ATLANTA – An estimated 32 million adults in the United States have hyperuricemia, which often precedes gout, based on data from the National Health and Nutrition Examination Survey.
The results were presented during a press conference Nov. 10 at the annual meeting of the American College of Rheumatology.
Previous studies have suggested that the prevalence of gout and hyperuricemia are on the rise in the United States, possibly because of factors including obesity, the metabolic syndrome, and hypertension, said Yanyan Zhu, Ph.D., of Boston University.
Dr. Zhu and colleagues reviewed National Health and Nutrition Examination Survey (NHANES) data from 1999 through 2008 on 24,693 individuals aged 20 years and older. The group included 11,816 men and 12,877 women. The data were compared with U.S. population estimates from the U.S. Census Bureau.
Hyperuricemia was defined using the standard NHANES definition of serum urate levels greater than 7.0 mg/dL for men, and greater than 5.7 mg/dL for women.
The results suggest a substantial potential burden from gout, especially in older adults, said Dr. Zhu. The prevalence of hyperuricemia was 31% in adults aged 65 years and older, vs. 18% in those aged 20-64 years. Overall, the prevalence of hyperuricemia increased with age, ranging from 16% in individuals aged 20-29 years to 37% among those aged 80 years and older. The estimates for hyperuricemia were similar for men and women (16.1 million vs. 15.8 million, respectively).
Gout rates in U.S. adults are rising, based on data from a related study also presented at the meeting. Dr. Zhu and her colleagues used NHANES data to estimate 8.3 million cases of gout in U.S. adults aged 20 years and older during 2007-2008.
In this study, the researchers compared NHANES data from 1988 through 1994 with NHANES data from 2007 through 2008. They found a 1.2% increase in gout among U.S. adults, from 2.7% during 1988-1994 to 3.9% during 2007-2008.
The increase was largely due to the significant rise in gout among men and older adults, the researchers noted. The prevalence of gout in men increased from 3.8% to 5.9% between the two time periods, and the prevalence in adults aged 80 years and older increased from 5.9% to 12.6%.
The NHANES data in the second study included 18,825 individuals from 1988 through 1994 and 5,707 from 2007 through 2008. These numbers also were compared with U.S. Census Bureau data.
Most physicians in the United States don’t regularly check patients’ uric acid levels, and fewer than 5% of adults with gout receive treatment, noted Dr. John Sundy of Duke University Medical Center, Durham, N.C. Dr. Sundy served as moderator when the study findings were presented at the press conference. More education is needed for doctors and patients so the available therapies can be used more effectively, he said.
Dr. Zhu said she had no financial conflicts to disclose. Her study coauthors are employed by or have received consulting fees from Takeda Pharmaceuticals International. Dr. Sundy has served as a consultant for multiple companies including Array Biopharma, Savient Pharmaceuticals, and Takeda Pharmaceuticals.