Gout / Hyperuricemia
Hyperuricemia (elevated uric acid levels) is the underlying cause of gout. This can occur for a number of reasons including dietary, genetic, or underexcretion of urate, the salts of uric acid. Renal (kidney) underexcreation of uric acid is the primary cause of hyperuricaemia in about 90% of cases while overproduction is the cause in less than 10%. About 10% of people with hyperuricemia develop gout at some point in their lifetime. The risk however varies depending on the degree of hyperuricemia.
Signs and Symptoms
Gout can present in a number of ways, although the most usual is a recurrent attack of acute inflammatory arthritis (a red, tender, hot, swollen joint). The metatarsal-phalangeal joint at the base of the big toe is affected most often, accounting for half of cases. Other joints such as the heels, knees, wrists and fingers may also be affected. Joint pain usually begins over 2-4 hours and during the night. The reason for onset at night is due to the lower body temperature during this time. Other symptoms that may occur along with the joint pain include fatigue and a high fever. Long-standing elevated uric acid levels (hyperuricemia) may result in other symptoms including hard, non-painful deposits of uric acid crystal known as tophi. Extensive tophi may lead to chronic arthritis due to bone erosion. Elevated levels of uric acid may also lead to crystals precipitating in the kidneysresulting in stone formation. Prevention Both lifestyle changes and medication can decrease uric acid levels. Dietary and lifestyle choices that are effective include reducing intake of food high in purines such as meat and seafood,
consuming adequate vitamin C, limiting alcohol and fructose consumption and avoiding obesity. Vitamin C intake of 1,500 mg per day decreases the risk of gout by 45% compared to 250 mg per day. Coffee but not tea consumption is associated with a lower risk of gout. Gout may be secondary to sleep apnea via the release of purines from oxygen-starved cells. Treatment of apnea can lessen the occurrence of attacks.
Without treatment an acute attack of gout will usually resolve in 5 to 7 days however 60% of people will have a second attack within one year. Those with gout are at increased risk of hypertension, diabetes mellitus, metabolic syndrome, renal and cardiovascular disease and thus at increased risk of death. This may be partly due to its association with insulin resistance, obesity but some of the increased risk appears to be independent.