Michelle Kelly-Irving

Socioeconomic status and the 25 × 25 risk factors as determinants of premature mortality: A multicohort study and meta-analysis of 1·7 million men and women

Summary Background In 2011, WHO member states signed up to the 25 × 25 initiative, a plan to cut mortality due to non-communicable diseases by 25% by 2025. However, socioeconomic factors influencing non-communicable diseases have not been included in the plan. In this study, we aimed to compare the contribution of socioeconomic status to mortality and years-of-life-lost with that of the 25 × 25 conventional risk factors. Methods We did a multicohort study and meta-analysis with individual-level data from 48 independent prospective cohort studies with information about socioeconomic status, indexed by occupational position, 25 × 25 risk factors (high alcohol intake, physical inactivity, current smoking, hypertension, diabetes, and obesity), and mortality, for a total population of 1 751 479 (54% women) from seven high-income WHO member countries. We estimated the association of socioeconomic status and the 25 × 25 risk factors with all-cause mortality and cause-specific mortality by calculating minimally adjusted and mutually adjusted hazard ratios [HR] and 95% CIs. We also estimated the population attributable fraction and the years of life lost due to suboptimal risk factors. Findings During 26·6 million person-years at risk (mean follow-up 13·3 years [SD 6·4 years]), 310 277 participants died. HR for the 25 × 25 risk factors and mortality varied between 1·04 (95% CI 0·98–1·11) for obesity in men and 2 ·17 (2·06–2·29) for current smoking in men. Participants with low socioeconomic status had greater mortality compared with those with high socioeconomic status (HR 1·42, 95% CI 1·38–1·45 for men; 1·34, 1·28–1·39 for women); this association remained significant in mutually adjusted models that included the 25 × 25 factors (HR 1·26, 1·21–1·32, men and women combined). The population attributable fraction was highest for smoking, followed by physical inactivity then socioeconomic status. Low socioeconomic status was associated with a 2·1-year reduction in life expectancy between ages 40 and 85 years, the corresponding years-of-life-lost were 0·5 years for high alcohol intake, 0·7 years for obesity, 3·9 years for diabetes, 1·6 years for hypertension, 2·4 years for physical inactivity, and 4·8 years for current smoking. Interpretation Socioeconomic circumstances, in addition to the 25 × 25 factors, should be targeted by local and global health strategies and health risk surveillance to reduce mortality. Funding European Commission, Swiss State Secretariat for Education, Swiss National Science Foundation, the Medical Research Council, NordForsk, Portuguese Foundation for Science and Technology.

Adverse childhood experiences and physiological wear-and-tear in midlife: Findings from the 1958 British birth cohort

Significance The role of early life experiences on health is of major concern to research. Recent studies have shown that chronic stress may “get under the skin” to alter human developmental processes and impact later health. Our findings suggest that early negative circumstances during childhood, collected prospectively in a British birth cohort, could be associated with physiological wear-and-tear in midlife as measured by allostatic load. This relationship was largely explained by health behaviors, body mass index, and socioeconomic status in adulthood, but not entirely. These results suggest that a biological link between adverse childhood exposures and adult health may be plausible. Our findings contribute to the development of more adapted public health interventions, both at a societal and individual level. Allostatic load (AL) is a measure of overall physiological wear-and-tear over the life course, which could partially be the consequence of early life exposures. AL could allow a better understanding of the potential biological pathways playing a role in the construction of the social gradient in adult health. To explore the biological embedding hypothesis, we examined whether adverse childhood experiences (ACEs) are associated with elevated AL in midlife. We used imputed data on 3,782 women and 3,753 men of the National Child Development Study in Britain followed up seven times. ACEs were measured using prospective data collected at ages 7, 11, and 16. AL was operationalized using data from the biomedical survey collected at age 44 on 14 parameters representing four biological systems. We examined the role of adult health behaviors, body mass index (BMI), and socioeconomic status as potential mediators using a path analysis. ACEs were associated with higher AL for both men and women after adjustment for early life factors and childhood pathologies. The path analysis showed that the association between ACEs and AL was largely explained by early adult factors at age 23 and 33. For men, the total mediated effect was 59% (for two or more ACEs) via health behaviors, education level, and wealth. For women, the mediated effect represented 76% (for two or more ACEs) via smoking, BMI, education level, and wealth. Our results indicate that early psychosocial stress has an indirect lasting impact on physiological wear-and-tear via health behaviors, BMI, and socioeconomic factors in adulthood.

The embodiment of adverse childhood experiences and cancer development: potential biological mechanisms and pathways across the life course

ObjectivesTo explore current evidence of the physiological embedding of stress to discuss whether adverse childhood experiences (ACE) causing chronic or acute stress responses may alter fundamental biological functions.MethodsA non-systematic review of the literature was carried out using keyword searches in Pubmed and the web of science from May to October 2011. In reference to the literature identified, we examine the potential biological pathways potentially linking exposure to ACE and cancer development and progression in adulthood.ResultsThese mechanisms, in interaction with social position, and mediated by subsequent environmental exposures, may ultimately lead to the development of cancer. The experience of acute or chronic stressors during sensitive periods of childhood development which can induce several known biological responses, are likely to have an impact on subsequent biological and behavioural functions depending on the timing of initial exposures, and subsequently mediated by later exposures. For this reason, childhood exposure to adversity is a likely source of both acute and chronic stressors, and can be examined as an important initial exposure on a pathway towards adult ill health.ConclusionsSuch pathways justify a life course approach to understanding cancer aetiology, which may have its origins early in life.

