Gene-x-environment analysis supports protective effects of eveningness chronotype on self-reported and actigraphy-derived sleep duration among those who always work night shifts in the UK Biobank

Previous research has linked having an eveningness chronotype with a higher tolerance for night shift work, suggesting the ability to work nights without health consequences may partially depend upon having a circadian clock optimized for these times. As chronotypes entrain over time to environmental cues, it remains unclear whether higher relative eveningness among healthy night workers reflects a moderating or mediating effect of chronotype on health. We address these concerns conducting a genome-wide association study and utilizing a polygenic score (PGS) for eveningness as a time-invariant measure of chronotype. On a sample of 53 211 workers in the UK Biobank (2006–2018), we focus on the effects of night shift work on sleep duration, a channel through which night shift work adversely affects health. We ask whether a higher predisposition toward eveningness promotes night shift work tolerance. Results indicate that regular night shift work is associated with a 13-minute (3.5%) reduction in self-reported sleep per night relative to those who never work these hours (95% confidence interval [CI] = −17:01, −8:36). We find that eveningness has a strong protective effect on night workers: a one-SD increase in the PGS is associated with a 4-minute (28%) reduction in the night shift work sleep penalty per night (CI = 0:10, 7:04). This protective effect is pronounced for those working the longest hours. Consistent patterns are observed with an actigraphy-derived measure of sleep duration. These findings indicate that solutions to health consequences of night shift work should take individual differences in chronotype into account.</p

Explaining the Associations of Education and Occupation with Childlessness:The Role of Desires and Expectations to Remain Childless

Although there are well-established relationships between women's higher education, labour force participation (LFP), and occupation on the one hand and childlessness on the other hand in the US, the underlying reasons and the role that childlessness desires and expectations play remain unclear. We use the National Longitudinal Survey of Youth in the United States (N=4,198 women) and apply both logistic regression models to examine the role of childlessness desires early in life, and multilevel models for repeated measures to examine the role of childlessness expectations throughout the life course. We find that higher educational attainment and LFP are positively associated with childlessness. We do not find, however, that higher educated and working women more often desire or expect to remain childless. In contrast, we find that among women who ultimately remain childless, those women who work fulltime and have higher status occupations have higher expectations to have children throughout their life course. These results suggest that education and occupation produce constraints, resulting in the postponement of childbearing which hinders women in realizing their desires and expectations. Since many working women remain childless despite the desire and expectation to become a mother, our findings stress the importance of work-life reconciliation. It furthermore highlights the importance of increasing public awareness regarding the decrease in fecundity with age

How Young Mothers Rely on Kin Networks and Formal Childcare to Avoid Becoming NEET in the Netherlands

Motherhood is often cited as one of the main reasons for young women to become NEET (not in employment, education, or training). Given the potential long-term negative implications of NEET status, it is important to understand which types of resources can help young mothers to avoid becoming NEET around childbirth. In this paper we investigate how the chances of young mothers to become and stay NEET around the time of first birth are related to the availability and characteristics of members of their social support network, especially partners and grandparents, to assist in childcare. In addition, we consider the local availability of formal childcare. We use population-wide register data from the Netherlands and estimate discrete-time eventhistory models. Our results show that young mothers who are cohabitating or married are less likely to become NEETs than single mothers. We also show that economic activity and relative wage of both young mothers and their partners decreases the likelihood to become NEET and to exit NEET. With respect to the grandparents, we find that having more grandparents live in the immediate vicinity is associated with a lower likelihood to become NEET and a higher likelihood to exit NEET. Furthermore, we find that young mothers with economically inactive parents are more likely to become and less likely to exit NEET. Lastly, we find evidence for crowding-out of informal and formal childcare. Formal and informal childcare sources interact in such a way that the role of either becomes less important as more of the other is available

Educational attainment and allostatic load in later life: Evidence using genetic markers

Education is strongly correlated with health outcomes in older adulthood. Whether the impact of education expansion improves health remains unclear due to a lack of clarity over the causal relationship. Previous health research within the social sciences has tended to use specific activities of daily living or self-reported health status. This study uses a broader and objective health measure – allostatic load (AL) – to take into consideration the exposures that accumulate throughout the life course. This paper applies a Mendelian Randomization (MR) approach to identify causality in relation to education on health as measured by AL. Using the Health and Retirement Study 2008 (N=3935), we adopt a polygenic score built from genetic variants associated with years of education. To test whether our analyses violate the exclusion assumption, we further run MR Egger regressions to test for bias from pleiotropy. We also explore the potential pathways between education and AL, including smoking, drinking, marital length, health insurance, etc. Using this genetic instrument, we find a 0.3 unit (19% of a standard deviation) reduction in AL per year of schooling. The effect is mainly driven by BMI and Hba1c. Smoking and marital stability are two potential pathways that also causally influenced by education. If our main and sensitivity analyses are valid, the results find support that a higher level of education is causally related to better health in older adulthood

Demographic science aids in understanding the spread and fatality rates of COVID-19

Governments around the world must rapidly mobilize and make difficult policy decisions to mitigate the coronavirus disease 2019 (COVID-19) pandemic. Because deaths have been concentrated at older ages, we highlight the important role of demography, particularly, how the age structure of a population may help explain differences in fatality rates across countries and how transmission unfolds. We examine the role of age structure in deaths thus far in Italy and South Korea and illustrate how the pandemic could unfold in populations with similar population sizes but different age structures, showing a dramatically higher burden of mortality in countries with older versus younger populations. This powerful interaction of demography and current age-specific mortality for COVID-19 suggests that social distancing and other policies to slow transmission should consider the age composition of local and national contexts as well as intergenerational interactions. We also call for countries to provide case and fatality data disaggregated by age and sex to improve real-time targeted forecasting of hospitalization and critical care needs

Quantifying impacts of the COVID-19 pandemic through life-expectancy losses: a population-level study of 29 countries.

BACKGROUND: Variations in the age patterns and magnitudes of excess deaths, as well as differences in population sizes and age structures, make cross-national comparisons of the cumulative mortality impacts of the COVID-19 pandemic challenging. Life expectancy is a widely used indicator that provides a clear and cross-nationally comparable picture of the population-level impacts of the pandemic on mortality. METHODS: Life tables by sex were calculated for 29 countries, including most European countries, Chile and the USA, for 2015-2020. Life expectancy at birth and at age 60 years for 2020 were contextualized against recent trends between 2015 and 2019. Using decomposition techniques, we examined which specific age groups contributed to reductions in life expectancy in 2020 and to what extent reductions were attributable to official COVID-19 deaths. RESULTS: Life expectancy at birth declined from 2019 to 2020 in 27 out of 29 countries. Males in the USA and Lithuania experienced the largest losses in life expectancy at birth during 2020 (2.2 and 1.7 years, respectively), but reductions of more than an entire year were documented in 11 countries for males and 8 among females. Reductions were mostly attributable to increased mortality above age 60 years and to official COVID-19 deaths. CONCLUSIONS: The COVID-19 pandemic triggered significant mortality increases in 2020 of a magnitude not witnessed since World War II in Western Europe or the breakup of the Soviet Union in Eastern Europe. Females from 15 countries and males from 10 ended up with lower life expectancy at birth in 2020 than in 2015