Increase in obesity and hypertension are likely contributors
A new study shows the prevalence of gout in the U.S. has risen over the last twenty years and now affects 8.3 million (4%) Americans. Prevalence of increased uric acid levels (hyperuricemia) also rose, affecting 43.3 million (21%) adults in the U.S. Greater frequency of obesity and hypertension may be associated with the jump in prevalence rates according to the findings now available in Arthritis & Rheumatism, a journal published by Wiley-Blackwell on behalf of the American College of Rheumatology (ACR).
Gout, an inflammatory arthritis triggered by crystallization of uric acid within the joints, causes severe pain and swelling. Medical evidence suggests that gout is strongly associated with metabolic syndrome—a group of health conditions characterized by central obesity, insulin resistance, high blood pressure and blood lipid issues—and may lead to heart attack, diabetes and premature death. Prior research found that gout incidence in the U.S. more than doubled from the 1960s to 1990s.
"Our study aim was to determine if the prevalence of gout and hyperuricemia among U.S. adults has continued to climb in the new millennium," said Dr. Hyon Choi, Professor of Medicine in the Section of Rheumatology and the Clinical Epidemiology Unit at Boston University School of Medicine in Massachusetts and senior investigator of the present study.
Researchers analyzed data from the latest U.S. National Health and Nutrition Examination Survey (NHANES) which was conducted in 2007 and 2008, comparing the data with those from previous NHANES surveys (1988-1994). There were 5,707 participants who completed the most recent NHANES survey which included questions regarding history of gout diagnosed by a healthcare professional. Researchers defined hyperuricemia as serum urate level greater than 7.0 mg/dL in men and 5.7 mg/dL in women.
Results from the nationally-representative sample of adult Americans suggest gout and hyperuricemia remain prevalent in the U.S. and compared to earlier NHANES data was 1% and 3% higher, respectively. After adjusting for obesity or hypertension, the differences in prevalence rates were substantially lessened. Further analysis revealed that gout prevalence was higher in men (6%) compared to women (2%); hyperuricemia occurred in 21.2% of men and 21.6% of women.
Dr. Choi concluded, "We found that the prevalences of gout and hyperuricemia continue to be substantial in the U.S. adult population. Improvements in managing modifiable risk factors, such as obesity and hypertension, could help prevent further escalation of gout and hyperuricemia among Americans."