Social Determinants of Cardiovascular Diseases

Social determinants of health can be understood as the social conditions in which individuals live and work; conditions that are shaped by the distribution of power, income and resources, as much on a global and national level as on a local level. Social determinants of cardiovascular diseases are found largely outside the healthcare and preventative healthcare systems; but it is important to think in terms of chains of cause and effect, which enable us to see these determinants at work within the system of curative and preventative care, including the management of traditional risk factors. Taking a dynamic perspective on these social determinants of health, and in particular viewing them in a biological and epidemiological context, emphasizes the fact that intervention as early in life as possible is desirable in order to prevent cardiovascular diseases. It is important to act early, before childhood adversities in these critical periods are permanently or irrevocably recorded in the body. In terms of behaviour, focussing health education on adults runs counter to the fact that, with age, it is increasingly difficult to change our behaviour and to overcome biological damage already inflicted. In an area where attention has long been focussed on individual risk factors, underlining the fact that these factors act from infancy allows us to highlight the collective influences on the development of these diseases. Reflecting on health determinants in this way suggests that perhaps the population strategy proposed by Geoffrey Rose may lead to an increase in social inequalities if the modest decrease in risk factors, for example in terms of nutrition, involves the population categories initially most privileged.

SRH and HrQOL: does social position impact differently on their link with health status?

BackgroundSelf-rated Health (SRH) and health-related quality of life (HRQoL) are used to evaluate health disparities. Like all subjective measures of health, they are dependent on health expectations that are associated with socioeconomic characteristics. It is thus needed to analyse the influence played by socioeconomic position (SEP) on the relationship between these two indicators and health conditions if we aim to use them to study health disparities. Our objective is to assess the influence of SEP on the relationship between physical health status and subjective health status, measured by SRH and HRQoL using the SF-36 scale.MethodsWe used data from the French National Health Survey. SEP was assessed by years of education and household annual income. Physical health status was measured by functional limitations and chronic low back pain.ResultsRegardless of their health status, people with lower SEP were more likely than their more socially advantaged counterparts to report poor SRH and poorer HRQoL, using any of the indicators of SEP. The negative impact of chronic low back pain on SRH was relatively greater in people with a high SEP than in those with a low SEP. In contrast, chronic low back pain and functional limitations had less impact on physical and mental component scores of quality of life for socially advantaged men and women.ConclusionsBoth SRH and HRQoL were lower among those reporting functional limitations or chronic low back pain. However, the change varied according SEP and the measure. In relative term, the negative impact of a given health condition seems to be greater on SRH and lower on HRQoL for people with higher SEP in comparison with people with low SEP. Using SRH could thus decrease socioeconomic differences. In contrast using HRQoL could increase these differences, suggesting being cautious when using these indicators for analyzing health disparities.

Controlling arterial hypertension in the French West Indies: a separate strategy for women?

BACKGROUND To estimate the prevalence, awareness and treatment of arterial hypertension in Guadeloupe. METHODS In 2007, a cross-sectional study of 1005 men and women (54%) aged 25-74 years from Guadeloupe, stratified by sex, age and region was set up to determine the prevalence of hypertension. Blood pressure (BP) was measured using an automated device and hypertension was defined as having a mean BP ≥ 140/90 mmHg or receiving drug treatment. RESULTS The prevalence of hypertension was 33% for men and 37% for women (P = 0.62). Among hypertensive respondents, 57% of men and 80% of women were aware of being hypertensive (P < 0.001). BP was controlled for 22 and 44% of hypertensive men and women, respectively (P < 0.001). Compared with men (14%), 31% of women were obese (≥ 30 kg/m²). In multivariate analyses, body mass index (BMI) was associated with hypertension in both sexes after controlling for age, occupation, education, alcohol consumption, smoking status and physical activity. Compared with subjects with a normal BMI, obese men were three times [odds ratio (OR) = 3.4, 95% confidence interval (CI) = 1.8-6.6 P < 0.001] and obese women two times more likely (OR = 2.0, 95% CI = 1.2-3.4, P = 0.017) to be hypertensive. In women, low educational attainment was also associated with hypertension (OR = 2.1 95% CI = 1.1-4.0, P = 0.030) and mean diastolic BP decreased as educational attainment increased after controlling for confounders (F = 5.0, df 2, P = 0.007). CONCLUSIONS Strong gender disparities in hypertension were identified. Separate strategies in addressing hypertension in men and women are needed, with an improvement in mens follow-up care and health promotion, focussed on nutrition, targeted at women.

