Associations of socioeconomic position in childhood and young adulthood with cardiometabolic risk factors: the Jerusalem Perinatal Family Follow-Up Study

Obesity risk in young adults from the Jerusalem Perinatal Study (JPS): the contribution of polygenic risk and early life exposure

BACKGROUND/OBJECTIVES

The effects of early life exposures on offspring life-course health are well established. This study assessed whether adding early socio-demographic and perinatal variables to a model based on polygenic risk score (PRS) improves prediction of obesity risk.

METHODS

We used the Jerusalem Perinatal study (JPS) with data at birth and body mass index (BMI) and waist circumference (WC) measured at age 32. The PRS was constructed using over 2.1M common SNPs identified in genome-wide association study (GWAS) for BMI. Linear and logistic models were applied in a stepwise approach. We first examined the associations between genetic variables and obesity-related phenotypes (e.g., BMI and WC). Secondly, socio-demographic variables were added and finally perinatal exposures, such as maternal pre-pregnancy BMI (mppBMI) and gestational weight gain (GWG) were added to the model. Improvement in prediction of each step was assessed using measures of model discrimination (area under the curve, AUC), net reclassification improvement (NRI) and integrated discrimination improvement (IDI).

RESULTS

One standard deviation (SD) change in PRS was associated with a significant increase in BMI (β = 1.40) and WC (β = 2.45). These associations were slightly attenuated (13.7-14.2%) with the addition of early life exposures to the model. Also, higher mppBMI was associated with increased offspring BMI (β = 0.39) and WC (β = 0.79) (p < 0.001). For obesity (BMI ≥ 30) prediction, the addition of early socio-demographic and perinatal exposures to the PRS model significantly increased AUC from 0.69 to 0.73. At an obesity risk threshold of 15%, the addition of early socio-demographic and perinatal exposures to the PRS model provided a significant improvement in reclassification of obesity (NRI, 0.147; 95% CI 0.068-0.225).

CONCLUSIONS

Inclusion of early life exposures, such as mppBMI and maternal smoking, to a model based on PRS improves obesity risk prediction in an Israeli population-sample.

Perinatal exposures and adolescence overweight: The role of shared maternal-offspring pathways

BACKGROUND AND AIMS

Early life exposures affect offspring health across the life-course. We aimed to examine whether prevalent perinatal exposures and obstetric complications are independently associated with offspring overweight in adolescence. We then assessed whether shared maternal-offspring pathways drive the association of perinatal exposures with offspring overweight.

METHODS

Using data from the Jerusalem Perinatal Study birth cohort, two perinatal scores were constructed: obstetric complications (OC) and prevalent perinatal exposures (PPE) scores. PPE score, generated by principal component analysis, included three primary components. Logistic regressions were used to assess associations of scores with offspring overweight, with and without adjustment for maternal life-course survival.

RESULTS

OC and PPE scores were independently associated with offspring overweight (OROC = 1.15, 95%CI:1.07,1.25; ORPPE1- SEP and lifestyle = 0.85, 95%CI:0.79,0.91; ORPPE2- Maternal body size = 1.20, 95%CI: 1.13,1.28; ORPPE3-Fetal growth = 1.18, 95%CI:1.11,1.26). Maternal survival was associated with offspring overweight (OR = 1.38, 95%CI:1.08,1.76), yet introducing PPE score to the same model attenuated this association (OR = 1.16, 95%CI:0.90, 1.49). When OC score and maternal survival were included in the same model, their associations with offspring overweight remained unchanged.

CONCLUSIONS

Mother-offspring shared factors, captured by maternal life-course survival, underlie the effect of prevalent perinatal exposures on offspring overweight. However, the effect of obstetric complications was independent, highlighting the contribution of additional pathways.

