European Journal of Epidemiology

BackgroundThe long preclinical phase of dementia can bias estimated effects of baseline exposures on dementia incidence. We demonstrate simulations informed by reverse Mendelian randomization (MR) findings to quantify the age-specific magnitude of reverse causation bias in analyses in observational studies of the effects of body mass index (BMI) on dementia. MethodsWe simulated longitudinal trajectories of BMI and dementia risk from ages 45 to 90 years, calibrating to published evidence on age-...

BackgroundEvidence on how leisure-time physical activity (LTPA) improves lifetime body mass index (BMI) remains fragmented and prone to confounding. MethodsWe pooled 14,993 adults (30-90 y; 52.7% women; cohorts: REGICOR-ACRISC, ILERVAS, ARTPER) with baseline estimated LTPA (moderate-to-vigorous LTPA [MVLTPA] in REGICOR-ACRISC), genotype, and repeated BMI values from electronic health records (1990-2024, 36,157 measures). LTPA was categorized into cohort-specific quartiles; MVLTPA in 0, <100, <2...

PURPOSEOver 6.9 million Americans above the age of 65 are living with Alzheimers Disease (AD) or related dementias (ADRDs), which are diseases characterized by cognitive decline and structural brain changes associated with accelerated brain aging. Cardiovascular risk factors, in particular hypertension, are well-studied risk factors for AD/ARD. Evidence suggests that the effects of hypertension on cognitive aging may vary by life stage, yet prior studies have focused on the effects of mid- or la...

ObjectiveSevere infections have been implicated in dementia risk, but their associations with detailed patterns of cognitive performance, and whether poorer cognition in turn increases risk for certain infections, remain unclear. We examined bidirectional associations between hospital-treated infections and domain-specific cognitive function in a cohort of older adults. MethodsWe analysed data from the English Longitudinal Study of Ageing Harmonised Cognitive Assessment Protocol (ELSA-HCAP), co...

BackgroundSmoking, unhealthy nutrition, alcohol consumption, and physical inactivity (SNAP behaviours) are major risk factors for multimorbidity but are often studied in isolation. Using longitudinal data, Suhag et al. identified clusters of older adults (aged [&ge;]50) with common SNAP behaviour patterns and distinct sociodemographic profiles and multimorbidity prevalence; whether and how these patterns generalise across adulthood remains unclear. AimTo conceptually replicate Suhag et al. acro...

BackgroundFinancial strain has been linked to adverse cardiovascular outcomes, yet whether this association persists beyond objective socioeconomic resources remains unclear. We examined associations of financial strain with incident heart disease and all-cause mortality among US adults aged 50 years or older. MethodsProspective cohort study using the Health and Retirement Study (2006-2022). Among 7219 participants completing the Psychosocial Leave-Behind Questionnaire, the exposure was ongoing...

BackgroundConcern about long-term health effects of repetitive head impacts in football has increased, but it remains unclear whether position-specific exposure patterns were associated with differential long-term all-cause mortality among elite players across the 20th century. MethodsWe conducted two retrospective cohort studies of elite male professional football players. The World Cup cohort included all players on the team rosters from FIFA World Cup tournaments (1930-1990), and the UEFA Eu...

COVID-19 has been shown to cause a range of harmful long-term effects on nearly every organ system1-3. These findings are based on retrospective studies comparing COVID-19 patients to patients with similar medical histories and demographics but no COVID-19 diagnosis4-16. However, concerns have emerged that these comparisons may be biased if COVID-19 patients had unrelated health conditions or other factors not recorded in their medical records17-21. Here, using a massive dataset of 14.4 billion ...

BackgroundSynthetic cohorts created by combining two cohorts can be useful when no single data set includes both the exposure and outcome data of interest. We estimate the effects of depression in early adulthood on later-life memory outcome using two nationally representative cohorts separately and in a synthetic sample. MethodsWe used the National Longitudinal Study of Youth 1979 (NLSY; N=5,747) and the Health and Retirement Study (HRS; N=6,846) and a synthetic cohort combining exposure data ...

ObjectivesGrowth Mindset and Grit have been proposed as key psychological resources for resilience and adaptation, yet their manifestation and social distribution in later life remain underexplored. This study examines the structure, distribution, and correlates of Growth Mindset and Grit in older adulthood using proxy indicators in the English Longitudinal Study of Ageing (ELSA). MethodsProxy indicators reflecting learning behaviour, personality traits, affect, and beliefs were used to derive ...

