Lifecourse socioeconomic trajectories and C-reactive protein levels in young adults: findings from a Brazilian birth cohort

The association between inflammatory and immune system biomarkers and the dietary inflammatory index in patients with COVID-19

Background

Inflammation and cytokine storm have been reported to be the main cause of acute symptoms of coronavirus disease (COVID-19). Diet-induced inflammation may affect the condition of patients with COVID-19. Therefore, this study aimed to investigate the relationship between disease severity, inflammatory and immune system biomarkers, and the dietary inflammatory index (DII) in patients with COVID-19.

Methods

This cross-sectional study was conducted on 500 adult patients with COVID-19. Patients were divided into mild, moderate, and severe conditions based on clinical and laboratory evidence. A validated food frequency questionnaire (FFQ) was used to determine DII and energy-adjusted DII (E-DII) scores. The serum C-reactive protein (CRP) level and blood cell count were measured for all patients. Multiple linear regression was used to explore the association between DII and E-DII and CRP, blood cell counts, and hospitalization in patients with COVID-19.

Results

Coronavirus disease (COVID-19) patients with higher DII had higher consumption of fat and carbohydrate and lower intakes of protein, anti-inflammatory nutrients, garlic, caffeine, tea, onion, and fiber (P < 0.05). There was a positive association between DII and CRP (β = 1.024, P < 0.001), hospitalization (β = 1.062, P < 0.001), WBC count (β = 0.486, P < 0.009), neutrophil count (β = 0.565, P < 0.001), and neutrophil-to-lymphocyte ratio (β = 0.538, P < 0.001) and a negative association between DII and the lymphocyte count (β = −0.569, P < 0.001). There was a positive association between E-DII and hospitalization (β = 1.645, P < 0.001), WBC count (β = 0.417, P < 0.02), and neutrophil-to-lymphocyte ratio (β = 0.35, P < 0.03).

Conclusion

There is a positive correlation between DII and inflammation, immune hyperactivation, and length of hospital stay in patients with COVID-19. Further longitudinal studies are necessary.

The Long Arm of childhood hypothesis and systematic low-grade inflammation: Evidence from parental education of older European adults

Childhood SES has been extensively studied as a predictor for health outcomes in adulthood, though the direct mechanisms remain unclear. The Long Arm of Childhood Model hypothesizes that this process is a chain of events, moderated by numerous factors such as family economic status and environment, health behaviors, as well as biological processes. We expand on this model with objective measures of health in older age, namely C-reactive protein (CRP), as chronic low grade inflammation, which has been found to be connected to both childhood SES as well as a number of cardiovascular diseases in adulthood. Using life history data from SHARE, as well as a novel dried blood spot dataset, we explore the protective role of parent education on the blood level of C-reactive protein in adulthood. Estimating a stepwise linear regression model, we find evidence that years of parental education are negatively associated with CRP in adulthood, with a one-year increase in mother's (father's) years of education decreasing adult CRP by 1.8% (1.1%). Using a modified Sobel test, we measure both the direct and indirect effects, estimating the extent in which later-life mediators significantly alter the relationship between parental education and CRP. While father's education is completely mediated by individual factors such as respondent's education, employment, and health behavior - we observe a lasting association from mother's education, suggesting a direct link between mother's education and CRP in adulthood.

Racial/ethnic variations in inflammatory markers: exploring the role of sleep duration and sleep efficiency

Individuals from minoritized racial/ethnic groups have higher levels of circulating inflammatory markers. However, the mechanisms underlying these differences remain understudied. The objective of this study was to examine racial/ethnic variations in multiple markers of inflammation and whether impaired sleep contributes to these racial/ethnic differences. Nurses from two regional hospitals in Texas (n = 377; 71.62% White; 6.90% Black; 11.14% Hispanic, 10.34% Asian; mean age = 39.46; 91.78% female) completed seven days of sleep diaries and actigraphy to assess mean and variability in total sleep time (TST) and sleep efficiency (SE). On day 7, blood was drawn to assess 4 inflammatory markers: C-reactive protein (CRP), Interleukin-6 (IL-6), Interleukin-1 beta (IL-1β), and tumor necrosis factor-alpha (TNF-α). Results from regression models showed differences in inflammatory markers by race/ethnicity, adjusting for age and gender. The associations between sleep parameters and inflammatory markers also varied by race/ethnicity. Among White nurses, lower mean and greater variability in actigraphy-determined TST and greater variability in diary-determined TST were associated with higher levels of IL-6. Among Black nurses, lower mean diary-determined SE was associated with higher levels of IL-6 and IL-1β. Among Hispanic nurses, greater diary-determined mean TST was associated with higher CRP. Among Asian nurses, greater intraindividual variability in actigraphy-determined SE was associated with lower CRP. Among nurses, we did not find racial/ethnic disparities in levels of inflammation. However, analyses revealed differential relationships between sleep and inflammatory markers by race/ethnicity. Results highlight the importance of using a within-group approach to understand predictors of inflammatory markers.

