Relation Between Serum Uric Acid and Risk of Cardiovascular Disease in Essential Hypertension: The PIUMA Study

The question of serum uric acid as an independent risk factor in subjects with essential hypertension remains controversial. For up to 12 years (mean, 4.0) we followed 1720 subjects with essential hypertension. At entry, all subjects were untreated and all were carefully screened for absence of cardiovascular disease, renal disease, cancer, and other important disease. Outcome measures included total cardiovascular events, fatal cardiovascular events, and all-cause mortality. During 6841 person-years of follow-up there were 184 cardiovascular events (42 fatal) and 80 deaths from all causes. In the 4 quartiles of serum uric acid (division points: 0.268, 0.309, and 0.369 mmol/L [4.5, 5.2, and 6.2 mg/dL] in men; 0.190, 0.232, and 0.274 mmol/L [3.2, 3.9, and 4.6 mg/dL] in women), the rate (per 100 person-years) of cardiovascular events was 2.51, 1.48, 2.66, and 4.27, that of fatal cardiovascular events was 0.41, 0.33, 0.38, and 1.23, and that of all-cause deaths was 1.01, 0.55, 0.93, and 2.01, respectively. The relation between uric acid and event rate was J-shaped in both genders. After adjustment for age, gender, diabetes, total cholesterol/HDL cholesterol ratio, serum creatinine, left ventricular hypertrophy, ambulatory blood pressure, and use of diuretics during follow-up, uric acid levels in the highest quartile were associated with increased risk for cardiovascular events (relative risk, 1.73; 95% CI, 1.01 to 3.00), fatal cardiovascular events (relative risk, 1.96; 95% CI, 1.02 to 3.79), and all-cause mortality (relative risk, 1.63; 95% CI, 1.02 to 2.57) in relation to the second quartile. In untreated subjects with essential hypertension, raised uric acid is a powerful risk marker for subsequent cardiovascular disease and all-cause mortality.