Nutrition & Obesity Flashcards
1
Q
Primary v Secondary Malnutrition
A
- Primary Malnutrition - dec intake
- Poverty, famine, neglect
- GI motility disorders, deglutition problems (poor dentition and stroke), cancer-induced anorexia, eating disorders, dementia/mental illness, alcoholism/drug abuse
- Secondary Malnutrition - adequate diet but dec digestion, absorption or assimilation due to disease (normal intake); more common in US
- Digestion Problems
- Absorption Problems
- Inc Metabolism / inc excretion (diarrhea)
- Inc requirements - burns, chronic infection, trauma, etc
2
Q
Nutrition Eval
A
Subjective - diet, allergies, supplements, appetite changes, barriers (bad dentures), GI symptoms, living situation (nursing facility, access to stores, etc)
- Physical Exam - cachexia, edema, condition of teeth/mouth, temporal wasting, hair changes, hand muscle wasting, nail bed deformities, ascites, rashes, xanthomas
- Labs (visceral proteins, Hb/hematocrit for anemia, BUN/nitrogen/creatinine)
3
Q
Unstressed v Stressed Starvation
A
- Unstressed Starvation - chronic primary malnutrition resulting in severe total caloric deficiency –marked loss of body fat and protein stores
- Stressed Starvation - acquired, maladaptive state w/ primary protein deficiency - often in time of metabolic stress; can be acute or chronic –> rapid muscle wasting, edema, tissue breakdown into ulcers and infections
4
Q
Visceral Proteins (at steady state)
A
Albumin (21 day half-life - lagging indicator)
Inc - dehydration
Dec - acute/chronic malnutrition, preg, fluid overload, severe liver disease, inflam/malignancy, nephrotic syndrome
Pre-albumin (transthyretin - half-life of 2/3 days so recent changes)
Inc -dehydration, renal fail
Dec - acute/chronic malnutrition, preg, fluid overload, severe liver disease, inflam/malignancy
Retinol Binding Protein
Inc - renal fail, alcoholism
Dec- acute/chronic malnutrition, chronic liver disease, zinc or Vit A def, hyperthyroid
5
Q
Nitrogen Balance, BUN and Creatinine
A
- Nitrogen Balance = (protein intake in grams/6.25) - (24 hr UUN + 4 grams N)
- Normal is 0 to -2
- 2 means anabolism and sufficient intake of protein
- BUN - elevated w/ high catabolism (protein breakdown) or inc protein intake
- Creatinine - if euvolemic and normal kidneys this can reflect dec muscle mass if low
6
Q
Undernutrition Risk Categories (4)
A
- Low <90% IBW
- Mod <85% IBW
- High <70% IBW
- Incompatible w/ life <60% IBW
**Est IBW for women = 100 + 5(#inches above 5ft)
for men = 110 +5(#inches above 5ft)
7
Q
6 Weight Categories
A
- Underweight - BMI <18.5
- Normal - BMI 18.5-24.9
- Overweight - BMI 25-29.9
- Obese Class I - BMI 30-34.9
- Obese Class II - BMI 35-39.9
- Obese Class III - BMI 40+
8
Q
3 Stages of Unstressed Starvation
A
- < 24 hr - liver glycogen stores depleted to maintain blood glucose, dec insulin/inc glucagon; AA release from muscle for use in gluconeogenesis and FA release for energy
- Days - 3 wks - no more liver glycogen so dep on gluconeogenesis; inc rate of protein breakdown but fat provides most energy (FA metabolism –> ketone bodies)
- Brain can use ketones or glucose
- > 3wks - inc ketone body prod (higher levels of ketones in blood so now make it into brain); less need for gluconeogenesis so dec protein breakdown; slower metabolism, salt/water retention
- Inc TSH, renin, aldosterone, ADH, growth hormone, cortisol
- Dec glucagon, insulin, LH, prolactin, IGF-1
9
Q
How do organs adapt to unstressed starvation chronically? (7)
A
- Dec physical activity
- Hypothermia
- Dec CO, HR, BP
- Dec urine output and GFR
- Dec motility, brush border enzyme levels and villus height in GI
- Impaired immune function
- Dec lean body mass, dec fat, edema and inc fatty liver
10
Q
Body Changes in Stressed Starvation (6)
A
- particular dec in protein stores and inc extracellular water (edema)
- Hypermetabolism
- Inc muscle breakdown for AA - skeletal and visceral (for gluconeogenesis, repair, inflammation)
- Insulin resistance and hyperglycemia
- Inc catecholamines, glucagon, cortisol, TNF-alpha, IL-1, IL-6
- Inc extracellular water (edema)
11
Q
Malnutrition Tx
A
- Refeeding Syndrome - dramatic response to reintroducing nutrition (anabolism –> rapid shift of electrolytes from outside cell –> inside cell –> hypokalemia, hypomagnesium, hypophosphatemia)
- Need additional vitamins; vitamin deficiencies become unmasked (esp thiamine)
- Can lead to… cardiac arrhythmia, neuro dysfunction or even death
- Small amounts of fats, proteins and carbs w/ K+, Mg+ and phos supplements + vitamins
- Avoid huge amounts of volume even if dehydrated b/c risk CHF
12
Q
2 Routes of Nutritional Delivery
A
- Enteral - always prefer oral; if sedated/dysphagia/aspiration then use feeding tube right to gut (nasogastric, nasojejunal, oro-gastric if sedated)
- TPN (total parenteral nutrition) -if have to bypass gut then use IV nutrition
- EXPENSIVE and greater infection risk
- PPN (peripheral) - lower Osm
- TPN (central line) - higher Osm
13
Q
Anorexia (dx, complications, tx)
A
- Dx - restricted calorie intake + intense fear of wt gain despite being under wt (w/ distorted image or undue influence of body weight on self worth)
- Restrictive type - no binging or purging but severely restrict intake
- Binge/purging type - w/o prolonged fasting b/n episodes of binging or purging
- Complications = heme and electrolyte abnormalities –> CHF, arrhythmias, hypokalemia, metabolic acidosis, anemia AND GI - constipation, gastritis, esophageal erosions, stomach rupture AND osteoporosis
- Tx - CBT most effective; careful of refeeding syndrome; may use SSRIs in combo w/ CBT (fluoxetine - Prozac)
14
Q
Cachexia
A
- invol wt loss, lean body mass wasting, weakness, anorexia
- Common in cancer, tb, HIV, autoimmune disorders, CHF, liver failure, etc
- TNF-alpha, interferon-gamma, IL-1 and IL-6 (+ secondary malabsorption)
- Tx -
- Nutritional support (often use gels or nutrient dense liquids)
- Appetite stimulants - prednisone, cannabinoids
- SSRIs/SNRIs
- Anti-emetics
- Muscle growth stimulation - anabolic hormones (testosterone) or GH
- Block cytokine production - melatonin, thalidomide
- Nutritional support (often use gels or nutrient dense liquids)
15
Q
6 Stimulatory Substances that Convey Hunger
A
- neuropeptide Y
- opioids
- Ghrelin (released by stomach - meal initiation)
- melanin conc hormone
- growth hormone releasing hormone
- endocannabinoids