Maternal serum C-reactive protein (CRP) and offspring attention deficit hyperactivity disorder (ADHD)

Exposure to infection and inflammation during the fetal period are associated with offspring neuropsychiatric disorders. Few previous studies have examined this association with ADHD with mixed findings. This study aims to examine the association between early gestational maternal C-reactive protein (CRP), prospectively assayed in stored maternal sera and the risk of ADHD in offspring. This study is based on the Finnish Prenatal studies of ADHD (FIPS-ADHD) with a nested case-control design. It includes all singleton-born children in Finland between January 1, 1998 and December 31, 1999 and diagnosed with ADHD. A total of 1079 cases and equal number of controls were matched on date of birth, sex and place of birth. Maternal CRP levels were assessed using a latex immunoassay from archived maternal serum specimens, collected during the first and early second trimester of pregnancy. Elevated maternal CRP when analyzed as a continuous variable was not associated with offspring ADHD (OR 1.05, 95% CI 0.96-1.15). No significant associations were seen in the highest quintile of CRP (OR 1.18, 95% CI 0.88-1.58). The results were similar in both sexes as well as among ADHD cases with or without comorbid ASD or conduct disorder. In this first study examining CRP, a biomarker for inflammation, during early pregnancy in relation to offspring ADHD, we report no significant associations. The lack of any association, when considered with positive findings seen in ASD and schizophrenia, and negative findings in bipolar disorder suggests different pathways linking maternal immune activation and development of various neuropsychiatric disorders.

Association of modifiable risk factors and IL-6, CRP, and adiponectin: Findings from the 1993 Birth Cohort, Southern Brazil

Background

The literature on the relationship between lifestyle behaviors and inflammatory markers is scarce.

Methods

A birth cohort was followed since birth up to 22 years in Southern Brazil. Interleukin-6 (IL-6), C-reactive protein (CRP) and adiponectin were measured in nonfasting blood samples drawn at 18 and 22 years of age. Exposures including smoking, alcohol intake, physical inactivity and obesity, were collected at 15, 18 and 22 years. Cross sectional analyses were based on the number of follow-up visits with these exposures and the association with IL-6, CRP and adiponectin at 22 years old. We also carried out a longitudinal Generalized Least Squares (GLS) random-effects analysis with outcomes at 18 and at 22 years old. All analyses were adjusted for several covariates.

Results

The sample comprised 3,479 cohort members at 22 years. The presence of obesity at ≥ 2 follow-ups showed the highest mean values (SE) for IL-6 [2.45 (1.05)] and CRP [3.74 (1.11)] and the lowest mean value for adiponectin [8.60 (0.37)] (adjusted analyses, females) compared with other exposures; the highest mean of IL-6 [1.65 (1.05)] and CRP [1.78 (1.11)] and the lowest mean of adiponectin [9.98 (0.38)] were for the number of follow-ups with ≥2 exposures compared to those with no exposures at any follow-up (adjusted analyses, females). The longitudinal analysis showed an increase in obesity associated with IL-6 and CRP in both sexes and an inverse association with adiponectin in females; smoking (in males) was associated with IL-6 and CRP, harmful alcohol intake was associated with CRP in males, and increased in physical activity was inversely associated with CRP in men.

Conclusion

We concluded that obesity is the main exposure positively associated with IL-6 and CRP and inversely associated with adiponectin (mainly in females). Smoking is also associated with these markers in the longitudinal analysis (in males).

Childhood socioeconomic status and inflammation: A systematic review and meta-analysis

Recent research suggests that risk for chronic diseases of aging including cardiovascular disease, diabetes, and even cancer can be programmed early in the lifespan as a result of exposure to chronic stressors like low socioeconomic status (SES) that are hypothesized to promote a pro-inflammatory response in immune cells that results in chronic, systemic inflammation. The present paper conducted a meta-analysis to establish whether exposure to low (versus higher) SES in childhood and adolescence is associated with higher levels of inflammation (as measured by C-reactive protein, IL-6, and fibrinogen) concurrently and in adulthood. We conducted meta-analyses with both unadjusted bivariate associations between SES and inflammation and with adjusted associations that controlled for a range of covariates including demographic factors, body mass index, smoking, physical activity and current SES. A systematic review of Pubmed and PsycINFO identified a total 35 studies (26 with unadjusted and 31 adjusted effect sizes) to be included in the meta-analysis. Random-effects meta-analysis showed that individuals who were exposed to low SES in childhood and adolescence had significantly higher levels of inflammatory markers (r = -0.07, p < .001, 95% CI = -0.09, -0.05). This association remained significant in adjusted analyses (r = -0.06, p < .001, 95% CI = -0.09, -0.03). However, the relationship between childhood SES and inflammation was non-significant in a meta-analysis with longitudinal studies that all controlled for adulthood SES (r = -0.03, p = .356, 95% CI = -0.08, 0.03). Future longitudinal research should utilize measurement of inflammatory markers at multiple time points to further examine the complex relationships between SES and health both in childhood and adulthood.

C-Peptide and cardiovascular risk factors among young adults in a southern Brazilian cohort

BACKGROUND

Proinsulin connecting peptide (C-Peptide) is a marker of the beta-cell function and has been considered a marker of insulin resistance whose evidence suggests were associated with cardiovascular mortality. Our study aims to evaluate the association of C-Peptide with metabolic cardiovascular risk factors among young adults followed since birth in southern Brazil.

METHODS

In 1982, maternity hospital in Pelotas, a southern Brazilian city, were visited daily and all births were identified. Live births whose family lived in the urban area of the city were identified, their mothers interviewed, and these subjects have been prospectively followed. Casual hyperglycemia patients were excluded from analysis. C-Peptide was assessed at 23 years, when transversely analyzed its association with cardiometabolic and hemodynamic risk factors, and longitudinally 30 years of age.

