SOURCE: Leiba A, et al. Uric acid levels within the normal range predict increased risk of hypertension: A cohort study. J Am Soc Hypertens 2015;9;600-609.
Currently accepted laboratory standards indicate that the upper limit of “normal” for uric acid levels is 7 mg/dL in men and 6 mg/dL in women. Uric acid has been recognized as a cardiovascular risk factor for more than 3 decades, thanks to data from the Framingham study. Nonetheless, whether uric acid causes — or is simply associated with — adverse cardiovascular outcomes is uncertain. Additionally, even if the association of uric acid with cardiovascular disease is determined to be causal, it will remain necessary to definitively prove that reductions in uric acid improve outcomes (without undue risk).
Using analysis from the largest HMO in Israel, healthy adults aged 40-70 years (n = 118,920) had baseline uric acid levels obtained in 2002, and were subsequently followed for 10 years. During this interval, almost one-quarter of these had a new diagnosis of hypertension recorded. The risk of hypertension in women and men began to increase well within the “normal” range. Compared to a uric acid of 2-3 mg/dL, even uric acid of 3-4 mg/dL were 15% more likely to become hypertensive; higher “normal” uric acid (5-6 mg/dL) was associated with a 66% increased incidence of hypertension. Results were similar for men. The authors suggested that our currently defined levels of “normal” for uric acid may have to be reconsidered.