Hyperuricemia
Encyclopedia
Hyperuricemia is a level of uric acid
in the blood
that is abnormally high. In humans, the upper end of the normal range is 360 µmol/L (6 mg/dL) for women and 400 µmol/L (6.8 mg/dL) for men.
, insulin resistance
, hypertension
, renal insufficiency, obesity
, diet
, use of diuretic
s, and consumption of alcoholic beverage
s. Of these, alcohol consumption is the most important.
Causes of hyperuricemia can be classified into three functional types: increased production of uric acid, decreased excretion of uric acid, and mixed type. Causes of increased production include high levels of purine in the diet and increased purine metabolism
. Causes of decreased excretion include kidney disease, certain drugs, and competition for excretion between uric acid and other molecules. Mixed causes include high levels of alcohol and/or fructose
in the diet, and starvation.
-rich diet is a common but minor cause of hyperuricemia. Diet alone generally is not sufficient to cause hyperuricemia. Purine content of foods varies (see Gout
). Foods high in the purines adenine
and hypoxanthine
may be more potent in exacerbating hyperuricemia.
Hyperuricemia of this type is a common complication of solid organ transplant
. Apart from normal variation (with a genetic component), tumor lysis syndrome
produces extreme levels of uric acid, mainly leading to renal failure. The Lesch-Nyhan syndrome
is also associated with extremely high levels of uric acid.
s, salicylates, pyrazinamide
, ethambutol
, nicotinic acid, ciclosporin
, 2-ethylamino-1,3,4-thiadiazole, and cytotoxic agents.
The gene SLC2A9
encodes a protein that helps to transport uric acid in the kidney. Several single nucleotide polymorphism
s of this gene are known to have a significant correlation with blood uric acid.
A ketogenic diet
impairs the ability of the kidney to excrete uric acid, due to competition for transport between uric acid and ketone
s.
Elevated blood lead
is significantly correlated with both impaired kidney function and hyperuricemia (although the causal relationship among these correlations is not known). In a study of over 2500 people resident in Taiwan, a blood lead level exceeding 7.5 microg/dL (a small elevation) had odds ratio
s of 1.92 (95% CI: 1.18-3.10) for renal dysfunction and 2.72 (95% CI: 1.64-4.52) for hyperuricemia.
High intake of alcohol (ethanol
), a significant cause of hyperuricemia, has a dual action that is compounded by multiple mechanisms. Ethanol increases production of uric acid by increasing production of lactic acid
, hence lactic acidosis
. Ethanol also increases the plasma concentrations of hypoxanthine and xanthine via the acceleration of adenine nucleotide degradation, and is a possible weak inhibitor of xanthine dehydrogenase. As a byproduct of its fermentation process, beer
additionally contributes purines. Ethanol decreases excretion of uric acid by promoting dehydration
and (rarely) clinical ketoacidosis
.
High dietary intake of fructose
contributes significantly to hyperuricemia. In a large study in the United States, consumption of four or more sugar-sweetened soft drinks per day gave an odds ratio
of 1.82 for hyperuricemia. Increased production of uric acid is the result of interference, by a product of fructose metabolism, in purine metabolism
. This interference has a dual action, both increasing the conversion of ATP
to inosine
and hence uric acid and increasing the synthesis of purine. Fructose also inhibits the excretion of uric acid, apparently by competing with uric acid for access to the transport protein SLC2A9
. The effect of fructose in reducing excretion of uric acid is increased in people with a hereditary (genetic) predisposition toward hyperuricemia and/or gout.
Starvation
causes the body to metabolize its own (purine-rich) tissues for energy. Thus, like a high purine diet, starvation increases the amount of purine converted to uric acid. A very low calorie diet
without carbohydrate
can induce extreme hyperuricemia; including some carbohydrate (and reducing the protein) reduces the level of hyperuricemia. Starvation also impairs the ability of the kidney to excrete uric acid, due to competition for transport between uric acid and ketone
s.
, sodium concentration, and temperature. Established treatments address these parameters.
, lowering the blood concentration of uric acid may permit any existing crystals of uric acid to be gradually dissolved into the blood, from whence the dissolved uric acid can be excreted. Maintaining a lower blood concentration of uric acid similarly should reduce the formation of new crystals. If the person has chronic gout
or known tophi
, then large quantities of uric acid crystals may have accumulated in joints and other tissues, and aggressive and/or long duration use of medications may be needed.
