Week 1 - D - Overweight and obesity in adolescents Flashcards
What is obesity defined as?
High body fat content associated with disease risk
When plotting a BMI chart, at what age is there the transit from UK-WHO to UK90 data?
Age 4 years old
What centile line shows the average? (for eg MBI, height, weight)
The 50th centile line
What centile line shows overwight on a BMI chart?
Which centile line shows clinically obese?
Centile line for overweight is 91st
Centile line for clincally obese (ie. very overweight) is 98th centile line
What does the 99.6th centile line show on a BMI chart?
An individual who is severely overweight
How is BMI calculated? (what is it measured in)
Calculated by dividing weight (in kg) by the square of the height (in metres)
Kg/metres squared
What does a BMI below the second centile usually reflect?
May reflect under-nutrition but could simply reflect small build
What BMI centile is it where if children lie below they are likely to have additional problems?
The 0.4th centile
What are some short and long term consequences for obesity in children?
Hyperlipidaemia
Hypertension
Sleep apnoea
T2DM
Long term - obesity persistence, premature mortality and morbidity
When should the BMI centile be calculated? (usually one of two reasons)
If weight is above the 75th centile
OR
if weight and height centiles differ
What are some endocrine causes of obesity in children?
Hypothyroidism
Hypopituitarism
Growth hormone insufficiency
Excessive corticosteroid adminsitartion
What are 4 inheritable disorders that can cause obesity?
Down-syndrome
Prader-Willi syndrome
Fragile X syndrome
Duchenne muscular dystrophy
What is the genetic abnormality in Down’s sydnrome and Fragile X syndrome?
Down’s syndrome - Presence of a third copy of chromosome 21
Fragile X syndrome - triplet repeat in the FMR1 (fragile X mental retardation 1) gene causing varying degree of disability
What happens in prader-willi syndrome? (which chromosme, complications)
Prader-willi - loss of function of specific genes on chromosome 15 causing the child to become constantly hungry leading to obesity and usually T2DM
About 3/4 of cases occur when part of the father’s chromosome 15 is deleted. In another 25% of cases, the affected person has two copies of the maternal chromosome 15 from the mother and lacks the paternal copy
When should anti-obesity drugs such as orlistat be prescribed to children?
How does orlistat work?
should only be prescribed for severely overweight adolescents aka morbidly obese (BMI >99.6th percentile) with comorbidities attending a special clinic
Its primary function is preventing the absorption of fats from the human diet by acting as a pancreatic lipase inhibitor, thereby reducing caloric intake as fats cannot be broken down and absorbed
