior studies attempt to isolate the causal effect of breastfeeding by netting out confounding characteristics, but we argue that the effects of breastmilk are unlikely to operate in a vacuum. The social forces that promote or constrain breastfeeding among different populations in American society can also shape its effects. Using rich intergenerational panel data from the NLSY79 Child and Young Adult cohort (n = 7902), we evaluate heterogeneous treatment effects in the relationship between breastfeeding and child development from ages 4 to 14 using stratification-multilevel propensity score models. We find that breastfeeding is associated with small benefits for behavioral development, math scores, and academic ability among those with the highest propensities to breastfeed. By contrast, its small benefits for reading comprehension and vocabulary are concentrated among children with the lowest propensities to breastfeed. Our findings suggest that the social process of selection into breastfeeding cannot be fully disentangled from its estimated effects. The social context not only shapes who breastfeeds in American society, but also who benefits most.

Rates of breastfeeding initiation and duration in the United States: data insights from the 2016-2019 Pregnancy Risk Assessment Monitoring System

Introduction

While breastfeeding rates in the United States have been increasing, they remain low by international standards with substantial racial, income and education disparities. This study uses recent population-based data to analyze sociodemographic differences in breastfeeding initiation, duration, and exposure to information and education.

Methods

We used the 2016-2019 Pregnancy Risk Assessment Monitoring System (PRAMS) to compare breastfeeding duration among a representative population from 43 states and the District of Columbia. We modeled the likelihood of never initiating breastfeeding by respondent's age, race and ethnicity, language, marital status, household income, educational attainment, parity and insurance status. We also compared sources of information and education for respondents who never breastfed to those who breastfed up to 6 months.

Results

Among 142,643 new mother respondents, representing an estimated population of 7,426,725 birthing individuals, 12.6% never breastfed, 60.4% reported breastfeeding at 3 months and 54.7% at 6 months. While 75.8% of college graduates reported breastfeeding at 3 months, this was only 37.8% of respondents with high school or less. Among those with the lowest six-month rates were non-Hispanic Black participants (36.3%) and those age < 20 (25.5%). Respondents with Medicaid coverage for their delivery were 25% more likely to have never breastfed than the privately insured. Respondents reporting household income <$20,000 were 57% more likely to have never breastfed as compared to those with household income>$85,000. While 64.1% of those breastfeeding at 6 months reported receiving information from "my" doctor', this was only 13.0% of those who never breastfeed.

Discussion

Improved breastfeeding rates could have significant effects on reducing health disparities in the United States. Clinical and public health policy initiatives need to include culturally sensitive breastfeeding education before and after childbirth, with psychological and direct support from obstetrics and primary care providers. Health plans should support home and community-based in-person and telelactation consulting services. Public policies such as paid family and medical leave and workplace accommodations will also be critical. Given the huge implications of breastfeeding rates on the development of infant immune defenses and a healthy microbiome, improving breastfeeding rates should be a much more important public health priority in the United States.

The association of state percent uninsured and the likelihood of low birth weight: evidence from the 2016-2019 Pregnancy Risk Assessment Monitoring System

OBJECTIVE

To evaluate the association of state-level lack of health insurance among women of reproductive age with variation in state low birth weight (LBW) rates.

STUDY DESIGN

This cross-section study analyzes data from the 2016-2019 Pregnancy Risk Assessment Monitoring Survey for respondents with singleton, live births.

METHODS

Respondents were divided into groups by state-level percent of uninsured women aged 19-44 years. Poisson regression was used to model the association between state percent uninsured and likelihood of LBW, controlling for individual sociodemographic and clinical risk factors. Sensitivity analyses were done for Medicaid and non-Hispanic Black subpopulations and alternative state characteristics, including Gini coefficients, total and public welfare expenditures, and state reproductive rights rankings.

RESULTS

In adjusted multiple regression analyses, compared to respondents from states with <7% uninsured, respondents from states with 7% or more uninsured had an increased risk of LBW status (7-8.99% uninsured: adjusted incidence rate ratio [aIRR] 1.11, 95% confidence interval [CI] 1.04-1.18; 9-11.99% uninsured: aIRR 1.09, 95% CI 1.02-1.17; >11.99% uninsured: aIRR 1.15, 95% CI 1.08-1.22). However, there was no evident dose-response gradient. Sensitivity analyses produced virtually identical findings for subpopulations, and no other state characteristics were significant.