Medication
s most often used to treat hyperuricemia are of two kinds: xanthine oxidase inhibitor
s and uricosuric
s. Xanthine oxidase inhibitors decrease the production of uric acid, by interfering with xanthine oxidase
. Uricosurics increase the excretion of uric acid, by reducing the reabsorption of uric acid once the kidneys have filtered it out of the blood. Some of these medications are used as indicated
, others are used off-label
. Several other kinds of medications have potential for use in treating hyperuricemia. In people receiving hemodialysis
, sevelamer
can significantly reduce serum uric acid, apparently by adsorbing urate in the gut. In women, use of combined oral contraceptive pills is significantly associated with lower serum uric acid.
Non-medication treatments for hyperuricemia include a low purine
diet (see Gout
) and a variety of dietary supplements. These treatments are regarded by many physicians as having little or no efficacy. Treatment with lithium
salts has been used as lithium improves uric acid solubility.
include sodium bicarbonate
, potassium citrate
, magnesium citrate
, and Shohl's Solution (now replaced by Bicitra). Medications that have a similar effect include acetazolamide
.
and, if very high, renal failure
. The metabolic syndrome
often presents with hyperuricemia.
Persons with gout, and by inference hyperuricemia, are significantly less likely to develop Parkinson's disease
, unless they also require diuretic
s.
, a lack of uricase (a genetic trait fixed
in this breed) contributes to hyperuricemia and corresponding hyperuricosuria
.
Uric acid
Uric acid is a heterocyclic compound of carbon, nitrogen, oxygen, and hydrogen with the formula C5H4N4O3. It forms ions and salts known as urates and acid urates such as ammonium acid urate. Uric acid is created when the body breaks down purine nucleotides. High blood concentrations of uric acid...
in the blood
Blood
Blood is a specialized bodily fluid in animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells....
that is abnormally high. In humans, the upper end of the normal range is 360 µmol/L (6 mg/dL) for women and 400 µmol/L (6.8 mg/dL) for men.
Causes
Many factors contribute to hyperuricemia, including: geneticsGenetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....
, insulin resistance
Insulin resistance
Insulin resistance is a physiological condition where the natural hormone insulin becomes less effective at lowering blood sugars. The resulting increase in blood glucose may raise levels outside the normal range and cause adverse health effects, depending on dietary conditions. Certain cell types...
, hypertension
Hypertension
Hypertension or high blood pressure is a cardiac chronic medical condition in which the systemic arterial blood pressure is elevated. What that means is that the heart is having to work harder than it should to pump the blood around the body. Blood pressure involves two measurements, systolic and...
, renal insufficiency, obesity
Obesity
Obesity is a medical condition in which excess body fat has accumulated to the extent that it may have an adverse effect on health, leading to reduced life expectancy and/or increased health problems...
, diet
Diet (nutrition)
In nutrition, diet is the sum of food consumed by a person or other organism. Dietary habits are the habitual decisions an individual or culture makes when choosing what foods to eat. With the word diet, it is often implied the use of specific intake of nutrition for health or weight-management...
, use of diuretic
Diuretic
A diuretic provides a means of forced diuresis which elevates the rate of urination. There are several categories of diuretics. All diuretics increase the excretion of water from bodies, although each class does so in a distinct way.- Medical uses :...
s, and consumption of alcoholic beverage
Alcoholic beverage
An alcoholic beverage is a drink containing ethanol, commonly known as alcohol. Alcoholic beverages are divided into three general classes: beers, wines, and spirits. They are legally consumed in most countries, and over 100 countries have laws regulating their production, sale, and consumption...
s. Of these, alcohol consumption is the most important.
Causes of hyperuricemia can be classified into three functional types: increased production of uric acid, decreased excretion of uric acid, and mixed type. Causes of increased production include high levels of purine in the diet and increased purine metabolism
Purine metabolism
-Biosynthesis:Purines are biologically synthesized as nucleotides and in particular as ribotides, i.e. bases attached to ribose 5-phosphate. A key regulatory step is the production of 5-phospho-α-D-ribosyl 1-pyrophosphate by PRPP synthetase, which is activated by inorganic phosphate and...
