Uric acid kidney stones is one of the common clinical manifestations of gouty nephropathy.
Clinical data show that the incidence of renal calculi in gout patients is 200 times higher than that in normal people. About 25% of gout patients have urinary calculi, of which about 80% belong to uric acid calculi. Uric acid kidney stones can cause hematuria, infection or obstruction besides severe renal colic. When uric acid calculi with infection, often can accelerate the growth of calculi and renal parenchyma damage, and in serious cases can even lead to pyelonephritis, hydronephrosis and other symptoms. Therefore, it is very important to prevent the formation of uric acid kidney stones.
The Formation Of Uric Acid Kidney Stones:
1, Low Urine Volume.
Low urine volume (less than 2 liters per day) increases the saturation of kidney stones in the urine, which can easily lead to the formation of various kidney stones, including uric acid kidney stones. Uric acid metabolized by the kidney needs to be excreted with the urine, less urine, uric acid accumulation on the more, high concentrations of uric acid salt will lead to the deposition of uric acid. Reduced urine volume caused by any cause, such as excessive sweating, chronic diarrhea, etc. may lead to uric acid kidney stone formation. Therefore, gout guidelines around the country encourage gout patients with normal heart and kidney function to drink more water to ensure adequate urine volume.
Hyperuricemia is defined as uric acid excretion in the urine more than 700 mg per day, and a variety of genetic and environmental factors can increase uric acid excretion in the urine. The uric acid pool in gout patients is significantly enlarged, and uric acid storage can be two to three times that of normal people, or even more. At this point, the kidney to uric acid clearance needs to exceed the physiological load, uric acid excretion caused by excessive urine uric acid concentration increased, causing uric acid deposition in the urinary system. Compared with hyperuricemia, renal tubular and urinary tract hyperuricemia is the most important and direct cause of significant damage to the urinary system, but to correct hyperuricemia, we must first improve hyperuricemia.
3, Low Urine PH.
Excessive acidic urine (pH less than 5.5) is the most important mechanism of uric acid nephrolithiasis. In fact, hyperuricemia is not enough to cause uric acid kidney stones if uric acid is not high enough and there is no low pH in the urine. The acidic environment causes more uric acid salts to turn into relatively insoluble uric acid, which results in the deposition of uric acid crystals. Uric acid excretion can be normal in uric acid renal calculi.
Conditions leading to acidic urine include loss of alkali (such as chronic diarrhea), increased uric acid production or increased production of endogenous acidic substances, and excessive intake of acidic food through the gastrointestinal tract. Diarrhea can lead to the loss of bicarbonate, reduce urine volume and increase urinary saturation, thus promoting the formation of stones. Vigorous exercise produces a lot of lactic acid and a lot of sweat (reducing uric acid) will also lead to a decrease in urine pH, a diet containing a lot of animal protein will increase the body’s acid load, resulting in increased urine acidity and hyperuricemia.
At the same time, acid urine is also associated with primary gout. The study found that 92% of gout patients had lower urinary pH than 5.6, regardless of whether there were kidney stones. Another study of gout patients with kidney stones found that urine pH averaged 5.4 in patients with kidney stones, and 5.6 in patients without kidney stones. Therefore, gout guidelines around the country are clearly recommended, for people without contraindications, alkaline urine this treatment measures applicable to all stages of gout.
Reducing uric acid, drinking more water and alkalinizing urine are the three major means to prevent renal acidic calculi, of which drinking more water is the simplest and most economical method; alkalinizing urine should be moderate (pH maintained at 6.2 to 6.9), excessive alkalization will prevent the dissolution of calculi instead; if normal people can not urinate in time for a long time, urine Uric acid concentration will accumulate to saturation value, and increase the probability of uric acid kidney stone formation. So, for patients with gout and hyperuricemia, it is the minimum requirement to drink more and not to hold back urine.