CONCLUSION

States with the highest level of insurance coverage had a significantly lower LBW rate than other states. However, there was little evidence for greater odds of LBW with the highest levels of uninsured. Individual risk factors dominated LBW models, while state differences in income inequality, reproductive health policy, and per capita spending explained little of the variance in LBW.

Association between infectious exposures in infancy and epigenetic age acceleration in young adulthood in metropolitan Cebu, Philippines

OBJECTIVES

The drivers of human life expectancy gains over the past 200 years are not well-established, with a potential role for historical reductions in infectious disease. We investigate whether infectious exposures in infancy predict biological aging using DNA methylation-based markers that forecast patterns of morbidity and mortality later in life.

METHODS

N = 1450 participants from the Cebu Longitudinal Health and Nutrition Survey-a prospective birth cohort initiated in 1983-provided complete data for the analyses. Mean chronological age was 20.9 years when venous whole blood samples were drawn for DNA extraction and methylation analysis, with subsequent calculation of three epigenetic age markers: Horvath, GrimAge, and DunedinPACE. Unadjusted and adjusted least squares regression models were evaluated to test the hypothesis that infectious exposures in infancy are associated with epigenetic age.

RESULTS

Birth in the dry season, a proxy measure for increased infectious exposure in the first year of life, as well as the number of symptomatic infections in the first year of infancy, predicted lower epigenetic age. Infectious exposures were associated with the distribution of white blood cells in adulthood, which were also associated with measures of epigenetic age.

CONCLUSIONS

We document negative associations between measures of infectious exposure in infancy and DNA methylation-based measures of aging. Additional research, across a wider range of epidemiological settings, is needed to clarify the role of infectious disease in shaping immunophenotypes and trajectories of biological aging and human life expectancy.

Birth size and the serum level of biological age markers in men

Previous studies showed that intrauterine growth restrictions, resulting in smaller body size at birth, are associated with altered development and the risk of age-related diseases in adult life. Thus, prenatal development may predict aging trajectories in humans. The study aimed to verify if body size at birth is related to biological age in adult men. The study sample consisted of 159 healthy, non-smoking men with a mean age of 35.24 (SD 3.44) years. Birth weight and length were taken from medical records. The ponderal index at birth was calculated. Biological age was evaluated based on serum levels of s-Klotho, hsCRP, DHEA/S, and oxidative stress markers. Pregnancy age at birth, lifestyle, weight, cortisol, and testosterone levels were controlled. The results showed no relationship between birth size and s-Klotho, DHEA/S level, inflammation, or oxidative stress. Also, men born as small-for-gestational-age (N = 49) and men born as appropriate-for-gestational-age (N = 110) did not differ in terms of biological age markers levels. The results were similar when controlled for pregnancy week at birth, chronological age, BMI, testosterone, or cortisol level. The results suggest that there is no relationship between intrauterine growth and biomarkers of aging in men aged 30-45 years from the affluent population.

Modeling the Likelihood of Low Birth Weight: Findings from a Chicago-Area Health System

OBJECTIVE

This study presents a statistical model of the incidence of low birth weight (LBW) births in a large, Chicago-area hospital system. The study was undertaken to provide a strategic framework for future health system interventions.

METHODS

Administrative and electronic health records were matched to census Zip Code Tabulation Area (ZCTA) household poverty data for 42,681 births in 2016-2019 at seven system hospitals, serving a diverse patient population. A logistic regression model of LBW incidence was estimated to test the independent significance of maternal sociodemographic characteristics after controlling for clinical risk factors.

RESULTS

The incidence of LBW was 6.3% overall but 11.3% among non-Hispanic Black patients as compared to 5.1% among non-Hispanic White patients. LBW incidence ranged from 9.2% for patients from the poorest ZCTA (20% + poor households) compared to 5.6% of patients from the most affluent (< 5% poor) ZCTA. Nulliparous patients, patients with pre-existing chronic conditions, and patients with hypertensive disorders of pregnancy were significantly more likely to have LBW births. After controlling for clinical risk factors and poverty level, non-Hispanic Black patients were still over 80% more likely and to have a LBW birth.

