society, human development, and public health (shh278)
DESCRIPTION
Society, Human Development, and Public Health (SHH278). Karestan Koenen Stephen Gilman Marie McCormick Lisa Berkman. Cardiovascular disease from a life-course perspective. What are the major risk factors for heart disease?. Smoking High blood pressure High blood cholesterol - PowerPoint PPT PresentationTRANSCRIPT
Society, Human Development, and Public Health (SHH278)
Karestan Koenen Stephen GilmanMarie McCormick
Lisa Berkman
What are the major risk factors for heart disease?
1. Smoking2. High blood pressure3. High blood cholesterol4. Overweight and obesity5. Physical inactivity6. Diabetes
Your guide to a healthy heartNational Institutes of HealthDecember 2005
Lawlor et al., 2006, Int J Obesity
Childhood IQ and BMI
Controlling for childhood factors
Also controlling for education
No IQ effect on BMI independentfrom education
Lawlor et al., 2006, Int J Obesity
IQEducationBMI
No effect of education on BMI within siblings: why?
Effect of education on BMIIndependent of childhood IQ
Socioeconomic status at birth and cardiovascular disease
• Father’s social class and cardiovascular disease mortality: 1.58 (1.32, 1.89) (Smith et al 1997)
• Social class in childhood and coronary heart disease: 1.57 (1.06, 2.30) (Power et al, 2005)
What are the major risk factors for heart disease?
1. Smoking2. High blood pressure3. High blood cholesterol4. Overweight and obesity5. Physical inactivity6. Diabetes
Your guide to a healthy heartNational Institutes of HealthDecember 2005
SES at birth: smoking
Childhood SES1st Cigarette
Regular Use
Quit
Maternal education (4yrs)
1.3
Low parental occupation
1.5
Family poverty 1.4 0.7
Adult SES
Education (4yrs) 1.5 2.5
Occupation
Gilman et al, 2003
SES at birth: cholesterol
• Father’s social class and cholesterol in adulthood: -0.05 (-.08, -.02) (Blane et al, 1996)
SES at birth: physical inactivity
• Low childhood social class and physical inactivity in adulthood: 1.29 (1.07, 1.56) (Regidor et al, 2004)
SES at birth: diabetes
• Childhood socioeconomic status and mortality from diabetes: 1.52 (1.32, 1.75) (Lawlor et al, 2006)
“Five of six studies reported associations between low early-life SES and little or no adult leisure-time physical activity, five of five found associations with high adult alcohol intake, and eight of twelve studies reported associations with higher smoking rates. Nine of 11 studies reported associations between lower early-life SES and elevated BMI and WHR.”
“Rapidly accumulating evidence is revealing an impact of childhood experiences on subsequent health, well-being, and competence which is more diverse, profound, and longlasting than was ever understood in the past.”
Hertzman & Weins, 1996
Organization of the Course
• Part I: Introduction to life-course epidemiology– Human evolution– Prenatal factors and adult disease– Mental illness
• Part II: Methods of life-course epidemiology– Lessons from clinical trials– Cohort studies
• Part III: Case studies in life-course epidemiology– Health disparities– Reproductive health– Mental health
• Part IV: Focus on specific developmetnal periods Leasons from clinical trials
– Childhood– Adolescence– Older adults/aging
• Course paper and presentation
Public health implications of the early life origins of disease…
• For etiologic models• “Life course epidemiology”• For intervention and prevention
Life course approach to epidemiology
• Life course models: how risk factors matter over time– Latency effects, critical and sensitive
period– Pathways, chains of risk– Cumulative risks
• Dimensions of time in life course research– Disease history– Life history– Social context
Definitions of ‘life course’ epidemiology
• what it is• …”the study of the long-
term effects on chronic disease risk of physical and social exposures during gestation, childhood, adolescence, young adulthood and later adult life. It includes studies of the biological, behavioral and psychosocial pathways that operate across and individual’s life course, as well as across generations, to influence the development of chronic diseases.”
• what it isn’t• “Merely the collection of
exposure data across the life course is not synonymous with a life course model of disease causation.”
• (Ben-Shlomo and Kuh, 2002)
Definitions of ‘life course’ epidemiology
• What– Population-based– Draws on multiple disciplinary perspectives– Elevates the dimension of time – Concerned with dynamic interactions between person and
environment • Why
– Static approaches of ‘modern epidemiology’ (case-control studies, for example) may obscure etiologic processes and intervention points
– Disease risk begins early in life and accumulates over time– Trajectories of risk initiated as early as conception
• How– Design: study persons over time across settings– Measures: developmentally sensitive and appropriate– Analysis: trajectories, timing
More on life course research1. What does ‘life course’ research do?
