Michelle Kelly-Irving

• PhD
• Researcher at French Institute of Health and Medical Research

Events causing stress responses during sensitive periods of rapid neurological development in childhood may be early determinants of all-cause premature mortality. Using a British birth cohort study of individuals born in 1958, the relationship between adverse childhood experiences (ACE) and mortality ≤50 year was examined for men (n = 7,816) and w...

To analyse whether Adverse Childhood Experiences (ACE) are associated with an increased risk of cancer. The National child development study (NCDS) is a prospective birth cohort study with data collected over 50 years. The NCDS included all live births during one week in 1958 (n = 18558) in Great Britain. Self-reported cancer incidence was based on...

Lower socioeconomic position (SEP) has consistently been associated with poorer health. To explore potential biological embedding and the consequences of SEP experiences from early life to adulthood, we investigate how SEP indicators at different points across the life course may be related to a combination of 28 inflammation markers. Using blood-d...

Understanding how human environments affect our health by “getting under the skin” and penetrating the cells, organs and physiological systems of our bodies is a key tenet in public health research. Here, we examine the idea that early life socioeconomic position (SEP) can be biologically embodied, potentially leading to the production of health in...

Chronic inflammation has been proposed as having a prominent role in the construction of social inequalities in health. Disentangling the effects of early life and adulthood social disadvantage on inflammation is key in elucidating biological mechanisms underlying socioeconomic disparities. Here we explore the relationship between socioeconomic pos...

Social inequality impacts health, is aggravated by the consequences of climate change, and may be influenced by inappropriate policy responses. These interdependent effects create a self-perpetuating loop exacerbating the impact of climate dysregulation on health in an uncontrolled and poorly understood way. Holistic approaches to public health suc...

Social inequality impacts health, is aggravated by the consequences of climate change, and may be influenced by inappropriate policy responses. These interdependent effects create a self-perpetuating loop exacerbating the impact of climate dysregulation on health in an uncontrolled and poorly understood way. Holistic approaches to public health suc...

Research has shown that our socially structured experiences elicit a biological response, leading to the observation that numerous biomarkers (objective biological measures that are representative of various biological processes) are socially patterned. This ‘social-to-biological’ research is of interest to researchers across multiple disciplines a...

Social inequality impacts health, is aggravated by the consequences of climate change, and may be influenced by inappropriate policy responses. These interdependent effects create a self-perpetuating loop exacerbating the impact of climate dysregulation on health in an uncontrolled and poorly understood way. Holistic approaches to public health suc...

Aim To discuss a reserves‐based model of Health, recently developed in the literature, defining Health and moving from conceptual considerations to methods of measuring Health, applicable to nursing practice and research. Design Discursive paper. Methods A discursive paper critically synthesising a reserves‐based model of Health for conceptualisi...

Social inequality impacts health, is aggravated by the consequences of climate change, and may be influenced by inappropriate policy responses. These interdependent effects create a self-perpetuating loop exacerbating the impact of climate dysregulation on health in an uncontrolled and poorly understood way. Holistic approaches to public health suc...

Background Multimorbidity, known as the co-occurrence of at least two chronic conditions, has become of increasing concern in the current context of ageing populations, though it affects all ages. Early life risk factors of multimorbidity include adverse childhood experiences (ACEs), particularly associated with psychological conditions and weight...

Objective To examine the association between smoking initiation in adolescence and subsequent different smoking trajectories of people who smoke, and to examine the combined effect of adverse childhood experiences (ACEs) and smoking initiation in adolescence on smoking trajectories of people who smoke. Design and Sample Data are from 8757 individu...

Background Are the observed biological differences between men and women physiological, liked to sexual dimorphism, or can they be explained, at least in part, by social gender mechanisms ? We applied several methodological strategies to answer 4 questions: (1) Are there biological differences between men and women, and to what extent? (2) Do these...

Background: Allostatic load (AL) is a multi-system composite index for quantifying physiological dysregulation caused by life course stressors. For over 30 years, an extensive body of research has drawn on the AL framework but has been hampered by the lack of a consistent definition. Methods: This study analyses data for 67,126 individuals aged...

Background The principal aim of this study was to explore if biological differences between men and women can be explained by gendered mechanisms. Methods We used data from the 1958 National Child Development Study, including all the living subjects of the cohort at the outcome collection wave (44–45 years). We explored several biomarkers as outco...

