About gout
If you have had an acute gouty attack, you know how painful it can be. Many of my patients say it is the most pain they’ve ever had. Your big toe is red-hot, swollen, and so tender that even the weight of a blanket on it makes you wince in pain (see diagram).
Gout is a joint disorder characterized by acute inflammation commonly affecting the big toe. The pain and swelling associated with gout are the result of the body’s inflammatory response to the accumulation of urate crystals in or around the joint. Uric acid is formed when your body breaks down molecules called purines, which are building blocks for your DNA. Purines are found in high quantities in certain foods, including anchovies, sardines, and organ meats, such as liver. But most of the uric acid produced in your body is a result of the breakdown of naturally occurring purines found in your system.
Typically, uric acid is dissolved in your blood as urate passes on through your kidneys and is then eliminated in the urine. Sometimes, blood uric acid levels may be elevated (hyperuricemia) because your body either produces too much uric acid or your kidneys don’t eliminate enough.
High levels of uric acid in the blood, or other triggers, can cause urate crystals to form in joint spaces and other tissues. The resulting inflammation, which is due to your white blood cells’ response to these crystals, is a gout attack. In some people, the crystals can form kidney stones (calculi).
Who’s At Risk And Why
Gout is more likely to affect men than women, especially men between the ages of 40 and 50. Women become more susceptible to gout after menopause. Gout appears to run in some families.
A number of factors may cause the body to produce too much uric acid or deter the kidneys from eliminating enough of it. Known risk factors for gout include:
• Excess weight
• Certain medical conditions, including high blood pressure, diabetes, and elevated fat levels
• Excessive alcohol intake
• Excessive intake of foods high in purine
• Certain medications, including some diuretics, low-dose aspirin, niacin, and the organ transplant anti-rejection drug, cyclosporine
• Surgery
• Severe illness or injury
Symptoms And Complications
Typically, gout pain comes on suddenly. The attack produces intense pain, usually in one joint at a time, but on rare occasions, it can affect multiple joints. The affected joint often appears swollen and red. Although often associated with the large or big toe, gout can also occur in other joints, including the knee, ankle, foot, hand or wrist. Gout attacks are usually short-lived. Pain and swelling in the affected joint usually go away over several days but may be stopped sooner with medications.
In some people, a high load of urate crystals may build up over several years and form large deposits called tophi in joints and nearby tissues. Tophi deposits look like lumps under the skin and typically appear near the affected joints, especially on the elbows, fingers, and toes. Deposits may also develop on the outer edge of the ear. Left untreated, the lumpy deposits can actually destroy adjacent bone.
Kidney stones are a complication of gout because extra uric acid can collect in the urinary tract and crystallize into stones. Very rarely, the crystals form right in the kidney and cause serious kidney problems.
The complications of gout, however, may go beyond your joints and kidneys. Research suggests that gout and hyperuricemia may increase your risk of cardiovascular disease and heart attack. Gout is characterized by inflammation and studies have shown that chronic inflammation contributes to cardiovascular disease. High uric acid levels may also affect the smoothness of the inside of blood vessels and make platelets in the blood “stickier,” so blood clots are more likely to form. And research has linked hyperuricemia with high blood pressure, high cholesterol, obesity and diabetes.
Diagnosis And Prevention
Hyperuricemia occurs when uric acid levels in the blood reach 6.7 mg/dL, the level at which uric acid crystals form. For reasons that still aren’t understood, uric acid levels sometimes go down when someone is having a gout attack, so a blood test at the time of an attack is not a reliable way to diagnose gout.
To determine whether you have gout, your doctor may remove some synovial fluid from the affected joint to view it under a microscope. The presence of urate crystals in the sample can confirm a diagnosis of gout. There are several arthritic conditions caused by crystal deposits of various kinds. The most common of these other disorders has a misleading name, pseudogout (it may not be gout, but there’s no question that it’s real); it’s caused by deposits of calcium pyrophosphate dihydrate crystals in the joints.
Treating Acute Attacks
The earlier an acute gout attack is treated, the faster the pain may clear up. As is true for many painful conditions, the first-line treatment for a gout attack is taking one of the nonsteroidal, anti-inflammatory drugs (NSAIDs), such as diclofenac, naproxen, ibuprofen, or indomethacin. For people who can’t take NSAIDs, a drug called colchicine, is an alternative. It’s been used for centuries specifically for gout. The problem with colchicines, however, is its side effects — nausea, vomiting, and diarrhea. NSAIDs can’t also be used by everyone with gout. People who have kidney disease, extremely high blood pressure, bleeding ulcers or those who take a blood-thinning medication may be treated with a corticosteroid joint injection.
Preventing Attacks
For years, gout patients were told they had to follow a purine-restricted diet to stave off attacks, but those diets weren’t consistently effective and people had a difficult time sticking to them. Now, the easier-said-than-done advice is to lose weight, and also cut back on alcohol, especially beer. Big meat and seafood eaters may be told to curb their appetites and instead eat more low-fat dairy foods. Diuretics tend to increase uric acid levels. If someone with gout is taking one, the doctor might explore lowering the dose or switching to a different medication.
Allopurinol has emerged as the first-line uric acid-lowering drug because it needs to be taken only once a day and reduces uric acid levels regardless of whether the root problem is overproduction of uric acid or inadequate clearance by the kidneys. Some people may develop a mild rash when they start allopurinol. Rarely, there’s a dangerous allergic reaction. The standard daily dose is 300 mg and the commonly accepted target level for uric acid is 6 mg/dL. One quirky aspect to realize about gout treatment is that uric acid-lowering medications, like allopurinol, can’t be started during an attack because they can make the attack worse.
A new drug, febuxostat, available in the US, is similar to allopurinol in the way it works. It is the first addition to the gout treatment armamentarium in more than 40 years. In head-to-head trials, febuxostat looked to be more effective than allopurinol at controlling uric acid levels, although that may have been because the allopurinol dose in the study was too low. As a new brand-name drug, febuxostat (marketed as Uloric) is far more expensive than allopurinol.
Probenecid is a third choice. Like allopurinol, it’s been on the market for decades, so it has a long track record. Probenecid works by increasing uric acid excretion by the kidneys so it can trigger development of kidney stones and is not a good option for people with kidney problems. Another drawback for probenecid is that it has to be taken twice a day.
Lifestyle Changes
Lifestyle changes that may help prevent repeat gout attacks include:
• Maintaining a healthy weight
• Avoiding foods high in purines
• Limiting or avoiding alcohol
• Increasing fluid intake
The best news about gout is that it may be the most controllable form of arthritis with medications that are easily available and effective.
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Gout resources: National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) — www.niams.nih.gov; American College of Rheumatology — www.rheumatology.org; and Arthritis Foundation — www.arthritis.org.
