Hyperuricemia and gout in Taiwan Aborigines - Prevalence, risk factors, and prevention
Chung-Tei Chou
Division of Allergy-Immunology-Rheumatology, Department of Medicine
Veterans General Hospital, Taipei, Taiwan
Prevalence of hyperuricemia and gout among Taiwan Aborigines. Two major studies have been conducted on gout in Taiwan Aborigines. Chou et al. spent one year examining 342 indigenous people of the Atayal tribe in aboriginal villages in central Taiwan. Gout was confirmed in 40 subjects, 95% of whom were male. We found the prevalence of hyperuricemia and gout in Atayal Aborigines to be 41.4% and 11.7%, respectively. Of the 40 gouty patients, 54% had tophi and 35% of their first-degree relatives had gout. The other epidemiological study focusing on the prevalence and risk factors of gout was completed by Chang et al. Unlike Chou’s study, the sample Aborigines in Chang’s study were older than 40 years and originated from 3 different tribes (Atayal, Paiwan, Bunun, and mixed). The findings showed 15.2% of males and 4.8% of females had gout, did not differ much from Chou’s study. Of the 3 tribes studied by Chang et al, prevalence was highest in Bunun men (28.1%), followed by Atayals (12.5%) and Paiwans (5.5%). In this study, no data regarding the hyperuricemia of different tribes was collected. However, in a previous study, Chang et al. showed 27% to 45% of aboriginal boys and 13% to 41% of aboriginal girls had hyperuricemia. Taken together, Chou and Chang confirmed the hypothesis that hyperuricemia and gout were frequent among indigenous people.
Risk factor for hyperuricemia and gout in Taiwan Aborigines. The genetic defect was mainly responsible for the prevalent hyperuricemia in Taiwan Aborigine. Recent study from Kaohsiung University Hospital has confirmed this. Years ago, I collected urine samples from Atayal Aborigines and ethnic Taiwanese with and without gout and found the uric acid clearance to be lower in Taiwan Aborigines with gout versus other populations (unpublished data). Although Chang et al. reported that the HGPRTTsou gene variant is partially responsible for the hyperuricemia in an aboriginal population in Taiwan, I strongly suggest the genetic defect in renal handling of uric acid clearance to be an important factor in enhancing the prevalence of hyperuricemia and gout in Taiwan Aborigines. Excessive alcohol intake in Aborigines was also thought to play a role to increasing serum uric acid levels or hyperuricemia. However, the alcoholism was not considered the only factor because the increase in uric acid levels began in childhood and they were too young to drink much alcohol. Therefore, except for race, gender and age, the most important factors in Aborigines with hyperuricemia and gout are “genetics” and “alcoholism”.
Prevention. The severe gout and greater number of tophi in Aborigines with gout indicate relatively poor primary health care in high mountain areas. Early detection of risk factors in this minority population and efforts to prevent those most susceptible people from worsen their hyperuricemia and gout are the responsibilities of both the government and rheumatologists.