RESULTS

At age 23, 4297 individuals were evaluated, and C-Peptide was measured in 3.807. In a cross-sectional analysis at 23 years of age, C-Peptide was positively associated with waist circumference, body mass index, glycaemia, triglycerides, and C-reactive protein. The association with HDL cholesterol was negative. In the longitudinal analysis at 30 years, C-Peptide remained associated with BMI, waist circumference, glycated hemoglobin, triglycerides, and C-reactive protein, whereas the association was negative for HDL.

CONCLUSION

In the Pelotas birth cohort, the C-Peptide was associated with obesity indicators (waist circumference and BMI) cross-sectional (23 years) and longitudinal (30 years). We also observed cross-sectional and longitudinal associations of C-Peptide with cardiometabolic and inflammatory risk factors.

Sex-specific epigenetic mediators between early life social disadvantage and adulthood BMI

AIM

The objective of this study was to identify potential epigenetic mediating pathways linking early life social disadvantage (ELSD) to adulthood BMI.

METHODS

Sex-specific epigenome-wide two-stage mediation analyses were conducted in blood and adipose tissue, and mediation estimates were obtained using cross-product mediation analysis. Pathway analyses were conducted using GREAT software (Bejerano Lab, CA, USA).

RESULTS

Candidate mediation CpG sites were identified in adipose tissue, but not blood, and were sex-specific. Significant mediation sites in females included CpG loci in genes: PKHG1, BCAR3, ADAM5P, PIEZO1, FGFRL1, FASN and DPP9, among others. Pathway analyses revealed evidence of enrichment for processes associated with TFG-β signaling and immunologic signatures. In males, significant mediation loci included sites in MAP3K5 and RPTOR, which have previously been associated with adipogenesis, inflammation and insulin resistance.

CONCLUSION

Our findings provide supportive evidence for the mediating role of epigenetic mechanisms in the effect of early life social disadvantage on adulthood BMI.

Individual and Neighborhood Stressors, Air Pollution and Cardiovascular Disease

Psychosocial and environmental stress exposures across the life course have been shown to be relevant in the development of cardiovascular disease (CVD). Assessing more than one stressor from different domains (e.g., individual and neighborhood) and across the life course moves us towards a more integrated picture of how stress affects health and well-being. Furthermore, these individual and neighborhood psychosocial stressors act on biologic pathways, including immune function and inflammatory response, which are also impacted by ubiquitous environmental exposures such as air pollution. The objective of this study is to evaluate the interaction between psychosocial stressors, at both the individual and neighborhood level, and air pollution on CVD. This study used data from the 2009–2011 Behavioral Risk Factor Surveillance System (BRFSS) from Washington State. Adverse childhood experiences (ACEs) measured at the individual level, and neighborhood deprivation index (NDI) measured at the zip code level, were the psychosocial stressors of interest. Exposures to three air pollutants—particulate matter (both PM_2.5 and PM₁₀) and nitrogen dioxide (NO₂)—were also calculated at the zip code level. Outcome measures included several self-reported CVD-related health conditions. Both multiplicative and additive interaction quantified using the relative excess risk due to interaction (RERI), were evaluated. This study included 32,151 participants in 502 unique zip codes. Multiplicative and positive additive interactions were observed between ACEs and PM₁₀ for diabetes, in models adjusted for NDI. The prevalence of diabetes was 1.58 (95% CI: 1.40, 1.79) times higher among those with both high ACEs and high PM₁₀ compared to those with low ACEs and low PM₁₀ (p-value = 0.04 for interaction on the multiplicative scale). Interaction was also observed between neighborhood-level stressors (NDI) and air pollution (NO₂) for the stroke and diabetes outcomes on both multiplicative and additive scales. Modest interaction was observed between NDI and air pollution, supporting prior literature on the importance of neighborhood-level stressors in cardiovascular health and reinforcing the importance of NDI on air pollution health effects. ACEs may exert health effects through selection into disadvantaged neighborhoods and more work is needed to understand the accumulation of risk in multiple domains across the life course.

Prenatal and early postnatal stress and later life inflammation

BACKGROUND

Evidence suggests that maternal psychological and social stress during the prenatal period and in childhood represent an important condition that may adversely impact the anatomy and physiology of the developing child with implications for a number of health-related conditions and disorders. In a large prospective study, we aim to address if social stressors in the prenatal and early postnatal periods, as individual exposures as well as their accumulation, are associated with a range of inflammatory markers in late middle-aged offspring.

METHODS

The study sample includes Danish men and women born between 1959 and 1961 (n = 1206) who were members of the Copenhagen Perinatal Cohort and participated in the Copenhagen Aging and Midlife Biobank in 2009-2011 (age 49-52). Information on social stressors was collected through an interview with the mothers at the first antenatal visit and postnatal stressor data was collected at year one follow-up. A series of ordinary least square regression models were performed with the stress measures as the exposures and C-reactive protein (CRP), Interleukin-6 (IL-6), Interleukin-10 (IL-10), and Tumor necrosis factor α (TNF-α) separately as the outcomes.

