Metabolism Disorders - Exam 4 Flashcards
What do congenital metabolic disorders arise from? What type of inheritance are the majority? How are they dx?
the absence or abnormality of an enzyme or its cofactor, leading to either accumulation or deficiency of a specific metabolite
autosomal recessive
Diagnosis via enzyme essays or genetic testing
What are the three products of carbohydrate metabolism?
glucose
fructose
galactose
What are the two components of sucrose? Lactose?
Sucrose = Glucose + Fructose
Lactose = galactose + glucose
_____ found in fruit, vegetables, honey, high fructose corn syrup, sucrose, sorbitol
____ is broken down from starches, lactose, maltose and sucrose
Fructose
Glucose
______ functions as the long-term storage for excess glucose. What are the two places it is stored? When is it formed?
glycogen
liver and muscle cells
Formed during periods of dietary carbohydrate loading
____ is converted to glucose for energy throughout the body and CNS. What is it responsible for?
liver glycogen
glucose homeostasis in between meals and during periods of fasting
_____ is converted to glucose during periods of ?????
muscle glycogen
high energy muscle activity
When is glycogen broken down?
Broken down when glucose demand is high or dietary availability is low
____ Defects in glycogen metabolism results in an accumulation of glycogen in the tissues. What two organ systems will determine clinical presentation?
glycogen storage diseases
liver and muscles
hypoglycemia
+/- hepatomegaly
muscle pain
cramps
rhabdomyolysis
cardiomyopathy
conduction defects
delayed growth in children
progressive weakness involving trunk and extremities
myoglobinuria
What am I?
When do s/s usually appear?
What is the tx?
glycogen storage disease
Symptoms occur after short periods of moderate to intense exercise
Avoid hypoglycemia by eating frequent smaller meals
Enzyme replacement therapy may be available for some subtypes
Treatment of complications (ie rhabdomyolysis)
What does myoglobinuria present like in a pt with glycogen storage disease?
Myoglobinuria will present as blood (heme) in urine on a dipstick. When the microscopic eval is done no RBC’s will be seen.
What are common lab findings on a pt with glycogen storage dz?
Lab findings of hypoglycemia, elevated LFT’s and/or CPK
Genetic testing
What is CPK? When it is used?
Creatinine Phosphokinase (CPK) - an enzyme that is located in the muscles, heart and the brain. When cells are damaged in these organs CPK is released.
aka enzyme released from muscle cells as they break down aka signals that muscle cells are breaking down (not a good thing)
will be high in glycogen storage dz
How is fructosemia inherited? What are the 3 subtypes?
autosomal recessive: inability to metabolize fructose
fructokinase (Essential Fructosuria)
fructose 1,6-bisphosphate aldolase - aka aldolase B (Hereditary Fructose Intolerance)
fructose 1,6-diphosphatase (FDPase) (aka fructose 1,6-bisphosphatase)
Essential Fructosuria is _____
Hereditary Fructose Intolerance is _____
FDPase is _____
fructokinase
fructose 1,6-bisphosphate aldolase - aka aldolase B
fructose 1,6-diphosphatase
_____ is a benign (asymptomatic) condition resulting from a lack of fructokinase. **What is the pathophys behind it? What is the tx?
Essential fructosuria
Incomplete metabolism of fructose in the liver leading to its excretion in urine aka fructose and sucrose just gets peed out
nothing! does NOT cause problems
Hereditary fructose intolerance is an inadequate breakdown of fructose causing a _____ of fructose-1-phosphate in the ???? (3 organs). What does it lead to?
toxic accumulation
liver, kidney and small intestine
cell death
vomiting, jaundice, hepatomegaly
crying due to abdominal pain
symptoms of hypoglycemia (lethargy/irritability/convulsions)
failure-to-thrive
infant is initially healthy and asymptomatic
What am I?
When do s/s appear?