. Causes of decreased excretion include kidney disease, certain drugs, and competition for excretion between uric acid and other molecules. Mixed causes include high levels of alcohol and/or fructose
Fructose
Fructose, or fruit sugar, is a simple monosaccharide found in many plants. It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorbed directly into the bloodstream during digestion. Fructose was discovered by French chemist Augustin-Pierre Dubrunfaut in 1847...
in the diet, and starvation.
Increased production
A purinePurine
A purine is a heterocyclic aromatic organic compound, consisting of a pyrimidine ring fused to an imidazole ring. Purines, including substituted purines and their tautomers, are the most widely distributed kind of nitrogen-containing heterocycle in nature....
-rich diet is a common but minor cause of hyperuricemia. Diet alone generally is not sufficient to cause hyperuricemia. Purine content of foods varies (see Gout
Gout
Gout is a medical condition usually characterized by recurrent attacks of acute inflammatory arthritis—a red, tender, hot, swollen joint. The metatarsal-phalangeal joint at the base of the big toe is the most commonly affected . However, it may also present as tophi, kidney stones, or urate...
). Foods high in the purines adenine
Adenine
Adenine is a nucleobase with a variety of roles in biochemistry including cellular respiration, in the form of both the energy-rich adenosine triphosphate and the cofactors nicotinamide adenine dinucleotide and flavin adenine dinucleotide , and protein synthesis, as a chemical component of DNA...
and hypoxanthine
Hypoxanthine
Hypoxanthine is a naturally occurring purine derivative. It is occasionally found as a constituent of nucleic acids where it is present in the anticodon of tRNA in the form of its nucleoside inosine. It has a tautomer known as 6-Hydroxypurine. Hypoxanthine is a necessary additive in certain cell,...
may be more potent in exacerbating hyperuricemia.
Hyperuricemia of this type is a common complication of solid organ transplant
Organ transplant
Organ transplantation is the moving of an organ from one body to another or from a donor site on the patient's own body, for the purpose of replacing the recipient's damaged or absent organ. The emerging field of regenerative medicine is allowing scientists and engineers to create organs to be...
. Apart from normal variation (with a genetic component), tumor lysis syndrome
Tumor lysis syndrome
In medicine , tumor lysis syndrome is a group of metabolic complications that can occur after treatment of cancer, usually lymphomas and leukemias, and sometimes even without treatment...
produces extreme levels of uric acid, mainly leading to renal failure. The Lesch-Nyhan syndrome
Lesch-Nyhan syndrome
Lesch–Nyhan syndrome , also known as Nyhan's syndrome, Kelley-Seegmiller syndrome and Juvenile gout, is a rare inherited disorder caused by a deficiency of the enzyme hypoxanthine-guanine phosphoribosyltransferase , produced by mutations in the HPRT gene located on X chromosome. LNS affects about...
is also associated with extremely high levels of uric acid.
Decreased excretion
The principal drugs that contribute to hyperuricemia by decreased excretion are the primary antiuricosurics. Other drugs and agents include diureticDiuretic
A diuretic provides a means of forced diuresis which elevates the rate of urination. There are several categories of diuretics. All diuretics increase the excretion of water from bodies, although each class does so in a distinct way.- Medical uses :...
s, salicylates, pyrazinamide
Pyrazinamide
Pyrazinamide is a drug used to treat tuberculosis. The drug is largely bacteriostatic, but can be bacteriocidal on actively replicating tuberculosis bacteria.-Abbreviations:...
, ethambutol
Ethambutol
Ethambutol is a bacteriostatic antimycobacterial drug prescribed to treat tuberculosis. It is usually given in combination with other tuberculosis drugs, such as isoniazid, rifampicin and pyrazinamide....
, nicotinic acid, ciclosporin
Ciclosporin
Ciclosporin , cyclosporine , cyclosporin , or cyclosporin A is an immunosuppressant drug widely used in post-allogeneic organ transplant to reduce the activity of the immune system, and therefore the risk of organ rejection...
, 2-ethylamino-1,3,4-thiadiazole, and cytotoxic agents.
