Abstract Evidence from the U.S., UK, and Europe documented that income inequality has modest effects on the social gradient of health. However, few studies investigate how the effect of income inequality on the social gradient of health evolves over the life course. This study aims to examine to what extent, and in what ways, does the effect of income on later-life health trajectory vary across more unequal and less unequal societies. This study used data from the Standardized World Income Inequality Database (SWIID, 2004-2020) and the Survey of Health, Ageing and Retirement in Europe (SHARE, 2004-2010). We used national-level Gini index to measure income inequality. We used life satisfaction as the health outcome. We performed multilevel modelling to analyze the data in which observations (level 1) are nested in participants (level 2), country-years (level 3), and countries (level 4). Our analysis revealed three findings. First, the effect of income on life satisfaction among older adults is more pronounced in unequal countries. Second, the effect of income inequality on life satisfaction weakens as individuals age. Third, the importance of income on life satisfaction across societies of varying levels of income inequality decreases over the life course of an individual. Findings from this study show that contextual-level income inequality can modify the effects of individual income on health as individuals age. This can help the policy makers and practitioners to target the vulnerable population and offer more effective intervention.

To test the hypothesis that early-life adversity accelerates the pace of biological aging, we analyzed data from the Dutch Hunger Winter Families Study (DHWFS, N = 951). DHWFS is a natural-experiment birth-cohort study of survivors of in-utero exposure to famine conditions caused by the German occupation of the Western Netherlands in Winter 1944 to 1945, matched controls, and their siblings. We conducted DNA methylation analysis of blood samples collected when the survivors were aged 58 to quantify biological aging using the DunedinPACE, GrimAge, and PhenoAge epigenetic clocks. Famine survivors had faster DunedinPACE, as compared with controls. This effect was strongest among women. Results were similar for GrimAge, although effect-sizes were smaller. We observed no differences in PhenoAge between survivors and controls. Famine effects were not accounted for by blood-cell composition and were similar for individuals exposed early and later in gestation. Findings suggest in-utero undernutrition may accelerate biological aging in later life.

This study aims to investigate changes in the income-health gradient over the later life course. We test the age-as-leveler, the cumulative advantage/disadvantage, and the persistent inequality pattern for physical and cognitive health domains, and analyze whether these patterns are gendered. We used HRS data (1992-2016) and Poisson growth curve models to predict multimorbidity (33,860 participants) as an indicator of physical health and memory (25,291 participants) as an indicator of cognitive health. We disentangled the within-participant from the between-participant effects. For multimorbidity, the income-health gradient weakened as individuals aged; whereas for memory, the income-health gradient strengthened as individuals aged. The cumulative advantage/disadvantage of higher/lower income on memory may be more pronounced among women than men. Findings were confirmed by sensitivity analyses. Findings suggest that the support for the age-as-leveler or cumulative advantage/disadvantage pattern may depend on health domains and the effect strength may depend on gender.

Some studies show that the protective effect of higher income on health weakens with old age (age-as-leveller pattern), whereas others show that it strengthens with old age (cumulative advantage/disadvantage pattern). Many existing studies are limited in that they use single-country and/or single-timepoint designs. To overcome these limitations and better understand how the income-health gradient evolves in older age, we used cross-national and longitudinal data of the Survey of Health, Ageing and Retirement in Europe (2004–2019, N = 73,407) and the China Health and Retirement Longitudinal Study (2011–2018, N = 10,067). We operationalised health using multimorbidity and three alternative indicators (functional disability, mobility disability, and memory). We performed Poisson growth curve modelling to capture the between-participant effects of age and the within-participant effects of aging. We obtained three consistent and robust findings for Europe (patterns were observed in most countries) and China. First, the protective effect of higher income on multimorbidity, functional disability, and mobility disability was weaker for older than for younger adults (between-participant age-as-leveller pattern). Second, only the protective effect of higher income on mobility disability weakened over the later life course (within-participant age-as-leveller pattern). Third, the protective effect of higher income on memory was stronger for older than for younger adults and strengthened over the later life course (between-participant and within-participant cumulative advantage/disadvantage pattern). Longitudinal data, growth curve modelling distinguishing the between-participant from within-participant effect, and adjustments for potential confounders based on the hypothesised causal structure enabled us to better navigate the landscape of causal inference. Findings suggest that the income-related gap in physical health but not in cognitive health narrows in old age for both Europe and China.

Child undernutrition and later-life non-communicable diseases (NCDs) are major global health issues. Literature suggests that undernutrition/famine exposure in childhood has immediate and long-term adverse health consequences. However, many studies have theoretical and methodological limitations. To add to the literature and overcome some of these limitations, we adopted a life course perspective and used more robust methods. We investigated the association between exposure to the 1959–1961 Chinese famine and later-life NCDs and if this association depends on: life stage at exposure, famine severity, and sex. We conducted a secondary data analysis of a large-scale, nationally representative, longitudinal study—the China Health and Retirement Longitudinal Study (2011–2018, 11,094 participants). We measured famine exposure/severity using self-reported experience, life stage using age at exposure, and health using the number of NCDs. We performed Poisson growth curve models. We obtained three findings. First, compared with unexposed participants, those exposed before age 18 had a higher risk of later-life NCDs, particularly if exposed in-utero (IRR = 1.90, 95% CI [1.70, 2.12], p < .001) and in the “first 1,000 days” of life (IRR = 1.86, 95% CI [1.73, 2.00], p < .001; for 0–6 months group, IRR = 1.95, 95% CI [1.67, 2.29], p < .001). Second, the famine effects among participants moderately and severely exposed were similar (IRR = 1.18, 95% CI [1.09, 1.28], p < .001 and IRR = 1.24, 95% CI [1.17, 1.32], p < .001). Third, the famine effects did not differ between females and males (IRR = 0.98, 95% CI [0.90, 1.07], p = .703). In an individual’s life course, in-utero and the “first 1,000 days” are a particularly sensitive time period with marked long-term implications for NCDs if undernutrition/famine is experienced in this period. However, this window remains open until young adulthood. This highlights the need to invest more in preventing and treating child/adolescent undernutrition to tackle later-life NCDs.

