Association of asymptomatic hyperuricemia and endothelial dysfunction in psoriatic arthritis

IntroductionCardiovascular disease is an increasingly recognized contributor to excess morbidity and mortality in psoriatic arthritis (PsA). Traditional cardiovascular risk factors do not adequately account for the extent of cardiovascular disease in PsA.Aim of the workTo examine the prevalence of subclinical atherosclerosis in patients with PsA to emphasize the potential role of serum uric acid on endothelial dysfunction, as an early predictor for atherosclerosis in PsA patients.Patients and methodsThis study included 60 PsA patients as well as 60 age and sex matched healthy controls. Assay of serum uric acid, interleukin-6 (IL-6) and soluble intercellular adhesion molecule-1 (sICAM-1) was done for all patients and controls. Patients were subjected to psoriasis area severity index (PASI) and assessment of disease activity. Patients and controls underwent brachial flow-mediated dilatation (FMD) assessment by color duplex sonography to determine endothelial dysfunction as well as extracranial carotid arteries assessment by high-resolution B-mode ultrasound to measure the common carotid intima-media thickness (CIMT) and the detection of atheromatous plaques.ResultsPsA patients have a high significant difference in CIMT, FMD of the brachial artery and mean levels of serum uric acid compared to healthy controls (p < 0.001). PsA patients with hyperuricemia have a high significant difference in CIMT and FMD of the brachial artery than those with normal serum uric acid. Serum uric acid levels showed a high significant positive correlation with each of CIMT, disease duration, markers of inflammation (ESR, CRP, IL-6, sICAM-1), disease activity score in 28 joints (DAS 28) and PASI (r = 0.71, 0.893, 0.956, 0.858, 0.853, 0.877, 0.907, 0.847, respectively, as p < 0.001). A high significant negative correlation was found between serum uric acid levels and FMD of the brachial artery as r = ?0.634, p < 0.001.ConclusionPatients with PsA have a high prevalence of subclinical atherosclerosis dependent on serum uric acid, suggesting that chronic systemic inflammation and endothelial dysfunction appear to be the link between asymptomatic hyperuricemia and atherosclerosis. Therefore, proper control of serum uric acid may play a preventive role in the development of atherosclerosis in PsA patients.