Clinical characteristics of and relationship between metabolic components and renal function among patients with early-onset juvenile tophaceous gout.
Age of onset of gout has recently decreased; however, patients with early-onset gout remain uncommon, and relevant information is scant. We hypothesized that these patients might exhibit differences in serum urates and other comorbidities compared with adult-onset patients. Early-onset gout patients (i.e., juveniles) with (n = 40) and without tophi (n = 47) were enrolled for study. Their clinical characteristics were compared with those of 353 patients with middle-age-onset tophaceous gout and 64 age-matched healthy participants. Early-onset gout patients with tophi exhibited significantly higher body mass indices and serum urate levels and lower estimated glomerular filtration rates (eGFR) than did those without tophi. Early-onset gout patients with or without tophi demonstrated significantly abnormal lipid profiles and impaired liver or renal function compared with healthy patients. Serum urate levels and gout duration were identified as the principal determinants of tophi development. The presence of tophi might be crucial in decreasing eGFR, which is inversely related to tophi duration or gout duration. Unexpectedly, the most common site of initial gout attacks in early-onset tophaceous gout patients was the ankle, not the toe, which was the most common site in middle-age-onset tophaceous gout patients. The most common site of first tophi occurrence in early-onset patients was a finger, not a toe, which was the most common site in middle-age-onset patients. Early-onset tophaceous gout patients are more likely to exhibit comorbidities and renal dysfunction than middle-age-onset patients and exhibit distinct first sites of gout attack and tophi occurrence patterns.