Hereditary Fructose Intolerance
Symptoms begin upon ingestion of fructose or sucrose: usually from fruit, sweetened cereal or sucrose containing formula
formula fed babies will show signs earlier but breast fed babies will be around 4-6 months when they first are introduced to baby food
How do you confirm dx of Hereditary Fructose Intolerance? What is the tx? What are 2 common complications?
genetic testing
complete avoidance of fructose and sucrose
liver and renal failure
Which type of fructosemia enzyme def is VITAL for gluconeogenesis? What is the result?
Fructose 1,6-bisphosphatase
deficiency of FDPase results in inadequate glucose production during periods of fasting (between meals and during sleep)
aka cannot produce glucose through gluconeogenesis due to lack of the enzyme
hypoglycemia
acidosis (due to lactate build up)
respiratory rate
nausea
vomiting
lethargy
What am I?
What is the tx?
Fructose 1,6-bisphosphatase Deficiency
avoid prolonged fasting
avoid fructose
**acidosis: body compensates by trying to blow off excess CO2 (acid) and respiratory rate will be elevated
What is galactosemia? How is it inherited?
autosomal recessive
lack of metabolism of galactose leading to a toxic accumulation of galactose-related molecules in various organs
Name 4 fruits/veggies that have galactose? What is the primary source?
tomatoes, brussels sprouts, bananas, and apple
human/cow milk and baby formula
What are the three different galactosemia enzyme deficiencies? What is the MC? What is the most severe?
**Galactose-1-phosphate uridyl transferase (GALT) deficiency (type 1- Classic galactosemia)
the most common and severe type
Galactokinase deficiency (GALK)(type 2)
Galactose epimerase deficiency (GALE)(type 3)
Normal at birth
decreased appetite
vomiting
diarrhea
hepatomegaly
jaundice
failure to thrive
cataract within 2 weeks
What am I?
What is the cataract formation due to?
Classic Galactosemia - GALT - Type 1
galactitol deposition
sepsis, intellectual deficits, movement disorders, ovarian failure (females), liver/kidney failure. Are all complications of ______
classic galactosemia
What is the major presenting difference between GALT and hereditary fructose intolerance?
Hereditary Fructose Intolerance will have hypoglycemia
GALT will have cataract formation
_____ type of galactosemia primarily presents with a cataract.
_____ ranges from asymptomatic to classic presentation
GALK
GALE: has a range of presenation
Is GALT enzyme def included in a newborn screening? What enzymes will be elevated? reduced?
YES!
RBC galactose-1-phosphate - elevated in GALT deficiency
GALT enzyme activity - reduced in GALT deficiency
What is the tx for GALT?
Minimize dietary galactose by
Discontinue breastfeeding or traditional formula
Use soy-based formulas (ie Alsoy, Isomil, ProSobee)
Later avoid dairy products; lactose-free may be safe later on
Galactose-1-phosphate uridyl transferase deficiency is ____
Uridine diphosphate galactose 4-epimerase def is _____
Galactokinase def is _____
GALT
(UDP) (GALE)
GALK
What are three main functions of AA? When does dysfunction occur? Are AA disorders included in the newborn screening?
building blocks for proteins and synthesis of hormones and neurotransmitters
Dysfunction occurs when the amino acids are unable to catabolize (break down) which results in an accumulation of the AA compound in the blood or urine aka cannot break down AA which leads to increased levels of AA in the serum
YES!
Phenylketonuria results in a deficiency of an enzyme called _____. How is it inherited? What is it responsible for?
phenylalanine hydroxylase (PAH)
autosomal recessive
PAH responsible for converting phenylalanine → tyrosine
What type of foods are high in phenylalanine? Low?
PKU leads to a toxic accumulation of phenylalanine in the _____. What happens next?
brain
Phenylalanine excess results in destruction of the myelin (fatty covering)of individual nerve fibers aka destroys myelin
What does the severity of PKU depend on? What is considered “classic PKU”? What ethnicity is MC?
amount of enzyme lost, ranges from mild - complete absence
classic = complete absence of enzyme
MC: in white and native american
normal at birth
loss of appetite
weakness
vomiting
irritability
Epilepsy
Abnormal gait/posture/stance
loss of executive functioning
decreased motor functioning
What am I?
What happens if left untreated? Why?