DISCUSSION

Study findings reveal the joint effects of social and clinical risk factors. Findings profile our highest-risk populations for targeted interventions. Promising prenatal care redesign programs include pregnancy patient navigators, home and group visits, eHealth telemonitoring, improved mental health screening, and diversification of the maternity care workforce. Decreasing LBW births should be a national public health policy priority and will require major investments in the most impacted communities.

Effectiveness of a community-based support programme to reduce social inequality in exclusive breastfeeding: study protocol for a cluster-randomised trial

BACKGROUND

Breastmilk is the ideal nutrition for infants, and breastfeeding protects infants and mothers from a range of adverse health outcomes. In Denmark, most mothers initiate breastfeeding but many cease within the first months resulting in just 14% reaching the World Health Organization recommendation of six months of exclusive breastfeeding. Furthermore, the low breastfeeding proportion at six months is characterised by a marked social inequality. A previous intervention tested in a hospital setting succeeded in increasing the proportion of mothers breastfeeding exclusively at six months. However, most breastfeeding support is provided within the Danish municipality-based health visiting programme. Therefore, the intervention was adapted to fit the health visiting programme and implemented in 21 Danish municipalities. This article reports the study protocol, which will be used to evaluate the adapted intervention.

METHODS

The intervention is tested in a cluster-randomised trial at the municipal level. A comprehensive evaluation approach is taken. The effectiveness of the intervention will be evaluated using survey and register data. Primary outcomes are the proportion of women who breastfeed exclusively at four months postpartum and duration of exclusive breastfeeding measured as a continuous outcome. A process evaluation will be completed to evaluate the implementation of the intervention; a realist evaluation will provide an understanding of the mechanisms of change characterising the intervention. Finally, a health economic evaluation will assess the cost-effectiveness and cost-utility of this complex intervention.

DISCUSSION

This study protocol reports on the design and evaluation of the Breastfeeding Trial - a cluster-randomised trial implemented within the Danish Municipal Health Visiting Programme from April 2022 to October 2023. The purpose of the programme is to streamline breastfeeding support provided across healthcare sectors. The evaluation approach is comprehensive using a multitude of data to analyse the effect of the intervention and inform future efforts to improve breastfeeding for all.

TRIAL REGISTRATION

Prospectively registered with Clinical Trials NCT05311631 https://clinicaltrials.gov/ct2/show/NCT05311631.

Explaining Physical Health Disparities and Inequalities Over the First Half of the Life Course: An Integrative Review of Add Health Studies

This integrative review of research utilizing the National Longitudinal Study of Adolescent to Adult Health draws on previous research detailing pathways linking early socioeconomic adversity in childhood and adolescence (Wave 1 in 1995 and prior) to physical health outcomes in young adulthood (Wave 5 in 2015). Health outcomes considered included specific diseases, disease risk, and morbidity as prospectively measured by parent-reported and self-reported health outcomes as well as clinical biomarkers. A heuristic research framework was developed from the comprehensive review focused on 4 study designs and identifying total associations, physiological pathways, stress pathways, and resources pathways linking early socioeconomic adversity to physical health outcomes for young adults, as well as potential modifiers of these pathways. The appropriateness of different analytical strategies used in these research studies including approaches for analysis of change in health are discussed. Taken together, review findings suggest the merit of an integrated perspective taking a long view over early life course to explain cumulative physical health risk over the first half of the life course by assessing multiple pathways simultaneously. Looking forward, the review findings also emphasize the need for the investigation of the continuity and change in these pathways over the second half of the life course.

The reach of fertility decline: a longitudinal analysis of human capital gains across generations

The impact of fertility decline on economic development remains central to population studies. Recent scholarship emphasizes parental investment in education as a mediator. We further develop the theoretical foundation, and empirical evidence, for the role of child health—specifically how fertility changes promote children’s physical and cognitive development and thereby complement human capital accumulation through educational gains. We test this using a two-generation model applied to Indonesian longitudinal data from 1993 to 2015. Characteristics of modern fertility regimes—older maternal ages, longer interpregnancy intervals, and lower average birth orders—generally benefit offspring cognitive development and schooling. We estimate that family planning expansion, and the resulting shift in fertility traits, induced an average increase of 0.34 years of offspring educational attainment by age 18 years. Maximal maternal educational and family planning expansion would jointly produce a 1.12-year gain, including 0.20 years more directly attributable to fertility shifts. Evidence is strengthened in parallel simulations from models of within-mother shifts, in which fertility shifts resulted in a 0.16-year gain in offspring schooling. Findings contribute new evidence for the rounding effects of women’s education and family planning expansion on human capital formation through child health within families and across generations.

