Environmental &
Nutritional Diseases
Ashley Inman
11-10-2014
Outline
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Environmental Diseases
Malnutrition
Obesity
Vitamin Deficiencies
Carbon Monoxide
• Important cause of accidental and suicidal
death
• Nonirritating, colorless, tasteless, odorless
gas
• Automotive engines, furnaces, cigarettes
• Hemoglobin has much stronger affinity for
CO than oxygen  carboxyhemoglobin
Lead Poisoning
• Binds to sulfhydryl groups in proteins and
interferes with calcium metabolism
• Exposure may occur through
contaminated air, food, and water
• Lead paint in older homes
• Children more susceptible due to higher
intestinal absorption and a more
permeable blood-brain barrier
Basophilic stippling
On PBS
Smoking
 Most prevalent preventable cause of
human death
Alcohol
• Acute:
– Mainly CNS effects
– Depressant that can lead to respiratory arrest
• Chronic:
– Liver: fatty change; cirrhosis
– Thiamine deficiency
– Alcoholic cardiomyopathy
– Pancreatitis (acute & chronic)
– Bleeding from gastritis and gastric ulcers
– Increased incidence of oral, esophageal, liver, and
breast cancer
Malnutrition
• Also called “protein energy malnutrition”
• Results from inadequate intake of proteins
and calories or problems with
digestion/malabsorption of proteins
• BMI <16 kg/m2 (normal 18.5-25 kg/m2)
• 2 main forms:
– Marasmus
– Kwashiorkor
Two protein compartments
• Somatic compartment:
– Proteins in skeletal muscle
– Reduced circumference of mid-arm
– Affected more by marasmus
• Visceral compartment:
– Protein stores in visceral organs (mostly liver)
– Decrease in serum proteins (albumin)
– Affected more by kwashiorkor
MARASMUS
• < 60% body weight
• Diet lacks protein & carbohydrate
• Loss of muscle mass (somatic
protein)- amino acids for energy
• Loss of subcutaneous fat (broomstick)
• Serum proteins (visceral
compartment) NORMAL
• EMACIATION- loss of muscle and fat
MARASMUS
• Head appears too large; “stick figure”
• Multiple vitamin deficiencies coexist
• Immune deficiency- especially T cell
immunity
KWASHIORKOR
• Protein deprivation > caloric deprivation
• **2nd birth First child is weaned too soon and
put on a high carbohydrate diet
• MORE dangerous than Marasmus
• Severe loss of visceral protein
• Hypoalbuminemia causes generalized EDEMA
which can mask the loss of weight
• Subcutaneous fat and muscle are SPARED
SIGNS OF KWASHIORKOR
• Flaky Paint Skin- alternating zones of hypoand hyper-pigmentation and desquamation
• Hair loss or color change
• FATTY LIVER- due to loss of
apolipoproteins; also small intestine
atrophy with loss of villi and disaccharidase
deficiency
• PITTING EDEMA and ascites due to
hypoalbuminemia
Signs Continued…
(Seen in both marasmus & kwashiorkor)
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Growth failure
Multivitamin deficiencies
Immune defects and infections
Anemia- usually hypochromic/microcytic
Cerebral atrophy in infants due to loss of
neurons and impaired myelinization of
white matter
• May have hypoplastic bone marrow
(mainly due to loss of RBC precursors)
Table 10-20
COMPARISON OF SEVERE MARASMUS-LIKE AND
KWASHIORKOR-LIKE SECONDARY PROTEIN-ENERGY
MALNUTRION
Syndrome
Clinical
Time
Course
Clinical
Features
Laboratory
Findings
Prognosis
Marasmuslike
Protein
energy
malnutrition
Chronic
illness
(e.g.,chronic
lung
disease,
cancer
Months
History of
weight loss
Muscle
wasting
Absent
subcutaneou
s fat
Normal or
mildly
reduced
serum
proteins
Variable;
depends on
underlying
disease
Kwashiorkor
-like protein
energy
malnutrition
Acute,
catabolic
illness (e.g.,
severe
trauma,
burns,
sepsis
Weeks
Normal fat
and muscle
Edema
Easily
Serum
albumin
<2.8 gm/dl
Poor
CACHEXIA
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CANCER and AIDS
Loss of muscle and fat
Fatigue
Good appetite
Higher metabolic rate
Cytokines- TNF, IL-6
Proteolysis-inducing factor (PIF)
ANOREXIA NERVOSA
• Self-induced starvation
