Serum uric acid change in relation to antihypertensive therapy with the dihydropyridine calcium channel blockers

Purpose We investigated serum uric acid changes in relation to the achieved clinic and ambulatory blood pressure after 8 weeks of antihypertensive therapy with two dihydropyridine calcium channel blockers. Materials and methods The study participants were patients with clinic and ambulatory hypertension, enrolled in a randomised controlled trial that compared amlodipine (5-10 mg, n = 215) and nifedipine gastrointestinal therapeutic system (GITS, 30-60 mg, n = 203). Hyperuricaemia was defined as a serum uric acid concentration of >= 420 mu mol/L in men and >= 360 mu mol/L in women. Analysis of covariance and multiple regression analyses were performed to study the associations between serum uric acid changes and the achieved clinic and ambulatory blood pressure during follow-up. Results At baseline, 67 (16.0%) of the 418 patients had hyperuricaemia. Antihypertensive treatment reduced clinic and 24-h daytime and night-time systolic/diastolic blood pressure by a mean (+/- standard error [SE]) change of -17.4 +/- 0.6/-8.6 +/- 0.4 mm Hg and -13.7 +/- 0.5/-8.3 +/- 0.3 mm Hg, -13.8 +/- 0.6/-8.4 +/- 0.4 mm Hg, and -12.7 +/- 0.7/-8.0 +/- 0.4 mm Hg, respectively. Antihypertensive treatment reduced serum uric acid by a mean (+/- SE) change of -9.3 +/- 2.8 mu mol/L. The serum uric acid changes differed according to the achieved clinic and ambulatory blood pressure, and were statistically significant (mean +/- SE -20.6 +/- 6.6 to -10.7 +/- 2.9 mu mol/L, p <= 0.04) at the systolic/diastolic ranges of 130-139/>= 90 mm Hg in clinic pressure, and <130/75-84 mm Hg, <145/80-84 mm Hg and <120/65-69 mm Hg in 24-h, daytime and night-time ambulatory pressure. Conclusion Our study showed that antihypertensive therapy with a dihydropyridine calcium channel blocker was associated with reduced serum uric acid, especially when 24-h ambulatory systolic blood pressure was controlled.