Classification of patients with gout and their clinical features / 中华风湿病学杂志

ABSTRACT

Objective:To investigate the classification of patients with gout, and further analyze their clinical features.Methods:Outpatients with gout were enrolled from January 2018 to July 2019 in Depart-ment of Rheumatology, Zhongshan Hospital. Subjects were classified into four groups according to their 24-hour urinaryexcretion and fractional excretion of urate. Clinical features of different groups were analyzed using one-way Analysis of Variance (ANOVA), Kruskal-Wallis H test, or χ2 test. Results:Finally, 378 subjects were enrolled in this cross-sectional study. Among them, 186(49.2%) were renal underexcretion type, 100(26.5%) were combined type, 57(15.1%) were renal overload type, 35(9.3%) were the normal type. Renal underexcretion type was the main subtype in any age-stratified groups. With aging, the proportion of combined type decreased, while the normal type increased. Participants in the combined type were the youngest [(42±14) years of age] with the highest estimated glomerular filtration rate [(94±18) ml·min -1·1.73 m -2], while their serum urate levels were the highest [(554±104) μmol/L]. Subjects in the normal type were the oldest [(60±15) years of age] with the lowest estimated glomerular filtration rate [(71±19) mL·min -1·1.73 m -2], however, their serum urate concentrations were the lowest [(427±118) μmol/L], The difference was statistically significant (age, F=13.98; estimated glomerular filtration rate, F=16.11; urate, F=17.14; P<0.01). Prevalence of urolithiasis were similar among the four groups ( χ2 =2.00, P>0.05). Conclusion:The renal underexcretion type is the main type of gout. Young patients are more likely to suffer from combined type with the highest serum urate levels and the best renal function.