RESULTS

The individual prenatal maternal stressors (being unmarried and having an unwanted pregnancy) and the prenatal index were associated with higher levels of CRP and IL-6 among offspring but not with IL-10 or TNF-α. Low social status, but not living away from parents or having an unmarried mother in the first year of life, was associated with higher levels of CRP and IL-6. The accumulation of social stressors in the early postnatal period was associated with higher levels of CRP and IL-6 but not IL-10 and TNF-α. The accumulation of stressors in the prenatal and postnatal periods combined was associated with higher levels of CRP and IL-6, but not with IL-10 or TNF-α.

CONCLUSIONS

The findings suggest that exposure to the accumulation of prenatal and early life stressors, is associated with higher levels of CRP and IL-6 in later life. This may indicate that the effects of early stressors on later inflammation operate through pathways with clear links to cardiovascular disease.

Socioeconomic status in childhood and C reactive protein in adulthood: a systematic review and meta-analysis

BACKGROUND

Inflammation plays a central role in cardiometabolic disease and may represent a mechanism linking low socioeconomic status (SES) in early life and adverse cardiometabolic health outcomes in later life. Accumulating evidence suggests an association between childhood SES and adult inflammation, but findings have been inconsistent.

METHODS

We conducted a systematic review and meta-analysis of observational studies to quantify the association between childhood (age <18 years) SES and the inflammatory marker C reactive protein (CRP) in adulthood. Studies were identified in Medline and Embase databases, and by reviewing the bibliographies of articles published from 1946 to December 2015. Study-specific estimates were combined into meta-analyses using random-effects models.

RESULTS

15 of 21 eligible studies (n=43 629) were ultimately included in two separate meta-analyses. Compared with those from the most advantaged families, participants from the least advantaged families had 25% higher CRP levels (ratio change in geometric mean CRP: 1.25; 95% CI 1.19 to 1.32) in minimally adjusted analyses. This finding was attenuated by the inclusion of adult body mass index (BMI) in adjusted models, suggesting BMI has a strong mediating role in CRP levels.

CONCLUSIONS

We observed an inverse association between childhood SES and adulthood CRP, potentially mediated through BMI. Investigating how childhood SES is associated with childhood BMI and CRP would provide insight into the effective timing of social and clinical interventions to prevent cardiometabolic disease.

Sex Differences in Associations Between Subjective Social Status and C-Reactive Protein in Young Adults

OBJECTIVE

In middle-aged and older samples, perceived subjective socioeconomic status (SSS) is a marker of social rank that is associated with elevated inflammation and cardiovascular disease risk independent of objective indicators of SES (oSES). Whether SSS is uniquely associated with elevated inflammation during young adulthood and whether these linkages differ by sex have not been studied using a nationally representative sample of young adults.

METHODS

Data came from the National Longitudinal Study of Adolescent to Adult Health. At Wave IV, young adults aged mostly 24 to 32 years reported their SSS, oSES, and a range of covariates of both SES and elevated inflammation. Trained fieldworkers assessed medication use, body mass index, and waist circumference, and also collected bloodspots from which high-sensitivity C-reactive protein (hs-CRP) was assayed. The sample size for the present analyses was n = 13,236.

RESULTS

Descriptive and bivariate analyses revealed a graded association between SSS and hs-CRP (b = -0.072, standard error [SE] = 0.011, p < .001): as SSS declined, mean levels of hs-CRP increased. When oSES indicators were taken into account, this association was no longer significant in women (b = -0.013, SE = 0.019, p = .514). In men, a small but significant SSS-hs-CRP association remained after adjusting for oSES indicators and additional potential confounders of this association in the final models (b = -0.034, SE = 0.011 p = .003; p < .001 for the sex by SSS interaction).

CONCLUSIONS

SSS is independently associated with elevated inflammation in young adults. The associations were stronger in men than in women. These data suggest that subjective, global assessments of social rank might play a role in developing adverse health outcomes.

Childhood Socioeconomic Circumstances, Inflammation, and Hemostasis Among Midlife Women: Study of Women's Health Across the Nation

BACKGROUND

Childhood socioeconomic status (SES) is related to risk for cardiovascular disease in adulthood, perhaps, in part, due to associations with inflammatory and hemostasis processes. We tested the hypotheses that childhood SES is related to C-reactive protein (CRP), fibrinogen, factor VIIc, and plasminogen activator inhibitor-1 (PAI-1) in midlife women and that the associations are mediated by adult SES and/or adult body mass index (BMI).

METHODS

Using data from the prospective Study of Women's Health Across the Nation, we classified 1067 black and white women into 3 multidimensional childhood SES groups based on latent class analysis. Biological measures were assessed across 7 years along with covariates and mediators and analyzed by mixed regression models, followed by tests for mediation.

RESULTS

Compared with women raised in high SES families, those from the lowest SES families had higher levels of CRP (b [standard error] = 0.37 [0.11]), PAI-1 (b = 0.23 [0.07]) factor VIIc (b = 0.05 [0.02]), and fibrinogen (b = 11.06 [4.89]), after adjustment for ethnicity, site, age, ratings of health between ages 11 and 18 years, visit, smoking status, menopausal status, stroke or heart attack, medications, and hormone use. Introduction of adult SES and BMI into the models reduced the childhood SES associations to nonsignificance for all four measures. Indirect mediation was apparent for adult education and BMI for CRP, and BMI for PAI-1.

