Path: Nutritional Pathology Flashcards
What is the difference b/w primary and secondary malnutrtion?
primary - intake is not sufficient
secondary - intake is sufficient, but improper use or storage, increased loss or need, malabsorption
When is a child considered to be malnourished?
body weight below 80% ideal
What are the two types of primary protein-energy malnutrition?
marasmus = calorie deficiency affects somatic protein compartment (skeletal muscle) kwashiorkor = protein deficiency affects visceral protein compartment (liver, etc)
What are the features of marasmus?
loss of SC fat and muscle
maintained serum albumin
emaciated w weight loss (less than 60% ideal BW)
immune deficiencies
What are the features of kwashiorkor?
sparing of SC fat and muscle low serum albumin and other proteins protuberant abdomen, edema due to hypoalbuminemia (60-80% ideal BW) skin lesions = flaky paint sign immunodeficiencies
What can cause secondary protein-energy malnutrition?
cachexia (cancer, AIDS)
chronic GI dz, elderly, severe trauma, sepsis, burns
What is the pathophysiologic basis for obesity?
disorder of energy balance, central sensor = hypothalamus
stomach releases ghrelin when food intake needed
fat cells release leptin when food intake not needed
What kinds of mutations can cause obesity?
mutations in genes encoding leptin, its receptor and components of anorexigenic pathway MC4R mutations (target of anorexigenic neurons)
What are the sources of vitamin A?
liver, dairy, dark yellow/orange fruits, green leafy vegetables, derived from retinoic acid
humans have a 6 month store in Ito cells
What are features of vitamin A def?
night blindness - earliest manifestation
xerophthalmia
squamous metaplasia of respiratory and urothelial mucosa
follicular dermatosis
immune deficiency
keratomalacia = softening and destruction of cornea
Bitot spots = opaque spots on eye from keratin debris
What are the features of vitamin A toxicity?
acute: headache, irritability, vomiting, stupor, papilledema
chronic: N/V, weight loss, lip dryness, skin peeling, hyperostosis w bone pain, osteoporosis, hepatomegaly w hepatic fibrosis
What are the teratogenic effects vitamin A toxicity?
cleft palate, CV, renal, limb defects, thymic agenesis, embryonic lethality
What are sources of vitamin D?
sunlight, fortified foods (milks, grains), fatty fish and fish oil, plants and grains
What are the features of vitamin D def?
rickets in children - overgrowth of cartilage at epiphyseal plates
osteomalacia in adults: deranged bone remodeling –> gross or micro fractures, wide unmineralized osteoid
What is the normal fxn of vitamin D?
absorption of calcium and phosphorous, mobilizes Ca from bone w PTH
What are the features of rickets?
frontal bossing, Harrison’s groove, delayed closure of cranial sutures, rachitic rosary, pigeon breast deformity, kyphoscoliosis and lumbar lordosis, genu valgus/varus, widened wrists and ankles, greenstick fractures, familial rickets
What are the features of vitamin D toxicity?
anorexia, N/V polyuria, polydipsia weakness, nervousness pruritus impaired renal fxn --> proteinuria, casts, azotemia metastatic calcifications
What are sources of vitamin E?
vegetables, grains, nuts and their oils, milk products, fish, meat, fortified breakfast cereals, supplements
What are the features of vitamin E deficiency?
rare, neuropathy, posterior column and spinocerebellar degeneration, hemolytic anemia, familial def from mutations in gene encoding TTPA
What are the features of vitamin E toxicity?
rare, muscle weakness, fatigue
nausea, diarrhea
antagonizes vit K action and enhances action of oral coumarin anticoagulants
What are the sources of vitamin K?
intestinal flora, diet, efficiently recycled
What are the features of vit K def?
bleeding diathesis, hemorrhagic dz of newborn
What are the features of vit K toxicity?
phylloquinone (vit K1) not toxic at 500x daily amount
menaquinone (vit K2 precursors) toxic –> anemia, hyperbilirubinemia, kernicterus in infants
vit K3 toxic - banned from supplements
What can cause vit K def?
coumarin anticoagulants create def
familial combined def of vit-k-dependent clotting factors due to mutation in gamma glutamyl carboxylase or vit K epoxide reductase
destruction of endogenous vit K synthesizing flora by antibiotics
neonatal period susceptible - bacteria not dev, liver small, breast milk levels low
What are the features of vitamin C def?
scurvy: hemorrhages (purpura and ecchymoses on the skin and mucosa, subperiosteal hemorrhages, neuro hemorrhages), skeletal changes (poor formation of matrix, bowing of legs, sternal depression, widening of epiphyses), papular rash ringed by hemorrhages, impaired wound healing
What syndromes can be caused by a vitamin B1 def?
dry beriberi (polyneuropathy)
wet beriberi (CV syndrome)
wernicke encephalopathy
korsakoff psychosis
subclinical def (think chronic alcoholics) - can convert to overt by extended IV glucose therapy (give thiamine with it!) or refeeding of malnourished
thiamine responsive megaloblastic anemia, DM, sensorineural deafness
What are the features of dry beriberi?
symmetric peripheral neuropathy
mixed motor and sensory symptoms
toe, foot, and wrist drop
What are the features of wet beriberi?
heart failure w peripheral edema
peripheral vasodilation –> high output cardiac failure
DCM
heart enlarged and globular, 4 chamber dilation, thin walls
What are the features of Wernicke encephalopathy?
reversible ophthalmoplegia, nystagmus ataxia global confusion, apathy, disorientation hemorrhage and necrosis in mamillary bodies, periventricular regions of thalamus, floor of 4th ventricle, ant cerebellum
What are the features of Korsakoff psychosis?
irreversible
memory disturbances: retrograde amnesia w confabulation, anterograde amnesia (can’t acquire new info), due to lesions in medial dorsal nucleus of thalamus
What are the features of vitamin B2 (riboflavin) def?
ariboflavinosis:
angular stomatitis or cheilosis, glossitis, interstitial keratitis, dermatitis of cheeks, scrotum and vulva
What are the features of vitamin B3 def (niacin)?
pellagra:
diarrhea (atrophy and ulceration of GI mucosa), dermatitis, photosensitivity, glossitis, dementia (degeneration of brain neurons)
necklace = erythema and scales around neck
What are the features of vitamin B6 (pyridoxine) def?
dermatitis, cheilosis, glossitis, peripheral neuropathy, convulsions, pyridoxine-dependent epilepsy
can be caused by long-term isoniazid
What are the features of vitamin B9 (folic acid) def?
megaloblastic anemia
GI signs and symptoms: sore tongue w taste bud atrophy, small bowel villous and crypt atrophy w megalocytosis, diarrhea and weight loss
fetal neural tube defects
What are the features of vitamin B12 (cobalamin) def?
same as vitamin B9 +
subacute combined degeneration of spinal cord - hits dorsal columns and descending corticospinal tracts
treatment w folate improves anemia but not neurological symptoms
