The Association between Educational Level and Cardiovascular and Cerebrovascular Diseases within the EPICOR Study: New Evidence for an Old Inequality Problem

Physical activity modification over time according to socioeconomic position: results from the EPIC-Italy cohort study

Objectives

Our study aimed to investigate how physical activity (PA) changes over an 11-year follow-up among adults from different socioeconomic positions (SEP) near retirement age. Moreover, an analysis of different PA types is considered.

Methods

We used data from the EPIC-Italy cohort. We evaluated PA using the Cambridge Physical Activity Index (CPAI) and the metabolic equivalent of tasks (MET) per hour of activity for recreational PA and household PA. Educational level was assessed using the Relative Index of Inequality (RII). Occupational classes were classified according to LIFEPATH Consortium knowledge. Logistic regression was used to analyse PA among SEP and changes during follow-up. Analyses were also conducted separately for sex.

Results

The higher educated were more prevalent in the higher quartile of recreational PA than the lower educated both at baseline and follow-up (37% vs 28% and 37% vs 27%, respectively). At the baseline, the lower educated had a higher risk of being physically inactive than the higher educated based on recreational PA (overall OR: 1.50, 95% CI 1.40 to 1.60). Manual workers did not show a higher risk of less PA than professionals/managers (overall OR: 1.03, 95% CI 0.91 to 1.16).At follow-up, the lower educated and manual workers showed a higher risk of being physically inactive (lower educated OR: 1.46, 95% CI 1.37 to 1.56; manual worker OR: 1.33, 95% CI 1.18 to 1.50). The analyses of changes in PA showed that those who were less educated or manual workers had a higher risk of worsening their PA during the follow-up period, particularly women in recreational PA and men in CPAI measurement.

Conclusion

Individuals who had a disadvantaged SEP showed a higher risk of performing less PA over time.

Serum heavy metals and breast cancer risk: A case-control study nested in the Florence cohort of the EPIC (European Prospective Investigation into Cancer and nutrition) study

BACKGROUND

Chronic exposure to heavy metals is of concern for its potential carcinogenic effect. An association with increased breast cancer (BC) risk was hypothesized, but literature data are conflicting and the question remains unresolved. We aimed to investigate the association between heavy metals and BC risk in a case-control study nested within the Florence section of the EPIC (European Prospective Investigation into Cancer and nutrition) cohort.

METHODS

We included 150 BC cases and an equal number of controls individually matched to cases by age and year of enrolment. In order to avoid confounding by smoking, the study was restricted to never smokers. Serum levels of six heavy metals (Cd, Co, Cr, Mn, Pb, and Tl) were quantified in pre-diagnostic samples using inductively coupled plasma mass spectrometry. Odds ratios (ORs) and corresponding 95 % confidence intervals (CI) were calculated via multivariable conditional logistic regression models.

RESULTS

Serum levels of cobalt were inversely associated with BC risk (OR for the comparison of 3rd vs. 1st tertiles: 0.33, 95 % CI 0.12-0.91, p-value 0.033). None of the other heavy metals under study was significantly associated with BC risk in multivariable models. For Cd, Cr, and Tl, over half of the study participants had serum levels below the limit of quantitation.

CONCLUSIONS

Our results do not support the hypothesis that exposure to heavy metals is associated with an increased BC risk among never smokers from the general population. The inverse association between cobalt serum levels and BC risk requires confirmation in future studies.

Mediating Role of Lifestyle Behaviors in the Association between Education and Cancer: Results from the European Prospective Investigation into Cancer and Nutrition

BACKGROUND

Many studies have shown that socioeconomic position (SEP) is associated with the incidence of malignant tumors at different sites. This study aims to estimate the association between educational level (as proxy for SEP) and cancer incidence and to understand whether the observed associations might be partially explained by lifestyle behaviors.

METHODS

The analyses were performed on data from the European Prospective Investigation into Cancer and Nutrition (EPIC) study, globally and by sex. We used Cox proportional hazards models together with mediation analysis to disentangle the total effect (TE) of educational level [measured through the Relative Index of Inequality (RII)] on cancer incidence into pure direct (PDE) and total indirect (TIE) effect, unexplained and explained by mediators, respectively. PDE and TIE were then combined to compute the proportions mediated (PM).