The gene SLC2A9
SLC2A9
Solute carrier family 2, facilitated glucose transporter member 9 is a protein that in humans is encoded by the SLC2A9 gene.SLC2A9 has also recently been found to transport uric acid, and genetic variants of the transporter have been linked to increased risk of development of both hyperuricemia and...
encodes a protein that helps to transport uric acid in the kidney. Several single nucleotide polymorphism
Single nucleotide polymorphism
A single-nucleotide polymorphism is a DNA sequence variation occurring when a single nucleotide — A, T, C or G — in the genome differs between members of a biological species or paired chromosomes in an individual...
s of this gene are known to have a significant correlation with blood uric acid.
A ketogenic diet
Ketogenic diet
The ketogenic diet is a high-fat, adequate-protein, low-carbohydrate diet that in medicine is used primarily to treat difficult-to-control epilepsy in children. The diet mimics aspects of starvation by forcing the body to burn fats rather than carbohydrates...
impairs the ability of the kidney to excrete uric acid, due to competition for transport between uric acid and ketone
Ketone
In organic chemistry, a ketone is an organic compound with the structure RCR', where R and R' can be a variety of atoms and groups of atoms. It features a carbonyl group bonded to two other carbon atoms. Many ketones are known and many are of great importance in industry and in biology...
s.
Elevated blood lead
Lead
Lead is a main-group element in the carbon group with the symbol Pb and atomic number 82. Lead is a soft, malleable poor metal. It is also counted as one of the heavy metals. Metallic lead has a bluish-white color after being freshly cut, but it soon tarnishes to a dull grayish color when exposed...
is significantly correlated with both impaired kidney function and hyperuricemia (although the causal relationship among these correlations is not known). In a study of over 2500 people resident in Taiwan, a blood lead level exceeding 7.5 microg/dL (a small elevation) had odds ratio
Odds ratio
The odds ratio is a measure of effect size, describing the strength of association or non-independence between two binary data values. It is used as a descriptive statistic, and plays an important role in logistic regression...
s of 1.92 (95% CI: 1.18-3.10) for renal dysfunction and 2.72 (95% CI: 1.64-4.52) for hyperuricemia.
Mixed
Causes of hyperuricemia that are of mixed type have a dual action, both increasing production and decreasing excretion of uric acid.High intake of alcohol (ethanol
Ethanol
Ethanol, also called ethyl alcohol, pure alcohol, grain alcohol, or drinking alcohol, is a volatile, flammable, colorless liquid. It is a psychoactive drug and one of the oldest recreational drugs. Best known as the type of alcohol found in alcoholic beverages, it is also used in thermometers, as a...
), a significant cause of hyperuricemia, has a dual action that is compounded by multiple mechanisms. Ethanol increases production of uric acid by increasing production of lactic acid
Lactic acid
Lactic acid, also known as milk acid, is a chemical compound that plays a role in various biochemical processes and was first isolated in 1780 by the Swedish chemist Carl Wilhelm Scheele. Lactic acid is a carboxylic acid with the chemical formula C3H6O3...
, hence lactic acidosis
Lactic acidosis
Lactic acidosis is a physiological condition characterized by low pH in body tissues and blood accompanied by the buildup of lactate especially D-lactate, and is considered a distinct form of metabolic acidosis. The condition typically occurs when cells receive too little oxygen , for example...
. Ethanol also increases the plasma concentrations of hypoxanthine and xanthine via the acceleration of adenine nucleotide degradation, and is a possible weak inhibitor of xanthine dehydrogenase. As a byproduct of its fermentation process, beer
Beer
Beer is the world's most widely consumed andprobably oldest alcoholic beverage; it is the third most popular drink overall, after water and tea. It is produced by the brewing and fermentation of sugars, mainly derived from malted cereal grains, most commonly malted barley and malted wheat...
additionally contributes purines. Ethanol decreases excretion of uric acid by promoting dehydration
Dehydration
In physiology and medicine, dehydration is defined as the excessive loss of body fluid. It is literally the removal of water from an object; however, in physiological terms, it entails a deficiency of fluid within an organism...
and (rarely) clinical ketoacidosis
Ketoacidosis
Ketoacidosis is a metabolic state associated with high concentrations of ketone bodies, formed by the breakdown of fatty acids and the deamination of amino acids. The two common ketones produced in humans are acetoacetic acid and β-hydroxybutyrate....