Phenylketonuria (PKU)
Blue eyes, light hair, and skin
Phenylalanine interferes with melanin production
How do you dx PKU?
newborn screening
Phenylalanine interferes with melanin production
What is the tx for PKU? What food do they need to avoid?
Dietary restriction of phenylalanine:
Avoid meats, dairy, nuts, aspartame
**supplement tyrosine
sapropterin
pegvaliase
______ activates PAH to promote the breakdown of phenylalanine. Can you rx to kids?
sapropterin (Kuvan)
_____ degrades phenylalanine. Can you rx to kids?
pegvaliase (Palynziq)
NO! adults only
Which of the two drugs that reduce blood phenylalanine must you have some enzyme present in order for it to work?
sapropterin (Kuvan) must have some enzyme present
**aka will not work in complete enzyme absence
______ A deficiency in the enzyme complex (branched-chain ketoacid dehydrogenase complex - [BCKDC]) required to break down branch-chain amino acids¹ (BCAA). How is it inherited?
Maple Syrup Urine dz
autosomal recessive
What is the function of BCAA (branch chain AA)? Name 3
stimulate the building of protein in muscle and possibly reduce muscle breakdown
leucine
isoleucine
valine
Def in branched-chain ketoacid dehydrogenase complex BCKDC] lead to ??? What is the result?
accumulation of these BCAA and their byproducts throughout the body
neuroinflammation
Elevation of plasma _____ causes maple syrup odor. Urine has a sweet odor, much like burnt caramel in ____. Name some common sources.
isoleucine
maple syrup urine dz
eggs, soy protein, white fish, pork, beef, tofu, parmesan, sesame
What is the MC form of maple syrup urine dz? How much enzyme activity? What is the form? enzyme activity?
Classic MSUD - < 3 percent enzyme activity
Non-classic MSUD - 3-30% enzyme activity
symptoms begins within 48 hours - 2 weeks
irritability
poor feeding
vomiting
lethargy
dystonia
apnea
seizures
cerebral edema, can die
What am I?
How is it dx?
classic MSUD
newborn screening
prenatal screening is available
onset is anytime during infancy or childhood
epigastric pain
vomiting
anorexia
muscle fatigue
hyperactivity
sleep disturbance
stupor
decreased cognitive function
dystonia
ataxia
s/s are exacerbated by physical stress
What am I?
What is the management for both types?
Non-classic MSUD
-strict protein restriction (medical grade formula/food)
-trial of thiamine supplementation for 4 weeks
-control metabolic decompensation by hemodialysis if needed
-liver transplant for classic MSUD because 10% enzyme is better than 0%
in maple syrup urine dz, you want to inhibit further protein catabolism and enhance protein synthesis by what 3 things?
Discontinue protein intake x 24-48 hours
IV glucose - provides calories (prevents protein catabolism for energy)
IV insulin if glucose is > 130 mg/dL
insulin enhances endogenous protein synthesis
homocystinuria is due to the dysfunction of the metabolism of the amino acid ____ results in an accumulation of _____ and diminished _____. What is the MC enzyme deficiency?
methionine
homocysteine
cysteine
cystathionine β-synthase
in homocystinuria, elevated ____ results in abnormal production of ____ and _____. What is there function?
homocysteine
elevated elastin and fibrillin
function: maintain the integrity of tissues such as blood vessels, lung, skin and ocular ligaments aka connective tissue and vasculature
What is the effect of homocysteine on the neurological system? What are the results?
excitatory effects on the neurologic system
results in cognitive developmental delays and seizures aka problems with motor development
What is a common ocular problem seen in pts with homocystinuria? Why does this happen?
lens dislocation
Low cysteine levels are thought to weaken the fibers holding the lens of the eye in place
What are the two MC presenting s/s of homocystinuria? What age?
dislocated optic lens and mental retardation
3-5 years old
long limbs, fingers and toes; hyperlaxity, crowded oral maxilla, high palatal arch
Pes excavatum (sternum sinks in)
Pes carinatum (protrusion of sternum)
Genu valgum (knock knees
evidence of thromboembolic related s/s
seizures
hemiplegia
aphasia
ataxia
pseudobulbar palsy
What am I?
