Analysis of risk factors for changes of renal artery resistance indexes in gout patients by ultrasound colour Doppler.

OBJECTIVES

Gout may disturb renal hemodynamics by promoting uric acid deposition; however, this relationship has not been elucidated with adequate clinical evidence. In this study, we measured the renal artery resistance index (ARI) in patients with gout to identify the risk factors and establish predictive models for elevated renal ARI in these patients.

METHODS

Renal artery ultrasound examination was performed in 235 primary gout patients and 50 healthy controls (HCs); subsequently, their renal interlobar ARI (RIARI), renal segmental ARI (RSARI) and overall intrarenal ARI (OIARI) were recorded. Each ARI > 0.7 was considered elevated.

RESULTS

RIARI, RSARI and OIARI were higher in patients with gout than in HCs (all <0.001). Nineteen (8.1%), 24 (10.2%) and 18 (7.7%) patients had elevated RIARI, RSARI and OIARI scores, respectively. Multivariate logistic regression analyses disclosed that: age ≥ 60 years (=0.000), abnormal beta2 microglobulin (βMG) (=0.028), and abnormal high-density lipoprotein cholesterol (HDLC) (=0.030) were independently associated with elevated RIARI; age ≥ 60 years (=0.000), and abnormal βMG (=0.013) were independently related to elevated RSARI; abnormal total protein (TP) (=0.014) were independently linked with elevated OIARI in gout patients. Consequently, predictive models for elevated ARI were established using nomograms based on the aforementioned independent risk factors, which showed a satisfactory value for estimating elevated RIARI [area under the curve (AUC):0.929], RSARI (AUC: 0.926) and OIARI (AUC: 0.660) in patients with gout, as validated by receiver operating characteristic curves.

CONCLUSION

Renal ARI were elevated in patients with gout, whose independent risk factors included older age and abnormal βMG, HDLC and TP levels.