Breastfeeding, pregnancy, medicines, neurodevelopment, and population databases: the information desert

BACKGROUND

The pharmacoepidemiology of the long-term benefits and harms of medicines in pregnancy and breastfeeding has received little attention. The impact of maternal medicines on children is increasingly recognised as a source of avoidable harm. The focus of attention has expanded from congenital anomalies to include less visible, but equally important, outcomes, including cognition, neurodevelopmental disorders, educational performance, and childhood ill-health. Breastfeeding, whether as a source of medicine exposure, a mitigator of adverse effects or as an outcome, has been all but ignored in pharmacoepidemiology and pharmacovigilance: a significant 'blind spot'.

WHOLE-POPULATION DATA ON BREASTFEEDING

WHY WE NEED THEM: Optimal child development and maternal health necessitate breastfeeding, yet little information exists to guide families regarding the safety of medicine use during lactation. Breastfeeding initiation or success may be altered by medicine use, and breastfeeding may obscure the true relationship between medicine exposure during pregnancy and developmental outcomes. Absent or poorly standardised recording of breastfeeding in most population databases hampers analysis and understanding of the complex relationships between medicine, pregnancy, breastfeeding and infant and maternal health. The purpose of this paper is to present the arguments for breastfeeding to be included alongside medicine use and neurodevelopmental outcomes in whole-population database investigations of the harms and benefits of medicines during pregnancy, the puerperium and postnatal period. We review: 1) the current situation, 2) how these complexities might be accommodated in pharmacoepidemiological models, using antidepressants and antiepileptics as examples; 3) the challenges in obtaining comprehensive data.

CONCLUSIONS

The scarcity of whole-population data and the complexities of the inter-relationships between breastfeeding, medicines, co-exposures and infant outcomes are significant barriers to full characterisation of the benefits and harms of medicines during pregnancy and breastfeeding. This makes it difficult to answer the questions: 'is it safe to breastfeed whilst taking this medicine', and 'will this medicine interfere with breastfeeding and/ or infants' development'?

Associations of Circulating Insulin-Growth Factor-1 With Cognitive Functions and Quality of Life Domains in Ambulatory Young Adults With Cerebral Palsy: A Pilot Study

Objective

Adults with cerebral palsy (CP) often have impaired cognitive functions. CP also has deteriorations in multiple quality-of-life (QoL) domains. The bio-psycho-social health psychology model posits that biological factor interacts with social and psychological functions. However, the biological determinant of psycho-social and functional outcomes in CP has been scarcely examined. Circulating Insulin-like growth factor-1 (IGF-1) is associated with cognitive deficits in older adults, we thus aimed to examine the associations of circulating IGF-1 with: (1) objectively measured cognitive functions, (2) self-reported cognitive functions, and (3) QoL measures in adults diagnosed with CP.

Methods

Seventy-two adults with CP and varying degrees of cognitive functions were recruited from an accredited clinical motion analysis laboratory at a regional Children's Hospital. Circulating IGF-1 was measured using post-fasting serum. The Wechsler Adult Intelligence Scale (WAIS) tests were administered to assess multiple cognitive functions, whereas the Patient-Reported Outcomes Measurement Information System (PROMIS) was used to measure multiple domains of self-reported health, including cognitive complaints and eight QoL domains.

Results

Sixty-eight participants had complete data [mean age = 25 (SD = 5.3), female = 52.8%]. Controlling for covariates, circulating IGF-1 was associated with multiple cognitive domains, including positively with declarative memory and executive function and inversely with visual-spatial and motor skills, and processing speed, while no association with subjective memory complaint was detected. Circulating IGF-1 was also inversely associated with four QoL domains, including depressive symptoms, executive function, physical function, and social roles and activities.

Conclusions

In CP, circulating IGF-1 might be a useful biological determinant of objective cognitive functions and several quality-of-life domains commonly impaired in CP.

Racial Inequities in Birth Weight by Maternal Age Among College-Educated Mothers: The Role of Early Disadvantage

INTRODUCTION

Non-Hispanic Black infants experience disproportionately high risks of low birth weight compared with non-Hispanic White infants, particularly among mothers with high educational attainment and greater socioeconomic advantage. This study investigates how maternal early-life disadvantage contributes to ongoing racial birth weight inequities among U.S. college‒educated mothers, specifically declining birth weights with age among non-Hispanic Black mothers.

