Excess comorbidities in gout: the causal paradigm and pleiotropic approaches to care

Gout is a common hyperuricaemic metabolic condition that leads to painful inflammatory arthritis and a high comorbidity burden, especially cardiometabolic-renal (CMR) conditions, including hypertension, myocardial infarction, stroke, obesity, hyperlipidaemia, type 2 diabetes mellitus and chronic kidney disease. Substantial advances have been made in our understanding of the excess CMR burden in gout, ranging from pathogenesis underlying excess CMR comorbidities, inferring causal relationships from Mendelian randomization studies, and potentially discovering urate crystals in coronary arteries using advanced imaging, to clinical trials and observational studies. Despite many studies finding an independent association between blood urate levels and risk of incident CMR events, Mendelian randomization studies have largely found that serum urate is not causal for CMR end points or intermediate risk factors or outcomes (such as kidney function, adiposity, metabolic syndrome, glycaemic traits or blood lipid concentrations). Although limited, randomized controlled trials to date in adults without gout support this conclusion. If imaging studies suggesting that monosodium urate crystals are deposited in coronary plaques in patients with gout are confirmed, it is possible that these crystals might have a role in the inflammatory pathogenesis of increased cardiovascular risk in patients with gout; removing monosodium urate crystals or blocking the inflammatory pathway could reduce this excess risk. Accordingly, data for CMR outcomes with these urate-lowering or anti-inflammatory therapies in patients with gout are needed. In the meantime, highly pleiotropic CMR and urate-lowering benefits of sodium-glucose cotransporter 2 (SGLT2) inhibitors and key lifestyle measures could play an important role in comorbidity care, in conjunction with effective gout care based on target serum urate concentrations according to the latest guidelines.

Unravelling the mysteries of gout by multimodality imaging

Gout is a common inflammatory arthritis that manifests as an aggregate of variably symptomatic monosodium urate crystals (MSU) in the joints and surrounding tissues in addition to multisystem involvement such as genitourinary and cardiovascular systems. In recent decades, there has been a documented increase in the prevalence and incidence of gout. Risk factors for gout include obesity, dietary influences, hypertension, renal impairment, and diuretic use. A prompt diagnosis followed by uric acid lowering treatment prior to the onset of bone destruction is the goal in any suspected case of gout. Advanced imaging modalities, such as dual energy computed tomography (DECT) and ultrasonography (US), employed for the diagnosis of gout are each accompanied by advantages and disadvantages. Conventional radiography (CR), although useful in visualizing joint erosions and mineralization, is limited in its ability to diagnose gout flare. Although synovial fluid aspiration remains the gold standard for MSU crystal visualization, less-invasive imaging modalities are preferred to avoid potential complications. DECT and US in particular are useful in the diagnosis of gout. In this review, we will discuss the current state and role of imaging in the detection of gout.