Is Uric Acid level a risk indicator?

Uric Acid and Cardiovascular Risk
Original source: New England Journal of Medicine Volume 359 — October 23, 2008 — Number 17
Authors: Feig (corresponding author), D. I., Kang, D.-H., Johnson, R. J.
Publication date: October 23, 2008
DOI (digital document ID): (not available)
Requires subscription? Yes
Publicly-available abstract: Yes

Synopsis:
The original publication is a review article: it summarizes a number of previous publications concerning uric acid (a waste product that our blood carries to our kidneys for excretion) and possible links to high blood pressure (hypertension), diabetes, metabolic syndrome, kidney disease, and cardiovascular disease.

The authors note that the average levels of uric acid in the blood have been rising, along with our risks of these diseases. This does not necessarily mean that one or more of these diseases cause uric acid levels to rise, or that high uric acid levels raise the risk of developing cardiovascular disease, kidney disease, diabetes, metabolic syndrome, etc.

The authors examine research in which uric acid levels are examined in the cases of people and test animals with kidney disease, hypertension, metabolic syndrome, and kidney disease. Some observations include the possibility that high consumption of fructose is a factor in increased uric acid levels, and that increased uric acid levels may be partly responsible for the development of hypertension, insulin resistance, and weight gain. High uric acid levels may also be a factor in, or a result of, impaired kidney function.

In all of these cases, lowering uric acid levels -- particularly with the drug allopurinol -- seems to alleviate the symptoms of the other conditions. However, these studies were conducted in small, specific groups of people and animals. The researchers are not sure that this is necessarily from lowering uric acid levels rather than specifically from the use of allopurinol (other drugs to lower uric acid levels did not provide as dramatic results). They note that allergy or sensitivity to allopurinol can be fatal, so it's not necessarily a drug of choice. They state that more research needs to be conducted -- both on the whole-body effects of uric acid levels and of possible alternatives to allopurinol.

Reliability:
Review articles are based on taking previously-published research and examining it in a new light. Sometimes this means taking small studies from a lot of different groups and compiling or comparing them; sometimes it means creating a general overview of a topic. In this case, the authors reference a number of publications (follow the links in the "References" list) and their conclusions, come up with a theory (that high blood levels of uric acid may be the cause of other metabolic diseases), and point this out as something that needs further testing to prove whether this is true, or just coincidence.

Practical Applications:
Uric acid is one of the items measured in a standard "metabolic panel" blood test -- the blood test most of us get every time go to the doctor for a check-up. It is one of the waste products that is processed by our kidneys into urine. High uric acid levels have been associated with gout, which -- like metabolic syndrome -- is one of many conditions that are associated with obesity. If researchers can prove a definite cause-and-effect relationship between high uric acid levels and other metabolic conditions, it may give doctors another set of tools to improve the health of some people with cardiovascular disease, diabetes, and/or metabolic syndrome.

This synopsis was based on the CME version of the complete article.