Life-course origins of social inequalities in metabolic risk in the population of a developing country

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.

Life-course social disparities in body mass index trajectories across adulthood: cohort study evidence from China health and nutrition survey

BACKGROUND

The social disparities in obesity may originate in early life or in adulthood, and the associations of socioeconomic position (SEP) with obesity could alter over time. It is unclear how lifetime-specific and life-course SEP influence adult obesity development in China.

METHODS

Based on the China Health and Nutrition Survey (CHNS), three SEP-related indicators, including the father's occupational position and the participant's education and occupational position, were obtained. The life-course socioeconomic changes and a cumulative SEP score were established to represent the life-course SEP of the participants in the study. The growth mixture modeling was used to identify BMI trajectories in adulthood. Multinomial logistic regression was adopted to assess the associations between SEP and adult BMI trajectories.

RESULTS

A total of 3,138 participants were included in the study. A positive correlation was found between the paternal occupational position, the participants' occupational position, education, and obesity in males, whereas an inverse correlation was observed among females. Males who experienced social upward mobility or remained stable high SEP during the follow-up had 2.31 and 2.52-fold risks of progressive obesity compared to those with a stable-low SEP. Among females, stable high SEP in both childhood and adulthood was associated with lower risks of progressive obesity (OR = 0.63, 95% CI: 0.43-0.94). Higher risks of obesity were associated with the life-course cumulative SEP score among males, while the opposite relationship was observed among females.

CONCLUSIONS

The associations between life-course SEP and BMI development trajectories differed significantly by gender. Special emphasis should be placed on males experiencing upward and stable high socioeconomic change.

Childhood Socioeconomic Position and Risk of Cardiovascular Disease in Adulthood: Systematic Review of Evidence From Low- and Middle-Income Countries

INTRODUCTION

Socioeconomic disadvantage in childhood is strongly associated with a higher risk of cardiovascular disease in high-income countries. However, the association in low- and middle-income countries, where childhood poverty remains prevalent, has not been reviewed.

METHODS

The authors systematically searched Embase, MEDLINE, and Global Health databases for articles on the association between childhood socioeconomic position and risk of cardiovascular disease in adulthood in low- and middle-income countries until September 2020. Outcomes included measures of cardiovascular disease, its subclinical markers (e.g., carotid intima-media thickness), and its major risk factors (e.g., hypertension, dyslipidemia, diabetes). Where available, associations were extracted before and after adjustment for socioeconomic position in adulthood. Results were synthesized qualitatively by outcome. The study protocol is registered on PROSPERO (CRD42018086984).

RESULTS

The search returned 3,568 unique abstracts, from which 29 eligible articles from 14 middle-income countries were identified, representing >150,000 participants. The most commonly reported outcomes were cardiovascular risk factors; very few studies reported prevalent measures of cardiovascular disease, and no studies reported cardiovascular disease incidence or mortality. Of the 46 reported associations between childhood socioeconomic position and risk of cardiovascular disease, 8 were inverse, 0 were positive, and 38 showed no clear evidence of association. All articles had high (16/29) or medium (13/29) risk of bias.

CONCLUSIONS

Current evidence from middle-income countries provides little support for an association between childhood socioeconomic position and risk of cardiovascular disease, and evidence from low-income countries is lacking. It would be premature to consider childhood poverty as a target for cardiovascular disease prevention in these settings.

Neighborhood disadvantage across the transition from adolescence to adulthood and risk of metabolic syndrome

This study investigates the association between neighborhood disadvantage from adolescence to young adulthood and metabolic syndrome using a life course epidemiology framework. Data from the United States-based National Longitudinal Study of Adolescent to Adult Health (n = 9500) and a structural equation modeling approach were used to test neighborhood disadvantage across adolescence, emerging adulthood, and young adulthood in relation to metabolic syndrome. Adolescent neighborhood disadvantage was directly associated with metabolic syndrome in young adulthood. Evidence supporting an indirect association between adolescent neighborhood disadvantage and adult metabolic syndrome was not supported. Efforts to improve cardiometabolic health may benefit from strategies earlier in life.

Threat vigilance and socioeconomic disparities in metabolic health

A quarter of the global population meets diagnostic criteria for metabolic syndrome (MetS). MetS prevalence stratifies by socioeconomic status (SES), such that low SES is associated with higher MetS risk starting in childhood. Despite this trend, some low-SES children maintain good metabolic health across the life span, but the factors responsible for their resilience are not well understood. This study examined the role of threat vigilance as either a moderator or a mediator of the effects of low early life SES on adult metabolic risk. Three hundred twenty-five Canadians aged 15-55 participated (M = 36.4 years, SD = 10.7; 55.4% female). We coded parental occupational status between the ages of 0 and 5 to index early life SES. We used the International Diabetes Federation case definition for MetS based on waist circumference, blood pressure, triglyceride levels, HDL cholesterol, and glycosylated hemoglobin measures. Threat vigilance was assessed using the Weapons Identification Procedure, a visual discrimination paradigm that captures implicit perceptions of threat. Analyses supported the moderator hypothesis: low early life SES was associated with MetS diagnosis exclusively among those with high levels of threat vigilance. This suggests that low early life SES environments that heighten vigilance to threat might be particularly detrimental for metabolic health. Conversely, low threat vigilance may buffer against the metabolic risks associated with socioeconomic disadvantage.

Gender differences in the pathways from childhood disadvantage to metabolic syndrome in adulthood: An examination of health lifestyles

We investigate whether socioeconomic status (SES) in childhood shapes adult health lifestyles in domains of physical activity (leisure, work, chores) and diet (servings of healthy [i.e., nutrient-dense] vs. unhealthy [energy-dense] foods). Physical activity and food choices vary by gender and are key factors in the development of metabolic syndrome (MetS). Thus, we examined gender differences in the intervening role of these behaviors in linking early-life SES and MetS in adulthood. We used survey data (n = 1054) from two waves of the Midlife in the U.S. Study (MIDUS 1 and 2) and biomarker data collected at MIDUS 2. Results show that individuals who were disadvantaged in early life are more likely to participate in physical activity related to work or chores, but less likely to participate in leisure-time physical activity, the domain most consistently linked with health benefits. Women from low SES families were exceedingly less likely to complete recommended amounts of physical activity through leisure. Men from low SES consumed more servings of unhealthy foods and fewer servings of healthy foods. The observed associations between childhood SES and health lifestyles in adulthood persist even after controlling for adult SES. For men, lack of leisure-time physical activity and unhealthy food consumption largely explained the association between early-life disadvantage and MetS. For women, leisure-time physical activity partially accounted for the association, with the direct effect of childhood SES remaining significant. Evidence that material deprivation in early life compromises metabolic health in adulthood calls for policy attention to improve economic conditions for disadvantaged families with young children where behavioral pathways (including gender differences therein) may be shaped. The findings also underscore the need to develop gender-specific interventions in adulthood.

