Lifecourse Epi Flashcards
(13 cards)
What is life course epidemiology?
Study of long term effects on health and disease throughout gestation, infancy, adolescence and adulthood. Combination of the adult lifestyle model with the early age approach (DOAD)
Why do we do life-course epic?
To understand biological, behavioural and psychosocial pathways throughout life/across generations that influence disease risk
What is the Barker hypothesis?
Production of a thrifty phenotype as a result of poor foetus nutrition. This leads to increased of disease in adult life.
What are the studies that suggested a foetal origin for adult disease?
Dutch Famine (1944) - limited food after WW2 - starvation event that provided an excellent opportunity as Netherlands is a developed country with excellent records. Follow up was made via telephone interview. Controls were used from non famine cities. Follow ups found association of famine with higher LDL/HDL ratio, antisocial personality disorder (when exposed to famine in 1/2 trimester), increase in CHD and increase in obesity (when exposed in 1st trimester)
Increase in CHD in poorest areas post war. Correlation found with past newborn death rates (low birth weight)
What are the proxy’s we can use for looking at foetal growth?
Birth weight (need to use standardised equation to take into account gestational age - from first day of last menstrual cycle) Birth length Ponderal Index (Length/weight3) Head circumference Placental to foetus weight ratio
What is the Barker Hertfordshire study?
Retrospective cohort study - men born between 1911 and 1930 - good birth weight (proxy for foetal growth) and growth in infancy. Found that heart disease more common in men small at birth and larger later in life. Also found associated with increased CHD mortality in those with low ponderal index, shortness, low placental weight.
What was the revised hypothesis from the Barker study?
Those with a low birth weight and get larger later in life have a increased risk of CHD and T2D. Biological programming occurs in critical periods that determine adult disease risk
What are the suggested stimuli for biological programming?
Under-nutrition in mid-late gestation, excessive exposure to glucocorticoids
What study confirmed Barkers hypothesis?
Helsinki study - over 4000 mean born between 1934 and 1944 - those with low birth weight (ponderol index) and low BMI at 11 - low risk of CHD (OR less than 1). Those with low ponderol index and high BMI at 11 had higher risk of CHD
What are the other outcomes suggested to be linked to the Barker hypothesis?
Anthropometry, musculoskeletal health, cognition, hearing, mental health, cholesterol
What is the critical period of health?
When environmental exposures have the greatest impact. Also when cognitive and behavioural skills are learned more easily
When are the critical periods of health?
in utero, infancy, childhood
What is a causal model?
details the life course approach, suggesting how exposures are related to each other (across foetal growth, infancy and adulthood) and to the outcome. Can be independent exposures or clustered exposures (where exposures influence each other and the outcome)
