High uric acid raises risk of death in adults

NEW YORK (Reuters Health) - In middle-aged Chinese adults, high blood levels of uric acid are a strong predictor of death from cardiovascular disease, stroke and all causes, according to results of a study conducted in Taiwan.

This finding was true not only in high-risk groups but in the general population, and potentially in low-risk groups as well, Dr. Wen-Harn Pan of the National Taiwan University, Taipei, and associates report in the journal Arthritis & Rheumatism.

Uric acid is a product of the breakdown of nitrogen compounds, and is normally excreted in urine. It has been recognized for decades that uric acid is found at high levels in the joints of people with gout. More recently, it has been suggested that uric acid may be a “danger signal” released by damaged cells that triggers inflammation and a strong immune response.

Pan’s team studied data on approximately 42,000 men and 49,000 women whose average age was 51 years. All of them had health exams between 1994 and 1996 and were followed until the end of 2003.

High uric acid -- defined as a blood level greater than 7 milligrams per deciliter -- was documented at the first exam in 40 percent of men and 11 percent of women. During an average follow-up of 8.2 years, 5,427 study subjects died and 1,151 of these deaths were attributed to cardiovascular disease.

In the overall study population, a high blood uric acid level was associated with a statistically significant increased risk of death from cardiovascular disease, stroke, congestive heart failure or any cause.

A high blood uric acid level had even greater impact on death among people with high blood pressure and diabetes.

According to Pan, a high blood uric acid level is a risk factor for cardiovascular-related death “even in those without traditional cardiovascular disease risk factors. It is important to examine whether uric acid is involved in the early stage of disease development.”

Summing up, Pan said: “Our data showed that people with higher uric acid levels had poorer survival than those with lower levels. However, whether lowering it would translate into improved survival awaits further clinical trials.”

SOURCE: Arthritis & Rheumatism, February 15, 2009.