Background Defining and measuring Health presents a challenge, partly due to its conceptual pluralism. To measure Health as an ability to adapt and self-manage, we developed an approach within the theoretical framework of resources and reserves over the life course, recently proposed in the literature. We aimed to (i) use the conceptual framework d...

Background. The principal aim of this study was to explore if biological differences between men and women can be explained by gendered mechanisms. Methods. We used data from the 1958 National Child Development Study, including all the living subjects of the cohort at the outcome collection wave (44-45 years). We explored several biomarkers as outc...

Background: Epidemiologists need tools to measure effects of gender, a complex concept originating in the social sciences which is not easily operationalized in the discipline. Our aim is to clarify useful concepts, measures, paths, effects, and analytical strategies to explore mechanisms of health difference between men and women. Methods: We r...

In late 2021, in issue 3 of the Revue française des affaires sociales, Jean-Charles Basson, Nadine Haschar-Noé and Marina Honta devoted a dossier to “The Production of Social Health Inequalities” in which they emphasised the social construction of health inequalities, the undermining of the legitimate access to health-related rights and healthcare...

Background: Exposome research aims to describe and understand the extent to which all the exposures in human environments may affect our health over the lifetime. However, the way in which humans interact with their environment is socially patterned. Failing to account for social factors in research exploring the exposome may underestimate the mag...

Context It is widely recognised that the Covid-19 pandemic has negatively impacted individuals’ mental health. However, little emphasis has been put on the possible influence of socio-economic factors in the relationship. In the context of the COVID-19 pandemic, our objectives were (i) to assess the relationship between education level and mental h...

In March 2020, the French government implemented nation-wide measures to reduce social contact and slow the progression of the emerging coronavirus responsible for COVID-19, the most significant being a complete home lockdown that lasted 8 weeks. Reunion Island is a French overseas department marked by large social inequalities. We draw the hypothe...

Objective: To analyse whether patient-general practitioner (GP) interaction, measured by their disagreement, varies among overweight or obese patients compared with normal-weight patients. Methods: Twenty-seven GPs and 585 patients participated in the quantitative phase of the multidisciplinary INTERMEDE project and answered "mirrored" questionn...

Background Exposome research aims to describe and understand the extent to which all the exposures in human environments may affect our health over the lifetime. However, the way in which humans interact with their environment is socially patterned. Therefore, including social factors in research exploring the exposome is fundamental and may contri...

Background Defining and measuring “Health” presents a challenge, partly due to its conceptual pluralism. To measure “Health” as an ability to adapt and self-manage, we developed an approach within the theoretical framework of resources and reserves over the life course, recently proposed in the literature. We aimed to (i) use the conceptual framewo...

Obtaining accurate estimates of the causal effects of socioeconomic position (SEP) on health is important for public health interventions. To do this, researchers must identify and adjust for all potential confounding variables while avoiding inappropriate adjustment for mediator variables on a causal pathway between the exposure and outcome. Unfor...

Background Few studies have examined the interactions between individual socioeconomic position and neighbourhood deprivation and the findings so far are heterogeneous. Using a large sample of diverse cohorts, we investigated the interaction effect of neighbourhood socioeconomic deprivation and individual socioeconomic position, assessed using educ...

BACKGROUND: Few studies have examined the interactions between individual socioeconomic position and neighbourhood deprivation and the findings so far are heterogeneous. Using a large sample of diverse cohorts, we investigated the interaction effect of neighbourhood socioeconomic deprivation and individual socioeconomic position, assessed using edu...

Background: Neighbourhood socio-economic inequities have been shown to affect COVID-19 incidence and mortality, as well as access to tests. This article aimed to study how associations of inequities and COVID-19 outcomes varied between the first two pandemic waves from a gender perspective. Methods: We performed an ecological study based on the CO...

Adverse childhood experiences (ACEs) have been identified as a strong determinant of smoking. We aimed to examine the association between ACEs and early smoking initiation and subsequent persistence and the contribution of five pathways including family factors, parental involvement, material living conditions, social activities and conscientiousne...

Persistent health inequalities pose a challenge to researchers and policymakers. Decades of research have illuminated mechanisms that underlie health inequalities, now we must move beyond these observations to enable policies that can reduce them. In this paper, we highlight tensions in the field of health inequalities research regarding the relati...

Background Data on health inequalities related to the dynamic of SARS-CoV-2 infection in France are scarce. The aim of this study was to analyse the association between an area-based deprivation indicator and SARS-CoV-2 incidence, positivity, and testing rates between May 2020 and April 2021. Methods We analysed data reported to the Système d'Info...

