Objective: To establish the association between ultrasound (US) burden with articular MSU crystals and renal morphology, blood supply, function and arteriosclerotic carotid arteries alterations in gout patients, individuals with asymptomatic hyperuricemia and no sign of inflammatory arthritis and psoriatic arthritis subjects with asymptomatic hyperuricemia.
Methods: 121 consecutive patients were included: 85 patients with gout, 27 subjects with asymptomatic hyperuricemia and 9 psoriatic arthritis patients. Subjects underwent US of both kidneys, common carotid arteries and bilateral US of the joints of the hands, elbows, knees, ankles and feet. For intrarenal blood flow we judged by measuring the renal resistive index (RRI). By US of the carotid arteries were determined intima-media thickness (IMT), common carotid artery resistive index (CCARI) and the presence of atherosclerotic plaques was registered.
Results: Individuals with articular US MSU deposits compared to those without had higher RRI (p = 0.035) and smaller kidney size (p = 0.014), but renal parenchymal thickness (p = 0.893), echogenicity (p = 0.291), IMT (p = 0.165), CCARI (p = 0.097), the frequency of nephrolithiasis (p = 0.438) and atherosclerotic plaques (p = 0.830) were similar. Subjects with US evidence of MSU crystals in two or more joint regions had the highest RRI (p = 0.002) and CCARI (p = 0.019). Compared to gout patients the risk of MSU crystal accumulation in the joints of asymptomatic hyperuricemia group was lower by 82.7%, OR = 0.173 (95% CI; 0.060 – 0.498, p = 0.001), while in psoriatic arthritis patients the risk was lower by 82%, OR = 0.180 (95% CI; 0.038-0.861, p = 0.032).
Conclusions: This study points out that subjects with larger extent of articular MSU burden have greater vascular stiffness. The accumulation of MSU crystals in the joints may be associated with the accumulation of crystals mainly in the renal interstitium.
