developmental origins of adult disease Flashcards
what is the barker hypothesis?
showed for the 1st time low birth weight infants are at greater risk of coronary heart disease later
common chronic diseases in adult life result from poor nutrition in womb
how can maternal nutritional status affect the fetus?
alter the epigenetic state of the fatal genome and printing gene expression
what can a nutrient poor maternal environment cause for the foetus in adulthood?
if they live in a nutrient rich environment => increased susceptibility to metabolic disease
if they live in nutrient poor environment => survival advantage
what is the thrifty hypothesis?
poor maternal nutrition +/- placental function leads to fatal undernutrition causing programming of glucose-insulin metabolism. therefore if baby receives poor postnatal nutrition with high energy expenditure then will result in thin adult (non-diabetic)
if baby is born into a good postnatal nutrition with energy excess then they will be an obese adult causing type 2 diabetes
what factors affect fetal undernutrition?
maternal diet
uteroplacental blood flow
placental transfer
fetal genome
what does fetal under nutrition cause in the fetus?
brain sparing => impaired development of blood vessels, liver, kidneys, pancreas
down regulation of growth => decrease insulin secretion and sensitivity
early maturation => increase cortisol
altered body composition => decrease muscle mass
how does fetal undernutrition cause T2DM and CHD?
hyperlipidaemia and hypertension, central obesity and insulin resistance
what are the late systemic effects of IUGR?
coronary heart disease
(risk of heart disease higher in LBW, before birth heart muscle cells sensitive to environment, malnutrition can speed up maturation, prerhaps in prep for early birth, reduced number cells, therefore diminished reserve for repair in later life, reduced growth limiting reserve)
hypertension (LBW babies have 3x fewer nephrons = renal HTN)
diabetes
osteoporosis (LBM that persists throughout life)
breast and ovarian cancer
what are the short term benefits of insulin resistance of fetus?
muscles of undernourished baby become resistant to insulin, raised blood sugar available to protect brain growth = thrifty hypothesis
how does diabetes develop in a fetus?
priority given to maintaining blood sugar rather than muscle storage, therefore thrifty handling of sugars becomes hard-wired and persists throughout life, therefore when food becomes more freely available after birth blood is flooded with sugar, obesity develops and makes body more resistant to insulin then diabetes develops
what are the three types of prevention?
primary
secondary = screening
tertiary
