Confounders of uric acid level for assessing cardiovascular outcomes.

Abstract

We read the article entitled Serum uric acid as a prognostic marker in the setting of advanced vascular disease: a prospective study in the elderly by Stolfo, et al.[1] with great interest. The authors evaluated the association of serum uric acid (SUA) levels with adverse cardiovascular events and deaths in an elderly population affected by advanced atherosclerosis. They founded meaningful association between SUA levels and of cardiovascular events and cancer related death. We believe that these findings will lead for further studies on uric acid. Recent studies have shown that hyperuricemia may damage endothelial function and increases the cardiovascular event risk.[2] Thus, investigation of the association between uric acid and cardiovascular events may contribute to understand the underlying mechanism. However SUA level may be affected by several factors and its exclusion is very difficult. In this well designed study, the authors had compared groups for traditional cardiovascular risk parameters such as hypertension, dyslipidemia, and diabetes mellitus, etc. Beyond these, alcohol consumption or hypothyroidism are well known confounders for uric acid level so it would have been better if the authors had compared these parameters too.[3],[4] Most diuretics elevate the SUA level and in this study the authors have shown that high SUA group has increased diuretic use.[1] In our daily practice, we use diuretics frequently in hypertension and congestive heart failure patients. Thus, it is possible that high SUA group may have lower ejection fraction rates. Poor outcomes are directly associated with left ventricle systolic dysfunction.[5] If the authors had mentioned about ejection fraction rates, a more comprehensive assessment would be possible. In conclusion this article enlightens the relationship between uric acid and poor cardiovascular outcomes. However new studies with more detailed risk factors assessment and using all echocardiographic parameters may contribute to our knowledge in this area.