Traditional risk factors and use of some anti-HIV drugs increase uric acid levels in HIV-positive patients

A significant number of HIV-positive individuals have elevated levels of uric acid in their blood, German researchers report in the July 13^th edition of AIDS. High levels of uric acid are a risk factor for the development of gout, a very painful condition that some other studies have shown to occur with increased frequency in HIV-positive patients. High levels of uric acid can also lead to uric kidney stones. The German investigators found in their observational study that traditional risk factors such as male sex, being overweight and kidney dysfunction were associated with elevations in uric acid as well as the use of certain antiretroviral drugs.

Between 2000 and 2005 a total of 270 HIV-positive patients in the German cities of Freiburg and Hamburg had levels of uric acid in their blood monitored at their routine clinic visits. The patients had a median age of 40 years and median body mass index was 24, within the healthy range. Overall, patients were taking antiretroviral therapy at 80% of study visits and had an undetectable viral load at 58% of visits. Median CD4 cell count was 408 cells/mm³.

Levels of uric acid were elevated in 75 patients (28%) at a total of 323 (14%) clinic visits. In multivariate analysis, male sex (p Ziagen) and tenofovir (Viread) had no relationship with levels of uric acid, nor did the level of HIV viral load.

The investigators speculate that mitochondrial toxicity caused by some drugs in the nucleoside reverse transcriptase inhibitor (NRTI) class may contribute to the increases in uric acid seen in their study, but they suggest that there are likely to have been multiple causes.

They acknowledge that their study had limitations, not least its relatively small sample size. In addition, the investigators accept that they did not gather data on the incidence and prevalence of gout. They conclude, “uric levels and gout require clinical attention, research into the pathophysiological mechanisms and systemic validation in randomised trials and large cohorts.”