Childhood circumstances, social mobility and the obesity transition: Evidence from South Africa

The distribution of obesity tends to shift from rich to poor individuals as countries develop, in a process of shifting sociodemographic patterns of obesity that has been called the 'obesity transition'. This change tends to happen with economic development, but little is known about the specific mechanisms that drive the change. We propose that improvements in childhood circumstances with economic development may be one of the drivers of the obesity transition. We explore whether the social gradient in body weight differs by childhood socioeconomic status (SES), proxied by the respondent's mother having Grade 12, using South Africa's nationally representative panel National Income Dynamics Study. In support of our hypothesis, we find that the social gradient in body weight is less positive for adults who had a high childhood SES, and already appears to have reversed among high-SES women who also had a high childhood SES. Upward social mobility over an individual's life course or across a single generation is associated with higher body weight compared to a stable high SES. But a high SES sustained in childhood and adulthood - or across more than one generation - may decrease adult obesity risk, and result in a reversal of the social gradient in body weight. Random effects within-between models show that the social gradient in body weight and its interaction with childhood SES are driven more by differences in income between individuals than by short-run changes in income within individuals, again suggesting that the obesity transition is driven by long-run changes rather than by very short-run changes. Our results are broadly robust to using several alternative measures of body weight, childhood SES and adult SES. Our results are consistent with the hypothesis that widespread improvements in childhood circumstances and nutrition with economic development may contribute to the shift to later stages of the obesity transition.

Obesity Prediction in Young Adults from the Jerusalem Perinatal Study: Contribution of Polygenic Risk and Early Life Exposures

We assessed whether adding early life exposures to a model based on polygenic risk score (PRS) improves prediction of obesity risk. We used a birth cohort with data at birth and BMI and waist circumference (WC) measured at age 32. The PRS was composed of SNPs identified in GWAS for BMI. Linear and logistic models were used to explore associations with obesity-related phenotypes. Improvement in prediction was assessed using measures of model discrimination (AUC), and net reclassification improvement (NRI). One SD change in PRS was associated with a significant increase in BMI and WC. These associations were slightly attenuated (13.7%-14.2%) with the addition of early life exposures to the model. Also, higher maternal pre-pregnancy BMI was associated with increase in offspring BMI and WC (p<0.001). For prediction obesity (BMI ≥ 30), the addition of early life exposures to the PRS model significantly increase the AUC from 0.69 to 0.73. At an obesity risk threshold of 15%, the addition of early life exposures to the PRS model provided a significant improvement in reclassification of obesity (NRI, 0.147; 95% CI 0.068-0.225). We conclude that inclusion of early life exposures to a model based on PRS improves obesity risk prediction in an Israeli population-sample.

Evaluating the association between socioeconomic position and cardiometabolic risk markers in young adulthood by different life course models

Background

Cardiometabolic health in adulthood is associated with socioeconomic position (SEP) in childhood. Although this has been studied by previous research several questions need to be addressed. E.g. knowledge about the association with timing, extent of the exposure as well as lifestyle and adult SEP, is essential to address the increasing social gradient in cardiometabolic diseases.

Methods

This study included a sub-sample (N = 264, 50% women, age 28–30) from an ongoing cohort study. We used a combination of national registers, longitudinal questionnaire data and clinical data. We examined the association between childhood SEP and cardiometabolic risk, measured by a score of multiple risk markers in young adulthood. SEP-indicators included mother’s educational level and household income. The association was evaluated by four different life course models; the latent effects model, the pathway model, the cumulative model and the social mobility model.

Results

We found an inverse association between mother’s educational level and cardiometabolic risk. The association was statistically significant evaluated by the pathway and cumulative life course models, however statistically insignificant evaluated by the latent effects model. No specific association with social mobility was observed. However, high adult educational level seems to have a protecting impact on the association. No association was found between household income and cardiometabolic risk in any of the applied life course models.

Conclusion

Low childhood SEP, represented by mother’s educational level but not household income, is associated with increased cardiometabolic risk in young adulthood. The accumulation of exposure, lifestyle and adult educational attainment are important for the association. In contrast, intergenerational social mobility does not seem to have a specific impact on the association and we find no evidence for a particular timing in childhood.

Environmental mismatch and obesity in humans: The Jerusalem Perinatal Family Follow-Up Study

BACKGROUND

According to the hypothesis of Gluckman and Hanson, mismatch between the developmental and postdevelopmental environments may lead to detrimental health impacts such as obesity. While several animal studies support the mismatch theory, there is a scarcity of evidence from human-based studies.

