11. Appetite and Weight Flashcards
(40 cards)
obesity health risks
6% UK deaths metabolic syndrome/type 2 diabetes CV disease liver disease cancer reproductive dysfunction joint problems psychological morbidity
metabolic syndrome
constellation of closely associated CV risk factors:
visceral obesity
dyslipidaemia
hyperglycaemia
hypertension
underlying mechanism = insulin resistance
pathophysiology of metabolic syndrome
increased free fatty acids (lipolysis of visceral fat, gluconeogenesis, dyslipidaemia)
pro-inflammatory cytokines - TNF alpha, IL-6
insulin resistance
decreased GLUT-4 expression
decreased tyrosine kinase activity
type 2 diabetes risks
age
obesity
family history
ethnicity
why is type 2 diabetes prevalence increasing?
ageing population
increased obesity prevalence (+diagnosed younger)
better detection /diagnosis
obesity and cardiovascular disease
metabolic disease + increased: blood volume and viscosity vascular resistance hypertension left ventricular hypertrophy coronary artery disease stroke
obesity and respiratory system
obstructive sleep apnoea
hypoxia/hypercapnia
pulmonary hypertension - right heart failure
accidents
obesity and GI/liver
non-alcoholic fatty liver
non-alcoholic steatohepatitis - may progress to cirrhosis, portal hypertension, hepatocellular cancer
gallstones
reflux
obesity and cancer
~10% cancer deaths in non smokers
breast, endometrial, oesophagus, colon, renal, thyroid
obesity - mechanisms of increased cancer
increased insulin
increased free IFG-1
increased oestrogen
adipocytokines
obesity and reproductive system
PCOS - oligonmenorrhoea, hirsutism, sub fertility, insulin resistance
male hypogonadism
adverse pregnancy outcomes
obesity and joints
osteoarthritis
gout
aetiology of obesity
genetic factors
environmental factors
programming
gut microbiome
genetic causes of obesity
rare - obesity associated syndromes, Prader-Willi, Bardet-Biedl
common - polygenic, susceptibility genes
+ hypothyroidism, Cushing’s
diet and obesity
high fat, high sugar
coca-colanisation of developing world
socio-economic factors
obesity and physical activity
20-50% total energy expenditure
obesity prevalence related to proxy measures: car ownership, TV viewing
socioeconomic factors
foetal programming
‘programming’: stimuli at critical periods have persistent biological effects
stressors: undernutrition, trace elements
mechanism: epigenetic modification
life course model
factors operating at every stage of life affect health outcomes later in life
pathway of risk between events and health outcomes
worst outcome: low birth weight, excessive weight gain in infancy, adult obesity
gut microbiome
integral to host homeostasis - absorption, reabsorption
influenced by diet: high fat high fibre
influence disease risk: obesity, type 2 diabetes
regulation of appetite and weight
slow acting hormones that regulate weight
rapid acting peptides that regulate meal sizes
slow acting hormones
regulate body weight
leptin insulin
signal body fat % to hypothalamus - decrease food intake and increase energy expenditure
rapid acting peptides
regulate meal sizes cholecystokinin (CCK) - reduce eating ghrelin - increase eating PYY - reduce eating act via hypothalamus
arcuate nucleus in hypothalamus
accelerator neurons neuropeptide Y: increases eating agouti-related peptide (ArRP): blocks melanocortin receptor brake neutrons: POMC neurone melanocortin peptides: decrease eating
leptin in mice
deficiency - mouse models of obesity
leptin treatment reduces obesity in leptin-deficient mice
