Introduction : Gout mainly affects middle-advanced age patients and it is the most common cause of arthritis in developed countries. Its prevalence and incidence seem to be increasing in recent years globally, also in Spain. Multiple studies performed in the last decades have shown a significant increase in cardiovascular risk (CVR) in gout, but there is little evidence about pathological vascular findings with ultrasound (US).
Objectives : To study whether patients with gout have an increased CVR, measured by cardiovascular risk factors (CVRF), established cardiovascular disease (CVD), US and/or angiodinamic vascular lesions, and altered analytical parameters related to CVR.
Methods : Consecutive patients over 18 years with a diagnosis of gout, according to American College of Rheumatology criteria, from 5 hospitals seen in the Rheumatology department of HM Hospitals between May 2014 and September 2015. Data collection was performed at a baseline visit with oriented interview and complete examination, including collection of blood pressure, heart rate, anthropometrics and the SCORE (Systemic Coronary Risk Evaluation). In addition, a complete analysis, joint and vascular US and angiodinamic study were requested.
Results : 150 gout patients were included (98% male, mean age 55.9±12.7 years (23-92), average evolution time 9.6±10.3 years (0-47)). 10% had tophi and 44% family history of gout. The involvement was predominantly monoarticular (66%), although 73% of patients had US elemental signs of gout in ≥2 joints. The prevalence of CVRF showed: 51% of hypertension, 32% of obesity, 30% of smoking and 5% of diabetes. Atherosclerotic plaques (AP) were detected in 38% of patients. The carotid intima-media thickness (cIMT) and the ankle brachial index (ABI) were pathological in 66% and 2%, respectively. 81% had endothelial dysfunction (ED) with altered flow-mediated vasodilation (FMV). Vitamin D deficiency was noted in 73% of the sample, as well as high levels of homocysteine (38%), C reactive protein (CRP) (13%) and erythrocyte sedimentation rate (ESR) (11%). In the multivariate analysis, the only determinant of ED was vitamin D, which showed a protective effect. The main determinant of the appearance of AP (OR = 25.58; 95%CI 8.04-81.41; p value <0.0001) and a pathological cIMT (OR = 13.02; 95%CI 5.05-33.5; value p <0.0001) was the SCORE. The only clinical characteristic associated with altered ABI was the presence of tophi (OR = 15.2; 95%CI 1.03-222.3; p = 0.047).
Discussion : Damage caused by gout is not only restricted to the joints, but also blood vessels. Experimental and clinical evidence has demonstrated ED induced by hyperuricemia and crystal-induced inflammation, but there is still a lack of reports of US vascular findings in gout. Our study found a high prevalence of ED, AP and pathological cIMT, highlighting the importance of US vascular examination in these patients.
Conclusion : There is a high CVR in patients with gout, with a substantial prevalence of traditional CVRF, hyperhomocysteinemia, AP, increased cIMT, and marked alteration of FMV. Vitamin D deficiency is associated with endothelial dysfunction.