L11 - Physiology of appetite and weight Flashcards
(47 cards)
Measurements - obesity
- BMI kg/m^2
- Waist circumference
- Skin-fold thickness
- Bioelectrical impedance analysis
- Ethnicity specific cut-offs
Co-morbidities associated with obesity
- Metabolic syndrome/type 2 diabetes
- Cardiovascular disease
- Respiratory disease
- Liver disease
- Cancer
- Reproductive dysfunction
- Joint problems
- Psychological morbidity
In which BMI range do health risks start to increase
- Overweight
What is metabolic syndrome
Metabolic syndrome is a cluster of conditions — increased blood pressure, high blood sugar, excess body fat around the waist, and abnormal cholesterol or triglyceride levels — that occur together, increasing your risk of heart disease, stroke and diabetes
Closely associated CV risk factors - Metabolic syndrome
○ Visceral obesity
○ Dyslipidaemia
○ Hyperglycaemia
○ Hypertension
Insulin resistance is the underlying pathophysiological mechanism
Factors associated with metabolic syndrome
- Central (visceral) fat
- Body mass index > 30
Obesity - pathophysiology
- Increase in free fatty acids (non-esterified fatty acids)
- Lipolysis of visceral fat leading to gluconeogenesis and dyslipidaemia
- Pro-inflammatory cytokines
- TNF-alpha, IL-6 (from ‘overloaded’ white adipose tissue) leads to insulin resistance
- Decrease in expression of GLUT-4 (insulin-sensitive glucose transporter)
- Decrease in tyrosine kinase activity of insulin receptor
What is the risk of type 2 diabetes determined by
- Age
- Obesity
- Family history
- Ethnicity
Factors that increase the risk of CV disease
- Metabolic syndrome PLUS
- Increase in blood volume and blood viscosity
- Increase in vascular resistance
- Increase in hypertension
- Increase in left ventricular hypertrophy
- Increase in coronary artery disease
- Increase in risk of stroke
How does obesity affect the respiratory system
- Obstructive sleep apnoea
- Hypoxia / hypercapnia
- Pulmonary hypertension
- Right heart failure
- Accidents - daytime somnolence
How does obesity affect the GI/liver
- Non-alcoholic fatty liver
- Non-alcoholic steatohepatitis
- May progress to cirrhosis, portal hypertension, hepatocellular cancer
- Gallstones
- Reflux
What percentage of cancer deaths in non-smokers are attributable to obesity
- 10% cancer deaths
Examples of types of cancers linked to obesity
- breast, endometrial, oesophagus, colon, gall bladder, renal, thyroid
Examples of mechanisms that contribute to cancer in obesity
- Increase in insulin levels
- Increase in free IGF-I
- Increase in oestrogen levels
- Adipo-cytokines
What is polycystic ovarian syndrome
a set of symptoms due to elevated androgens (male hormones) in females
How does obesity affect the reproductive system
- Polycystic ovarian syndrome
- Oligomenorrhoea, hirsutism, acne
- Subfertility
- Endometrial hyperplasia
- Insulin resistance
- Male hypogonadism
- Adverse pregnancy outcomes
How does obesity affect joints
- Osteoarthritis
- Gout
Psychological effects of obesity
- Depression
- Eating disorders
Genetic syndromes associated with obesity
- Prader-willi
- Bardet-biedl
What is prader-willi syndrome
Is a genetic disorder due to loss of function of specific genes. In newborns, symptoms include weak muscles, poor feeding, and slow development.
Beginning in childhood, the person becomes constantly hungry, which often leads to obesity and type 2 diabetes
What is bardet-biedl syndrome
is a ciliopathic human genetic disorder that produces many effects and affects many body systems. It is characterized principally by obesity, retinitis pigmentosa, polydactyly, hypogonadism, and kidney failure in some cases
Link between diet and obesity
- High fat
- High sugar
What is fetal programming
Fetal programming, also known as prenatal programming, is a theory which suggests that the environment surrounding the fetus during its developmental phase, plays a seminal role in determining its disease risk during the later stages.
What is the life course model
- Factors operating at every stage of life affect health outcomes later in life