How do you dx?
What is the tx?
Homocystinuria
dx: newborn screening
Elevated levels of homocysteine and methionine in the plasma or urine
tx: protein restriction
Vit B6, B12, folate supplements
cysteine supplements
Betaine
What is pseudobulbar palsy?
inability to control facial muscles and emotions - uncontrollable laughing or crying at inappropriate times
What will the lab values look like on a pt with homocystinuria? Why do you supplement B6, B12 and folate?
elevated homocysteine and methionine in the plasma or urine
helps convert homocysteine to methionine
______ helps convert homocysteine to methionine. What dz?
Betaine
homocystinuria
What is a lysosome? Where are they formed? What is the broad primary function?
an organelle in the cytoplasm of eukaryotic cells that contains degradative enzymes enclosed in a membrane
golgi body
keep the cell healthy
What are some additional functions of a lysosome?
digests nutrients for use by the cell
Release enzymes outside of the cell to destroy materials around the cell
Digests unwanted materials (ie virus/bacteria) from inside and outside the cell (garbage disposal of a cell)
breaks down cells that have died
cell membrane repair
_____ are a part of the cell wall. They protect the cell from _____, assist in ____ and serve as _____ for the cell.
Glycosphingolipids
degrading enzymes
signal transduction
receptors
What are the 4 types of glycosphingolipids? What dz goes with each?
Gangliosides ->Tay-Sachs Disease
Cerebrosides -> Gaucher Disease
Globotriaosylceramide -> Fabry Disease
Sphingomyelin -> Niemann-pick Disease
Gangliosides -> ______
Cerebrosides -> ______
Tay-Sachs Disease
Gaucher Disease
Globotriaosylceramide -> ______
Sphingomyelin -> ______
Fabry Disease
Niemann-pick Disease
What is the underlying broad cause of lysosomal storage disoders?
Disorders that results from an abnormality in the biosynthesis of the lysosome which results in impaired enzyme activation
What is the cause of Gaucher dz?
Results from a deficiency in glucocerebrosidase (GCase)
What is the function of Gcase? What dz? _____ are component of cell membranes, that are released when cells are degraded
Gcase breaks down a fatty chemical called glucocerebroside into glucose and ceramide
Glucocerebrosides
What are Gaucher cells? What do they look like? Where are they found? What is the result?
A lack of GCase results in excessive glucocerebroside which builds up in macrophages
“wrinkled tissue paper”
spleen, liver, bone marrow, (and brain in severe cases)
results in chronic inflammation and fibrosis
How is Gaucher dz inherited? What is the MC ethnicity?
autosomal recessive
Ashkenazi Jewish ancestry
What are the 3 types of Gaucher dz? Which one is worse? Which types have CNS involvement? Which one is MC in the US? MC in the world?
G1, G2, G3
G2- has an early onset and is more aggressive
Type 2 and 3
US- G1
world: G3
What is a symptom that is common in all types of Gaucher dz? Describe it. What is the result?
bone crisis
Localized excruciating pain, local erythema, fever, and leukocytosis
Gaucher cells (lipid-laden macrophages) infiltrate bone marrow resulting in infarction, ischemia, necrosis, and cortical bone destruction
What are some characteristics of G1 Gaucher dz?
Bone marrow fibrosis, osteopenia, HSM,
No CNS involvement!!
Slow progression - most often dx before age 20
Normal life span
What are some characteristics of G2 Gaucher dz?
early onset and more aggressive
CNS involvement - Seizures, ataxia, hypotonia, MR
Death often by age 2
What are some characteristics of G3 Gaucher dz?
MC world wide
Both bone and neurologic involvement
slower rate of neurologic symptoms
Death often before adulthood
How do you dx Gaucher dz?