RESULTS

After an average of 14 years of follow-up, 52,422 malignant tumors were ascertained. Low educated participants showed higher risk of developing stomach, lung, kidney (in women), and bladder (in men) cancers, and, conversely, lower risk of melanoma and breast cancer (in post-menopausal women), when compared with more educated participants. Mediation analyses showed that portions of the TE of RII on cancer could be explained by site-specific related lifestyle behaviors for stomach, lung, and breast (in women).

CONCLUSIONS

Cancer incidence in Europe is determined at least in part by a socioeconomically stratified distribution of risk factors.

IMPACT

These observational findings support policies to reduce cancer occurrence by altering mediators, such as lifestyle behaviors, particularly focusing on underprivileged strata of the population.

Is area-level socioeconomic deprivation associated with mortality due to circulatory system diseases in Poland?

BACKGROUND

Socioeconomic deprivation (SED) is known to influence cardiovascular health. However, studies analyzing the relationship between deprivation and circulatory system diseases (CSD) in Central and Eastern Europe are limited. This study aimed to assess the relationship between SED and mortality due to CSD at a population level in 66 sub-regions of Poland.

METHODS

The 2010-2014 data regarding mortality and SED components were obtained from the Central Statistical Office. An area-based SED index was calculated based on the higher education rates, employment structure, wages, unemployment, and poverty. The dynamics of changes in mortality due to CSD was expressed by the number of deaths prevented or postponed (DPP) in terciles of the SED index. The associations between the mortality from CSD and SED index were analyzed using multivariate Poisson regression models and generalized estimating equations.

RESULTS

Among men, the percentage of DPP in 2014 was 13.1% for CSD, 23.4% for ischemic heart disease (IHD), and 21.4% for cerebrovascular diseases (CeVD). In the case of women, the proportion of DPP was 12.8, 25.6, and 21.6%, respectively. More deprived sub-regions experienced a greater decrease in CSD-related mortality than less deprived sub-regions. The disparity in mortality reduction between more deprived and less deprived sub-regions was even more pronounced for women. After adjusting for smoking prevalence, average BMI, population density, and changes in mortality over time, it was found that the SED index over the 2010-2014 time period was significantly associated with CSD- and IHD-related mortality for men (respectively 5.3 and 19.5% expected mortality increase per 1-unit increase of SED index), and with IHD- and CeVD-related mortality for women (respectively 30.3 and 23.0% expected mortality increase per 1-unit increase of SED index).

CONCLUSIONS

Significant differences in mortality changes due to CSD in Poland could be observed in relation to socioeconomic deprivation, resulting in reduced health inequalities. To reduce CSD mortality, more comprehensive preventive measures, including approaches addressing the socioeconomic factors, mainly poverty, education and employment, are needed, particularly in less urbanized areas.

Education inequalities in cardiovascular and coronary heart disease in Italy and the role of behavioral and biological risk factors

BACKGROUND AND AIMS

Behavioral and biological risk factors (BBRF) explain part of the variability in socioeconomic differences in health. The present study aimed at evaluating education differences in incidence of cardiovascular disease (CVD) and coronary heart disease (CHD) in Italy and the role of BBRF.

METHODS AND RESULTS

All subjects aged 30-74 years (n = 132,686) who participated to the National Health Interview Surveys 2000 and 2005 were included and followed-up for ten years. Exposure to smoking, physical activity, overweight/obesity, diabetes and hypertension at baseline was considered. Education level was used as an indicator of socioeconomic status. The outcomes were incident cases of CVD and CHD. Hazard ratios by education level were estimated, adjusting for sociodemographic covariates and stratifying by sex and geographic area. The contribution of BBRF to education inequalities was estimated by counterfactual mediation analysis, in addition to the assessment of the risk attenuation by comparing the models including BBRF or not. 22,214 participants had a CVD event and 6173 a CHD event. After controlling for sociodemographic factors, the least educated men showed a 21% higher risk of CVD and a 17% higher risk of CHD compared to the most educated (41% and 61% among women). The mediating effect (natural indirect effect) of BBRF between extreme education levels was 52% for CVD and 84% for CHD among men (16% among women for CVD).

CONCLUSIONS

More effective strategies aiming at reducing socioeconomic disparities in CVD and CHD are needed, through programs targeting less educated people in combination with community-wide initiatives.