Background Epidemiologists need tools to measure effects of gender , a complex concept originating in the humanities and social sciences which is not easily operationalized in the discipline. Methods We conducted a conceptual analysis and applied causal and mediation analysis methodology to standard questions in order to propose a methodologically...

Background This study aims to examine whether higher social protection expenditure reduces the negative association of life-course socioeconomic disadvantages with subjective and objective health status and trajectories in later life. Methods We used SHARE data from participants living in 20 European countries aged 50 to 96. Seven waves allowed to...

Background In the context of the Covid-19 pandemic, several factors such as age, chronic disease or obesity have been associated with adverse outcomes and mortality from Covid-19. However, the social distribution of Covid-19 infection among men and women was largely neglected in France, mainly due to a lack of data. The aim of this study is to desc...

Background: This systematic review aimed to summarize evidence reporting epigenetic and/or neuro-immuno-endocrine embedding of adverse childhood events (ACEs) in children, with a particular focus on the short-term biological effect of those experiences. Methods: A search was conducted in PsycINFO®, PubMed®, Isi Web of Knowledge and Scopus, until Ju...

Understanding how structural, social and psychosocial factors come to affect our health resulting in health inequalities is more relevant now than ever as trends in mortality gaps between rich and poor appear to have widened over the past decades. To move beyond description, we need to hypothesize about how structural and social factors may cause h...

Understanding how structural, social and psychosocial factors come to affect our health resulting in health inequalities is more relevant now than ever as trends in mortality gaps between rich and poor appear to have widened over the past decades. To move beyond description, we need to hypothesise about how structural and social factors may cause h...

La distribution sociale de l'infection au SARS-CoV-2 et le rôle du genre ont été largement négligés en France, principalement en raison du manque de données. L'objectif de cet article est d'analyser le risque d'infection au SARS-CoV-2 en fonction du sexe, en étudiant l'influence d'autres dimensions sociales dans cette relation, en particulier la pr...

Education is associated with later health, and notably with an indicator of physiological health measuring the cost of adapting to stressful conditions, named allostatic load. Education is itself the result of a number of upstream variables. We examined the origins of educational attainment through the lens of interactions between families and scho...

The purpose of this chapter is to provide a brief summary of the way in which the social becomes biological, also conceptualised as the biological embodiment of the social environment. Firstly, this synthesis presents and defines the concept of embodiment and its usefulness when aiming to understand the construction of the social gradient in health...

Introduction. The knowledge of Costa Rica's situation regarding the social gradient in mortality is still incomplete. Methods. National Electoral Rolls, which included all adult Costa Rican citizens were used. The event was death between 2010 and 2018. The exhaustive final sample included 2,747,616 people for 23,985,602 person-years of follow-up. A...

Individuals experiencing socioeconomic disadvantage in childhood have a higher rate of inflammation-related diseases decades later. Little is known about the mechanisms linking early life experiences to the functioning of the immune system in adulthood. To address this, we explore the relationship across social-to-biological layers of early life so...

Background Health care evaluation models can be useful to assign different levels of priority to interventions or policies targeting different age groups or different determinants of health. We aimed to assess early mortality in counterfactual scenarios implying reduced adverse childhood experience (ACE) and/or improved educational attainment (chil...

Background Socioeconomic position as measured by education may be embodied and affect the functioning of key physiological systems. Links between social disadvantage, its biological imprint, and cause-specific mortality and morbidity have not been investigated in large populations, and yet may point towards areas for public health interventions bey...

Background: Adverse childhood experiences (ACEs) have been associated with poorer health across the life course. Previous studies have used cumulative risk scores (ACE scores) or individual ACEs but these two approaches have important shortcomings. ACE scores assume that each adversity is equally important for the outcome of interest and the single...

Introduction: As part of the National Health Strategy, the High Council for Public Health (HCSP) was tasked with leading a reflection on a “comprehensive and concerted child health policy”. Policy-making requires relevant knowledge and statistical benchmarks. It therefore seemed useful to examine the French statistical system and active research t...

Background: Evidence suggests that the inflammatory reaction, an adaptive response triggered by a variety of harmful stimuli and conditions involved in the risk and development of many chronic diseases, is a potential pathway through which the socioeconomic environment is biologically embedded. Difficulty in interpreting the role of the inflammato...

