The Number of People with Gout Continues to Rise

Newswise — Gout rates—and related cases of hyperuricema—have increased over the past two decades, according to research presented this week at the American College of Rheumatology Annual Scientific Meeting in Atlanta. Hyperuricemia is an abnormally high level of uric acid in the blood that can lead to gout – a painful and potentially disabling form of arthritis that has been recognized since ancient times. Initial symptoms of gout usually consist of intense episodes of painful swelling in single joints, most often in the feet (especially the big toe). Gout occurs when excess uric acid (a normal waste product) accumulates in the body, and needle‐like crystals deposit in the joints. This may happen because uric acid production increases or, more often, the kidneys are unable to remove uric acid from the body adequately. The prevalence of gout in the United States more than doubled between the 1960s and 1990s, but many have been unsure whether the trend continued over the past two decades. To determine if it continued, researchers recently compared the number of U.S. adults diagnosed with gout using two National Health and Nutrition Examination Surveys—NHANES III 1988-1994 and NHANES 2007-2008—which are a group of surveys used to assess the health and nutrition of American adults and children. They also used the same surveys to compare prevalence of hyperuricemia and average serum urate levels between the same time periods.

The 2007-2008 survey included 5,707 participants who were at least 20 years old—of which 2,797 were men and 2,910 were women—to estimate the overall prevalence of gout during this time period. The prevalence was then compared to data from the 1988-1994 survey that included 18,825 participants who were at least 20 years old – of which 8,816 were men and 10,009 were women. The researchers then used the same data and surveys to measure hyperuricemia (defined, for this study, as having serum urate level greater than 7.0mg/dL in men and greater than 5.7 mg/dL in women).

During the 2007-2008 timeframe, researchers identified the overall prevalence of gout among U.S. adults as 8.3 million, which corresponded to 3.9 percent of U.S. adults. This is 1.2 percent higher than the 1988-1994 timeframe figure of 2.7 percent, and researchers attribute this increase to increased gout prevalence among men and senior citizens. Over the same time period, hyperuricemia prevalence increased by 3.2 percent (from 18.2 percent to 21.4 percent), and average serum urate levels also rose by 0.15 mg/dl.

Given these findings, the researchers concluded that the number of U.S. adults with gout not only remained substantially high, but may have increased, after the 1990s. In addition, the results revealed that as gout rates went up, the rates of hyperuricemia also rose, reconfirming the connection between the two.

“These findings indicate that the prevalence of gout and hyperuricemia continue to be substantial in the new millennium,” explains Yanyan Zhu, PhD; research assistant professor at the Boston University School of Medicine and lead investigator in the study. “Factors contributing to the increase are also heightening additional risk factors including obesity and hypertension, and better management could help prevent the further rise of gout and other associated complications.”

The American College of Rheumatology is an international professional medical society that represents more than 8,000 rheumatologists and rheumatology health professionals around the world. Its mission is to advance rheumatology. The ACR/ARHP Annual Scientific Meeting is the premier meeting in rheumatology. For more information about the meeting, visit www.rheumatology.org/education or join the conversation on Twitter by using the official hashtag: #ACR2010. ###

Editor’s Notes: Yanyan Zhu, PhD, will present this research during the ACR Annual Scientific Meeting at the Georgia World Congress Center at 5:30 PM on Wednesday, November 10 in Room A 404. Dr. Hyon Choi will be available for media questions and briefing at 8:30 AM on Wednesday, November 10 in the on-site press conference room, B 212.

Learn more about living well with rheumatic disease as well as rheumatologists and the role they play in health care.

Presentation Number: 2154

Increasing Gout Prevalence in the US Over the Last Two Decades: the National Health and Nutrition Examination Survey (NHANES)Yanyan Zhu, PhD (Boston University School of Medicine, Boston MA) Bhavik Pandya, PharmD (Takeda Pharmaceuticals International, Inc, IL)Hyon Choi, MD, DrPH (Boston University School of Medicine, Boston MA)

Body: Objective: The prevalence of gout in the US more than doubled between the 1960s and 1990s, but it is unknown whether the increasing trend continued over the past 2 decades. To address this issue, we compared the prevalence of gout between National Health and Nutrition Examination Survey (NHANES) III (1988-1994) and NHANES 2007-2008. We also compared the prevalence of hyperuricemia and mean serum urate (sUA) levels between the same time periods.

Methods: Using data from 5,707 participants (2,797 men and 2,910 women) aged 20 years and older in NHANES 2007-2008, we estimated overall, gender-specific, and age-specific prevalence of gout and compared it with data from 18,825 participants (8,816 men and 10,009 women) aged 20 years and older in NHANES III (1988-1994). Using the same data, we compared sUA levels between NHANES III and NHANES 2007-2008. The NHANES definition of hyperuricemia was sUA level >7.0 mg/dL in men and >5.7 mg/dL in women. During the NHANES survey, all participants were asked about a history of health-professional diagnosed gout.Results: The overall prevalence of gout among US adults was 3.9% (8.3 million adults) in 2007-2008 (Table). This gout prevalence was significantly higher than that in NHANES III (2.7%), with a difference of 1.2% (95% confidence interval [CI], 0.6 to 1.9). The difference was primarily due to increased prevalence among men and the elderly. Correspondingly, the prevalence of hyperuricemia in 2007-2008 (21.4%) was significantly higher than that in NHANES III (18.2%), with a difference of 3.2% (95% CI, 1.2% to 5.2%). The mean sUA level significantly increased over the same time period (difference 0.15 mg/dL; 95% CI, 0.07 to 0.24 mg/dL). Conclusions: These findings from 2 separate nationally representative samples of US adults suggest that the prevalence of gout remains substantial and may have increased over the last 2 decades, particularly among men and the elderly. Correspondingly, the prevalence of hyperuricemia increased during the same period.Disclosure: Yanyan Zhu, nothing to disclose; Bhavik Pandya, Takeda Pharmaceuticals International, Inc.: Employment (full or part-time); Hyon Choi, Takeda Pharmaceuticals International, Inc.: Consulting fees.

View press release with full abstract at www.rheumatology.org