Patients with gout and elevated serum uric acid levels, but no symptoms, still displayed ultrasound evidence of urate deposition, tissue inflammation, and bone erosion in their first metatarsophalangeal (MTP) joint on ultrasound when compared with patients who had normal serum uric acid levels.
Patients with elevated uric acid levels, but no symptoms, showed no evidence of tissue inflammation or joint damage on ultrasound, but the frequency of subclinical urate deposition in these patients was similar to that in patients with gout.
Sarah Stewart and colleagues in New Zealand highlighted the importance of distinguishing between gout and isolated hyperuricemia that is asymptomatic.
Disability and pain related to inflammation of the first MTP joint are common in patients with gout. Ultrasound represents a noninvasive and cost-efficient way to confirm features of urate deposition, inflammation, and bone erosion associated with gout but not asymptomatic hyperuricemia.
The authors presented their comparison of ultrasound findings in the first MTP joint of patients with symptomatic gout and patients with asymptomatic hyperuricemia in a recent Arthritis Care & Research article.
In the study, 86 adults were recruited in Auckland, New Zealand; 23 had a diagnosis of gout, 29 did not have gout but had a serum uric acid level ≥ 6.9 mg/dL, and 34 in the control group had serum uric acid levels < 6.9 mg/dL.
High-resolution ultrasound was used to determine the presence of joint effusion, erosion, synovial hypertrophy, and synovitis, as well as tophi presence and magnitude.
• Of the patients with gout, 83% had a history of acute MTP joint arthritis and 26% had clinical evidence of tophi in that joint.
• Patients with gout were more likely to have severe erosions of the MTP joint (odds ratio, 101.8, P<0.001), more severe synovial hypertrophy (OR, 11.73, P=0.002), and more severe synovitis (OR, 47.51, P=0.002) than controls.
Arthritis New Zealand provided financial support for this study.
Sarah Stewart, Nicola Dalbeth, Alain C. Vandal, et al. “Ultrasound Features of the First Metatarsophalangeal Joint in Gout and Asymptomatic Hyperuricemia: Comparison With Normouricemic Individuals.” Arthritis Care Res (Hoboken). 2017;69:875-883. doi: 10.1002/acr.23082. Epub 2017 May 8.