•

Physical activity and healthy diet have been recommended to prevent/treat metabolic syndrome (MetS).

•

Childhood SES is associated with development of MetS via physical activity and diet.

•

Gender is key to understanding the behavioral pathways linking childhood SES and MetS.

•

Low childhood SES is associated with unhealthy diet for men and insufficient leisure-time activity for both genders.

•

Leisure-time activity and unhealthy diet mediate the effect of childhood SES on MetS, particularly for men.

Are health inequalities rooted in the past? Income inequalities in metabolic syndrome decomposed by childhood conditions

Background: Early life is thought of as a foundation for health inequalities in adulthood. However, research directly examining the contribution of childhood circumstances to the integrated phenomenon of adult social inequalities in health is absent. The present study aimed to examine whether, and to what degree, social conditions during childhood explain income inequalities in metabolic syndrome in mid-adulthood. Methods: The sample (N = 12 481) comprised all 40- and 50-year-old participants in the Västerbotten Intervention Program in Northern Sweden 2008, 2009 and 2010. Measures from health examinations were used to operationalize metabolic syndrome, which was linked to register data including socioeconomic conditions at age 40–50 years, as well as childhood conditions at participant age 10–12 years. Income inequality in metabolic syndrome in middle age was estimated by the concentration index and decomposed by childhood and current socioeconomic conditions using decomposition analysis. Results: Childhood conditions jointed explained 7% (men) to 10% (women) of health inequalities in middle age. Adding mid-adulthood sociodemographic factors showed a dominant contribution of chiefly current income and educational level in both gender. In women, the addition of current factors slightly attenuated the contribution of childhood conditions, but with paternal income and education still contributing. In contrast, the corresponding addition in men removed all explanation attributable to childhood conditions. Conclusions: Despite that the influence of early life conditions to adult health inequalities was considerably smaller than that of concurrent conditions, the study suggests that early interventions against social inequalities potentially could reduce health inequalities in the adult population for decades to come.

Early-Life Socioeconomic Disadvantage and Metabolic Health Disparities

OBJECTIVE

A quarter of the world's population have metabolic syndrome (MetS). MetS prevalence is stratified by socioeconomic status (SES), such that low SES is associated with higher MetS risk. The present study examined the relative roles of early-life SES and current SES in explaining MetS risk.

METHODS

Participants (N = 354; ages = 15-55 years, M [SD] = 36.5 [10.7] years; 55% female; 72.9% white, 16.9% Asian, 10.2% others) were evaluated for SES and MetS. All were in good health, defined as free of chronic medical illness and acute infectious disease. Using occupational status as a proxy for SES, we recruited roughly equal numbers of participants with low-low, low-high, high-low, and high-high combinations of early-life and current SES. We used the International Diabetes Federation definition for MetS using race- and sex-specific cutoffs for waist circumference, triglyceride levels, high-density lipoprotein cholesterol, blood pressure, and glycosylated hemoglobin levels.

RESULTS

Analyses revealed a main effect of low early-life SES on increased MetS risk according to the three separate definitions. They included the traditional MetS diagnosis (odds ratio [OR] = 1.53, confidence interval [CI] = 1.01-2.33, p = .044), the number of MetS components for which diagnostic thresholds were met (OR = 1.61, CI = 1.10-2.38, p = .015), and a continuous indicator of metabolic risk based on factor analysis (F(1,350) = 6.71, p = .010, partial η = .019). There was also a significant interaction of early-life SES and current SES in predicting MetS diagnosis (OR = 1.54, CI = 1.02-2.34). The main effects of current SES were nonsignificant in all analyses.

CONCLUSIONS

These findings suggest that MetS health disparities originate in childhood, which may be an opportune period for interventions.

Stress across the life course and depression in a rapidly developing population: the Guangzhou Biobank Cohort Study

OBJECTIVE

The objective of this study was to examine the role of stress across the life course in the development of depression among older adults in a non-Western developing setting.

METHODS

Multivariable linear and multinomial logistic regression were used in cross-sectional analyses of 9729 Chinese participants (mean age 60.2 years) from phase 3 of the Guangzhou Biobank Cohort Study (2006-2008) to investigate the association of childhood adversities and adulthood stressors with depression.

RESULTS

Childhood adversities were associated with mild depression (odds ratio (OR) 1.78, 95% confidence interval (CI) 1.58, 2.02) and moderate-to-severe depression (OR 2.30, 95% CI 1.68, 3.15), adjusted for age, sex, education and childhood socio-economic status. Past-year adulthood stressors were also associated with mild depression (OR 1.96, 95% CI 1.54, 2.02) and moderate-to-severe depression (OR 3.55, 95% CI 2.21, 5.68), adjusting additionally for occupation and income. Adulthood stressors were more strongly associated with depressive symptoms among individuals with a history of childhood adversities.

CONCLUSIONS

Childhood adversities and adulthood stressors were independently associated with an increased risk of depression among older ambulatory adults, although adulthood stressors were more strongly associated with depression following exposure to childhood adversities. This is consistent with evidence from Western settings in which the social context of risk and protective factors for depression may differ and implies that the role of stress in the aetiology of depression is not context specific.

Social Patterning in Adiposity in Adolescence: Prospective Observations from the Chinese Birth Cohort ''Children of 1997''

INTRODUCTION

Low early life socio-economic position is more strongly associated with adiposity among women than men. We examined whether the sex difference of social patterning in general and central adiposity exists before adulthood.

METHODS

In Hong Kong's "Children of 1997" birth cohort, we used multivariable regression to examine the association of parental education, a marker of early life socio-economic position, with body mass index (BMI) (n = 7252, 88% follow-up) and waist-height ratio (n = 5636, 68% follow-up), at 14 years.

RESULTS

Parental education of Grade 9 or below, compared to Grade 12 or above, was associated with higher waist-height ratio z-score particularly in girls (0.30, 95% confidence interval (CI) 0.19, 0.41) compared to boys (0.12, 95% CI 0.02, 0.22) (p for sex interaction = 0.02). Lower parental education was associated with greater BMI z-score in adolescents of locally born mothers, but not adolescents of migrant mothers, with no difference by sex.

CONCLUSIONS

Different social patterning in different markers of adiposity may imply different sociological and biological mediating pathways. A stronger association between low early life socio-economic position and waist-height ratio in adolescent girls may indicate sex-specific influences of SEP related early life exposures on central adiposity.

Socioeconomic position during childhood and physical activity during adulthood: a systematic review

OBJECTIVES

A growing body of evidence links socioeconomic position early in life and physical activity during adulthood. This systematic review aimed to summarize this evidence.