CONCLUSIONS

Women raised in lower SES families had elevated markers of inflammation and hemostasis, in part, due to elevated BMI and education in adulthood.

Obesity Among Young Adults in Developing Countries: A Systematic Overview

This article discusses the overweight/obesity situation among young adults in developing countries. For this target population, obesity prevalence ranges from 2.3 to 12 %, and overweight is 28.8 %, mostly affecting females. Weight is now increasing during this life stage of transition at a higher rate, 1 kg/year, than in developed countries. Maternal factors and early childhood socioeconomic status are associated with BMI in young adults along with changing environmental and behavioural factors in some low and middle income countries, brought about by demographic and socioeconomic transitions. Young adults with 'normal weight' obesity need identification using other convenient low cost measures (skin folds or waist circumference) along with BMI. Obesity prevention or management interventions were not identified, but clearly needed to help stem the obesity pandemic. Young people generally give little priority to their future health, so such interventions need to be conducted at some optimal age, be innovative, country specific and culturally acceptable.

Gestational age and newborn size according to parental social mobility: an intergenerational cohort study

Background

We examined the associations between socioeconomic trajectories from birth to adulthood and gestational age and birth size in the next generation, using linked data from two population-based birth cohorts carried out in a Brazilian city. By comparing socioeconomic trajectories of mothers and fathers, we attempted to identify-specific effects of maternal and paternal socioeconomic trajectory on offspring birth weight, birth length, head circumference and gestational age at birth.

Methods

2 population-based birth cohort studies were carried out in 1982 and 2004 in Pelotas (Brazil); 156 mothers and 110 fathers from the earlier cohort had children in 2004. Gestational age and birth length, weight and head circumference were measured. Analyses were carried out separately for mothers and fathers. Mediation analyses assessed the role of birth weight and adult body mass index (BMI).

Results

Among mothers, but not for fathers, childhood poverty was strongly associated with smaller size in the next generation (about 400 g in weight and 1.5 cm in height) and shorter gestations (about 2 weeks). Adult poverty did not play a role. For mothers, the associations with gestational age, birth length and weight—but not with head circumference—persisted after adjusting for maternal birth weight and for the height and weight of the grandmother. Maternal birth weight did not mediate the observed associations, but high maternal BMI in adulthood was partly responsible for the association with gestational age.

Conclusions

Strong effects of early poverty on gestational age and birth size in the next generation were observed among mothers, but not among fathers. These findings suggest a specific maternal effect of socioeconomic trajectory, and in particular of early poverty on offspring size and duration of pregnancy.

Socioeconomic disparities in the health of african americans with rheumatoid arthritis from the southeastern United States

OBJECTIVE

To examine cross-sectional baseline data from the Consortium for the Longitudinal Evaluation of African Americans with Early Rheumatoid Arthritis registry for the association between socioeconomic status (SES) with clinical and self-report health outcomes.

METHODS

We analyzed data on 937 African Americans who provided comprehensive sociodemographic data in addition to self-reported health outcomes. SES measures included educational attainment, homeownership, household income, and occupation. Outcomes included measures of disease activity, joint damage, autoantibody status, and self-reported measures. Multivariable linear, logistic, and zero-inflated Poisson regression models were used to estimate associations of each SES measure with rheumatoid arthritis (RA) outcomes, controlling for sex, age, disease duration, comorbid conditions, body mass index, smoking, methotrexate/leflunomide use, and biologic agent use.

RESULTS

The mean age was 54 years, 86% were women, and the mean RA disease duration was 7.8 years. Approximately 24% had less than a high school degree, 56% had a nonprofessional occupation, 75% had a household income ≤$30,000, and 55% were nonhomeowners. In multivariable regression models, significantly increased associations of disease activity measures and self-reported health outcomes were observed with low household income (≤$30,000/year) and nonhomeownership. Education less than high school was primarily associated with self-reported health outcomes. Among participants with disease duration <2 years, associations of SES were confined to self-reported measures.

CONCLUSION

Our results indicate significant socioeconomic disparities in self-reported physical and mental health, clinical disease activity measures, and autoantibody status among African Americans with RA not explained by differences in demographics, medication use, and health behaviors.

Healthy Chilean Adolescents with HOMA-IR ≥ 2.6 Have Increased Cardiometabolic Risk: Association with Genetic, Biological, and Environmental Factors

OBJECTIVE

To determine the optimal cutoff of the homeostasis model assessment-insulin resistance (HOMA-IR) for diagnosis of the metabolic syndrome (MetS) in adolescents and examine whether insulin resistance (IR), determined by this method, was related to genetic, biological, and environmental factors.

METHODS

In 667 adolescents (16.8 ± 0.3 y), BMI, waist circumference, glucose, insulin, adiponectin, diet, and physical activity were measured. Fat and fat-free mass were assessed by dual-energy X-ray absorptiometry. Family history of type 2 diabetes (FHDM) was reported. We determined the optimal cutoff of HOMA-IR to diagnose MetS (IDF criteria) using ROC analysis. IR was defined as HOMA-IR values above the cutoff. We tested the influence of genetic, biological, and environmental factors on IR using logistic regression analyses.

