Background The role of serum uric acid as an independent risk factor for cardiovascular disease (CVD) remains unclear, although hyperuricemia is associated with CVD such as ischemic heart diseases (IHD), cerebrovascular accidents (CVA), or peripheral arterial occlusive diseases (PAOD). In particular, no study showed long-term cumulative effect of serum uric acid on CVD in gout patients with treatment.
Objectives The aim of this study is to evaluate long-term cumulative effect of serum uric acid on CVD and determine predictive factors of CVD in gout patient with uric acid lowering treatment.
Methods All patients who had a first visit for gout at Samsung Medical Center between 1995 and 2003, and follow-up until December 2012 or expired during follow-up period were included and retrospective analyzed. Cox regression according to level of control of uric acid defined as time-dependent covariate of each uric acid level and the ratio of numbers of uric acid level more than 6 umol/l to total numbers of measured uric acid level was performed to assess the effect of long-term cumulative uric acid level on CVD in gout patients with treatment.
Results Three-hundred twenty seven patients with gout were observed. Mean age at diagnosis of gout was 45.7 and mean follow-up duration was 14.1 years. Of these, 67 (20.5%) patients developed CVD during follow-up period, which included 34 IHD, 28 CVA, and 5 PAOD. CVD related death was observed in 10 patients (3.1%). Mean duration of gout at diagnosis of CVD was 13.3 years. For every 1 umol/l increase of uric acid level, the risk of CVD revealed to be increased 1.32-fold after adjusting age, smoking, family history of premature CVD, obesity, chronic kidney disease, time-dependent diabetes mellitus, hypertension, and hyperlipidemia (adjusted HR 1.32 (1.17-1.48), p<0.0001). In particular, the patients who had high proportion of events of uric acid over 6 umol/l was associated with increased CVD risk (adjusted HR 3.82 (1.08-13.56), p=0.037). Subgroup analysis by Cox regression showed that time-dependent uric acid level is related to increase the risk of IHD and severe CVD (adjusted HR 1.42 (1.23-1.64) p<0.001 and adjusted HR 1.33 (1.77- 1.33 (1.17-1.50), p<0.0001, respectively). Age at diagnosis of gout, family history of premature CVD, and diabetes mellitus were significantly associated with increased risk of CVD (adjusted HR 1.11 (1.02-1.06), p<0.0001, 13.30 (7.52-23.52), p<0.0001, and 2.65 (1.35-5.18), p=0.005, respectively).
Conclusions Our data demonstrated serum uric acid level was associated with increased risk of CVD in gout patients with treatment, which is a first data determined the long-term cumulative effect of uric acid on CVD. To control hyperuricemia is important to prevent CVD beyond gout itself in patients with gout.
Disclosure of Interest None declared
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.