Aim: Inflammation represents a potential pathway through which socioeconomic position (SEP) is biologically embedded. Materials & methods: We analyzed inflammatory biomarkers in response to life course SEP by integrating multi-omics DNA-methylation, gene expression and protein level in 178 European Prospective Investigation into Cancer and Nutritio...

Introduction Lorsque l’on observe des différences de santé en fonction du sexe, la question des mécanismes, biologiques ou sociaux, de ces différences peut être posée. Dans cette optique, nous avons défini l’effet de genre (c’est-à-dire l’effet du sexe reposant sur des mécanismes sociaux) comme une interaction entre le sexe attribué à la naissance...

Background: The recent COVID-19 outbreak has generated an unprecedented public health crisis, with millions of infections and hundreds of thousands of deaths worldwide. Using hospital-based or mortality data, several COVID-19 risk factors have been identified, but these may be confounded or biased. Methods: Using SARS-CoV-2 infection test data (...

Previous research has demonstrated a graded relationship between the number of Adverse Childhood Experiences reported (an ACE score) and child outcomes. However, ACE scores lack specificity and ignore the patterning of adversities, which are informative for interventions. The aim of the present study was to explore the clustering of ACEs and whethe...

Funded by the European Commission Horizon 2020 programme, the Lifepath research consortium aimed to investigate the effects of socioeconomic inequalities on the biology of healthy aging. The main research questions included the impact of inequalities on health, the role of behavioral and other risk factors, the underlying biological mechanisms, the...

Disadvantaged socioeconomic position (SEP) is widely associated with disease and mortality, and there is no reason to think this will not be the case for the newly emerged coronavirus disease 2019 (COVID-19) that has reached a pandemic level. Individuals with a more disadvantaged SEP are more likely to be affected by most of the known risk factors...

Individuals growing up during childhood in a socioeconomically disadvantaged family experience a higher rate of inflammation-related diseases later in life. Little is known about the mechanisms linking early life experiences to the functioning of the immune system decades later. Here we explore the relationship across social-to-biological layers of...

Objectives: This study aimed to examine the cumulative disadvantage of different forms of childhood misfortune and adult-life socioeconomic conditions with regard to trajectories and levels of self-rated health in old age and whether these associations differed between welfare regimes (Scandinavian, Bismarckian, Southern European, and Eastern Euro...

Objective: To examine the confounding role of social determinants across the life course in the relationship of nutritional lifestyle patterns with cancer in women. Methods: In the National Child Development Study, 37 items regarding diet, alcohol and physical activity frequencies were recorded at ages 33 and 42 years. Some 6,169 women were inclu...

Objective Early life adversity has been associated with increased risk of inflammation and inflammation-related diseases in adulthood. This study aimed to examine the association of childhood socioeconomic conditions with chronic low-grade inflammation over adolescence. Methods We used information on 2942 members (1507 girls and 1435 boys) of the...

Rationale: Socioeconomic disparities have been documented in major non-communicable diseases and in their risk factors, such as obesity, hypertension, diabetes, smoking, physical inactivity, unhealthful diet and heavy drinking. However, a key research question has remained unanswered: is there a separate biological embodiment of socio-economic con...

Aims: Sleep disturbances exhibit a strong social patterning, and inadequate sleep has been associated with adverse health outcomes, including cardiovascular disorders (CVD). However, the contribution of sleep to socioeconomic inequalities in CVD is unclear. This study pools data from eight European cohorts to investigate the role of sleep duration...

Background Early life adversity has been associated with increased risk of inflammation and inflammation-related diseases in adulthood. This study aimed to examine the association of parental socioeconomic position with chronic inflammation over adolescence. Methods We used information on 2942 members (1507 girls and 1435 boys) of the EPITeen coho...

Background Adverse socioeconomic conditions in childhood affect systemic low-grade inflammation in adulthood. Studies in animals and humans suggest that socioeconomic conditions get under the skin from early life thus contributing to shape pro-inflammatory phenotypes. Although the existence of socioeconomic differences in gene regulation of the imm...

Background It now established that social factors impact the quality of ageing, through the lifecourse stimulation/dysregulation of key physiological systems. Composite scores such as allostatic load, focusing on the response to stress, can be used to measure individual physiological wear-and-tear. Methods Using data from the Understanding Society...