METHODS

Medline and EMBASE were searched for studies that assessed socioeconomic position before age 18 years and physical activity at age ≥18 years. Studies were rated according to three key methodological quality criteria: (1) was childhood socioeconomic position assessed prospectively? (2) Was socioeconomic position during adulthood included in the statistical analysis? (3) Was a validated instrument used to measure of physical activity?

RESULTS

Forty-two publications were included. Twenty-six (61.9 %) found a significant association between socioeconomic position early in life and physical activity during adulthood. Twenty-one studies met at least two methodological quality criteria. Among those, the proportion was higher: 15/21 (71.4 %). Associations were of weak to moderate strength, positive for physical activity during leisure time, and negative for transports and work.

CONCLUSIONS

The bulk of the evidence supports the notion that there is a life course association between socioeconomic position early in life and physical activity during adulthood. Studies using more rigorous methodology supported this conclusion more consistently.

Childhood socioeconomic position and adult leisure-time physical activity: a systematic review

Regular leisure-time physical activity (LTPA) benefits health and is thought to be less prevalent in lower socioeconomic groups. Evidence suggests that childhood socioeconomic circumstances can impact on adult health and behaviour however, it is unclear if this includes an influence on adult LTPA. This review tested the hypothesis that a lower childhood socioeconomic position (SEP) is associated with less frequent LTPA during adulthood. Studies were located through a systematic search of MEDLINE, Embase, PsycINFO, CINAHL and SPORTDiscus and by searching reference lists. Eligible studies were English-language publications testing the association between any indicator of childhood SEP and an LTPA outcome measured during adulthood. Forty-five papers from 36 studies, most of which were European, were included. In most samples, childhood SEP and LTPA were self-reported in midlife. Twenty-two studies found evidence to support the review's hypothesis and thirteen studies found no association. Accounting for own adult SEP partly attenuated associations. There was more evidence of an association in British compared with Scandinavian cohorts and in women compared with men. Results did not vary by childhood SEP indicator or age at assessment of LTPA. This review found evidence of an association between less advantaged childhood SEP and less frequent LTPA during adulthood. Understanding how associations vary by gender and place could provide insights into underlying pathways.

Socioeconomic status and biological markers of health: an examination of adults in the United States and Taiwan

OBJECTIVE

The study documents whether socioeconomic status (SES) differentials in biological risk are more widely observed and larger in the United States than Taiwan.

METHOD

Data come from the Social Environment and Biomarkers of Aging Study in Taiwan and the Midlife in the United States study. We use regression analyses to test whether four summary measures of biological risk are significantly related to categorical measures of education, income, and subjective social status among four country-sex-specific subgroups.

RESULTS

Physiological dysregulation is significantly, negatively related to SES in both the United States and Taiwan, especially for males. The prevalence and magnitude of the relationships are similar in the two countries: 12 of 24 possible SES-biological summary score relationships are significant in the United States and 11 of 24 are significant in Taiwan.

DISCUSSION

Overall, SES differentials in biological risk do not appear to be more widely observed or larger in the United States than in Taiwan.

Age- and sex-specific relationships between household income, education, and diabetes mellitus in Korean adults: the Korea National Health and Nutrition Examination Survey, 2008-2010

Background

To investigate the effects of age and sex on the relationship between socioeconomic status (SES) and the prevalence and control status of diabetes mellitus (DM) in Korean adults.

Methods

Data came from 16,175 adults (6,951 men and 9,227 women) over the age of 30 who participated in the 2008-2010 Korea National Health and Nutrition Examination Survey. SES was measured by household income or education level. The adjusted odds ratios (ORs) and corresponding 95% confidence intervals (95% CI) for the prevalence or control status of diabetes were calculated using multiple logistic regression analyses across household income quartiles and education levels.

Results

The household income-DM and education level-DM relationships were significant in younger age groups for both men and women. The adjusted ORs and 95% CI for diabetes were 1.51 (0.97, 2.34) and 2.28 (1.29, 4.02) for the lowest vs. highest quartiles of household income and education level, respectively, in women younger than 65 years of age (both P for linear trend < 0.05 with Bonferroni adjustment). The adjusted OR and 95% CI for diabetes was 2.28 (1.53, 3.39) for the lowest vs. highest quartile of household income in men younger than 65 (P for linear trend < 0.05 with Bonferroni adjustment). However, in men and women older than 65, no associations were found between SES and the prevalence of DM. No significant association between SES and the status of glycemic control was detected.

Conclusions

We found age- and sex-specific differences in the relationship of household income and education with the prevalence of DM in Korea. DM preventive care is needed for groups with a low SES, particularly in young or middle-aged populations.

Metabolic syndrome and sex-specific socio-economic disparities in childhood and adulthood: the Korea National Health and Nutrition Examination Surveys

AIMS

To examine whether adulthood and/or childhood sex-specific socio-economic disparities are associated with metabolic syndrome and its components in a developed non-Western setting.

METHODS

Based on the Fourth Korea National Health and Nutrition Examination Surveys, 14 888 people aged ≥ 20 years were analysed to evaluate the effect of adult and childhood socio-economic status on metabolic syndrome. Metabolic syndrome was defined according to the National Cholesterol Education Program Adult Treatment Panel III guidelines. Logistic regression analyses were conducted to calculate the odds ratios for metabolic syndrome and each component of metabolic syndrome in later life.

RESULTS

The age-standardized prevalence of metabolic syndrome was 26.6% for men and 21.3% for women. Compared with the highest level of education, men with the lowest education level were significantly less likely to have metabolic syndrome (odds ratio 0.76, 95% CI 0.60-0.96), whereas the opposite association was found in women (odds ratio 3.29, 95% CI 2.45-4.42). Men who were manual labourers and economically inactive had a lower prevalence of metabolic syndrome compared with those with non-manual jobs (odds ratio 0.82, 95% CI 0.69-0.98 and odds ratio 0.79, 95% CI 0.64-0.99, respectively), but the reverse association was observed in women (odds ratio 1.34, 95% CI 1.04-1.73 and odds ratio 1.40, 95% CI 1.09-1.81, respectively). A significant interaction between combined adulthood and childhood socio-economic status on the presence of metabolic syndrome was observed (P < 0.05).

CONCLUSIONS

Our findings suggest that sex-specific socio-economic disparities in childhood and adulthood have differential effects on the prevalence of metabolic syndrome and its individual components in Korea.

Education is associated with lower levels of abdominal obesity in women with a non-agricultural occupation: an interaction study using China's Four Provinces survey

Background

The prevalence of obesity is increasing rapidly in low- and middle-income countries (LMICs) as their populations become exposed to obesogenic environments. The transition from an agrarian to an industrial and service-based economy results in important lifestyle changes. Yet different socioeconomic groups may experience and respond to these changes differently. Investigating the socioeconomic distribution of obesity in LMICs is key to understanding the causes of obesity but the field is limited by the scarcity of data and a uni-dimensional approach to socioeconomic status (SES). This study splits socioeconomic status into two dimensions to investigate how educated women may have lower levels of obesity in a context where labour market opportunities have shifted away from agriculture to other forms of employment.