NOT included in the newborn screening in WV
dx through Low beta-glucosidase leukocyte enzyme activity Hallmark
genetic testing
What is the tx for Gaucher dz?
recombinant glucocerebrosidase (Imiglucerase)
eliglustat (Cerdelga) and miglustat (Zavesca)
_____ in Gaucher dz, helps to break down glucocerebroside but is not effective in reducing or reversing most CNS symptoms
recombinant glucocerebrosidase (Imiglucerase)
_____ is Gaucher dz, helps to block production of glucocerebroside (fatty substance)
Substrate-reduction therapy (SRT): eliglustat (Cerdelga) and miglustat (Zavesca)
What is Tay-Sachs dz? How is it inherited?
neurodegenerative disorder resulting from a mutation of the lysosomal enzyme, hexosaminidase A (Hex A)
autosomal recessive
What is the role of hexosaminidase A (Hex A)? What dz?
hexosaminidase A helps to break down a fatty substance called GM2 ganglioside
Tay-Sachs dz
What does a build up of GM2 ganglioside result in? What are 3 types of Tay- Sachs dz?
destruction of neurons in the brain and spinal cord
3 subtypes - varies based upon amount of enzyme present
infantile, juvenile, adult onset
Normal presentation until 3-6 month of age
exaggerated startle (Moro) reflex
gross muscle weakness
vision and hearing loss
intellectual disability
seizures and paralysis
What am I?
What is the hallmark finding?
What is the life expectancy?
infantile Tay- Sachs dz
cherry-spot on fundoscopy
life expectancy: 2-5 years, death often complications of pneumonia
Why do you see a cherry red spot on the fovea in infantile Tay-Sachs dz?
accumulation of GM2 ganglioside in retinal ganglion cells
Symptom onset usually between 2-5 years of age
respiratory infections
behavioral problems
slow loss of motor control and mental function
Progresses to a state of unresponsiveness/unawareness for years prior to death
death 10-15 years old
What am I?
What is the MC cause of death?
juvenile Tay-Sachs dz
infectious related
Clumsiness in childhood
Progressive motor weakness in adolescence
Dysarthria in adulthood
Intelligence declines slowly
40% experience mental health symptoms
What am I?
How do you dx? Is it included in the newborn screening?
adult onset Tay- Sachs dz
Newborn screening
Hex A enzyme analysis results a low enzyme level
What is the tx for Tay- Sachs dz?
no effective tx
supportive care: tx aimed at symptoms
What is the prevention for Tay-Sachs dz?
screening and genetic counseling
What if Fabry dz? How is it inherited?
A deficiency of alpha galactosidase A (GLA) leading to an accumulation of globotriaosylceramide (GL3), a fatty substance in the blood vessels
**X-linked inheritance: so more than likely will be seen in MALES
What does a build up of GL3 lead to? What dz? What organ systems are most affected?
builds up in the blood and blood vessel wall resulting in narrowed blood vessels which leads to inadequate oxygen
Fabry dz
skin, kidneys, heart, CNS
Angiokeratomas
Hypo- or anhidrosis
Corneal and lens opacities
Acroparesthesia
Progressive, small-vessel disease
What am I?
Where are the angiokeratomas commonly found? What are they caused by?
Fabry dz
found primarily between the umbilicus and the knees. glycolipid buildup in endothelial cells weakening the capillary walls
What is the cause of death in Fabry dz? How do you dx?
Progressive, small-vessel disease of the kidney, heart, and brain ultimately results in death
GLA enzyme activity - decreased
Confirmed with genetic testing
What is the tx for Fabry dz?
Enzyme-replacement: agalsidase beta (Fabrazyme)
Chaperone therapy: migalastat (Galafold)
control symptoms and prevent complication: ASA, antihypertensive, statins
_____ increases GLA enzyme activity preventing accumulation of GL3. Adults only
Chaperone therapy: migalastat (Galafold)
What is Niemann-pick dz? What are the MC organs affected? What is the special cell type called?
a deficiency of acid sphingomyelinase (ASM) leading to an accumulation of sphingomyelin within macrophages and other cells, eventually causing cell death and organ malfunction
spleen, liver, lungs, bone marrow, and brain
The macrophage cells of NPD are referred to as “foam” cells due to their soap-suds appearance
What are the 3 subtypes of Niemann-pick dz? Which one is the most aggressive?