.
High dietary intake of fructose
Fructose
Fructose, or fruit sugar, is a simple monosaccharide found in many plants. It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorbed directly into the bloodstream during digestion. Fructose was discovered by French chemist Augustin-Pierre Dubrunfaut in 1847...
contributes significantly to hyperuricemia. In a large study in the United States, consumption of four or more sugar-sweetened soft drinks per day gave an odds ratio
Odds ratio
The odds ratio is a measure of effect size, describing the strength of association or non-independence between two binary data values. It is used as a descriptive statistic, and plays an important role in logistic regression...
of 1.82 for hyperuricemia. Increased production of uric acid is the result of interference, by a product of fructose metabolism, in purine metabolism
Purine metabolism
-Biosynthesis:Purines are biologically synthesized as nucleotides and in particular as ribotides, i.e. bases attached to ribose 5-phosphate. A key regulatory step is the production of 5-phospho-α-D-ribosyl 1-pyrophosphate by PRPP synthetase, which is activated by inorganic phosphate and...
. This interference has a dual action, both increasing the conversion of ATP
Adenosine triphosphate
Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...
to inosine
Inosine
Inosine is a nucleoside that is formed when hypoxanthine is attached to a ribose ring via a β-N9-glycosidic bond....
and hence uric acid and increasing the synthesis of purine. Fructose also inhibits the excretion of uric acid, apparently by competing with uric acid for access to the transport protein SLC2A9
SLC2A9
Solute carrier family 2, facilitated glucose transporter member 9 is a protein that in humans is encoded by the SLC2A9 gene.SLC2A9 has also recently been found to transport uric acid, and genetic variants of the transporter have been linked to increased risk of development of both hyperuricemia and...
. The effect of fructose in reducing excretion of uric acid is increased in people with a hereditary (genetic) predisposition toward hyperuricemia and/or gout.
Starvation
Starvation
Starvation is a severe deficiency in caloric energy, nutrient and vitamin intake. It is the most extreme form of malnutrition. In humans, prolonged starvation can cause permanent organ damage and eventually, death...
causes the body to metabolize its own (purine-rich) tissues for energy. Thus, like a high purine diet, starvation increases the amount of purine converted to uric acid. A very low calorie diet
Very Low Calorie Diet
Very low calorie diet is a diet with very or extremely low daily food energy consumption. It is defined as a diet of per day or less. VLCDs are formulated, nutritionally complete, liquid meals containing 800 kilocalories or less per day. VLCDs also contain the recommended daily requirements for...
without carbohydrate
Carbohydrate
A carbohydrate is an organic compound with the empirical formula ; that is, consists only of carbon, hydrogen, and oxygen, with a hydrogen:oxygen atom ratio of 2:1 . However, there are exceptions to this. One common example would be deoxyribose, a component of DNA, which has the empirical...
can induce extreme hyperuricemia; including some carbohydrate (and reducing the protein) reduces the level of hyperuricemia. Starvation also impairs the ability of the kidney to excrete uric acid, due to competition for transport between uric acid and ketone
Ketone
In organic chemistry, a ketone is an organic compound with the structure RCR', where R and R' can be a variety of atoms and groups of atoms. It features a carbonyl group bonded to two other carbon atoms. Many ketones are known and many are of great importance in industry and in biology...
s.
Treatment
Precipitation of uric acid crystals, and conversely their dissolution, is known to be dependent on the concentration of uric acid in solution, pHPH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
, sodium concentration, and temperature. Established treatments address these parameters.
Concentration
Following Le Chatelier's principleLe Châtelier's principle
In chemistry, Le Chatelier's principle, also called the Chatelier's principle, can be used to predict the effect of a change in conditions on a chemical equilibrium. The principle is named after Henry Louis Le Chatelier and sometimes Karl Ferdinand Braun who discovered it independently...