Background This study explores (i) the relationship between socioeconomic position (SEP) across the life course and circulating C-reactive protein (CRP), a marker of systemic inflammation, in 6 European cohort studies (in up to N = 23 008) participating in the Lifepath project and (ii) interrogate the hypothesis of a cumulative biological risk (all...

Today, the reduction of social inequalities in health is on the political agenda in public health. The complex reality of the determinants of these health inequalities remains difficult to understand and translate into practical actions. One of the reasons is that the circulation of expertise amongst researchers, actors in the field, and public dec...

Disadvantaged socioeconomic conditions in childhood heighten systemic inflammatory levels in adulthood; however, life-course mechanisms underlying this association are largely unknown. In the present observational study, we investigated the roles of adulthood socioeconomic and lifestyle factors in mediating this association. Participants were from...

Objectives: This study aimed to assess whether cumulative disadvantage in childhood misfortune and adult-life socioeconomic conditions influence the risk of frailty in old age and whether welfare regimes influence these associations. Methods: Data from 23358 participants aged 50 years and older included in the longitudinal SHARE survey were used...

Background Retrospectively recalled adverse childhood experiences (ACEs) are associated with adult mood problems, but evidence from prospective population cohorts is limited. The aims of this study were to test links between prospectively ascertained ACEs and adult mood problems up to age 50, to examine the role of child mental health in accounting...

Background: Using the couple as unit of analysis raises methodological challenges. This study aims to discuss the appropriate proxy to use in statistical analyses when couples provide discordant answers on the following couple-level variables: household monthly income and length of marital relationship. Methods: During 12 months (July 2013-June...

Background Lower socioeconomic position (SEP) has consistently been associated with poorer health. Chronic inflammation has been proposed as having a prominent role in the construction of social inequalities in health. Disentangling the effects of social disadvantage along the life course on inflammation is key in elucidating biological mechanisms...

At the crossroads between sciences, epidemiology brings together the social and the biological to examine social inequalities in health. The concept of biological capital represents the accumulated history of biological experiences, alongside the other forms of accumulated capital, notably cultural, economic and social. The ability to access the th...

Objective It is often asserted that the crowding phenomenon in emergency departments (ED) can be explained by an increase in visits considered as non-urgent. The aim of our study was to quantify the increase in ED visit rates and to determine whether this increase was explained by non-severe visit types. Methods This observational study covers all...

Living in deprived neighbourhoods may have biological consequences, but few studies have assessed this empirically. We examined the association between neighbourhood deprivation and allostatic load, a biological marker of wear and tear, taking into account individual's socioeconomic position. We analysed data from three cohort studies (CoLaus-Switz...

Objectives: To explore needs of parents of very preterm infants hospitalised in Neonatal Intensive Care Units according to their socioeconomic position, obstetric history and infant's characteristics. Methodology: Sequential explanatory mixed methods study. Individual quantitative questionnaires (n = 118 mothers; 89 fathers) during infants' hosp...

Background: Childhood misfortune is associated with late-life depressive symptoms, but it remains an open question whether adult socioeconomic and relational reserves could reduce the association between childhood misfortune and late-life depressive symptoms. Methods: Using the Survey of Health, Ageing and Retirement in Europe (SHARE), data from...

An intense scientific debate has recently taken place relating to the “bad luck” hypothesis in cancer development, namely that intrinsic random, and therefore unavoidable, mutagenic events would have a predominant role in tumorigenesis. In this article we review the main contributions to this debate and explain the reasons why the claim that cancer...

Adverse childhood experiences (ACEs) have emerged as a major research theme. They make reference to an array of potentially harmful exposures occurring from birth to eighteen years of age and may be involved in the construction of health inequalities over the lifecourse. As with many simplified concepts, ACEs present limitations. They include diver...

Adverse childhood experiences (ACEs) have emerged as a major research theme. They make reference to an array of potentially harmful exposures occurring from birth to eighteen years of age and may be involved in the construction of health inequalities over the lifecourse. As with many simplified concepts, ACEs present limitations. They include diver...

Social position is known to play a role in the quality of ageing, notably through the stimulation/dysregulation of key physiological systems in response to external stresses. Using data from one wave of Understanding Society including 9088 participants, we defined, as an extension of the allostatic load, a synthetic Biological Health Score (BHS) ca...

Background The processes at play in the implementation of one program in different contexts are complex and not yet well understood. In order to facilitate both the analysis and transfer of interventions, a “key functions/implementation/context” (FIC) model was developed to structure the description of public health interventions by distinguishing...