• Like PEM plus:
– Amenorrhea (decreased secretion of gonadotropinreleasing hormone w/ subsequent endocrine effects)
– Hypothyroidism
– Scaly, yellow skin and lanugo
– Decreased bone density (mimicks postmenopausal
osteoporosis)
• Anemia, lymphopenia, hypoalbuminemia
• HYPOKALEMIA AND CARDIAC
ARRHYTHMIA  SUDDEN DEATH
BULIMIA
• Binge eating followed by induced
vomiting
• < ½ have amenorrhea, but menstrual
irregularities common
• Weight and gonadotropin levels near
normal
BULIMIA
• Major complications due to frequent
vomiting and chronic use of laxatives:
– Hypokalemia and CARDIAC ARYTHMIA
– Aspiration of gastric contents
– Mallory-Weiss Syndrome- longitudinal
laceration of the esophagus or stomach
– Boerhaave’s Syndrome- rupture of
esophagus or stomach
Obesity
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Hypertension
Insulin resistance
DM type II
High serum lipids
Atherosclerosis
Gallstones
Osteoarthritis
Malignancy
Nonalcoholic fatty liver disease
Sleep apnea
Metabolic Syndrome
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Visceral/intra-abdominal adiposity
Insulin resistance
Hyperinsulinemia
Glucose intolerance
Hypertension
Hypertriglyceridemia
Low HDL cholesterol
VITAMINS
• Fat Soluble- A, D, E, K
– Absorbed in the ileum
– Toxic- accumulate in fatty tissues
• Water soluble- B’s, C, Folate
– Toxicity rare b/c excreted in urine
• Fat soluble vitamins are more readily stored,
BUT they are poorly absorbed in fat
malabsorption disorders (cystic fibrosis, celiac
disease, ileal resection)
VITAMINS
• ENDOGENOUS Synthesis- D, K and
Niacin
• DIET- all the others
• Vitamin Deficiency can be PRIMARY (diet)
or Secondary (malabsorption)
VITAMIN A (RETINOL)
•Functions:
– Night vision
– Growth and differentiation of mucus-secreting
epithelium
– Immunity (children)
•Vitamin A stored in ITO CELLS in the liver;
6-month supply
VITAMIN A DEFICIENCY
• Night blindness (insufficient retinal rhodopsin)
• Xerophthalmia (dry eye)- keratinized squamous
epithelium replaces mucus-secreting epithelium
• Bitot spots (keratin debris) and keratomalacia
(destruction of the cornea)
• Squamous metaplasia in LUNG (infections) and
BLADDER (stones)
• Increased mortality in measles and diarrhea
Corneal Destruction
VITAMIN A TOXICITY
• Increased intracranial pressure
• Papilledema, headache, vomiting
• Bone pain and hypercalcemia (increased
osteoclast activity)
VITAMIN D
• Major function is to maintain adequate
plasma levels of CALCIUM and
PHOSPHORUS
VITAMIN D FUNCTIONS
• Stimulates intestinal absorption of calcium
and phosphorus
• Interacts with PTH to regulate blood
calcium levels
• Stimulates PTH-dependent re-absorption
of calcium in the distal renal tubule
VITAMIN D DEFICIENCY
• HYPOCALCEMIA and loss of bone:
RICKETS or OSTEOMALACIA
– Malnutrition
– Intestinal malabsorption (pancreatic
insufficiency)
– Inadequate sunlight exposure
– Liver disease
– Renal disease
Vitamin D Deficient
Normal
RICKETS
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Osteoid with inadequate mineralization
Disorganized fibroblasts and capillaries
Microfractures
Deformed bones
• Square head, “rachitic” rosary, pigeon
breast deformity, lumbar lordosis, and
bowed legs
OSTEOMALACIA
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Abnormal bone remodeling
Inadequate mineralization of new bone
Normal contours
Fractures and microfractures
– Mostly involving the vertebrae and
femoral neck
VITAMIN D TOXICITY
• Not caused by prolonged exposure to
sunlight; results from oral overdose
• Metastatic calcification of soft tissues
• In children: growth retardation
• In adults: renal calculi; bone pain
VITAMIN E
• “Antioxidant”
• Deficiency- nervous system- degeneration
of posterior column axons
– Loss of position and vibration sense; ataxia,
muscle weakness
– Hemolytic anemia of premature infants
• Toxicity: decreasd synthesis of vitamin Kdependent coagulation factors
VITAMIN K