, lowering the blood concentration of uric acid may permit any existing crystals of uric acid to be gradually dissolved into the blood, from whence the dissolved uric acid can be excreted. Maintaining a lower blood concentration of uric acid similarly should reduce the formation of new crystals. If the person has chronic gout
Gout
Gout is a medical condition usually characterized by recurrent attacks of acute inflammatory arthritis—a red, tender, hot, swollen joint. The metatarsal-phalangeal joint at the base of the big toe is the most commonly affected . However, it may also present as tophi, kidney stones, or urate...
or known tophi
Tophus
A tophus is a deposit of monosodium urate crystals in people with longstanding high levels of uric acid in the blood. Tophi are pathognomonic for the disease gout...
, then large quantities of uric acid crystals may have accumulated in joints and other tissues, and aggressive and/or long duration use of medications may be needed.
Medication
Medication
A pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...
s most often used to treat hyperuricemia are of two kinds: xanthine oxidase inhibitor
Xanthine oxidase inhibitor
A xanthine oxidase inhibitor is any substance that inhibits the activity of xanthine oxidase, an enzyme involved in purine metabolism. In humans, inhibition of xanthine oxidase reduces the production of uric acid, and several medications that inhibit xanthine oxidase are indicated for treatment of...
s and uricosuric
Uricosuric
Uricosuric medications are substances that increase the excretion of uric acid in the urine, thus reducing the concentration of uric acid in blood plasma. In general, this effect is achieved by action on the proximal tubule...
s. Xanthine oxidase inhibitors decrease the production of uric acid, by interfering with xanthine oxidase
Xanthine oxidase
Xanthine oxidase Xanthine oxidase Xanthine oxidase (XO (sometimes 'XAO'), a form of xanthine oxidoreductase that generates reactive oxygen species. Is an enzyme that catalyzes the oxidation of hypoxanthine to xanthine and can further catalyze the oxidation of xanthine to uric acid...
. Uricosurics increase the excretion of uric acid, by reducing the reabsorption of uric acid once the kidneys have filtered it out of the blood. Some of these medications are used as indicated
Indication (medicine)
In medicine, an indication is a valid reason to use a certain test, medication, procedure, or surgery. The opposite of indication is contraindication.-Drugs:...
, others are used off-label
Off-label use
Off-label use is the practice of prescribing pharmaceuticals for an unapproved indication or in an unapproved age group, unapproved dose or unapproved form of administration...
. Several other kinds of medications have potential for use in treating hyperuricemia. In people receiving hemodialysis
Hemodialysis
In medicine, hemodialysis is a method for removing waste products such as creatinine and urea, as well as free water from the blood when the kidneys are in renal failure. Hemodialysis is one of three renal replacement therapies .Hemodialysis can be an outpatient or inpatient therapy...
, sevelamer
Sevelamer
Sevelamer is a phosphate binding drug used to prevent hyperphosphatemia in patients with chronic renal failure. When taken with meals, it binds to dietary phosphate and prevents its absorption...
can significantly reduce serum uric acid, apparently by adsorbing urate in the gut. In women, use of combined oral contraceptive pills is significantly associated with lower serum uric acid.
Non-medication treatments for hyperuricemia include a low purine
Purine
A purine is a heterocyclic aromatic organic compound, consisting of a pyrimidine ring fused to an imidazole ring. Purines, including substituted purines and their tautomers, are the most widely distributed kind of nitrogen-containing heterocycle in nature....
diet (see Gout
Gout
Gout is a medical condition usually characterized by recurrent attacks of acute inflammatory arthritis—a red, tender, hot, swollen joint. The metatarsal-phalangeal joint at the base of the big toe is the most commonly affected . However, it may also present as tophi, kidney stones, or urate...
) and a variety of dietary supplements. These treatments are regarded by many physicians as having little or no efficacy. Treatment with lithium
Lithium
Lithium is a soft, silver-white metal that belongs to the alkali metal group of chemical elements. It is represented by the symbol Li, and it has the atomic number 3. Under standard conditions it is the lightest metal and the least dense solid element. Like all alkali metals, lithium is highly...
salts has been used as lithium improves uric acid solubility.
pH
Serum pH is neither safely or easily altered. Therapies that alter pH principally alter the pH of urine, to discourage a possible complication of uricosuric therapy: formation of uric acid kidney stones due to increased uric acid in the urine (see Nephrolithiasis). Dietary supplements that can be used to make the urine more alkalineAlkalinity
Alkalinity or AT measures the ability of a solution to neutralize acids to the equivalence point of carbonate or bicarbonate. The alkalinity is equal to the stoichiometric sum of the bases in solution...
include sodium bicarbonate
Sodium bicarbonate
Sodium bicarbonate or sodium hydrogen carbonate is the chemical compound with the formula Na HCO3. Sodium bicarbonate is a white solid that is crystalline but often appears as a fine powder. It has a slightly salty, alkaline taste resembling that of washing soda . The natural mineral form is...