BackgroundThe risk of chronic diseases and multimorbidity increases with age, yet, individuals of the same age can strongly differ in healthspan, ranging from early manifestation of age-related disease to robust health into very old age. Plasma biomarkers, including metabolites and proteins, can capture intrinsic health status, thereby providing insights into the nature of this variation. These biomarkers have been widely explored to understand chronic and early disease risk but less so for dise...

Mendelian randomization has emerged as a transformative approach for inferring causal relationships between risk factors and disease outcomes. However, applying Mendelian randomization to disease progression - a critical step in validating pharmacological targets - is hampered by index event bias. This form of selection bias occurs because analyses of disease progression are necessarily restricted to individuals who have already experienced the disease event. Here, we present a comprehensive eva...

Background and ObjectivesRecent large-scale studies have consistently linked healthy dietary patterns to improved cardiometabolic health; however, the underlying biological pathways remain largely unclear, especially in non-European populations. In this study, we leverage data from four population-based cohorts (UK Biobank, NEO study, GNHS, and 10K) to investigate both common and cohort-specific biological pathways linking healthy dietary patterns to cardiometabolic disease through multi-omics p...

Chronic pain has been identified as a risk factor for cognitive decline in later life. However, most studies measure pain at a single time point and none have investigated whether variations in pain severity are associated with changes in cognitive function over time. This project aimed to assess the relationship between individual-level change in pain severity and decline in cognitive function over time. We used data from the English Longitudinal Study of Ageing (ELSA), a cohort of nationally r...

BackgroundEpigenetic clocks based on DNA methylation (DNAm) provide quantitative indicators of biological aging. However, the extent to which diverse lifestyle factors influence DNAm-based aging measures remains unclear, especially in Japanese populations. We aimed to evaluate the associations between 52 lifestyle-related factors and multiple epigenetic aging indicators, including six DNAm ages (Horvath, Hannum, PhenoAge, GrimAge, GrimAge v2, and PCPhenoAge specific to Japanese Population), the ...

BackgroundDeath certificates record both an underlying cause and contributing conditions, yet mortality statistics predominantly report only the underlying cause. We quantify this "hidden burden" across all ICD-10 conditions in Australian mortality data using the multiple-to-underlying ratio (MUR): total death certificate mentions divided by underlying cause deaths. MethodsWe analysed Australian Bureau of Statistics Causes of Death 2023 data (N = 187,268 registered deaths) to compute the ratio ...

Advances in our understanding of the biology of skeletal muscle ageing are being made at pace, with great potential for these findings to inform the identification of novel treatments for sarcopenia. However, translation of findings from animal models to humans has been hampered by limitations of existing human muscle biopsy studies. Devised to directly address this challenge, the Muscle Ageing and Sarcopenia Study (MASS) Lifecourse is a unique resource for the study of human muscle ageing acros...

BackgroundWhile multi-omics approaches, incorporating polygenic risk scores (PRS), metabolomics, and proteomics have shown promise in predicting major adverse cardiovascular events (MACE), their added value beyond cardiovascular disease (CVD) risk factors remains underexplored. We aimed to assess whether integrating multi-omics biomarkers into the SCORE2 model improves the prediction of MACE in apparently healthy individuals. MethodsThis study included 24,042 UK Biobank participants without CVD...

IntroductionUnderstanding the links between metabolism, ageing and age-related phenotypes may clarify the role of ageing in disease onset and improve risk prediction. MethodsWe conducted a cross-cohort assessment of biological age using broad-spectrum LC-MS metabolomics in 2,295 participants, aged 20-89, from the UK Airwave study (N=960) and The Irish Longitudinal Study of Ageing (N=1,335). ResultsN2,N2-dimethylguanosine, C-glycosyltryptophan, bile acid glucuronides, and zeta-carotene were ass...

Biological ageing begins before birth, with early-life exposures shaping late-life health. These exposures drive health inequities early, yet specific exposures and the composition of the ageing exposome remain largely undefined. This gap may persist as the field lacks agnostic investigations accounting for non-linearity, interactions and subtle signals. We aimed to identify exposures predictive of epigenetic ageing accumulated during childhood and adolescence and explore the composition of the...