• Clotting factors II (prothrombin), VII, IX
and X are carboxylated in the liver and
Vitamin K is a cofactor
• Also, carboxylation of protein C and S
(anticoagulants)
• Vitamin K is “recycled” in the liver and
gut bacteria make the vitamin, but some
dietary source is required
Vitamin K Deficiency
• Causes
– fat malabsorption
– reduced gut bacterial flora
• administration of wide specturm antibiotics
• neonatal period before gut is colonized
– liver disease
• Effects of vitamin K deficiency
– bleeding diathesis
– 3% prevalence of vitamin K-deficiency
among neonates warrants prophylactic
vitamin K therapy for all newborns
Vitamin K Deficiency
THIAMINE (B1)
• Not in polished rice, white flour or refined
sugar
• ¼ of all alcoholics are thiamine deficient
• Cofactor in oxidative decarboxylation 
deficiency of thiamine results in
DECREASED ATP
• Cardiovascular and nervous system
problems
THIAMINE DEFICIENCY
Dry beriberi (polyneuropathy): myelin
degeneration
Wet beriberi (cardiovascular):
vasodilitation produces heart failure
and edema
Wernicke-Korsakoff Syndrome:
Wernicke- ataxia/confusion
Korsakoff- amnesia, confabulation
NIACIN (B3)
• NAD and NADP are cofactors in oxidationreduction reactions
• Grains, legumes and seed oils (corn-based
diets)
• Deficiency of tryptophan (used to synthesize
niacin)
• Deficiency- PELLAGRA (3 D’s)
dermatitis, diarrhea (epithelial atrophy) and
dementia (posterior column changes as in B-12
deficiency)
Niacin, Pellagra
• 3 D’s of Pellagra
– Dermatitis
– Diarrhea
– Dementia
VITAMIN C (ASCORBIC ACID)
• (Citrus) fruits and vegetables
• Bone disease in growing children
• Hemorrhage and poor wound healing in children
and adults
• Vitamin C is a cofactor in formation and
maturation of procollagen
• Hydroxylation is impaired and crosslinks are not
formed
VITAMIN C DEFICIENCY
• SCURVY
• Capillary and venule walls are weak with
hemorrages (purpura and ecchymoses)
• Trauma- hematoma and hemarthrosis (joints)
• Child- too much cartilage and not enough
osteoid protein); bowed legs and deformed
chest
• Bacterial infection associated with gingival
hemorrhage
Vitamin C deficiency
Vitamin C Deficiency
“Rickets”
Normal
Cobalamin (B12)
• Stores last 3-5 years
• Only in animal products (eggs, meat, dairy)
• Requires intrinsic factor for reabsorption in
terminal ileum
• Functions in DNA synthesis
• Deficiency:
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Pernicious anemia (most common)
D. latum
Terminal ileum disease (Crohn’s)
Strict vegan diet
Cobalamin (B12) Deficiency
• Megaloblastic anemia
• CNS: posterior column and lateral
corticospinal tract demyelination
• Glossitis
FOLATE
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Marginal body stores
Most common vitamin deficiency in U.S.
Functions in DNA synthesis
Neural tube defects in the fetus
Megaloblastic anemia (no neurologic dx)
Glossitis
Certain drugs can lead to deficiency:
– Alcohol, methotrexate, phenytoin, oral contraceptives,
trimethoprim, 5-fluorouracil
Zinc
• Trace element
• Component of enzymes (oxidases)
• Causes of deficiency:
– Alcoholism
– Diabetes mellitus
– Chronic diarrhea
Zinc Deficiency
• Acrodermatitis (rash around eyes, mouth,
nose, and anus)
• Anorexia
• Diarrhea
• Growth retardation
• Impaired wound healing
• Hypogonadism/ Infertility
Other Trace Elements
• Copper:
– Deficiency: microcytic anemia; poor wound healing
– Toxicity: Wilson’s disease
• Selenium:
– Function: component of glutathione peroxidase
– Deficiency: dilated cardiomyopathy
• Chromium deficiency:
– Function: component of glucose tolerance factor and
cofactor for insulin
– Deficiency: impaired glucose tolerance
Other Trace Elements
• Iodine:
– Function: synthesis of thyroid hormone
– Deficiency: goiter; hypothyroidism
• Fluoride:
– Function: component of calcium
hydroxyapatite in bone and teeth
– Deficiency: dental caries
– Excess: chalky deposits on teeth; calcification
of ligaments