What is Hypouricemia?
Much less research has been done on the roles of uric acid in the human body. In addition, it had been said that low uric acid levels do not induce health problems. Therefore, whether hypouricemia can lead to a disease or not has not been confirmed. However, the complications associated with low uric acid levels have been reported.
Exercise-Induced Acute Renal Failure
One of the common complications of renal hypouricemia is exercise-induced acute renal failure. Although the cause of exercise-induced acute renal failure has not been identified yet, there are some hypothesis presenting the possible effects of active oxygen or clogging of uric acid in the kidneys.
You may have heard of active oxygen. Active oxygen is a substance that is constantly present in the human body and plays a role to eliminate viruses in the body and boost our immunity. However, on the other hand, active oxygen can also oxidize cells and contribute to age our body. Uric acid has an antioxidative effect which suppresses the effect of active oxygen.
Active oxygen in the body increases with exercise or stress. Rapid and excessive increase of active oxygen can cause blood vessels in the kidneys to narrow, and the kidneys cannot receive sufficient blood. This blood shortage will lead to acute renal failure. People who have hypouricemia are more likely to experience exercise-induced acute renal failure due to the low levels of uric acid which suppresses the effect of active oxygen.
Another hypothesis is that exercise causes a rapid increase in the production of uric acid, which is precipitated into the renal tubules, leading to tubular obstruction.
These hypotheses also have contradictory evidence. Since the treatment and prevention of this exercise-induced acute renal failure still require clarification of its mechanism, further research is necessary.
It has been observed that approximately 10% of patients with renal hypouricemia had histories of exercise-induced acute renal failure or symptoms associated with the disease. Since exercise-induced acute renal failure has a tendency to repeat, try to refrain from intensive exercise and always stay well-hydrated.
Urolithiasis is a complication that is observed in approximately 7% of patients having xanthinuria (uric acid cannot be produced due to deficiency of XDH**) or renal hypouricemia. It is thought that the reason behind this is that renal hypouricemia causes an increase of uric acid excretion in urine in the kidneys as a result of decrease of uric acid excretion into the intestine.
For xanthinuria, poor metabolism to uric acid causes an increase of a substance called xanthine at a prior stage, increasing the likelihood to induce urolithiasis.
Although urolithiasis is common in adults, it is a complication that could occur regardless of a person’s age as a case of urolithiasis has been reported in a 15-months-old infant.
The calculus does not cause pain while it is in the kidneys; however, it causes severe pain when it moved from the kidneys to the ureter. Calculus can cause not only pain but also disturbance of urinary excretion and hematuria because of the injury to the ureter caused by the calculus .
Lack of water can cause formation of calculus due to an increase of urine concentration. In order to prevent urolithiasis, make sure to drink water frequently to avoid dehydration and excessive increase of urine concentration.
* Drug which has anti-inflammatory, analgesic, or antipyretic action
** An enzyme that metabolizes hypoxanthine to xanthine, and xanthine to uric acid