Abstract Adults with histories of early-life adversity experience younger age-of-onset for aging-related disease and shorter lifespan, suggesting an accelerated pace of biological aging. To test this hypothesis, we analyzed data from an established natural experiment: in-utero exposure to famine conditions induced by a Nazi blockade of the Southern Netherlands in Winter 1944-5. We analyzed data from the Dutch Hunger Winter Families Study (DHWFS, N=951). DHWFS enrolled survivors of in-utero famine exposure, matched controls born in the same hospitals as the survivors immediately prior to and following the famine period, and siblings of these individuals. Blood samples were collected when the famine survivors were aged 58. We analyzed blood DNA methylation data to measure the GrimAge and PhenoAge 2nd-generation epigenetic clocks and the DunedinPACE 3rd-generation clock. We tested if famine survivors were biologically older and aging faster as compared to controls. We found that famine survivors had faster DunedinPACE pace of aging, as compared with controls, but similar PhenoAge and GrimAge biological ages. In sex-stratified analyses, we found stronger effects of famine exposure in women as compared with men, including for the GrimAge and PhenoAge clocks; among women, famine exposure was associated with faster DunedinPACE and older GrimAge and PhenoAge, whereas in men effect-sizes were near zero. Famine effects were not accounted for by blood-cell composition and were similar for individuals exposed early and later in gestation. Sibling-difference analyses reproduced size and direction of effect estimates. Findings provide natural-experiment evidence for long-term effects of in-utero famine exposure on the pace biological aging.

Abstract Frailty in old age is a major public health challenge. Frail older adults are at higher risk of adverse health outcomes and in greater needs for health services as compared to non-frail older adults. An emerging perspective views frailty as a dynamic process and older adults are likely to transition to improved frailty status. However, little is known about the socioeconomic determinants of frailty trajectories over the later life course. This study investigated how frailty evolves and transitions over time and how socioeconomic status impacts frailty trajectories. Data from the Survey of Health, Ageing and Retirement in Europe 2004-2020 (N=4,621 adults aged 50-105 in Switzerland) were analyzed. Fried’s phenotype was used to operationalize frailty. Changes in frailty status at a 2-year interval were used to identify frailty trajectories. Growth curve models were performed to investigate how age, sex, education, occupation, and income determined frailty trajectories over the later life course. This study had three findings. First, three frailty states were identified: non-frail, pre-frail, and frail. Second, five frailty trajectories were identified: stable frail, worsening, mixed, improving, and stable non-frail. Third, individuals aged 65 and above, women, and socioeconomically disadvantaged individuals had a higher risk of being stable frail and having a worsening frailty trajectory. Findings indicate that frailty intervention programs in Switzerland need to prioritize individuals in middle age and old age, women, and individuals with lower socioeconomic status to tackle the challenge of frailty.

Abstract Barker’s fetal origins hypothesis and the critical period theory suggest that early life events have long-term health effects. However, evidence of the famine exposure in early life and its effects on health in later life is scarce and inconsistent. To explore the effects of early-life exposure to the Chinese famine of 1959-1961 on later-life multimorbidity, we performed Poisson growth curve models using CHARLS Life History 2014 and CHARLS 2011-2018 (42,775 observations from 12,060 respondents). Our analyses revealed two findings. First, there was an overall detrimental effect of the early-life famine exposure on multimorbidity, although there was no effect of severity of famine exposure. Second, there was no overall interaction between famine exposure and life stages, although a more parsimonious model suggested that the detrimental effect of famine exposure was more pronounced in earlier life stages than in later life stages. Findings suggest that early life is a critical period in the life course and provides developmental origins of health and disease in later life.

AimThe knowledge on multimorbidity and its impact on healthcare systems is lacking in low‐ and middle‐income countries. We aimed to estimate the prevalence of multimorbidity, and analyze the health service use of middle‐aged and older persons with multimorbidity in urban China.MethodsStudy participants included 3737 urban residents aged ≥45 years from the China Health and Retirement Longitudinal Study 2011. A total of 16 pre‐specified self‐reported chronic conditions were used to measure multimorbidity, which was defined as having two or more conditions. Logistic regression was used to analyze the characteristics and health service use of persons with multimorbidity. Analyses were weighted to adjust for sampling design and non‐response.ResultsOf the study population, 51.9% were men and 20.1% were aged >70 years. Hypertension (33.1%) was the most prevalent condition, followed by arthritis (25.4%), digestive disease (18.7%), dyslipidemia (18.3%) and heart disease (17.7%). The prevalence of multimorbidity was 45.5% (95% CI 41.4–49.7%). Multivariate analyses showed that the prevalence of multimorbidity was significantly higher in respondents who are older and socioeconomically disadvantaged than that in their counterparts. Multimorbid patients used 72.7% of outpatient services and 77.3% of inpatient services. After controlling for demographic, socioeconomic, health behavior and health insurance factors, condition counts still had a positive relationship with outpatient or inpatient service use.ConclusionsThe burden of multimorbidity is high among the middle‐aged and older urban Chinese population. Management of multimorbidity therefore deserves more attention from health policymakers, providers and educators of health professionals in China and in other low‐ and middle‐income countries. Geriatr Gerontol Int 2018; 18: 1447–1452.