Methods

The Four Provinces Study in China 2008/09 is a household-based community survey of 4,314 people aged ≥60  years (2,465 women). It was used to investigate an interaction between education (none/any) and occupation (agricultural/non-agricultural) on high-risk central obesity defined as a waist circumference ≥80 cm. An interaction term between education and occupation was incorporated in a multivariate logistic regression model, and the estimates adjusted for age, parity, urban/rural residence and health behaviours (smoking, alcohol, meat and fruit & vegetable consumption). Complete case analyses were undertaken and results confirmed using multiple imputation to impute missing data.

Results

An interaction between occupation and education was present (P = 0.02). In the group with no education, the odds of central obesity in the sedentary occupation group were more than double those of the agricultural occupation group even after taking age group and parity into account (OR; 95%CI: 2.21; 1.52, 3.21), while in the group with any education there was no evidence of such a relationship (OR; 95%CI: 1.25; 0.92, 1.70). Health behaviours appeared to account for some of the association.

Conclusion

These findings suggest that education may have a protective role in women against the higher odds of obesity associated with occupational shifts in middle-income countries, and that investment in women’s education may present an important long term investment in obesity prevention. Further research could elucidate the mechanisms behind this association.

Factors associated with the pressure pain threshold in healthy Chinese men

OBJECTIVE

The goal of present study was to examine the influence of demographic characteristics, lifestyle, and metabolic factors on pressure-induced pain threshold.

DESIGN AND SETTING

The study population comprised 2,517 healthy men at second-phase recruitment of a population-based cohort in China. The pressure pain threshold (PPT) at two locations, triceps and inguinal lines, was obtained using a digital pressure algometer. Education and occupation, as well as lifestyle factors, were self-reported in a face-to-face interview. Blood lipid and fasting glucose were measured as a routine healthy check-up program.

RESULTS

A lower PPT was found among men with younger age, higher level of education, and non-manual occupation. In addition, men with central obesity and moderate leisure time physical exercise were more sensitive to muscle mechanical stimuli. PPT was significantly correlated with high-density lipoprotein cholesterol (β for triceps = 0.064, and β for inguinal lines = 0.052) in a multivariate linear regression model, after controlling for multiple variables. Elevated PPT was also found among subjects with hyperglycemia (both P for triceps and inguinal lines <0.001) and excess drinking (P for triceps = 0.005).

CONCLUSIONS

It is important for physicians and researchers to consider these variables when evaluating pain sensitivity in clinic and in research. The underling mechanisms between these factors and pressure pain perception are worthy of further exploration.

Socioeconomic disparities in prevalence, treatment, and control of hypertension in middle-aged Koreans

Background

We investigated socioeconomic inequalities in hypertension prevalence, treatment, and control among middle-aged Koreans.

Methods

We analyzed data from 4275 adults aged between 40 and 64 years who participated in the Korean National Health and Nutrition Examination Survey, 2007 and 2008. Education, income, and occupational level were evaluated to assess the relationship of socioeconomic status with hypertension prevalence, treatment, and control.

Results

There were significant differences in socioeconomic status among individuals with no hypertension, controlled hypertension, and uncontrolled hypertension in both sexes. In multiple logistic regression models, as compared with men who had more than 12 years of education, those with 7 to 12 years and less than 7 years of education had odds ratios (ORs) for untreated hypertension of 2.14 (95% CI: 1.18 to 3.90) and 2.98 (95% CI: 1.42 to 6.28), respectively (P for trend <0.05). As compared with women who had more than 12 years of education, those with 7 to 12 years and less than 7 years of education had ORs for hypertension prevalence of 1.75 (95% CI: 1.10 to 2.78) and 1.88 (95% CI: 1.12 to 3.16), respectively (P for trend <0.05). Women who worked as manual labors had an OR for uncontrolled hypertension of 1.50 (95% CI: 1.02 to 2.22) as compared with women in other jobs. There was no statistically significant association between income level and hypertension control.

Conclusions

Socioeconomic status was independently associated with hypertension prevalence and care, which suggests a need for health policy efforts to reduce the socioeconomic disparity in hypertension management.

Sex differences in the relationship between socioeconomic status and metabolic syndrome: the Korean National Health and Nutrition Examination Survey

AIMS

To investigate sex differences in the relationship between socioeconomic status (SES) and the prevalence of metabolic syndrome (MetS) in Korean adults.

METHODS

We examined the relationship between SES, as measured by household income or education level, and the prevalence of MetS in Korean adults who participated in the 2007-2008 Korean National Health Examination and Nutrition Survey (KNHANES). The adjusted odds ratios (ORs) for MetS were calculated using multivariate logistic regression analysis across household income and education level quartiles.

RESULTS

We found significant differences between men and women in the association between SES and MetS, with a positive association for men and an inverse association for women. The adjusted OR and 95% confidence interval (95% CI) for MetS for the highest vs. lowest quartile of household income was 1.59 (1.15-2.20) in men. The adjusted ORs for MetS for the highest vs. lowest quartile of household income and education level were 0.54 (0.41-0.72) and 0.26 (0.17-0.38) in women, respectively.

CONCLUSIONS

We found sex differences in the relationship between SES and the prevalence of MetS in Korea. These findings suggest that sex-specific public health interventions that consider SES are needed for the prevention and treatment of MetS.

Childhood socioeconomic position, adult socioeconomic position and social mobility in relation to markers of adiposity in early adulthood: evidence of differential effects by gender in the 1978/79 Ribeirao Preto cohort study

Background:

Longitudinal studies drawn from high-income countries demonstrate long-term associations of early childhood socioeconomic deprivation with increased adiposity in adulthood. However, there are very few data from resource-poor countries where there are reasons to anticipate different gradients. Accordingly, we sought to characterise the nature of the socioeconomic status (SES)-adiposity association in Brazil.

Methods:

We use data from the Ribeirao Preto Cohort Study in Brazil in which 9067 newborns were recruited via their mothers in 1978/79 and one-in-three followed up in 2002/04 (23–25years). SES, based on family income (salaries, interest on savings, pensions and so on), was assessed at birth and early adulthood, and three different adiposity measures (body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR)) ascertained at follow-up. The association between childhood SES, adult SES and social mobility (defined as four permutations of SES in childhood and adulthood: low–low, low–high, high–low, high–high), and the adiposity measures was examined using linear regression.