METHODS

Study analyses used cohort data from the National Longitudinal Study of Adolescent to Adult Health. Racial inequities in birth weight by maternal age and early-life disadvantage were assessed using completed reproductive histories among college-educated mothers at ages 33-44 years collected in 2016‒2018 and regression-based marginal standardization techniques. Early-life disadvantage was measured using a study-based composite measure of early-life concentrated poverty and social disadvantage in homes, neighborhoods, and schools, collected in previous waves. Primary analyses were completed in 2020‒2021.

RESULTS

Among non-Hispanic Black mothers who experienced high early-life disadvantage, a 1-year increase in maternal age at delivery was associated with lower birth weight by 26.07 g (95% CI= -48.74, -3.40). Similar declines were not found among non-Hispanic Black mothers with low early-life disadvantage. Non-Hispanic White mothers experienced increased birth weight with maternal age, 6.85 g (95% CI= -1.12, 14.82) per year, which did not significantly vary by early-life disadvantage.

CONCLUSIONS

Early-life disadvantage modifies whether and how college-educated mothers experience birth weight decline with older age. The effects of early-life contexts and embedded racial inequities on maternal health inequities and differential weathering warrant further public health attention.

Adverse Childhood Experiences among Reproductive Age Women: Findings from the 2019 Behavioral Risk Factor Surveillance System

INTRODUCTION

Adverse childhood experiences (ACEs) are associated with many negative health outcomes. Despite this well-documented association, most research on how health conditions affect women's preconception and perinatal health overlooks ACEs.

METHODS

This study analyzes self-reported ACE history and health outcomes among young adults (ages 18-39) using data from the 2019 Behavioral Risk Factor Surveillance System. Our aims were to 1) assess differences by gender in overall ACE scores and specific ACEs; 2) identify trends in women's ACE scores by birth cohort; and 3) estimate the association of ACE scores with health conditions that increase risk for adverse perinatal outcomes.

RESULTS

Findings include that women had higher overall ACE scores than men and that women were more likely to report experiencing seven of the eight ACEs queried. More than 23% of women respondents reported an ACE score of 4+, with a 3-percentage point difference between the youngest and oldest women in our sample. Compared with those reporting zero ACEs, women with four or more ACEs were almost four times as likely to report a history of depression and more than twice as likely to report fair or poor health, even after accounting for sociodemographic characteristics. Women with four or more ACEs were 62% more likely to have obesity, 41% more likely to report a hypertension diagnosis, and 36% more likely to report a diabetes diagnosis than those with zero ACEs.

CONCLUSIONS

ACEs are a root cause in the development of adverse health conditions in young women, and their prevention should be central to policies aimed at improving women and children's well-being.

Inequality and child health: dynamic population health interventions

PURPOSE OF REVIEW

Established social gradients across a wide range of child health issues including obesity, anxiety, infectious diseases, injuries, prematurity and low birth weight suggest that much illness is avoidable and there is an imperative to intervene in this whole of society issue. This review examines recent advances in understanding of the pathways to health and health inequalities and their application to interventions to improve health equity.

RECENT FINDINGS

Children's health develops over the life course in ways that are profoundly influenced by their entire developmental ecosystem including individual, family, community and system-level factors. Interventions to address child health inequalities must include action on the structural determinants of health, a greater focus on family and community health development, and attention to the acquisition of developmental capabilities. Nascent dynamic population health initiatives that address whole developmental ecosystems such as All Children Thrive, Better Start Bradford and Generation V, hold real promise for achieving child health equity.

SUMMARY

Pathways to health inequalities are driven by social and structural determinants of health. Interventions to address inequalities need to be driven less by older biomedical models, and more by prevailing ecological and complex systems models incorporating a life course health development approach.

Social connectedness as a mediator for horticultural therapy's biological effect on community-dwelling older adults: Secondary analyses of a randomized controlled trial

BACKGROUND

Elevated levels of inflammatory marker and a lack of social connectedness are two prominent risk factors for developing dementia and depression. Horticultural therapy (HT) has been shown to improve social connectedness and inflammatory markers. However, the underpinning mechanisms of HT remained unknown. Within this study, we hypothesized that improved social connectedness mediates the effects of HT on IL-6 levels.

