Gout is a frequent inflammatory arthritis in men after 45 years old. In this common (CG) form, gout is associated with comorbidities (CMs) including metabolic syndrome, hypertension, type 2 diabetes (T2D), obesity, chronic kidney disease and cardiovascular (CV) diseases. In contrast, very few data are available for early onset gout (EOG), defined as first flare before 30 years old.
The aim of this study was to compare gout characteristics and CMs between EOG and CG.
We retrospectively included all gout patients (pts) with ineffective ULT who were referred to our department between 2014 and 2018, and who had at least one visit between 9 and 15 months after first visit. At baseline, ineffective ULT was defined by a serum urate level (SUL) above target (> 360 µmol/L). Demographic characteristics, gout history and CMs, treatments were systematically recorded.
Among 213 pts, 39 (18.3%) had experienced a first gout flare before 30 years old. Mean age of first flare in EOG was 24.8 (± 5.5) years. Familial history of gout was more frequent in EOG than in CG (60.6 vs 24.6%). First flare involved the 1st metatarsophalangeal joint in 70% of EOG pts. EOG pts had more severe gout than CG pts: longer disease duration (15.4 vs 6.9 years, p<0.0001), more flares in the last 12 months (4.7 vs 3.0, p<0.0001), more tophi (61.5 vs 36.9%, p=0.005) and higher febuxostat (FBX) dosage (110 vs 83 mg/day, p=0.02) to achieve SUL target.
Pts with CG had more CMs than EOG pts: CV diseases, hypertension, T2D, dyslipidemia and kidney transplantation. Non-alcoholic fatty liver disease was more frequent in EOG than CG (61.1 vs 24.1%). Drug-related hyperuricemia (HU) including low dose aspirin, thiazides and loop diuretics was less frequently observed in EOG.
At final visit, 62.8 and 67.9% of EOG and CG patients, respectively, achieved SUL target (p=0.56). Proportion of pts taken ULT was similar in both groups as well as proportion of pts treated with allopurinol or FBX.
Conclusion: EOG is more severe and EOG pts have less CMs. Moreover, EOG has a higher inheritability trait than CG patients suggesting different pathological mechanisms.