Results:

There was evidence that the association between SES and the three markers of adiposity was modified by gender in both adulthood (P<0.02 for all outcomes) and childhood SES (P<0.02 for WC and WHR). Thus, in an unadjusted model, linear regression analyses showed that higher childhood SES was associated with lower adiposity in women (coefficient (95% confidence intervals) BMI: −1.49 (−2.29,−0.69); WC: −3.85 (−5.73,−1.97); WHR: −0.03 (−0.04,−0.02)). However, in men, higher childhood SES was related to higher adiposity (BMI: 1.03 (0.28,−1.78); WC: 3.15 (1.20, 5.09); WHR: 0.009 (−0.001, 0.019)) although statistical significance was not seen in all analyses. There was a suggestion that adult SES (but not adult health behaviours or birthweight) accounted for these relationships in women only. Upward mobility was associated with protection against greater adiposity in women but not men.

Conclusion:

In the present study, in men there was some evidence that both higher childhood and adulthood SES was related to a higher adiposity risk, while the reverse gradient was apparent in women.

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.

The utility of collaborative biobanks for cardiovascular research

Differences between animal and human atherosclerosis have led to the requirement for clinical data, imaging information and biological material from large numbers of patients and healthy persons. Where such "biobanks" exist, they have been fruitful sources for genomewide association, diagnostic accuracy, ethnicity, and risk stratification cohort studies. In addition once established, they attract funding for future projects. Biobanks require a network of medical contributors, secure storage facilities, bioinformatics expertise, database managers, and ethical working practices to function optimally. There is the opportunity for collaboration between individual biobanks to further amplify the advantages afforded.

Intergenerational influences on diabetes in a developing population: the Guangzhou Biobank Cohort Study

OBJECTIVES

Intergenerational "mismatch" and/or growth conditions may be relevant to the epidemic of diabetes in developing populations. In a rapidly developing southern Chinese population, we tested whether maternal environment, proxied by maternal literacy, or family socio-economic position (SEP), proxied by paternal literacy, were associated with fasting glucose and diabetes. To assess if intergenerational mismatch contributed, we tested whether the associations varied by life course SEP.

METHODS

In 19,818 older (≥50 years) adults from the Guangzhou Biobank Cohort Study (phases 2 and 3), we used censored and logistic regression to assess the associations of maternal and paternal literacy with fasting glucose, elevated fasting glucose and diabetes and whether these associations varied by sex, age or life course SEP.

RESULTS

Maternal, but not paternal, literacy was negatively associated with fasting plasma glucose (β-coefficient -0.06 mmol/l, 95% confidence interval (CI) -0.11 to -0.01) and elevated fasting glucose (odds ratio (OR) 0.92, 95% CI 0.86-0.99) adjusted for age, sex, study phase, life course SEP, childhood growth, adiposity, number of offspring, and birth order. Associations of maternal and paternal literacy with fasting glucose, elevated fasting glucose and diabetes did not vary by sex, age or life course SEP.

CONCLUSION

Offspring of literate mothers had lower risk for impaired glucose tolerance than offspring of illiterate mothers. Being raised by literate mothers may increase the likelihood of children with higher SEP and lower long-term disease risk, or better maternal conditions over generations may be associated with lower fasting glucose.

Illiteracy, low educational status, and cardiovascular mortality in India

BACKGROUND

Influence of education, a marker of SES, on cardiovascular disease (CVD) mortality has not been evaluated in low-income countries. To determine influence of education on CVD mortality a cohort study was performed in India.

METHODS

148,173 individuals aged ≥ 35 years were recruited in Mumbai during 1991-1997 and followed to ascertain vital status during 1997-2003. Subjects were divided according to educational status into one of the five groups: illiterate, primary school (≦ 5 years of formal education), middle school (6-8 years), secondary school (9-10 years) and college (> 10 years). Multivariate analyses using Cox proportional hazard model was performed and hazard ratios (HRs) and 95% confidence intervals (CIs) determined.

RESULTS

At average follow-up of 5.5 years (774,129 person-years) 13,261 deaths were observed. CVD was the major cause of death in all the five educational groups. Age adjusted all-cause mortality per 100,000 in illiterate to college going men respectively was 2154, 2149, 1793, 1543 and 1187 and CVD mortality was 471, 654, 618, 518 and 450; and in women all-cause mortality was 1444, 949, 896, 981 and 962 and CVD mortality was 429, 301, 267, 426 and 317 (ptrend < 0.01). Compared with illiterate, age-adjusted HRs for CVD mortality in primary school to college going men were 1.36, 1.27, 1.01 and 0.88 (ptrend < 0.05) and in women 0.69, 0.55, 1.04 and 0.74, respectively (ptrend > 0.05).

CONCLUSIONS

Inverse association of literacy status with all-cause mortality was observed in Indian men and women, while, for CVD mortality it was observed only in men.

Life long endogenous estrogen exposure and later adulthood cognitive function in a population of naturally postmenopausal women from Southern China: the Guangzhou Biobank Cohort Study

BACKGROUND

Estrogen has neurotrophic and neuroprotective properties in animal and in vitro studies. Epidemiological studies are inconclusive, but suggest a positive association between endogenous estrogen exposure (measured by reproductive period, the number of years between menarche and menopause) and later life cognitive function.

METHODS

Structural equation modeling was used in a cross-sectional study of 11,094 naturally postmenopausal multiparous Chinese older (≥50 years) women from the Guangzhou Biobank Cohort Study (phases 2 and 3) to assess the interrelationship of four proxies of higher endogenous estrogen exposure (longer reproductive period, older age of first pregnancy, lower parity and shorter average duration of breast feeding per child) with immediate and the delayed 10-word recall score in phases 2 and 3, and with the mini-mental state examination (MMSE) score in phase 3 (5641 women).

RESULTS

Adjusted for age, education, childhood and adulthood socio-economic position and physical activity, longer reproductive period was associated with higher scores (0.02 words per year, 95% confidence interval (CI) 0.008-0.02 for delayed recall and 0.05 MMSE score, 95%CI 0.04-0.07, respectively). Lower parity and shorter average duration of breast-feeding per child were also associated with better cognitive function.

CONCLUSIONS

In a large cohort of naturally postmenopausal Chinese women proxies of greater endogenous estrogen exposure were associated with better cognitive function. These findings support biological evidence for a cognitively protective role of endogenous estrogen.

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.

Parental death during childhood and adult cardiovascular risk in a developing country: the Guangzhou Biobank Cohort Study

Background

In observational studies from western countries childhood emotional adversity is usually associated with adult cardiovascular disease. These findings are open to contextual biases making evidence from other settings valuable. We examined the association of a potential marker of childhood emotional adversity with cardiovascular disease risk factors in a developing country.

