Initiating guideline-concordant gout treatment improves arterial endothelial function and reduces intercritical inflammation: a prospective observational study.

BACKGROUND: Patients with gout have arterial dysfunction and systemic inflammation, even during intercritical episodes, which may be markers of future adverse cardiovascular outcomes. We conducted a prospective observational study to assess whether initiating guideline-concordant gout therapy with colchicine and a urate-lowering xanthine oxidase inhibitor (XOI) improves arterial function and reduces inflammation. METHODS: Thirty-eight untreated gout patients meeting American College of Rheumatology (ACR)/European League Against Rheumatism classification criteria for gout and ACR guidelines for initiating urate-lowering therapy (ULT) received colchicine (0.6 mg twice daily, or once daily for tolerance) and an XOI (allopurinol or febuxostat) titrated to ACR guideline-defined serum urate (sU) target. Treatment was begun during intercritical periods. The initiation of colchicine and XOI was staggered to permit assessment of a potential independent effect of colchicine. Brachial artery flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD) assessed endothelium-dependent and endothelium-independent (smooth muscle) arterial responsiveness, respectively. High-sensitivity C-reactive protein (hsCRP), IL-1ß, IL-6, myeloperoxidase (MPO) concentrations, and erythrocyte sedimentation rate (ESR) assessed systemic inflammation. RESULTS: Four weeks after achieving target sU concentration on colchicine plus an XOI, FMD was significantly improved (58% increase, p = 0.03). hsCRP, ESR, IL-1ß, and IL-6 also all significantly improved (30%, 27%, 19.5%, and 18.8% decrease respectively; all p ≤ 0.03). Prior to addition of XOI, treatment with colchicine alone resulted in smaller numerical improvements in FMD, hsCRP, and ESR (20.7%, 8.9%, 13% reductions, respectively; all non-significant), but not IL-1ß or IL-6. MPO and NMD did not change with therapy. We observed a moderate inverse correlation between hsCRP concentration and FMD responsiveness (R = - 0.41, p = 0.01). Subgroup analyses demonstrated improvement in FMD after achieving target sU concentration in patients without but not with established cardiovascular risk factors and comorbidities, particularly hypertension and hyperlipidemia. CONCLUSIONS: Initiating guideline-concordant gout treatment reduces intercritical systemic inflammation and improves endothelial-dependent arterial function, particularly in patients without established cardiovascular comorbidities.