Decomposing the educational gradient in allostatic load across European populations. What matters the most: differentials in exposure or in susceptibility?

Drinking alcohol in moderation is associated with lower rate of all-cause mortality in individuals with higher rather than lower educational level: findings from the MORGAM project

The association between socioeconomic status (SES) and alcohol-related diseases has been widely explored. Less is known, however, on whether the association of moderate drinking with all-cause mortality is modified by educational level (EL). Using harmonized data from 16 cohorts in the MORGAM Project (N = 142,066) the association of pattern of alcohol intake with hazard of all-cause mortality across EL (lower = primary-school; middle = secondary-school; higher = university/college degree) was assessed using multivariable Cox-regression and spline curves. A total of 16,695 deaths occurred in 11.8 years (median). In comparison with life-long abstainers, participants drinking 0.1-10 g/d of ethanol had 13% (HR = 0.87; 95%CI: 0.74-1.02), 11% (HR = 0.89; 0.84-0.95) and 5% (HR = 0.95; 0.89-1.02) lower rate of death in higher, middle and lower EL, respectively. Conversely, drinkers > 20 g/d had 1% (HR = 1.01; 0.82-1.25), 10% (HR = 1.10; 1.02-1.19) and 17% (HR = 1.17; 1.09-1.26) higher rate of death. The association of alcohol consumption with all-cause mortality was nonlinear, with a different J-shape by EL levels. It was consistent across both sexes and in various approaches of measuring alcohol consumption, including combining quantity and frequency and it was more evident when the beverage of preference was wine. We observed that drinking in moderation (≤ 10 g/d) is associated with lower mortality rate more evidently in individuals with higher EL than in people with lower EL, while heavy drinking is associated with higher mortality rate more evidently in individuals with lower EL than in people with higher EL, suggesting that advice on reducing alcohol intake should especially target individuals of low EL.

Understanding health inequalities in Wales using the Blinder-Oaxaca decomposition method

Background

Throughout Wales and the world, health inequality remains a problem that is interconnected with a wider and complex social, economic and environmental dynamic. Subsequently, action to tackle inequality in health needs to take place at a structural level, acknowledging the constraints affecting an individual's (or community's) capability and opportunity to enable change. While the 'social determinants of health' is an established concept, fully understanding the composition of the health gap is dependent on capturing the relative contributions of a myriad of social, economic and environmental factors within a quantitative analysis.

Method

The decomposition analysis sought to explain the differences in the prevalence of these outcomes in groups stratified by their ability to save at least £10 a month, whether they were in material deprivation, and the presence of a limiting long-standing illness, disability of infirmity. Responses to over 4,200 questions within the National Survey for Wales (n = 46,189; 2016-17 to 2019-20) were considered for analysis. Variables were included based on (1) their alignment to a World Health Organization (WHO) health equity framework ("Health Equity Status Report initiative") and (2) their ability to allow for stratification of the survey sample into distinct groups where considerable gaps in health outcomes existed. A pooled Blinder-Oaxaca model was used to analyse inequalities in self-reported health (fair/poor health, low mental well-being and low life satisfaction) and were stratified by the variables relating to financial security, material deprivation and disability status.

Results

The prevalence of fair/poor health was 75% higher in those who were financially insecure and 95% higher in those who are materially deprived. Decomposition of the outcome revealed that just under half of the health gap was "explained" i.e., 45.5% when stratifying by the respondent's ability to save and 46% when stratifying by material deprivation status. Further analysis of the explained component showed that "Social/Human Capital" and "Income Security/Social Protection" determinants accounted the most for disparities observed; it also showed that "Health Services" determinants accounted the least. These findings were consistent across the majority of scenarios modeled.

Conclusion

The analysis not only quantified the significant health gaps that existed in the years leading up to the COVID-19 pandemic but it has also shown what determinants of health were most influential. Understanding the factors most closely associated with disparities in health is key in identifying policy levers to reduce health inequalities and improve the health and well-being across populations.

Stress-induced aberrations in sensory processing predict worse cognitive outcomes in healthy aging adults

It is well recognized that not all individuals age equivalently, with functional dependence attributable, at least in part, to stress accumulated across the lifespan. Amongst these dependencies are age-related declines in cognitive function, which may be the result of impaired inhibitory processing (e.g., sensory gating). Herein, we examined the unique roles of life and biological stress on somatosensory gating dynamics in 74 adults (22-72 years old). Participants completed a sensory gating paired-pulse electrical stimulation paradigm of the right median nerve during magnetoencephalography (MEG) and data were subjected to advanced oscillatory and time-domain analysis methods. We observed separable mechanisms by which increasing levels of life and biological stress predicted higher oscillatory gating ratios, indicative of age-related impairments in inhibitory function. Specifically, elevations in life stress significantly modulated the neural response to the first stimulation in the pair, while elevations in biological stress significantly modulated the neural response to the second stimulation in the pair. In contrast, neither elevations in life nor biological stress significantly predicted the gating of time-domain neural activity in the somatosensory cortex. Finally, our study is the first to link stress-induced decline in sensory gating to cognitive dysfunction, suggesting that gating paradigms may hold promise for detecting discrepant functional trajectories in age-related pathologies in the future.

Roles of allostatic load, lifestyle and clinical risk factors in mediating the association between education and coronary heart disease risk in Europe

BACKGROUND

Previous studies have shown that differential exposure to lifestyle factors may mediate the association between education and coronary heart diseases (CHD). However, few studies have examined the potential roles of allostatic load (AL) or differential susceptibility.

METHODS

25 310 men and 26 018 women aged 35-74 and CHD free at baseline were identified from 21 European cohorts and followed for a median of 10 years, to investigate the mediating role of AL, as well as of smoking, alcohol use and body mass index (BMI), on educational differences in CHD incidence, applying marginal structural models and three-way decomposition.

RESULTS

AL is a mediator of the association between educational status and CHD incidence, with the highest proportion mediated observed among women and largely attributable to differential exposure, (28% (95% CI 19% to 44%)), with 8% (95% CI 0% to 16%) attributable to differential susceptibility. The mediating effects of smoking, alcohol and BMI, compared with AL, were relatively small for both men and women.

CONCLUSION

Overall, the educational inequalities in CHD incidence were partially mediated through differential exposure to AL. By contrast, the mediation of the educational gradient in CHD by investigated lifestyle risk factors was limited. As differential susceptibility in men was found to have a predominant role in the accumulation of AL in low educational classes, the investigation of AL-related risk factors is warranted.