Musculoskeletal ultrasound evaluates renal injury and predicts renal outcome in patients with gout

Introduction. Kidney injury diagnosis is often delayed in patients with gout. We aimed to determine the characteristics of gout patients with CKD using musculoskeletal ultrasound (MSUS) and whether MSUS could be used as an auxiliary assessment to evaluate kidney injury and predict renal outcome in patients with gout.Methods. Clinical information, laboratory indicators and MSUS findings were collected and compared between gout-only patients (gout-CKD) and gout patients with CKD (gout+CKD). Multivariate logistic regression was applied to identify risk factors for clinical and MSUS characteristics in both groups. Correlation analysis between MSUS signs and kidney-related indicators was performed, and the effects of MSUS characteristics on renal prognosis were evaluated.Results. In total, 176 patients with gout were included, namely, 89 gout-CKD and 87 gout+CKD cases. After adjusting for confounders, the gout patients with CKD showed more frequent episodes in the previous year, higher ultrasound semiquantitative scores and more tophi than gout patients without CKD. Additionally, the number of tophi, bone erosion and synovial hypertrophy measured by MSUS were found to be negatively correlated with the eGFR. The existence of tophi was independently associated with an increased risk of a >= 10% decline in eGFR in the first-year follow-up (OR 3.56, 95% CI 1.382-9.176).Conclusions. Ultrasound-detected tophi, bone erosion and synovial hypertrophy were associated with kidney injury in gout patients. The existence of tophi was associated with faster renal function deterioration. MSUS could be a potential auxiliary diagnostic method to evaluate kidney injury and predict renal outcome in gout patients.