Sufferers of gout and elevated uric acid levels have significantly increased death risks

A new study led by researchers at the Graduate Entry Medical School (GEMS), University of Limerick (UL) has found that people suffering from gout and elevated serum uric acid have significantly increased risks of death. In their study, individuals with a diagnosis of gout experienced a 42 % higher risk of death from all causes and a 58% higher risk of cardiovascular death. The risks were greatest for individuals with the highest uric acid concentrations.

In the study, Professor Austin Stack, Professor and Chair of Medicine, UL and colleagues examined the relationships of gout and serum uric acid with mortality over a 10 year period in 15, 773 individuals from the Third National Health and Nutrition Examination Survey (NHANES III)

“Most published studies to date have not looked at the combined impact of gout and elevated uric acid concentrations on the risk of death in representative samples of the population” according to Professor Stack a Consultant Nephrologist at University Hospital Limerick and the lead author of the study.

“In this nationally representative study we set out to examine in detail the risks conferred to individuals who had a diagnosis of gout and who had elevated serum uric acid levels and the results were quite extraordinary.”

“First, we found that individuals with a diagnosis of gout had a great abundance of many known cardiovascular conditions and risk factors such as diabetes, hypertension, physical inactivity, obesity and smoking. These would certainly put individuals into a high risk category. But even when we took these factors into account; individuals in the study with gout died earlier than those without and also experienced a higher risk of dying from heart disease.”

“We also demonstrated for the first time that the adverse impact of gout increases with rising uric acid concentration. Subjects with the highest uric acid levels experienced a 77% higher risk of death and a 209% risk of cardiovascular death.”  he said.

The study also demonstrated that elevated serum uric acid levels are an independent risk factor for death and cardiovascular mortality. In our study, we found that the mortality impact of elevated uric acid was present for both men and women; most races and almost all disease and lifestyle categories. “What is remarkable” said Stack “is that even among individuals considered having healthy lifestyles; for example- non-smokers; lifetime non-drinkers, and physically active people, their risk of death increased by between 9-13% for every 60 µmol/L increase in serum uric acid.”

Because of its observational nature, the study does not prove that gout or elevated uric acid causes cardiovascular disease. However, it does lend further credibility to the hypothesis that gout and elevated uric acid levels are important and easily identifiable risk markers for cardiovascular disease and early death. Serum uric acid can be easily measured through blood testing and is a potentially important target for intervention not only to reduce the risk of gout but even more importantly the more serious threat of cardiovascular death. The time has come to evaluate the efficacy of treatments that lower uric acid levels in reducing cardiovascular death and preventing premature death.

Gout is an inflammatory arthritis that is due to uric acid crystal deposition in joints and typically causes acute painful swelling of one or more joints (the big toe commonly). It affects about 4 % of the adult population while elevated uric acid levels can affect up to 20 % according to US data. In Ireland, it is estimated that about 180, 000 individuals suffer from gout (Irish population 4.59 million).

The study ‘Independent and Conjoint Associations of Gout and Hyperuricaemia with Total and Cardiovascular Mortality’ is published by Quarterly Journal of Medicine (QJM): An International Journal of Medicine and authored by  ¹²Austin G. Stack, ³Alan Hanley, ¹Liam F. Casserly, ¹Cornelius J. Cronin, ¹Ahad A. Abdalla, ¹Tom J. Kiernan, ⁴Bhamidipati.V.R. Murthy, ²Avril. Hegarty, ²Ailish Hannigan and ²Hoang.T. Nguyen

http://qjmed.oxfordjournals.org/content/early/2013/04/05/qjmed.hct083.short?rss=1

The Graduate Entry Medical School is leading a number of national and international projects to evaluate the health status and clinical outcomes for patients with chronic disease in order to improve patient outcomes. The study was performed at the Graduate Entry Medical School in collaboration with the Departments of Nephrology and Cardiology University Hospital Limerick.