RESULTS

Of the participants, 16% were obese and 9.4 % met criteria for MetS. The optimal cutoff for MetS diagnosis was a HOMA-IR value of 2.6. Based on this value, 16.3% of participants had IR. Adolescents with IR had a significantly higher prevalence of obesity, abdominal obesity, fasting hyperglycemia, and MetS compared to those who were not IR. FHDM, sarcopenia, obesity, and low adiponectin significantly increased the risk of IR.

CONCLUSIONS

In adolescents, HOMA-IR ≥ 2.6 was associated with greater cardiometabolic risk.

Life course socioeconomic position and C-reactive protein: mediating role of health-risk behaviors and metabolic alterations. The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

BACKGROUND

Chronic inflammation has been postulated to be one mediating mechanism explaining the association between low socioeconomic position (SEP) and cardiovascular disease (CVD). We sought to examine the association between life course SEP and C-reactive protein (CRP) levels in adulthood, and to evaluate the extent to which health-risk behaviors and metabolic alterations mediate this association. Additionally, we explored the possible modifying influence of gender.

METHODS AND FINDINGS

Our analytical sample comprised 13,371 participants from ELSA-Brasil baseline, a multicenter prospective cohort study of civil servants. SEP during childhood, young adulthood, and adulthood were considered. The potential mediators between life course SEP and CRP included clusters of health-risk behaviors (smoking, low leisure time physical activity, excessive alcohol consumption), and metabolic alterations (obesity, hypertension, low HDL, hypertriglyceridemia, and diabetes). Linear regression models were performed and structural equation modeling was used to evaluate mediation. Although lower childhood SEP was associated with higher levels of CRP in adult life, this association was not independent of adulthood SEP. However, CRP increased linearly with increasing number of unfavorable social circumstances during the life course (p trend <0.001). The metabolic alterations were the most important mediator between cumulative SEP and CRP. This mediation path accounted for 49.5% of the total effect of cumulative SEP on CRP among women, but only 20.2% among men. In consequence, the portion of the total effect of cumulative SEP on CRP that was mediated by risk behaviors and metabolic alterations was higher among women (55.4%) than among men (36.8%).

CONCLUSIONS

Cumulative SEP across life span was associated with elevated systemic inflammation in adulthood. Although health-risk behaviors and metabolic alterations were important mediators of this association, a sizable fraction of this association was not mediated by these factors, suggesting that other pathways might play a role, especially among men.

Multilevel examination of the association of urbanization with inflammation in Chinese adults

We examine the associations between overall urbanicity and specific physical and social components of community-level urbanization with C-reactive protein (CRP) in adults participating in the China Health and Nutrition Study. Higher overall urbanicity and environment-related urbanicity component scores, including education, housing quality, and access to markets, were associated with elevated CRP in multilevel models controlling for clustering by community. These associations differed by age and gender and persisted after controlling for individual-level anthropometric, diet, and pathogenic risk factors. These results highlight the importance of place in relation to inflammation across the spectrum of rural and urban environments.

Pathogenic and obesogenic factors associated with inflammation in Chinese children, adolescents and adults

OBJECTIVES

Influenced by pathogen exposure and obesity, inflammation provides a critical biological pathway linking changing environments to the development of cardiometabolic disease. This study tests the relative contribution of obesogenic and pathogenic factors to moderate and acute CRP elevations in Chinese children, adolescents and adults.

METHODS

Data come from 8795 participants in the China Health and Nutrition Study. Age-stratified multinomial logistic models were used to test the association between illness history, pathogenic exposures, adiposity, health behaviors and moderate (1-10 mg/L in children and 3-10 mg/L in adults) and acute (>10mg/L) CRP elevations, controlling for age, sex and clustering by household. Backward model selection was used to assess which pathogenic and obesogenic predictors remained independently associated with moderate and acute CRP levels when accounting for simultaneous exposures.

RESULTS

Overweight was the only significant independent risk factor for moderate inflammation in children (RRR 2.10, 95%CI 1.13-3.89). History of infectious (RRR 1.28, 95%CI 1.08-1.52) and non-communicable (RRR 1.37, 95%CI 1.12-1.69) disease, overweight (RRR 1.66, 95%CI 1.45-1.89) and high waist circumference (RRR 1.63, 95%CI 1.42-1.87) were independently associated with a greater likelihood of moderate inflammation in adults while history of infectious disease (RRR 1.87, 95%CI 1.35-2.56) and overweight (RRR 1.40, 95%CI 1.04-1.88) were independently associated with acute inflammation. Environmental pathogenicity was associated with a reduced likelihood of moderate inflammation, but a greater likelihood of acute inflammation in adults.

CONCLUSIONS

These results highlight the importance of both obesogenic and pathogenic factors in shaping inflammation risk in societies undergoing nutritional and epidemiological transitions.

Childhood adversity and inflammatory processes in youth: a prospective study

BACKGROUND

Retrospective studies show that childhood adversity is associated with systemic inflammation in adulthood. Few prospective studies have examined whether childhood adversity influences inflammation in an observable manner during childhood or adolescence and if these effects are sustained over time.

METHODS

Using longitudinal data from the Avon Longitudinal Study of Parents and Children, we examined associations between acute adverse events at seven time points prior to age 8 and inflammation at ages 10 and 15. Inflammatory markers at age 10 included interleukin-6 (IL-6; N=4655) and C-reactive protein (CRP; N=4647), and CRP was measured again at age 15 (N=3286). We further evaluated whether body mass index (BMI), depression, or cigarette smoking mediated associations between adverse events and inflammation.