Associations of dairy product consumption with mortality in the European Prospective Investigation into Cancer and Nutrition (EPIC)-Italy cohort

BACKGROUND

The relation of dairy product consumption to health and mortality is controversial.

OBJECTIVES

We investigated associations of consumption of various dairy products with mortality in the Italian cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC)-Italy study.

METHODS

Dairy product consumption was assessed by validated semiquantitative FFQs. Multivariable Cox models stratified by center, age, and sex and adjusted for confounders estimated associations of milk (total, full fat, and reduced fat), yogurt, cheese, butter, and dairy calcium consumption with mortality for cancer, cardiovascular disease, and all causes. Nonlinearity was tested by restricted cubic spline regression.

RESULTS

After a median follow-up of 14.9 y, 2468 deaths were identified in 45,009 participants: 59% from cancer and 19% from cardiovascular disease. No significant association of consumption of any dairy product with mortality was found in the fully adjusted models. A 25% reduction in risk of all-cause mortality was found for milk intake from 160 to 120 g/d (HR: 0.75; 95% CI: 0.61, 0.91) but not for the highest (>200 g/d) category of intake (HR: 0.95; 95% CI: 0.84, 1.08) compared with nonconsumption. Associations of full-fat and reduced-fat milk consumption with all-cause and cause-specific mortality were similar to those for milk as a whole.

CONCLUSIONS

In this Italian cohort characterized by low to average milk consumption, we found no evidence of a dose-response association between milk consumption and mortality and also no association of consumption of other dairy products investigated with mortality.

DNA methylation, colon cancer and Mediterranean diet: results from the EPIC-Italy cohort

The biological mechanisms through which adherence to Mediterranean Diet (MD) protects against colon cancer (CC) are poorly understood. Evidence suggests that chronic inflammation may be implicated in the pathway. Both diet and CC are related to epigenetic regulation. We performed a nested case-control study on 161 pairs from the Italian component of the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort, in which we looked for the methylation signals in DNA extracted from leucocytes associated with both CC and MD in 995 CpGs located in 48 inflammation genes. The DNA methylation signals detected in this analysis were validated in a subgroup of 47 case-control pairs and further replicated (where validated) in 95 new pairs by means of pyrosequencing. Among the CpG sites selected a-priori in inflammation-related genes, seven CpG sites were found to be associated with CC status and with MD, in line with its protective effect. Only two CpG sites (cg17968347-SERPINE1 and cg20674490-RUNX3) were validated using bisulphite pyrosequencing and, after replication, we found that DNA methylation of cg20674490-RUNX3 may be a potential molecular mediator explaining the protective effect of MD on CC onset. The use of a 'meet-in-the-middle' approach to identify the overlap between exposure and predictive markers of disease is innovative in studies on the relationship between diet and cancer, in which exposure assessment is difficult and the mechanisms through which the nutrients exert their protective effect is largely unknown.

Education, sex and risk of stroke: a prospective cohort study in New South Wales, Australia

OBJECTIVE

To determine whether the association between highest educational attainment and stroke differed by sex and age; and whether potential mediators of observed associations differ by sex.

DESIGN

Prospective cohort study.

SETTING

Population based, New South Wales, Australia.

PARTICIPANTS

253 657 stroke-free participants from the New South Wales 45 and Up Study.

OUTCOME MEASURES

First-ever stroke events, identified through linkage to hospital and mortality records.

RESULTS

During mean follow-up of 4.7 years, 2031 and 1528 strokes occurred among men and women, respectively. Age-standardised stroke rate was inversely associated with education level, with the absolute risk difference between the lowest and highest education group greater among women than men. In relative terms, stroke risk was slightly more pronounced in women than men when comparing low versus high education (age-adjusted HRs: 1.41, 95% CI 1.16 to 1.71 and 1.25, 95% CI 1.07 to 1.46, respectively), but there was no clear evidence of statistical interaction. This association persisted into older age, but attenuated. Much of the increased stroke risk was explained by modifiable lifestyle factors, in both men and women.

CONCLUSION

Low education is associated with increased stroke risk in men and women, and may be marginally steeper in women than men. This disadvantage attenuates but persists into older age, particularly for women. Modifiable risk factors account for much of the excess risk from low education level. Public health policy and governmental decision-making should reflect the importance of education, for both men and women, for positive health throughout the life course.