Term
| Gout results in deposition of ______ in synovial fluid and other tissues or the formation _______ stones in the kidney. |
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Definition
| monosodium urate crystals, uric acid |
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Term
In general gout is uncommon before what age?
In women, gouty arthritis attacks are uncommon before? |
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Definition
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Term
What is hyperuricemia?
What is significant about this level? |
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Definition
serum uric acid conc.>7mg/dL (420μmol/L)
this concentration is the limit of solubility for monosodium urate in plasma
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Term
| At what serum concentration is monosodium urate more likely to precipitate in the tissues? |
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Definition
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Term
| At a pH=7, what % of uric acid exists as monosodium urate? |
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Definition
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Term
Uric acid is an end product of _____ metabolism?
Since humans lack uricase, the uric acid cannot be broken into the water-soluble product ______. |
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Definition
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Term
| Increased serum uric acid occurs by 1 of 2 mechanisms. What are they? |
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Definition
1. overproduction of uric acid
2. underexcretion of uric acid |
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Term
| Is overproduction or underexcretion more prominent? |
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Definition
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Term
| Which medications can contribute to decreased excretion of uric acid? |
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Definition
Salicylates (<2g/day)
Diuretics
Alcohol
Levodopa-Carbidopa (Sinemet)
Ethamutol (Myambutol)
Pyrazinamide
Nicotinic acid (Niacin)
Cyclosporine (Sandimmune) |
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Term
| Overproduction of uric acid may result from abnormalities in the enzymes that regulate purine metabolism. What are the 2 documented enzymatic abnormalities? |
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Definition
1. increased phosphoribosylpyrophosphate synthetase activity
2. deficiency of hypoxanthine-guanine phosphoribosyltransferase |
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Term
| What level of uric acid production over 24-hours indicates overexcretion? (on a non-restricted diet) |
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Definition
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Term
2/3-3/4 of all uric acid produced daily is excreted where?
normally, uric acid is filtered in the ________, reabsorbed in the_________, and secreted __________. |
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Definition
kidneys
glomeruli, proximal tubule, distally |
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Term
Which joint is commonly affected by an acute gout attack?
What is podagra? |
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Definition
metatarsophalangeal joint
acute attack of gout in the great toe (>50% of all attacks) |
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Term
| What % of pt experience podagra at some point in the disease? |
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Definition
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Term
| In addition to podagra, gout can aggect: |
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Definition
| insteps, heels, ankles, knees, fingers, wrists, and elbows |
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Term
| What are some modifiable risk factors for gout? |
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Definition
1. alcohol consumption
2. obesity
3. HTN
4. occupational/environmental exposure to lead |
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Term
| How long does an untreated attack last? |
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Definition
| 7-10 days, peaking 1-2 days after onset |
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Term
| What are the nodular masses of monosodium urate cyrstals deposited in the soft tissues called? |
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Definition
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Term
| What are the most common sites of tophi? |
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Definition
| base of great toe, fingers, wrist, hand, olecranon bursae, and Achilles tendon |
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Term
When do tophi generally occur?
What are the complications of tophi? |
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Definition
approximately 12 years after the initial attack
pain, soft tissue damage, deformity, joint destruction, nerve compression syndromes (carpal tunnel syndrome) |
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Term
| What are the 3 renal manifestations of gout? |
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Definition
1. nephrolithiasis
2. acute gouty nephropathy
3. chronic gouty nephropathy |
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Term
How often does nephrolithiasis occur?
What is the pathophysiology of nephrolithiasis? |
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Definition
10-25% of pt with primary gout
uric acid crystals become more soluble as the urine pH becomes alkaline. acidic urine can become saturated with uric acid crystals and spontaneously form a stone (other stones may also develop as uric acid acts as a nidus for calcium oxalate or phosphate stones) |
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Term
| What causes acute gouty nephropathy? |
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Definition
| massive malignant cell turnover that occurs with the treatment of myeloproliferative or lymphoproliferative disorders, blockage of urine flow secondary to the precipitation of uric acid in collecting ducts and ureters can lead to acute renal failure |
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Term
Chronic urate nephropathy can occur after long-term deposition of cyrstals where?
Microtophi cause a massive inflammatory reaction resulting in what? |
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Definition
renal parenchyma
proteinuria and the inability of the kidney to concentrate urine |
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