OBJECTIVES

Our study aims to examine whether a mismatch between the developmental and young-adult environments affect obesity in young adults of the Jerusalem Perinatal Family Follow-Up Study.

METHODS

Data from The Jerusalem Perinatal Family Follow-Up Study birth cohort was used to characterize early and late environments using offspring and parental sociodemographic and lifestyle information at birth, age 32 (n = 1140) and 42 (n = 404). Scores characterizing the early and late environments were constructed using factor analysis. To assess associations of mismatch with obesity, regression models were fitted using the first factor of each environment and adiposity measures at age 32 and 42.

RESULTS

Having a stable non-beneficial environment at birth and young-adulthood was most strongly associated with increased adiposity, while a stable beneficial environment was most favorable. The transition from a beneficial environment at birth to a less beneficial environment at young-adulthood was associated with higher obesity measures, including higher BMI (β = 0.979; 95% CI: 0.029, 1.929), waist circumference (β = 2.729; 95% CI: 0.317, 5.140) and waist-hip ratio (β = 0.017; 95% CI: 0.004, 0.029) compared with those experiencing a beneficial environment at both time points. Transition from a less beneficial environment at birth to a beneficial environment at adulthood was also associated with higher obesity measurements (BMI -β = 1.116; 95% CI: 0.085, 2.148; waist circumference -β = 2.736; 95% CI: 0.215, 5.256).

CONCLUSIONS

This study provides some support for the mismatch hypothesis. While there is indication that an accumulation of the effects of the non-beneficial environment has the strongest detrimental impact on obesity outcomes, our results also indicate that a mismatch between the developmental and later environments may result in maladaptation of the individual leading to obesity.

Intergenerational social mobility and body mass index trajectories - A follow-up study from Finland

Evidence remains unclear on how intergenerational social mobility is associated with body mass index (BMI) and its long-term changes. Our study identified BMI trajectories from middle to older age by intergenerational social mobility groups and stratified the analyses by gender and two birth cohorts (birth years 1940‒1947 and 1950–1962). We used questionnaire-based cohort data that consists of four survey phases: 2000–2002, 2007, 2012, and 2017. In Phase 1, participants were 40–60-year-old employees of the City of Helsinki, Finland. Our analytical sample consisted of 6,971 women and 1,752 men. Intergenerational social mobility was constructed based on self-reported parental and own education—both divided into high and low—yielding four groups: stable high socioeconomic position (SEP) (high-high), upward social mobility (low-high), downward social mobility (high-low), and stable low SEP (low-low). BMI was calculated from self-reported height and weight from all four phases. Using mixed-effects linear regression, we found increasing BMI trajectories in all four social mobility groups until the age of 65. Women and men with stable high SEP had lower BMI trajectories compared to those with stable low SEP. In the younger birth cohort, women with upward social mobility had a lower BMI trajectory than women with stable low SEP. Additionally, women and men with downward social mobility had higher BMI trajectories than those with stable high SEP. In the older birth cohort, however, the BMI trajectories of upward and downward social mobility groups were somewhat similar and settled between the BMI trajectories of stable high and stable low SEP groups. Our results indicate that the associations between intergenerational social mobility and BMI may depend on gender and birth cohort. Nevertheless, to reduce socioeconomic inequalities in unhealthy weight gain, obesity prevention actions that focus on people who are likely to remain in low SEP might be worthwhile.

•

Few studies exist on social mobility and long-term body mass index (BMI) changes.

•

Rising BMI trajectories were found in all social mobility groups.

•

Stable low socioeconomic position (SEP) was related to higher BMI trajectories.

•

Stable high SEP and upward social mobility may protect from excessive weight gain.

•

Social mobility–BMI associations differed by gender and birth cohort.