Methods

We used multivariable regression in cross-sectional analysis of older (≥50 years) men (n = 7,885) and women (n = 20,886) from the Guangzhou Biobank Cohort Study (2003–8) to examine the adjusted association of early life (<18 years) parental death (none, one or two deaths) with blood pressure, fasting glucose, LDL-cholesterol, HDL-cholesterol, triglycerides, body mass index (BMI), waist-hip ratio (WHR) and white blood cell count (WBC). We used seated height and delayed 10-word recall to assess content validity of parental death as a measure of childhood emotional adversity. We also examined whether associations varied by sex.

Results

Early life parental death was associated with shorter age- and sex-adjusted seated height. It was also associated with lower 10-word recall score adjusted for age, sex, socio-economic position, leg length and lifestyle. Similarly, adjusted early life parental death was not associated with blood pressure, fasting glucose, LDL-cholesterol or HDL-cholesterol but was associated with lower BMI (−0.40, 95% confidence interval (CI) −0.62 to −0.19 for 2 compared with no early life parental deaths) and triglycerides. Associations varied by sex for WHR and WBC. Among men only, early life parental death was associated with lower WHR (−0.008, 95% CI −0.015 to −0.001) and WBC (−0.35 10⁹/L, 95% CI −0.56 to −0.13).

Conclusions

In a non-western population from a developing country, childhood emotional adversity was negatively associated with some cardiovascular risk factors, particularly among men. Our study suggests that some of the observed associations in western populations may be socially rather than biologically based or may be population specific.

The influence of multiple indices of socioeconomic disadvantage across the adult life course on the metabolic syndrome: the Vietnam Experience Study

Few studies have explored the relationship between individual and combined multiple indicators of socioeconomic status across the life course and the metabolic syndrome, or attempted to understand the mechanisms underlying any associations. The present study examined the associations between 4 indicators of socioeconomic status, individually and in combination, and metabolic syndrome risk in a study of male US veterans and examined the influence of health behaviors, intelligence, and psychologic distress on these associations. Participants (N = 4253) were drawn from the Vietnam Experience Study. From military service files, telephone interviews, and a medical examination, occupational, sociodemographic, health behavior, intelligence, psychologic, and health data were collected. The 4 indices of socioeconomic status were as follows: education achieved, early adulthood income, household income in midlife, and occupational prestige in midlife. Metabolic syndrome was diagnosed from the following: body mass index, fasting blood glucose or a diagnosis of diabetes, blood pressure-a diagnosis of hypertension or taking antihypertensives, high-density lipoprotein cholesterol, and triglyceride levels. In models that adjusted for age, men in the lower 2 groups on the combined measure of socioeconomic status experienced a higher risk of metabolic syndrome. This association was accounted for mainly by education achieved, household income in midlife, and occupational prestige in midlife. Intelligence appeared to explain much of this association. Combined socioeconomic status measures across the life course were related to metabolic syndrome but in a threshold rather than dose-response manner. Intelligence appeared to mediate this relationship.

Is childhood meat eating associated with better later adulthood cognition in a developing population?

Inadequate childhood nutrition is associated with poor short-term academic and cognitive outcomes. Dietary supplementation with meat is associated with better cognitive outcome in children. Whether childhood nutrition has life long effects on cognitive function is unclear. We examined the association of childhood meat eating with adulthood cognitive function in southern China where the older population lived through significant hardship during their early years. Multivariable linear regression was used in a cross-sectional study of 20,086 Chinese men and women aged ≥ 50 years from the Guangzhou Biobank Cohort Study (phases 2 and 3) 2005–8. We assessed the association of childhood meat eating with delayed 10-word and immediate recall score. Adjusted for age, sex, education, childhood and adulthood socio-economic position and current physical activity, childhood meat eating almost daily, when compared to yearly or never childhood meat eating, was positively associated with delayed recall score (additional number of words recalled out of 10 = 0.22 [95% confidence interval = 0.11–0.31]). Similarly adjusted, childhood meat eating about once a month, about once a week and almost daily were positively associated with immediate recall score (additional number of words recalled out of 30 = 0.38 [0.23–0.54], 0.73 [0.56–0.89] and 0.76 [0.55–0.98] respectively). More frequent childhood meat eating was associated with better cognition through to old age. If confirmed, these results highlight the importance of adequate childhood nutrition and they also emphasise the childhood and adolescent antecedents of adult disease, with corresponding public health implications for healthy aging.

Estimated birth weight and adult cardiovascular risk factors in a developing southern Chinese population: a cross sectional study

Background

Birth weight is negatively associated with cardiovascular diseases and diabetes, but the associations are less well-established in developing populations where birth weight is often unavailable. We studied the association of birth weight and cardiovascular risk, using birth rank as an instrumental variable, in Southern China.

Methods

We used published data on birth weight by birth rank from an appropriate population and baseline data from the Guangzhou Biobank Cohort Study phases 2 & 3 (2005-8) to examine the adjusted associations, using instrumental variable analysis, of birth weight with clinically measured cardiovascular risk factors and the metabolic syndrome in older (≥ 50 years) men (n = 5,051) and women (n = 13,907).

Results

Estimated birth weight was associated with lower blood pressure (systolic -0.25 mm Hg 95% confidence interval (CI), -0.53 to 0.03 and diastolic -0.33 mm Hg 95% CI -0.48 to -0.18 per standard deviation higher birth weight), but had little association with glucose, lipids, waist-hip ratio, body mass index or the metabolic syndrome, adjusted for age, sex, early environment and number of offspring.

Conclusion

Birth weight may impact blood pressure; however associations of birth weight with other cardiovascular risk factors may not be related to foetal exposures, but speculatively could be an historical co-incidence, with corresponding implications for prevention.

Factors related to obesity among Iranian men: results from the National Health Survey

OBJECTIVE

To our knowledge, only a few Iranian studies have investigated factors associated with obesity among men. The aims of the present study were to explore the associations between sociodemographic factors, smoking and obesity in Iranian men and compare these associations between Iranian men and women.

DESIGN

We used data from the National Health Survey in Iran. A generalised estimating equations model included 11,697 men and 14,854 women aged 20-69 years (12,850 households). Body weight and height were objectively measured. BMI was calculated as kg/m2, and subjects were classified into obese (BMI >or= 30 kg/m2) and non-obese (BMI < 30 kg/m2).

RESULTS

Among men, adjusted obesity OR were 0.62 (95 % CI 0.52, 0.74), 1.09 (95 % CI 0.90, 1.32), 1.003 (95 % CI 1.00, 1.007) and 0.57 (95 % CI 0.40, 0.81) for smokers, married, economic index and active workforce groups, respectively. Using low education as the reference group, the obesity OR for men were 1.06 (95 % CI 0.89, 1.26) and 0.75 (95 % CI 0.57, 0.99) for the moderate and high education groups, respectively. Using rural as the reference group, the obesity OR was 1.87 (95 % CI 1.56, 2.26) for urban men.