• From a developmental, sociological perspective, it “broadens the study of individual careers to explicitly locate intraindividual change within a broader historical and social context. Integral to the life course perspective are issues of…• Location in time (history) and place (society and
culture)• Linked lives, integration of individuals’ lives at the
social and institutional levels• Human agency• Timing of lives” (Elder)
2. What does a ‘life course’ orientation offer?• A theory• Framework or perspective• A method
In epidemiology, life course models posit different types of risk factor associations over time, which presumably suggest different causal paths to diseaseEarly-Life Exposures and Risk for Adult Outcomes
• Latency model
• Pathway models– Accumulation
– MediationPower and Hertzman 1997; Power 1991; Lynch, Kaplan, and Shema 1997; Hertzman and Weins 1996
Childhood Adulthood
Latency model
• Typical scenario– Exposure early in life– Disease onset after many years– Risk persists independently of intervening
events
• Application– Fetal programming (Barker)– Critical or sensitive periods– Social and biological risk factors
Evidence for Latent Risks?
• Prenatal famine and adult affective disorder
• Birth complications and psychosis
Brown et al, 2000
Relative risk of adult affective disorder among offspring of mothers exposed to famine in the prenatal period:
1st Trimester 1.23 (0.79-1.93)
2nd Trimester 1.40 (0.98-1.99)
3rd Trimester 1.50 (1.05-2.02)*
Unexposed 1.00
Relative risk of adult psychotic disorders among adults whose mothers experienced hypoxic-ischemia related birth complications: 2.06 (1.93-2.47)*
Zornberg et al 2000
Social & Biological Latent Risks
Relative Risk of Schizophrenia
FAMILY HISTORY
Mother & Father Affected 46.90 (17.56-125.26)*
Neither affected(Population Attributable Risk: 3.8%)
1.00
PLACE OF BIRTH
Capital 2.40 (2.13-2.70)*
Suburb of capital 1.62 (1.37-1.90)*
Rural area(Population Attributable Risk: 34.6%)
1.00
Mortensen et al, 1999
Pathway Models
• Typical scenarios– Risk factors early in life– Cause a series of intervening events– Interact with social and biological factors
throughout the life course– Ultimately lead to adverse health
outcomes
Evidence for latency/pathways effects over the life course
1. Does childhood class predict adult health?– If yes: possible latency effects
2. Does childhood class predict adult risk factors?– If yes: possible pathway effects
Evidence for latency/pathways effects over the life course
• Does childhood class predict adult cardiovascular risk?– RR for low vs. high = 2.6 95% CI(1.5,4.5)
• Does childhood class predict adult risk factors?– Correlation bt adult and childhood SES=.32, p<.001
• Does adult SES predict adult health?– RR for low vs. high = 1.6 95% CI(1.1,2.5)
• Is childhood class or adult class a more important determinant of adult health?– RR for Childhood adjusted for Adult = 2.3 – RR for Adult adjusted for Childhood = 1.4
• Is childhood class an important determinant of adult health after adjusting for sex, family liability, child/adolescent health characteristics, childhood IQ, childhood maltreatment, adult SES:– RR = 1.6 95% CI (0.9, 2.9)
Pathways
• Debate: conceptualizing a causal model of adult illness– Childhood versus adult SES– Causes versus confounders– Mediators versus confounders
“Living conditions cannot simply be left to fluctuate as people pass through childhood and their reproductive and working years and into old age, because health and quality of life at any one stage is affected by prior circumstances and events. …
“The life course may be regarded as combining biological and social elements which interact with each other. Individuals’ biological development takes place within a social context which structures their life chances, so that advantages and disadvantages tend to cluster cross sectionally and accumulate longitudinally.”
Bartley et al, 1997
SHDH Approach to Life Course Research
• Society: Social context– Social– Psychological– Biological
• Human Development: Life History– Development– Life transitions
• Health: Disease History– The progression of disease over the life course– Precursors, prodromes, onset, course, recovery– Continuities, discontinuities
DISEASE HISTORY SOCIAL CONTEXT LIFE HISTORY
Conception,Birth Development
Transitions ToAdulthood Old AgeMidlife
ExposureAccumulation of Risk Factors
LatencyPeriod
Intervening Factors
Early Manifestations(Prodromal Period)
Onset Recurrence,Remission
Socioeconomic Status, Traumatic Exposures, Life Events, Social Connections
Sub-populations: sex, race/ethnicity
DIMENSIONS OF LIFE COURSE EPIDEMIOLOGYDIMENSIONS OF LIFE COURSE EPIDEMIOLOGY
Life course research: it’s about time
• Life course research is inherently developmental in nature• Development = change• We want to observe (and if possible, intervene in) the
processes of change• Locate individual change within the contexts of place,
time, and social hierarchy• Risks for disease often occur early in life
– Origins of social inequalities begin early– Can they be modified later?
• Variations in social context occur throughout the life span– Measures of SES used in health studies may vary
according to the stage of the life span
Policy Implications
• Intervening early in life– Prevent, reduce exposures with latent effects– Avoid negative chains of events
• Interrupting pathways– Prevent (reduce the likelihood of) specific
negative health outcomes– Is it possible to entirely overcome the health
consequences of social adversity early in life?• Multiple adverse health consequences in
adulthood• Multiple pathways