NPA, NPB, NPC
NPA- most aggressive
Onset within 6 months after birth
Rapidly progressive CNS deterioration
spasticity
interstitial lung disease (ILD)
massive HSM
failure to thrive
What am I?
What is the life expenctancy?
NPA
death within 2 years
late childhood/adolescent
Progressive HSM
cirrhosis (“foam” cells replace liver cells)
interstitial lung disease
What am I?
What is the life expectancy? What is the cause of death?
NPB
Death in adolescence or early adulthood from liver/lung failure
middle-late childhood after normal early development
Liver, spleen, and/or lung involvement is present in > than 85% of patients
start out clumsy but progresses to ataxia, dysphagia, dystonia, seizures
What am I?
What is death secondary to?
NPC
aspiration pneumonia
How do you dx Niemann-pick dz? Is it included in the newborn screening?
genetic testing
NOT included in WV screening
What is the tx for NPA and NPC? What is the tx for NPB?
supportive care
oxygen therapy and blood transfusions prn
avoid contact sports if +spleen present
olipudase alfa-rpcp (Xenpozyme)
What is Pompe dz caused by? How it is inherited?
Results from a deficiency in acid αlfa-glucosidase (GAA) resulting in an inability to break glycogen into glucose for energy
Autosomal recessive mutation
In Pompe dz, _______ accumulates within the lysosome in all tissues leading to a lysosomal-mediated degradation of glycogenesis and _____
glycogen
tissue destruction
What are the 3 subtypes of Pompe dz?
Classic infantile-onset
Non-classic infantile-onset
Late-onset
onset within a few months of birth
hypotonia
myocardiopathy
HSM
rapidly progressive
What am I?
What is the life expenctancy?
Classic infantile Pompe dz
death before 1 year
onset by 12 months after birth
delayed motor skills (rolling over, sitting)
progressive muscle weakness leads to respiratory dysfunction
cardiomegaly without heart failure
What am I?
What is the life expectancy?
Non-classic infantile Pompe dz
death by early childhood: due to complication from organ dysfunction
late childhood, adolescence, or adulthood
slowly progressive muscle weakness of the legs, trunk, respiratory muscles
milder than other forms
What am I?
What is the life expectancy?
Late-onset Pompe dz (least enzyme defective)
older age: cause of death is respiratory failure
How do you dx Pompe dz? Is it included in the newborn screening?
Acid alpha-glucosidase (GAA) enzyme levels - decreased
Genetic testing confirms dx
NOT included in the newborn screening in WV
What is the tx for Pompe dz? What is important to remember? What do you need to monitor for?
Enzyme replacement therapy - alglucosidase alfa (Lumizyme)
Antibody formation to enzyme replacement therapy
monitor: continued risk of gradual weakness, fractures, dysphagia, and sleep apnea despite treatment
How is phosphate absorbed? What 2 other things are important?
absorbed from ingested food in the small intestines and excreted by the kidneys
need Vit D and PTH
What are functions of phosphate? What is the normal range? Where is it stored?
bone and teeth formation
building block for cell for energy, cell membranes, and DNA
2.5-4.5
85% is stored in the bone
15% is stored in the intra/extra cellular compartments
What are 3 pathophys processes that contribute to hyperphosphatemia?
increased phosphate intake
decreased phosphate excretion
shift of intracellular phosphate to extracellular space
What is the MC cause of decreased phosphate excretion? What are additional reasons?
MC- CKD**
hypoparathyroidism, increased Vit D, acute kidney dysfunction
a shift of intracellular phosphate to extracellular space is caused by ______ and _____ exacerbates hyperphosphatemia in disorders of kidney dysfunction
rhabdomyolysis
tumor lysis syndrome
aka transport of phosphate from inside the cell into the serum and it overwhelms the kidneys
How are calcium and phosphate related?
calcium decreases, phosphate increased.
inversely related
What is the tx for hyperphosphatemia? What is the tx for mild hyperphosphatemia?
acute severe disease:
no CKD: IV fluids
CKD present: hemodialysis
treatment is directed to underlying condition
___________
mild: dietary restrictions: avoid dairy item, meats and beans
moderate/severe: phosphate binders
calcium acetate (PhosLo)
lanthanum carbonate (Fosrenol)
sevelamer (Renagel)
_____ chelates phosphate in intestine to form insoluble calcium phosphate, which is excreted in feces. What is the indication? What forms does it come in?
calcium acetate (PhosLo)
Hyperphosphatemia in End Stage Renal Failure (ESRD)- On Dialysis
capsule and solution
Need to avoid ____ and calcium acetate. Is calcium acetate safe in pregnancy?
