disorders of appetite Flashcards
what are the definitions of polydipsia and adipsia?
Polydipsia
- excessive thirst or excess drinking
Adipsia
- inappropriate lack of thirst
- with consequent failure to drink in order to correct hyperosmolality
what are the definitions of anorexia and obesity?
Anorexia - lack or loss of appetite for food
Obesity: abnormal or excessive fat accumulation that presents a risk to health
what are some pathological conditions related to thirst?
polydipsic disorders:
primary
secondary
adipsic disorders: A B C D
what is secondary polydipsia?
More common
Medical issues that disrupt any step in osmoregulation or alter ADH can cause secondary polydipsia
what are causes of secondary polydipsia?
Chronic medical conditions: Diabetes insipidus & mellitus Kidney failure Conn’s syndrome Addison's disease Sickle cell anaemia
Medications: Diuretics Laxatives Both result in dehydration Antidepressants
Dehydration: Acute illness Sweating Fevers Vomiting Diarrhoea Underhydration
what is the difference between diabetes mellitus and insipidus with regards to polydipsia?
Insipid means ‘tasteless’ Mellitus means ‘honeyed’ or ‘sweet’ (sweet urine) Diabetes Mellitus (DM): General population - common Related to high blood sugar Treatment of high blood sugar
Diabetes Insipidus (DI): General population - uncommon Related to pituitary problems Impaired ADH production Treatment with desmopressin
what other medical conditions can lead to polydipsia?
Acute kidney failure
Conn’s syndrome:
Primary aldosteronism
Addison’s disease:
Hypoadrenocorticism
what are causes of primary polydipsia?
Mental illness - psychogenic polydipsia (or acquired): Schizophrenia Mood disorders - depressionandanxiety Anorexia Drug use
Braininjuries
Organic brain damage
why is polydipsia a problem?
Kidney and bone damage Headache Nausea Cramps Slow reflexes Slurred speech Low energy Confusion Seizures
what is adipsia?
Decreased or absent feeling of thirst
Type A – most common
Type B
Type C
Type D
Increasedosmolality of urine -> Stimulates secretion of ADH -> Water retention -> Sensation of thirst decreases
what are eating disorders?
Mental disorderdefined by abnormal eating habits, includes: Binge eating disorder Anorexia nervosa Bulimia nervosa Pica Rumination syndrome Avoidant/restrictive food intake disorder also overeating ones
Global eating disorderprevalence ↑ed from 3.4% to 7.8% between 2000 and 2018.
70 million people live with eating disorder
what is the pathophysiology of anorexia?
Signs:
Low BMI, continuous weight loss, amenorrhea, halitosis, mood swings, dry hair, skin & hair thinning
Causes:
Genetic, environmental, psychological, sociological
Mechanism:
Serotonin
Less tryptophan ingested in diet (precursor to serotonin), so less serotonin
Mild: BMI > 17
Moderate: BMI of 16–16.99
Severe: BMI of 15–15.99
Extreme: BMI < 15
why is the prevalence of obesity increasing?
It is not lack of exercise:
Physical activity started to decline prior to obesity epidemic
it is:
Cheap, calorie-rich/nutrient poor beverages, sweets and fast food
how do we screen for obesity?
Height, weight and abdominal girth
Medical history:
Dietary and physical activity patterns, psychosocial factors, weight-gaining medications, familial traits
BMI = kg/m2
BMI of ≥30 or ≥25 + comorbidity or risk factor
how do we treat obesity?
most effective is diet+exercise
just diet is next most effective