Socioeconomic status throughout life and body mass index: a systematic review and meta-analysis

This article aimed to systematically review the association between socioeconomic status according to the life course models and the body mass index (BMI) in adults. A review was performed following the guidelines of the PRISMA. The studies were identified in the MEDLINE/PubMed, LILACS and Web of Science databases. The eligible articles investigated the association between at least one life course model (risk accumulation, critical period or social mobility) and BMI. In order to assess the quality of the selected articles, the NOS checklist was applied to each study. Eleven articles were selected for the systematic review, and seven articles were selected for the meta-analysis. The average score and the median in the NOS checklist were 6.4, within a maximum possible score of 8 points. The most used model was social mobility. Regarding meta-analysis, there was association between lower life course socioeconomic status and BMI among women. BMI mean difference (MD) was higher among those who remained with low socioeconomic status throughout life when compared with those who maintained a high socioeconomic status (MD: 2.17, 95%CI: 1.48; 2.86). Before that, the BMI MD was higher among those with upward mobility, compared with those who maintained a high socioeconomic status throughout life (MD: 1.20, 95%CI: 0.73; 1.68). The risk of overweight was also higher among women who maintained low socioeconomic status (summary RR: 1.70, 95%CI: 1.05; 2.74); however, according to the GRADE, the studies presented very low quality evidence. For men, no association was observed. Having low socioeconomic status sometime during life is associated with higher BMI in adulthood.

The Contribution of Diet Quality to Socioeconomic Inequalities in Obesity: A Population-based Study of Swiss Adults

Socioeconomically disadvantaged people are disproportionally more likely to develop obesity and obesity-related diseases. However, it remains unclear to what extent diet quality contributes to socioeconomic inequalities in obesity. We aimed to assess the role of diet quality in the association between socioeconomic status (SES) and obesity. Data originated from the national nutrition survey, a cross-sectional sample of the adult Swiss population (N = 1860). We used education and income as proxies for SES; calculated the Alternate Healthy Eating Index (AHEI) as a measure of diet quality; and used body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), and waist-to-height ratio (WHtR) as obesity markers. We applied counterfactual mediation modelling to generate odds ratios, 95% confidence intervals, and the proportion mediated by diet quality. Individuals with less than a tertiary education were two to three times more likely to be obese, regardless of the marker (OR (95% CI): 3.36 (2.01, 5.66) using BMI; 2.44 (1.58, 3.75) using WC; 2.48 (1.63, 3.78) using WHR; and 2.04 (1.43, 2.96) using WHtR). The proportion of the association between educational level and obesity that was mediated by diet quality was 22.1% using BMI, 26.6% using WC, 31.4% using WHtR, and 35.8% using WHR. Similar findings were observed for income. Our findings suggest that diet quality substantially contributes to socioeconomic inequalities in obesity while it does not fully explain them. Focusing efforts on improving the diet quality of disadvantaged groups could help reduce social inequalities in obesity.

Intergenerational Educational Pathways and Self-Rated Health in Adolescence and Young Adulthood: Results of the German KiGGS Cohort

Health differences in social mobility are often analysed by income differences or different occupational positions. However, in early adulthood many young people still have very diffuse income situations and are not always fully integrated into the labour market despite many having finished school. This article focusses on the link between intergenerational educational pathways and self-rated health (SRH) among young adults considering their SRH in adolescence. The data source used is the German KiGGS cohort study. The analysis sample comprises 2175 young people at baseline (t0: 2003⁻2006 age 14⁻17) and first follow-up (t1: 2009⁻2012 age 19⁻24). Combining parent's and young people's highest school degree, the data can trace patterns of intergenerational educational pathways (constant high level of education, upward mobility, downward mobility, constant low level of education). Young people's SRH was recorded at t0 and t1. During adolescence and young adulthood, participants were less likely to report poor SRH if they had a constant high intergenerational education or if they were upwardly mobile. The differences were particularly striking among young adults: average marginal effects (AME) for poor SRH showed much higher risk among downwardly mobile compared to peers with an intergenerational constant high education (AME: 0.175 [0.099; 0.251]), while the upwardly mobile had a significantly lower risk for less than good SRH than peers with an intergenerational constant low level of education (AME: -0.058 [-0.113; -0.004]). In the context of great societal demands and personal developmental needs, educational differences in health tend to increase in young adulthood. Public Health should pay more attention to educational and health inequalities in young adulthood.