Blood pressure and working conditions in hospital nurses and nursing assistants. The ORSOSA study

BACKGROUND Healthcare workers often are unsatisfied with their working conditions despite declaring to like their jobs. Psychosocial constraints in the workplace have increased recently due to changes in work organization. These psychosocial constraints are linked to cardiovascular diseases. AIM To analyze the relationship between blood pressure levels and organizational occupational risk factors in female hospital workers, using a new questionnaire (the Nursing Work Index-Extended Organization [NWI-EO] questionnaire), which quantifies psychological and organizational work factors. METHODS The ORSOSA study is a national, multicentre, cohort study conducted in seven voluntary French university hospitals, including 214 work units with a total of 2307 nurses and 1530 nursing assistants. RESULTS Systolic and diastolic blood pressure appeared to be significantly associated with age (P<0.001) and excess weight (P<0.001). The difference between systolic blood pressure in day-shift and night-shift workers was 2.5mmHg (P<0.001). The NWI-EO dimension most strongly correlated with systolic and diastolic blood pressure was poor team relationships (P<0.01 for both). For a one-point difference in the NWI-EO stress score, systolic blood pressure was higher by a mean of 0.2mmHg. CONCLUSION These results suggest that poor relationships within teams are related to high blood pressure among hospital workers. They add to the evidence that working conditions should be considered and investigated further among other risk factors as a pathway to primary prevention of hypertension and cardiovascular diseases.

A life course approach to explore the biological embedding of socioeconomic position and social mobility through circulating inflammatory markers.

Lower socioeconomic position (SEP) has consistently been associated with poorer health. To explore potential biological embedding and the consequences of SEP experiences from early life to adulthood, we investigate how SEP indicators at different points across the life course may be related to a combination of 28 inflammation markers. Using blood-derived inflammation profiles measured by a multiplex array in 268 participants from the Italian component of the European Prospective Investigation into Cancer and Nutrition cohort, we evaluate the association between early life, young adulthood and later adulthood SEP with each inflammatory markers separately, or by combining them into an inflammatory score. We identified an increased inflammatory burden in participants whose father had a manual occupation, through increased plasma levels of CSF3 (G-CSF; β = 0.29; P = 0.002), and an increased inflammatory score (β = 1.96; P = 0.029). Social mobility was subsequently modelled by the interaction between father’s occupation and the highest household occupation, revealing a significant difference between “stable Non-manual” profiles over the life course versus “Manual to Non-manual” profiles (β = 2.38, P = 0.023). Low SEP in childhood is associated with modest increase in adult inflammatory burden; however, the analysis of social mobility suggests a stronger effect of an upward social mobility over the life course.

What role does socio-economic position play in the link between functional limitations and self-rated health: France vs. USA?

BACKGROUND Our objective was to analyse the influence of education on the link between functional limitation (FL) and self-rated health (SRH) in two countries, France and the USA. METHODS The data of the North American NHANES study (n = 9254) and the French National Health Survey (n = 25 559) were used. FL was measured by the ADL and IADL scales. We constructed a logistic regression model with SRH as the outcome and included variables for education, FL and the interaction between education and FL. All results were adjusted for age. RESULTS Poor SRH was more frequently reported in France than in the USA (24.1% vs. 18.4% for men, 29.0% vs. 19.7% for women). The most highly educated persons in the USA had similar FL (25.4% for men, 32.9% for women) to the least educated French persons (22.8% for men, 31.8% for women). In the USA, FL was associated more strongly with poor SRH in the most educated men than in the least educated. In France, the same interaction was observed although the link was weaker than in the USA. FL was more strongly associated with poor SRH in the most educated women than in the least educated in both countries. CONCLUSION Functional limitation had a greater impact on the most highly educated persons in both France and the USA. Using SRH as a measure of health for evaluating social inequalities could lead to underestimation of the true magnitude of functional health inequalities existing within and between countries.

Biological marks of early-life socioeconomic experience is detected in the adult inflammatory transcriptome

Consistent evidence is accumulating to link lower socioeconomic position (SEP) and poorer health, and the inflammatory system stands out as a potential pathway through which socioeconomic environment is biologically embedded. Using bloodderived genome-wide transcriptional profiles from 268 Italian participants of the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, we evaluated the association between early life, young and later adulthood SEP and the expression of 845 genes involved in human inflammatory responses. These were examined individually and jointly using several inflammatory scores. Our results consistently show that participants whose father had a manual (as compared to nonmanual) occupation exhibit, later in life, a higher inflammatory score, hence indicating an overall increased level of expression for the selected inflammatory-related genes. Adopting a life course approach, these associations remained statistically significant upon adjustment for later-in-life socioeconomic experiences. Sensitivity analyses indicated that our findings were not affected by the way the inflammatory score was calculated, and were replicated in an independent study. Our study provides additional evidence that childhood SEP is associated with a sustainable upregulation of the inflammatory transcriptome, independently of subsequent socioeconomic experiences. Our results support the hypothesis that early social inequalities impacts adult physiology.