RESULTS

Adverse events in middle childhood (occurring between ages 6 to 8), as well as cumulative adversity from birth to 8 years, were associated with higher levels of IL-6 and CRP at age 10. Adverse events reported in early childhood (1.5years) or middle childhood, and cumulative adversity from birth through 8years predicted increased levels of CRP at age 15, and these associations persisted after adjustment for CRP at age 10. Some, but not all, of these associations were mediated by BMI.

CONCLUSIONS

This study documents that exposure to adverse events prior to age 8 is associated with elevated inflammation at age 10 and in mid-adolescence. These findings provide prospective evidence for a biological mechanism by which early experiences may shape long-term health. Future studies with earlier assessments of inflammation are necessary in order to elucidate potential sensitive periods and mechanisms that link childhood adversity to later disease vulnerability.

Trends in mortality from septicaemia and pneumonia with economic development: an age-period-cohort analysis

Background

Hong Kong population has experienced drastic changes in its economic development in the 1940s. Taking advantage of Hong Kong’s unique demographic and socioeconomic history, characterized by massive, punctuated migration waves from Southern China, and recent, rapid transition from a pre-industrialized society to the first ethnic Chinese community reaching “first world” status over the last 60 years (i.e., in two or three generations), we examined the longitudinal trends in infection related mortality including septicemia compared to trends in non-bacterial pneumonia to generate hypotheses for further testing in other recently transitioned economies and to provide generalized aetiological insights on how economic transition affects infection-related mortality.

Methods

We used deaths from septicemia and pneumonia not specified as bacterial, and population figures in Hong Kong from 1976–2005. We fitted age-period-cohort models to decompose septicemia and non-bacterial pneumonia mortality rates into age, period and cohort effects.

Results

Septicaemia-related deaths increased exponentially with age, with a downturn by period. The birth cohort curves had downward inflections in both sexes in the 1940s, with a steeper deceleration for women. Non-bacterial pneumonia-related deaths also increased exponentially with age, but the birth cohort patterns showed no downturns for those born in the 1940s.

Conclusion

The observed changes appeared to suggest that better early life conditions may enable better development of adaptive immunity, thus enhancing immunity against bacterial infections, with greater benefits for women than men. Given the interaction between the immune system and the gonadotropic axis, these observations are compatible with the hypothesis that upregulation of the gonadotropic axis underlies some of the changes in disease patterns with economic development.

Life-course origins of social inequalities in adult immune cell markers of inflammation in a developing southern Chinese population: the Guangzhou Biobank Cohort Study

BACKGROUND

Socioeconomic position (SEP) throughout life is associated with cardiovascular disease, though the mechanisms linking these two are unclear. It is also unclear whether there are critical periods in the life course when exposure to better socioeconomic conditions confers advantages or whether SEP exposures accumulate across the whole life course. Inflammation may be a mechanism linking socioeconomic position (SEP) with cardiovascular disease. In a large sample of older residents of Guangzhou, in southern China, we examined the association of life course SEP with inflammation.

METHODS

In baseline data on 9,981 adults (≥ 50 years old) from the Guangzhou Biobank Cohort Study (2006-08), we used multivariable linear regression and model fit to assess the associations of life course SEP at four stages (childhood, early adult, late adult and current) with white blood, granulocyte and lymphocyte cell counts.

RESULTS

A model including SEP at all four life stages best explained the association of life course SEP with white blood and granulocyte cell count for men and women, with early adult SEP (education) making the largest contribution. A critical period model best explained the association of life course SEP with lymphocyte count, with sex-specific associations. Early adult SEP was negatively associated with lymphocytes for women.

CONCLUSIONS

Low SEP throughout life may negatively impact late adult immune-inflammatory status. However, some aspects of immune-inflammatory status may be sensitive to earlier exposures, with sex-specific associations. The findings were compatible with the hypothesis that in a developing population, upregulation of the gonadotropic axis with economic development may obscure the normally protective effects of social advantage for men.

Educational attainment but not measures of current socioeconomic circumstances are associated with leukocyte telomere length in healthy older men and women

Low socioeconomic status (SES) may be associated with accelerated biological aging, but findings relating SES with telomere length have been inconsistent. We tested the hypotheses that shorter telomere length and telomerase activity would be related more robustly to education, an early life indicator of socioeconomic position, than to current indicators of socioeconomic circumstances. Healthy men and women aged 53-76 years from the Whitehall II epidemiological cohort provided blood samples from which telomere length was assessed in 448 and telomerase activity in 416. Educational attainment was classified into four levels, while household income and grade of employment were measured as indicators of current socioeconomic circumstances. Age, gender, blood pressure, glycated hemoglobin, high density lipoprotein cholesterol, smoking, body mass index and physical activity were included as covariates. We found that lower educational attainment was associated with shorter telomere length after controlling statistically for biological and behavioral covariates. Neither household income nor employment grade was related to telomere length. The association between telomere length and education remained significant after adjusting for current socioeconomic circumstances. In men, highest levels of telomerase activity were found in the lowest education group. We conclude that low SES defined in terms of education but not current socioeconomic circumstances is associated with shortened telomeres. Low educational attainment may be an indicator of long-term SES trajectories, and be associated with accumulated allostatic load resulting in telomere shortening. Education may also promote problem-solving skills leading to reduced biological stress responsivity, with favorable consequences for biological aging.

