Comparing the prevalence of rheumatic diseases in China with the rest of the world.

Geographic or ethnic differences in the occurrence of disease often provide insights into causes of disease and possible opportunities for disease prevention. Persons in China appear to have a consistently lower prevalence of rheumatoid arthritis and fibromyalgia than persons in the United States and Europe; reasons for these prevalence differences might include genetic differences, differences in environmental exposures or a combination of both. With increasing obesity, gout is becoming endemic in China. Finally, symptomatic knee osteoarthritis is extremely common in China and constitutes a major public health problem there.