Digoxin
fairly safe in pregnancy
_____ binds with phosphate inhibiting GI absorption. What forms does it come in? Is it safe in preg?
Fosrenol (lanthanum carbonate)
powder, cheweable tablet. DO NOT MIX WITH WATER!! can be sprinkled on food
NOT preferred in preg. Use calcium acetate
_____ polymeric phosphate binder - decreases serum phosphate concentrations without changing calcium, aluminum, or bicarbonate concentrations. What forms does it come in? Is it safe in pregnancy?
sevelamer (Renagel/Renvela)
powder and tablet
aka: does not effect calcium, aluminum or bicarb levels
expected to be safe due to lack of systemic absorption
What are the 3 major subcategories of inadequate intake of hypophosphatemia?
inadequate intake:
-Intestinal malnutrition
-Vitamin D deficiency
-Excessive use of antacids
What is the MC of hypophosphatemia due to increased excretion?
hyperparathyroidism
What are some causes of hypophsphatemia due from extracelluar to intracelluar shift?
Tx of diabetic ketoacidosis, refeeding syndrome, hungry bone syndrome
weakness, bone pain, muscle pain, rhabdomyolysis
evidence of heart failure
focal neurologic findings, seizures, altered mental status
What am I?
What is the tx?
hypophosphatemia
mild: increase phosphate intake
moderate: phosphate supplement
What is the function of magnesium? What is the normal range?
protein, carbohydrate, and fat metabolism
maintenance of normal cell membrane function
assistance in PTH regulation
normal: 1.7- 2.1
99% is stored intracellular or bone
1% in extracellular space which is the stuff that shows up in labwork
What are some food sources of magnesium?
green vegetables, cereals, grains, nuts, legumes, and chocolate
What are some common pt types who have hypomagnesium?
alcoholics
parenteral nutrition
extremely poor diet
hungry bone syndrome
N/V/D pts
How does hypomagnesium present? What do you need to monitor?
s/s of hypokalemia and hypocalcemia
everything is increased!
cardiac arrhythmias
muscular weakness, tremors, seizure, paresthesias, nystagmus
Chvostek and Trousseau signs
heart: order EKG
What is the tx for hypomegnesemia?
increase dietary intake
severe: IV magnesium (give slowly!!)
mild/moderate: oral magnesium, replenish calcium/potassium if needed
What is the etiology of Paget dz?
typically begins with excessive bone resorption followed by an increase in bone formation. overactive osteoclasts results in compensatory osteoblastic activity
unknown etiology
_____ a large multinucleate bone cell that absorbs bone tissue during growth and healing
osteoclast “cutter”
_____ a cell that secretes the matrix for bone formation
osteoblast “builder”
Describe the bones of a pt with Paget dz? What bones are MC?
structurally disorganized mosaic of bone that is mechanically weaker, larger, less compact, more vascular, and more susceptible to fracture than normal adult bone
axial skeleton: spine, pelvis, femur, sacrum, and skull
Bone pain
Secondary osteoarthritis
Bony deformity
Excessive warmth
Neurologic complications
lytic lesions
What am I?
What is the MC neuro complication?
Paget dz
hearing loss
What does alkaline phosphatase and bone specific alkaline phosphatase lab values look like in Paget dz?
Elevated alkaline phosphatase and bone specific alkaline phosphatase (BSAP)
indicates increased osteoblast activity
What is the tx for Paget dz? What are some complications?
bisphosphonate: alendronate (Fosamax), ibandronate (Boniva), risedronate (Actonel), zoledronic acid (Reclast)
NSAIDs for joint pain
Calcium and Vit D supplementation
bone fractures, neoplasms, joint dz
