High prevalence of hyperuricemia in elderly Taiwanese

Abstract

Serum urate status, the prevalence of hyperuricemia and their relationship to the metabolic syndrome in elderly Taiwanese were described using data from the Elderly Nutrition and Health Survey in Taiwan (1999-2000), in which a stratified multi-stage clustered sampling scheme was applied. Complete data from biochemical assays and anthropometric measures for 1225 males and 1167 females were included in the analysis. The mean urate level and 95% confidence interval was 411 (398, 424) microM for males and 357 (347, 367) microM for females. Males had significantly higher serum urate levels than females across all age groups (P<0.05). No significant difference in mean serum urate was found among the four age groups of males. On the other hand, females of 75-79 years had significantly higher serum urate levels (376 microM) than that of the 65-69 and>or=80 age groups. The overall prevalence of hyperuricemia (>or=416.7 microM (7.0 mg/dL) in the elderly was 36% (46% for males and 26% for females). Among the participants, 4.2% of males and 1.1% of females were taking medication to lower uric acid. The elderly (males 455 microM; females 416 microM) of the Mountain areas, mainly indigenes, had the highest mean serum urate overall, however, the highest prevalence of hyperuricemia in males was found in the PengHu islands (62%) and that for females in the Mountain areas (51%). The odds ratio (OR) for hyperuricemia was 2.84 for males in the PengHu islands and 4.33 for females in Mountain areas, compared with their counterparts in the third stratum in the northern areas. Adjusting for obesity, alcohol and other related covariates did not alter the relative rank of the ORs in the various strata. Elderly males (22%) had a significantly lower rate of metabolic syndrome (MS) than females (39%) (P<0.05). For both genders, those with MS had a significantly higher mean serum urate (males 436 microM vs. 405 microM; females 389 microM vs. 338 microM) and prevalence of hyperuricemia (males 56% vs. 43%; females 38% vs.19%) (P<0.05). The population attributable risk for MS from hyperuricemia was 18.8% in men and 15.5% in women. In conclusion, the mean serum urate and prevalence of hyperuricemia in the elderly in Taiwan were higher than those found in other populations and was significantly associated with MS. Gene-environmental interaction may play a key role since great geographical variation exists within various Han Chinese groups in Taiwan and between Han Chinese and Taiwanese indigenes.