Background Gout is the most common cause of inflammatory arthritis in men, and its prevalence has gradually increased among the general population over the last few decades. There is strong evidence that increased serum uric acid levels and gout are associated with subclinical atherosclerosis and an increased risk of cardiovascular and renal events. Risk factors for cardiovascular disease (CVD) are many and there are different ways to assess them. As it would be difficult to determine the independent role of an individual CVD risk factor in gout patients (pts).
Objectives The aim of the present study was to investigate the effect of gout on target organs: heart, kidneys and vessels. We chose to evaluate ultrasonographic parameters which by themselves are independent predictors of CVD risk: intima-media thickness (IMT) of common carotid arteries, left ventricular mass index (LVMI) and renal resistive index (RRI).
Methods A total of 87 pts were divided into the following groups: controls (n=37) in mean age 47.4±13.8 years, 19 females and 18 males, asymptomatic hyperuricemia (n=21) in mean age 57.1±10.7 years, 10 females and 11 males, gouty arthritis pts (n=29) in mean age 56.6±9.1years, 3 females and 26 males, without tophi (n=19) and gouty tophi (n=10). All pts underwent a complex multimodal ultrasonography to evaluate: IMT, LVMI and RRI. Ultrasound examinations of kidneys, heart and carotid arteries were performed on Aloka-SSD-4000 with three transducers with the following characteristics: 1. RRI was measured in both kidneys at the level of interlobar arteries with transducer 3.5MHz working with pulse repetition frequency (PRF) of 2.5MHz. 2. Cardiac morphology was examined with 2.5MHz transducer Phased Array. 3. IMT was measured with 10MHz linear transducer with PRF of 5MHz. Examinations were performed by one researcher, who was blinded for the protocol of the study. Statistical analyses were done by Mann-Whitney and Spearman tests.
Results In all examined pts RRI correlated moderately with LVMI (r=0.423, p<0.001) and there was a good correlation between RRI and IMT (r=0.696, p<0.001). We observed a significant difference in IMT, LVMI and RRI between gout pts and controls (p<0.001). When we compared asymptomatic hyperuricemia pts with gout pts we found that IMT was greater in those with gout and the difference was significant (p=0.015), but we didn't estimate a significant difference in LVMI (p=0.172) and RRI (p=0.245) in these two groups. Comparing parameters between gouty tophi pts and pts without tophi, we observed that tophi pts had significantly increased RRI (mean ± SD, 0.70±0.06) to those without tophi (mean ± SD, 0.64±0.06), (p=0.039), but there wasn't a significant difference in LVMI, (p=0.96) and IMT, (p=0.101). We also detected a lower creatinine clearance in gouty tophi pts compared to gout pts without tophi, not reaching a statistical significance, (p=0.058).
Conclusions From our results we can only suppose that with the progression of disease and with the appearance of tophi, vessels are affected not only by atherosclerotic type, but also by arteriosclerotic type. Maybe this can explain why RRI was significantly increased in pts with tophi compared to gout pts without tophi.
Disclosure of Interest None declared