METHODS

The present study is a secondary analysis of a randomized controlled trial investigating the bio-psycho-social effects of HT. Social connectedness was operationalized as positive relationships with others (PRWO), a sub-scale of the Ryff's scale of psychological well-being. IL-6 was quantified using a commercial ELISA kit. Outcomes were assessed at baseline, 3-month and 6-month post-intervention. Mediation analyses with bootstrapping were run to investigate our primary hypothesis. All analyses were controlled for covariates.

RESULTS

We recruited 59 participants (78% women; 67.10 ± 4.31 years). 29 participants partook in HT and 30 participants were included in the waitlist control group. At baseline, social connectedness was significantly correlated with IL-6 levels (β = -0.12, 95% CI = -0.21 to -0.03, p = 0.008). Furthermore, social connectedness at 3-month significantly mediated the effects of HT on IL-6 levels at 6-month (β = 0.32, 95% CI = 0.09 to 0.54, p = 0.005; β = -0.25, 95% CI = -0.45 to -0.05, p = 0.016).

CONCLUSIONS

These findings highlight the critical roles of social connectedness as a social determinant of health in eliciting HT's biological effects. When administering HT, interventionalists should consider social connectedness as a modifiable factor for ameliorating increased inflammation in older adults.

Body mass and the epidemic of chronic inflammation in early mid-adulthood

OBJECTIVES

Chronic inflammation is a potentially important mechanism through which social inequalities may contribute to health inequalities over the life course. Excess body fat contributes to chronic inflammation, and younger adults in the US have come of age during a pronounced secular increase in body mass index (BMI). We aim to document levels of chronic inflammation in a nationally representative sample of 33-to-44 year-old adults in the US, and to describe associations with BMI, race/ethnicity, and education.

METHODS

High sensitivity C-reactive protein (CRP) was measured in Wave V (2016-18) of the National Longitudinal Study of Adolescent to Adult Health, with complete data available for 4349 participants. Sex-stratified weighted regression models were implemented to investigate CRP in association with education, race/ethnicity, and BMI.

RESULTS

Geometric mean CRP was 1.9 mg/L, and 35.4% of the sample had CRP >3 mg/L. Females had significantly higher CRP than males. Body mass index was a strong positive predictor of CRP, and education level was negatively associated with CRP. Associations between education and CRP were substantially attenuated after adjusting for BMI. High risk CRP increased linearly with BMI even among the obese: 87.0 percent of females and 74.1 percent of males with class 3 obesity (BMI ≥40) were predicted to have high risk CRP > 3 mg/L.

CONCLUSIONS

The obesity epidemic is producing an epidemic of chronic inflammation in early mid-adulthood in the US. Strong associations between BMI and chronic inflammation portend high risk for future disease-and inequitable distribution of disease-as the cohort ages.

Testing the buffering hypothesis: Breastfeeding problems, cessation, and social support in the UK

OBJECTIVES

Physical breastfeeding problems can lead women to terminate breastfeeding earlier than planned. In high-income countries such as the UK, breastfeeding problems have been attributed to the cultural and individual "inexperience" of breastfeeding, ultimately leading to lower breastfeeding rates. Yet, cross-cultural evidence suggests breastfeeding problems still occur in contexts where breastfeeding is common, prolonged, and seen publicly. This suggests breastfeeding problems are not unusual and do not necessarily lead to breastfeeding cessation. As humans evolved to raise children cooperatively, what matters for breastfeeding continuation may be the availability of social support during the postnatal period. Here, we test the hypothesis that social support buffers mothers from the negative impact breastfeeding problems have on duration.

METHODS

We run Cox models on a sample of 565 UK mothers who completed a retrospective online survey about infant feeding and social support in 2017-2018.

RESULTS

Breastfeeding problems were important predictors of cessation; however, the direction of the effect was dependent on the problem type and type of support from a range of supporters. Helpful support for discomfort issues (blocked ducts, too much milk) was significantly associated with reduced hazards of cessation, as predicted. However, helpful support for reported milk insufficiency was assoicated with an increased hazard of cessation.

CONCLUSIONS

Experiencing breastfeeding problems is the norm, but its impact may be mitigated via social support. Working from an interdisciplinary approach, our results highlight that a wide range of supporters who provide different types of support have potential to influence maternal breastfeeding experience.