CONCLUSIONS

Our findings may point towards a better understanding of the social and cultural mechanisms of obesity in Iranian men. The above sociodemographic factors are large contributors to obesity and provide the greatest opportunity for actions and interventions designed for prevention and treatment.

How does socioeconomic development affect risk of mortality? An age-period-cohort analysis from a recently transitioned population in China

During the 20th century, the Hong Kong Chinese population experienced 2 abrupt but temporally distinct macroenvironmental changes: The transition from essentially preindustrial living conditions to a rapidly developing economy through mass migration in the late 1940s was followed by the emergence of an infant and childhood adiposity epidemic in the 1960s. The authors aimed to delineate the effects of these 2 aspects of economic development on mortality, thus providing a sentinel for other rapidly developing economies. Sex-specific Poisson models were used to estimate effects of age, calendar period, and birth cohort on Hong Kong adult mortality between 1976 and 2005. All-cause and cause-specific mortality, including mortality from ischemic heart disease (IHD), cardiovascular disease excluding IHD, lung cancer, other cancers, and respiratory disease, were considered. Male mortality from IHD and female mortality from other cancers increased with birth into a more economically developed environment. Cardiovascular disease mortality increased with birth after the start of the infant and childhood adiposity epidemic, particularly for men. Macroenvironmental changes associated with economic development had sex-specific effects over the life course, probably originating in early life. The full population health consequences of these changes are unlikely to manifest until persons who have spent their early lives in such environments reach an age at which they become vulnerable to chronic diseases.

Intergenerational 'mismatch' and adiposity in a developing population: the Guangzhou biobank cohort study

Intergenerational 'mismatch' between maternal and adult environments, common in developing economies, has been hypothesized as contributing to obesity. In a rapidly developing population, we examined whether maternal conditions, proxied by maternal literacy, were associated with adult adiposity, proxied by body mass index (BMI) and waist-hip ratio (WHR) and whether these associations were modified by later life conditions, proxied by socio-economic position (SEP) at three life stages. We also examined if maternal conditions had sex-specific associations with adult adiposity. In a cross-sectional study of 19,957 adults (> or =50 years) from the Guangzhou Biobank Cohort Study (phases 2 and 3 in 2005-2008), we used multivariable linear regression to assess the association of maternal literacy with BMI and WHR, and whether the associations varied with sex, age or SEP. The adjusted association of maternal literacy with WHR varied with sex. In women, but not men, maternal illiteracy was associated with higher WHR and BMI, adjusted for age; these associations remained, although attenuated, after adjusting for lifestyle, life course SEP and paternal literacy. There was little evidence that associations varied with SEP at any stage, although continuity of poor conditions into early life may have exacerbated the association of maternal illiteracy with higher WHR in women. Poor maternal conditions in developing populations may increase vulnerability to adiposity in women. Whether such sex-specific intergenerational effects are driven by epigenetics, maternal sex hormones or other mechanisms, remains to be determined. However, mismatched maternal and later life conditions do not appear to be associated with adiposity. Our findings, although preliminary, imply that a transient epidemic of obesity may occur in the first generation of women who experience economic development.

Differences in the association of cardiovascular risk factors with education: a comparison of Costa Rica (CRELES) and the USA (NHANES)

Background

Despite different levels of economic development, Costa Rica and the USA have similar mortalities among adults. However, in the USA there are substantial differences in mortality by educational attainment, and in Costa Rica there are only minor differences. This contrast motivates an examination of behavioural and biological correlates underlying this difference.

Methods

The authors used data on adults aged 60 and above from the Costa Rican Longevity and Healthy Ageing Study (CRELES) (n=2827) and from the US National Health and Nutrition Examination Survey (NHANES) (n=5607) to analyse the cross-sectional association between educational level and the following risk factors for cardiovascular disease (CVD): ever smoked, current smoker, sedentary, high saturated fat, high carbohydrates, high calorie diet, obesity, severe obesity, large waist circumference, HDL cholesterol, LDL cholesterol, triglycerides, hemoglobin A1c, fasting glucose, C-reactive protein, systolic blood pressure and BMI.

Results

There were significantly fewer hazardous levels of risk biomarkers at higher levels of education for more than half (10 out of 17) of the risk factors in the USA, but for less than a third of the outcomes in Costa Rica (five out of 17).

Conclusions

These results are consistent with the context-specific nature of educational differences in risk factors for CVD and with a non-uniform nature of association of CVD risk factors with education within countries. Our results also demonstrate that social equity in mortality is achieved without uniform equity in all risk factors.

Prior TB, smoking, and airflow obstruction: a cross-sectional analysis of the Guangzhou Biobank Cohort Study

BACKGROUND

Prior pulmonary TB has been shown to be associated with a higher risk of airflow obstruction, which is the hallmark of COPD, but whether smoking modifies this relationship is unclear. We investigated the relationships between prior TB, smoking, and airflow obstruction in a Chinese population sample.

METHODS

Participants in the Guangzhou Biobank Cohort Study underwent spirometry, chest radiography, and a structured interview on lifestyle and exposures. Prior TB was defined as the presence of radiologic evidence suggestive of inactive TB. Airflow obstruction was based on spirometric criteria.

RESULTS

The prevalence of prior TB in this sample (N = 8,066, mean age: 61.9 years) was 24.2%. After controlling for sex, age, and smoking exposure, prior TB remained independently associated with an increased risk of airflow obstruction (odds ratio = 1.37; 95% CI, 1.13-1.67). Further adjustment for exposure to passive smoking, biomass fuel, and dust did not alter the relationship. Smoking did not modify the relationship between prior TB and airflow obstruction.

CONCLUSIONS

Prior TB is an independent risk factor for airflow obstruction, which may partly explain the higher prevalence of COPD in China. Clinicians should be aware of this long-term risk in individuals with prior TB, irrespective of smoking status, particularly in patients from countries with a high TB burden.

Life course socioeconomic conditions and metabolic syndrome in adults: the Atherosclerosis Risk in Communities (ARIC) Study

PURPOSE

This study examined the effect of childhood, adulthood, and cumulative socioeconomic status (cumSES) on the prevalence of metabolic syndrome (MetS) in middle-aged adults in the Atherosclerosis Risk in Communities Study (1987-1989).

METHODS

Participants included 2,461 black and 8,536 white men and women 45 to 64 years of age without diabetes. Socioeconomic status (SES) measures from childhood, early adulthood, and mature adulthood were used to create a cumSES score. Childhood SES, early adult SES, mature adult SES and cumSES scores were grouped into two categories (high/low). Age- and center-adjusted prevalence ratios and 95% confidence intervals for MetS, using the Third Report of the Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (ATP III) criteria, by SES were estimated by log-linear regression for race-sex groups.

