Gout — a type of arthritis characterized by sudden, severe bouts of pain, stiffness and swelling in the joints, particularly the joints of the big toes — was once known as “the disease of kings.” England’s King Henry VIII famously suffered from gout, as did King George IV and Spain’s King Charles V.
In fact, gout was so associated with the rich foods and indulgent lifestyle of the upper classes that in 1900 a London Times writer quipped, “The common cold is well-named — but the gout seems instantly to raise the patient’s social status.”
More than 100 years later, gout has become an everyman (and everywoman) disease — and one whose prevalence continues to creep upward. According to a study published Thursday in the journal Arthritis & Rheumatism, some 3.9 percent of American adults (6.1 million men and 2.2 million women) have doctor-diagnosed gout. That’s up from 2.7 percent about 20 years ago.
Another 21 percent of Americans (43.3 million men and women) have hyperuricemia, an abnormally high level of uric acid in their blood. The crystallization of uric acid within the joints is what causes gout, and individuals with high levels of uric acid are more likely to develop the condition.
Earlier research had found that the incidence of gout in the United States more than doubled between the 1960s and the 1990s. The new study analyzed data from the latest National Health and Nutrition Examination Survey (NHANES), which was conducted in 2007-2008. Researchers compared that data with NHANES surveys conducted in 1988-1994.
Why are increasing numbers of Americans developing gout? The study cites several likely suspects, including our Western diet, sedentary lifestyle, expanding waistlines, rising blood pressures, and increased use of diuretics and aspirin.
By modifying two risk factors — obesity and high blood pressure — any further escalation in the incidence of gout could be prevented, the study’s authors added.
To find out more about hyperuricemia and gout, I spoke with Dr. Eric Matteson, who heads the rheumatology department at the Mayo Clinic in Rochester.
MinnPost: Are you surprised by this new study’s findings?
Eric Matteson: Not at all. Gout’s a disease that has to do with the metabolism of protein breakdown products into uric acid. There are a lot of things that influence that, including the body’s ability to excrete uric acid. The ability to get rid of uric acid is related to kidney function, and kidney function is related to high blood pressure and diabetes. Diabetes is a [growing] national problem. Some of [the rise in the prevalence of gout] can also be seen in the obesity epidemic because obesity is a major risk factor for kidney disease and high blood pressure, and those are directly related to gout.
MP: We think of gout as being — historically, at least — a disease of kings and the wealthy. That’s no longer true, is it?
EM: Not at all. It was true maybe in an older day, and probably for a couple of reasons. In past times, the only people even written about were the nobility. Also, it was only the wealthier people who actually had the wherewithall to have a diet that might make them overweight. But gout is a disease that can affect anyone. The obesity epidemic affects everyone, and that’s part of the reason, I think, that we’re seeing this increase.
MP: Men get gout more often than women. Do we know why?
EM: Yes. One of the major factors in gout is the ability of the kidney to excrete uric acid, and there are some enzymes in the kidney that are responsible for that. Deficiencies of these enzymes are more common in males than in females. That’s a partial explanation. Dietary reasons are another. Beer drinkers are particularly susceptible to getting gout, and men are likely to drink more beer than women. [Beer is one of several foods that are high in purines, a natural chemical that can increase the accumulation of uric acid in the body.]
MP: Is gout just a really painful big toe?
EM: No. Any joint can be affected. [Uric acid crystals] can also be deposited in other places, including in blood vessels and in the kidneys.
MP: Do people often have gout and not know it?
EM: Gout commonly means gouty arthritis, so if you have gout you know it, because it’s very painful. But you may not know you have high levels of uric acid until something happens.
MP: Is having high levels of uric acid considered dangerous?
EM: Having high levels of uric acid is definitely associated with an increased risk for heart disease. [The association] is likely due to irritation of the walls of the blood vessels through the actions of the uric acid. That’s some new information we hadn’t really appreciated before. In the past, we tended not to do anything about high levels of uric acid unless the person had gout or were developing kidney stones from the uric acid crystals. But today we think about that somewhat differently. We know that even if you’re not having gouty arthritis, if you have very high levels of uric acid, then that by itself is bad for you.
MP: How is the hyperuricemia treated?
EM: There are several ways to treat it. The most common is to use a drug that metabolizes the uric acid in such a way that it’s easier for the kidneys to expel it. Another way is to improve the efficiency with which the kidney excretes uric acid. That’s a different type of drug. And then there are drugs that treat gouty attacks when they occur.
MP: How does our uric acid become tested?
EM: It’s not a usual practice to test uric acid as part of a normal checkup. Years ago we used to do that because uric acid was part of a chemistry panel and you just had one charge for your chemistry panel, and there could be lots of things on it. But with different types of insurance reform, they would no longer pay for that. So each test is now done separately and billed separately — actually at more cost — and uric acid is not one of the routine tests that many insurance companies will pay for. They will only pay for it if there is a strong reason to suspect that a person has high uric acid, such as if they’ve had a gout attack. Consequently, doctors don’t routinely check for it.
MP: So people may have hyperuricemia and not know it.
MP: When should people ask to have their uric acid levels checked?
MP: Is it possible to have high uric acid if you’re not obese or if you don’t have high blood pressure?
MP: Is that because there’s a genetic component to the condition?
EM: Yes. A number of enzymes process uric acid, and there are known deficiencies in these enzymes and transporter proteins that you can inherit.
MP: So hyperurecemia and gout can run in families.
EM: Yes, indeed.
MP: What can individuals do to reduce their risk of developing gout? Does cutting back on meat help?
EM: It’s not clear how helpful reducing meat consumption by itself is. Generally, a good balanced diet is recommended. People who follow a more vegetarian-type diet tend to have lower uric acid levels, but it’s not necessary to give up meat. But the reduction of alcohol, particularly beer, is usually helpful.
MP: What other lifestyle changes will help?
EM: Losing weight is very helpful. Making sure that you always keep yourself adequately hydrated is also important. And general fitness. Being fit helps reduce your probability of becoming obese and of having diabetes and high blood pressure. And if you have those conditions, it helps you to manage them better. There’s no substitute for fitness and exercise.
MP: How are we doing in Minnesota in regards to gout? Is our incidence higher or lower than the rest of the U.S.?
EM: I would venture to say that since our obesity rates in Minnesota are somewhat lower than the national average and because our general activity levels are higher, we’re probably at somewhat less risk for gout. But we have to bring this risk down to the individual. In the end it’s the individual person that matters. What are your individual risk factors, and what are you doing about them? That’s what really matters.
(This interview has been condensed.)