lecture 7 - gouty arthritis Flashcards
What are some of the gout comorbidities?
Diabetes, cardiovascular disease, renal disease, hypertension
What are the environmental risk factors for developing gout?
High intake of purine rich foods (red meat, seafood), alcohol consumption, oestrogen, insulin, obesity, fructose consumption
What gene is most strongly associated with developing gout?
ABCG2 gene - a transporter for uric acid secretion
What are the signs/symptoms of gout?
Recurrent attacks of inflammatory arthritis, tophi (hard deposits of uric acid in joints), kidney stones
What is acute gout?
An attack of arthritis to one joint, resolving within days.
What is chronic gout?
Prolonged urate crystal deposition causes tophii deposition and progressive arthropathy. Generally associated with renal impairment
What is the pathophysiology of gout?
Excess urate/uric acid precipitates into monosodium urate crystals which are deposited into joints. This triggers an inflammatory reaction and proteolytic enzymes are released causing pain and joint damage.
What dietary substance is associated with gout?
Purines - the are metabolised into urate
What are some of the causes of excessive urate in gout?
Reduced renal clearance of urate, increased dietary purine intake, reduced gut excretion of urate
How is gout diagnosed?
Synovial fluid aspirate to check for monosodium urate crystals, blood test for serum urate, imaging to look for tophi
Why do diuretics increase the risk of developing gout?
They often bind preferentially OATs in the kidney, which reduces OATs available for uric acid secretion
What are the pharmacological treatments for gout?
Anti-inflammatories (naproxen, colchicine), Urate lowering (allopurinol)
What is the mechanism of action of allopurinol?
Xanthine oxidase inhibitor - Inhibits the enzyme than converts xanthine to uric acid, therefore reducing uric acid production