, potassium citrate
Potassium citrate
Potassium citrate is a potassium salt of citric acid with the molecular formula C6H5K3O7. It is a white, slightly hygroscopic crystalline powder. It is odorless with a saline taste....
, magnesium citrate
Magnesium citrate
Magnesium citrate, a magnesium salt of citric acid, is a chemical agent used medicinally as a saline laxative and to completely empty the bowel prior to a major surgery or colonoscopy. It is available without a prescription, both as a generic brand or under the brand name Citromag or Citroma. It is...
, and Shohl's Solution (now replaced by Bicitra). Medications that have a similar effect include acetazolamide
Acetazolamide
Acetazolamide, sold under the trade name Diamox, is a carbonic anhydrase inhibitor that is used to treat glaucoma, epileptic seizures, Idiopathic intracranial hypertension , altitude sickness, cystinuria, and dural ectasia...
.
Temperature
Low temperature is a commonly reported trigger of acute gout: an example would be a day spent standing in cold water, followed by an attack of gout the next morning. This is believed to be due to temperature-dependent precipitation of uric acid crystals in tissues at below normal temperature. Thus, one aim of prevention is to keep the hands and feet warm, and soaking in hot water may be therapeutic.Prognosis
Increased levels predispose for goutGout
Gout is a medical condition usually characterized by recurrent attacks of acute inflammatory arthritis—a red, tender, hot, swollen joint. The metatarsal-phalangeal joint at the base of the big toe is the most commonly affected . However, it may also present as tophi, kidney stones, or urate...
and, if very high, renal failure
Renal failure
Renal failure or kidney failure describes a medical condition in which the kidneys fail to adequately filter toxins and waste products from the blood...
. The metabolic syndrome
Metabolic syndrome
Metabolic syndrome is a combination of medical disorders that, when occurring together, increase the risk of developing cardiovascular disease and diabetes. It affects one in five people in the United States and prevalence increases with age...
often presents with hyperuricemia.
Persons with gout, and by inference hyperuricemia, are significantly less likely to develop Parkinson's disease
Parkinson's disease
Parkinson's disease is a degenerative disorder of the central nervous system...
, unless they also require diuretic
Diuretic
A diuretic provides a means of forced diuresis which elevates the rate of urination. There are several categories of diuretics. All diuretics increase the excretion of water from bodies, although each class does so in a distinct way.- Medical uses :...
s.
Dalmatian dogs
In Dalmatian dogsDalmatian (dog)
The Dalmatian is a breed of dog whose roots are often said to trace back to Dalmatia, a region of Croatia where the first illustrations of the dog have been found. The Dalmatian is noted for its unique black- or brown-spotted coat and was mainly used as a carriage dog in its early days...
, a lack of uricase (a genetic trait fixed
Fixation (population genetics)
In population genetics, fixation is the change in a gene pool from a situation where there exist at least two variants of a particular gene to a situation where only one of the alleles remains...
in this breed) contributes to hyperuricemia and corresponding hyperuricosuria
Hyperuricosuria
Hyperuricosuria is a medical term referring to the presence of excessive amounts of uric acid in the urine. Notable direct causes of hyperuricosuria are dissolution of uric acid crystals in the kidneys or urinary bladder, and hyperuricemia...
.
External links
- GeneReviews/NCBI/NIH/UW entry on UMOD-Related Kidney Disease Includes: Familial Juvenile Hyperuricemic Nephropathy, Medullary Cystic Kidney Disease 2
- OMIM entries on UMOD-Related Kidney Disease Includes: Familial Juvenile Hyperuricemic Nephropathy, Medullary Cystic Kidney Disease 2
- GeneReviews/NCBI/NIH/UW entry on Familial Juvenile Hyperuricemic Nephropathy Type 2
- OMIM entries on Familial Juvenile Hyperuricemic Nephropathy Type 2