RESULTS

Black and white women with low childhood SES, early adult SES, mature adult SES or cumSES were more likely to have the MetS than those with high SES. These associations remained after adjustment for physical activity, smoking status, and drinking status. In contrast, there was no association of SES with MetS in men.

CONCLUSIONS

Our findings suggest that socioeconomic disadvantage early in life and across the life course influences risk of the MetS in black and white women.

Individual socioeconomic factors conditioning cardiovascular disease risk

BACKGROUND

Our objective is to ascertain whether the socioeconomic situation of individuals has an influence on the cardiovascular disease (CVD) risk estimation.

METHODS

The subjects were part of VAMPAHICA study and had been recently diagnosed as hypertensive. The study subjects were seen in primary care centers, were aged between 15 and 75 years and have never been treated for hypertension (HT). Normotensive individuals were also included in the study sample. All individuals answered a questionnaire that included questions related to sociodemographic and socioeconomic variables as well as habit and lifestyle variables. Of a total of 424 individuals initially invited to answer the questionnaire, 388 finally did so. Due to missing data in the dependent variables, 304 individuals were included in the European Society of Hypertension (ESH) risk tables and 287 in the Systematic Coronary Risk Evaluation (SCORE) tables. The response variable CVD risk, which is a polytomic variable, was estimated using an ordered probit model.

RESULTS

We found that individual's socioeconomic status, expressed mainly as their level of education, was an independent variable that had repercussions on the estimated CVD risk. This finding was more evident in the SCORE tables, and when risk was stratified according to the ESH tables the repercussions were only marginal. In particular, we found that individuals with only primary education had a 27% higher probability of CVD risk (> or =5%) in the SCORE tables, whereas individuals with a higher level of education had 50% less probability of high risk.

CONCLUSIONS

The CVD risk estimation tables for the general population (SCORE) reflect the socioeconomic factor better than the CVD risk stratification tables for HT (ESH tables). Target organ damage (TOD) is an important factor for stratifying risk in the ESH tables; however, the SCORE tables do not take this into account. Therefore, socioeconomic factors may already be incorporated in the ESH tables through an intermediate variable, such as TOD.

Association of educational level with risk of obesity and abdominal obesity in Iranian adults

BACKGROUND

The impact of education on obesity may vary according to population and geographic region. The objective of the present study was to determine the association between education and obesity.

METHODS

A cross-sectional study of 3600 subjects aged 20-70 years was conducted by using a cluster sampling technique in an adult population residing in the north of Iran, in 2004. Weight, height, waist and hip circumference were measured and data concerning education level, demographic characteristics and physical activities were collected by interview. Logistic regression analysis was used to estimate the association between education and general obesity (body mass index >or=30) as well as abdominal obesity (waist circumference >88 cm in women and 102 cm in men).

RESULTS

The adjusted odds ratio (OR) for general obesity at education level of high school and college compared with illiterate and primary level was 0.55 [95% confidence interval (CI): 0.43-0.71]. A greater negative association was observed for education at university level (OR = 0.32, 95% CI: 0.22-0.47) irrespective to sex. However, with regard to abdominal obesity, after controlling for confounding factors, the adjusted OR for education at university level remained significant only in women but not in men.

CONCLUSION

The findings of this study indicate that education level is inversely associated with general obesity in both sexes but with abdominal obesity only in women.

Life-course socio-economic factors, skin colour and abdominal obesity in adulthood in a Brazilian birth cohort

OBJECTIVE

Obesity is an increasingly prevalent nutritional disorder throughout the world. In particular, abdominal obesity is associated with cardiovascular and metabolic risk. The present study aimed to evaluate the effects of skin colour and life-course socio-economic indicators on waist circumference (WC), hip circumference (HC) and waist:hip ratio (WHR) in young adults.

DESIGN

Population-based birth cohort study. Individuals born in 1982 in Pelotas (southern Brazil) were visited on a number of occasions from birth to age 23-24 years. A sample of the cohort was sought in 2006 and 972 individuals were located. The analysis was restricted to individuals with complete data available (442 males, 414 females).

RESULTS

In men, family income at birth and in 2004-5 were positively associated with WC and HC, but not with WHR. Regardless of current income, men born to wealthier families had larger WC and HC as adults. Skin colour was not associated with any of the outcomes. In women, early poverty was associated with smaller HC, and current poverty with larger WC. Poverty at any age thus led to higher WHR. Black women had larger WC and HC than white women, but there were no differences in WHR. All the associations were partially mediated by education and behavioural variables.

CONCLUSIONS

The effects of early socio-economic position on WC and HC persist even after adjustment for adult socio-economic position, highlighting the importance of interventions during the first years of life.

Associations between childhood socioeconomic position and adulthood obesity

Childhood socioeconomic position (SEP) is inversely associated with cardiovascular disease and all-cause mortality. Obesity in adulthood may be a biologic mechanism. Objectives were to systematically review literature published between 1998 and 2008 that examined associations of childhood SEP with adulthood obesity. Five databases (Cochrane Library, MEDLINE, EMBASE, PsycINFO, Web of Science) were searched for studies from any country, in any language. Forty-eight publications based on 30 studies were identified. In age-adjusted analyses, inverse associations were found between childhood SEP and adulthood obesity in 70% (14 of 20) of studies in females and 27% (4 of 15) in males. In studies of females showing inverse associations between childhood SEP and adulthood obesity, typical effect sizes in age-adjusted analyses for the difference in body mass index between the highest and lowest SEP were 1.0-2.0 kg/m(2); for males, effect sizes were typically 0.2-0.5 kg/m(2). Analyses adjusted for age and adult SEP showed inverse associations in 47% (8 of 17) of studies in females and 14% (2 of 14) of studies in males. When other covariates were additionally adjusted for, inverse associations were found in 4 of 12 studies in females and 2 of 8 studies in males; effect sizes were typically reduced compared with analyses adjusted for age only. In summary, the findings suggest that childhood SEP is inversely related to adulthood obesity in females and not associated in males after adjustment for age. Adulthood SEP and other obesity risk factors may be the mechanisms responsible for the observed associations between childhood SEP and adulthood obesity.

Childhood poverty and abdominal obesity in adulthood: a systematic review

Adverse socioeconomic conditions in childhood can have lasting effects on health, but evidence is lacking from prospective studies concerning the effects of early poverty on abdominal obesity in adulthood. Cross-sectional studies in adults from middle and high-income countries show that current socioeconomic status is inversely related to obesity in women, but the pattern in men is not consistent. A systematic review was undertaken to assess the influence of early socioeconomic status on waist circumference, hip circumference, and waist-hip ratio in adulthood. Thirteen relevant articles were located (five cross-sectional and eight cohort), including only one from a middle-income country and the remainder from high-income settings. In all the studies, childhood poverty was associated with higher levels of abdominal obesity in women. In men, the associations were weaker, and no clear pattern emerged.