Childhood meat eating and inflammatory markers: the Guangzhou Biobank Cohort Study

BACKGROUND

We hypothesized that socio-economic development could, via nutritionally driven levels of pubertal sex-steroids, promote a pro-inflammatory state among men but not women in developing countries. We tested this hypothesis, using recalled childhood meat eating as a proxy for childhood nutrition, in southern China.

METHODS

We used multivariable linear regression in the Guangzhou Biobank Cohort Study phase 3 (2006-8) to examine the adjusted associations of recalled childhood meat eating, <1/week (n = 5,023), about once per week (n = 3,592) and almost daily (n = 1,252), with white blood cell count and its differentials among older (≥ 50 years) men (n = 2,498) and women (n = 7,369).

RESULTS

Adjusted for age, childhood socio-economic position, education and smoking, childhood meat eating had sex-specific associations with white blood cell count and lymphocyte count, but not granulocyte count. Men with childhood meat eating almost daily compared to <1/week had higher white blood cell count (0.33 109/L, 95% confidence interval (CI) 0.10 to 0.56) and higher lymphocyte count (0.16 109/L, 95% CI 0.07 to 0.25). Adjustment for obesity slightly attenuated these associations.

CONCLUSION

If confirmed, this hypothesis implies that economic development and the associated improvements in nutrition at puberty may be less beneficial among men than women; consistent with the widening sex differentials in life expectancy with economic development.

Early life socioeconomic adversity is associated in adult life with chronic inflammation, carotid atherosclerosis, poorer lung function and decreased cognitive performance: a cross-sectional, population-based study

BACKGROUND

Socioeconomic gradients in health persist despite public health campaigns and improvements in healthcare. The Psychosocial and Biological Determinants of Ill-health (pSoBid) study was designed to uncover novel biomarkers of chronic disease that may help explain pathways between socioeconomic adversity and poorer physical and mental health.

METHODS

We examined links between indicators of early life adversity, possible intermediary phenotypes, and markers of ill health in adult subjects (n = 666) recruited from affluent and deprived areas. Classical and novel risk factors for chronic disease (lung function and atherosclerosis) and for cognitive performance were assessed, and associations sought with early life variables including conditions in the parental home, family size and leg length.

RESULTS

Associations were observed between father's occupation, childhood home status (owner-occupier; overcrowding) and biomarkers of chronic inflammation and endothelial activation in adults (C reactive protein, interleukin 6, intercellular adhesion molecule; P < 0.0001) but not number of siblings and leg length. Lung function (forced expiratory volume in 1 second) and cognition (Choice Reaction Time, the Stroop test, Auditory Verbal Learning Test) were likewise related to early life conditions (P < 0.001). In multivariate models inclusion of inflammatory variables reduced the impact and independence of early life conditions on lung function and measures of cognitive ability. Including variables of adult socioeconomic status attenuated the early life associations with disease biomarkers.

CONCLUSIONS

Adverse levels of biomarkers of ill health in adults appear to be influenced by father's occupation and childhood home conditions. Chronic inflammation and endothelial activation may in part act as intermediary phenotypes in this complex relationship. Reducing the 'health divide' requires that these life course determinants are taken into account.

High-sensitivity C-reactive protein concentrations among patients with and without diabetes in a multiethnic population of Singapore: CREDENCE Study

OBJECTIVES

To determine whether high-sensitivity C-reactive protein (hs-CRP) concentrations differ between Chinese, Malays, and Indians with and without type 2 diabetes mellitus and to look for an association with demographic, metabolic and therapeutic variables.

METHODS

Phase 1: We retrieved records of 50 Chinese, 51 Malay, and 67 Indian individuals who had routine health screening blood tests. Phase 2: We recruited 111 Chinese, 68 Malays, and 67 Indians with type 2 diabetes mellitus and measured their hs-CRP in addition to standard laboratory tests.

RESULTS

Phase 1: The median hs-CRP was 0.6 mg/L (0.2-6.2) in Chinese, 1.2 mg/L (0.2-7.9) in Malays, and 1.9 mg/L (0.2-10.0) in Indians. The Indians had higher hs-CRP compared to Chinese (P < 0.05) when adjusted for age, sex, body mass index (BMI), lipids, blood pressure, and smoking, and a significant correlation was seen between female sex, smoking status, fasting glucose and triglyceride concentration, and hs-CRP in all three ethnicities. Phase 2: The median hs-CRP was 1.2 mg/L (0.2-9.9) in Chinese, 2.2 mg/L (0.2-9.0) in Malays, and 2.3 mg/L (0.2-9.8) in Indians. Indians had higher hs-CRP when compared to Chinese (P < 0.05) and a significant correlation was seen between BMI, female gender, diabetes, and the use of metformin and hs-CRP in all three ethnicities (P < 0.05) when adjusted for the above variables and use of aspirin, angiotensin-converting enzyme inhibitor/angiotensin receptor blockers (ACE-I/ARB), statin, metformin, rosiglitazone, sulfonylurea, glinides, acarbose, and insulin.

CONCLUSION

hs-CRP concentrations are significantly higher in Indians compared to the Chinese (in both the diabetic and nondiabetic individuals) after adjustment for the various demographic, metabolic, and therapeutic variables.