Changes in socio-economic status and lipoproteins in Chilean adolescents: a 16-year longitudinal study

OBJECTIVE

The present longitudinal study assessed whether changes in socio-economic status (SES) from infancy to adolescence were associated with plasma lipoprotein concentrations in adolescence, of which low HDL-cholesterol (HDL-C) and high LDL-cholesterol (LDL-C), TAG and total cholesterol (TC) concentrations are associated with higher cardiovascular risk.

DESIGN

SES, assessed using the modified Graffar Index, was calculated at 1, 5, 10 and 16 years. Principal components factor analysis with varimax rotation extracted two orthogonal SES factors, termed 'environmental capital' and 'social capital'. Generalized linear models were used to analyse associations between environmental and social capital at 1 and 16 years and outcomes (HDL-C, LDL-C, TAG, TC) at 16 years, as well as changes in environmental and social capital from 1-5, 5-10, 10-16 and 1-16 years, and outcomes at 16 years.

SETTING

Santiago, Chile.ParticipantsWe evaluated 665 participants from the Santiago Longitudinal Study enrolled at infancy in Fe-deficiency anaemia studies and examined every 5 years to age 16 years.

RESULTS

Social capital in infancy was associated with higher HDL-C in adolescence. Environmental capital in adolescence was associated with higher LDL-C and TC during adolescence. Changing environmental capital from 1-16 years was associated with higher LDL-C. Changing environmental capital from 1-5 and 1-16 years was associated with higher TC.

CONCLUSIONS

Improvements in environmental capital throughout childhood were associated with less healthy LDL-C and TC concentrations in adolescence. We found no evidence of associations between changing environmental capital and HDL-C or TAG, or changing social capital and HDL-C, LDL-C, TAG or TC.

Associations of social environment, socioeconomic position and social mobility with immune response in young adults: the Jerusalem Perinatal Family Follow-Up Study

OBJECTIVES

Immune response to cytomegalovirus (CMV) impacts adult chronic disease. This study investigates associations of childhood and adulthood social environment, socioeconomic position (SEP) and social mobility with CMV response in young adults.

DESIGN

Historical prospective study design.

SETTING

Subcohort of all 17 003 births to residents of Jerusalem between 1974 and 1976.

PARTICIPANTS

Participants included 1319 young adults born in Jerusalem with extensive archival and follow-up data, including childhood and adulthood SEP-related factors and anti-CMV IgG titre levels and seroprevalence measured at age 32.

MAIN EXPOSURE AND OUTCOME MEASURES

Principal component analysis was used to transform correlated social environment and SEP-related variables at two time points (childhood and adulthood) into two major scores reflecting household (eg, number of siblings/children, religiosity) and socioeconomic (eg, occupation, education) components. Based on these components, social mobility variables were created. Linear and Poisson regression models were used to investigate associations of components and mobility with anti-CMV IgG titre level and seroprevalence, adjusted for confounders.

RESULTS

Lower levels of household and socioeconomic components in either childhood or adulthood were associated with higher anti-CMV IgG titre level and seropositivity at age 32. Compared with individuals with stable favourable components, anti-CMV IgG titre level and risk for seropositivity were higher in stable unfavourable household and socioeconomic components (household: β=3.23, P<0.001; relative risk (RR)=1.21, P<0.001; socioeconomic: β=2.20, P=0.001; RR=1.14, P=0.01), downward household mobility (β=4.32, P<0.001; RR=1.26, P<0.001) and upward socioeconomic mobility (β=1.37, P=0.04; RR=1.19, P<0.001). Among seropositive individuals, associations between household components and mobility with anti-CMV IgG titre level were maintained and associations between socioeconomic components and mobility with anti-CMV IgG titre level were attenuated.

CONCLUSIONS

Our study provides evidence that accumulating low SEP from childhood through adulthood and social mobility may compromise immune response in young adulthood.