[Serum uric acid prevalence and changes post various antihypertensive agents in patients with essential hypertension]

To survey the prevalence of hyperuricacidemia and serum uric acid (SUA) changes and electrolyte changes after 6 weeks antihypertensive treatment with thiazide diuretics, losartan or losartan+hydrochlorothiazide (Hyzaar) in patients with essential hypertension (EH).

A total of 1080 consecutive EH patients [662 males, mean age (60.9 +/- 12.3) years] who seeked for medical consultation in study hospitals in Fuzhou city during October 2004 and October 2006 were included in this study. The blood pressure before and after antihypertensive treatments were obtained in 1000 patients, and the renal function and electrolyte before and after antihypertensive treatments were obtained in 600 patients. Patients with SBP > 140 and/or DBP > 90 mm Hg 2 weeks after initial antihypertensive agents were cotreated with felodipine, patients with SBP > 140 and/or DBP > 90 mm Hg 4 weeks after initial antihypertensive agents were cotreated with beta and/or alpha blockers.

The prevalence of hyperuricacidemia in EH patients was 25.83% (279/1080). Body mass index (BMI) and creatinine were significantly higher while creatinine clearance rate (Ccr) calculated by Cockcroft-Gault equation was significantly lower in EH patients with hyperuricacidemia than EH patients without hyperuricacidemia (all P < 0.05). Similar antihypertensive effects were observed in EH patients treated with thiazide diuretics (n = 200), losartan (n = 324) or losartan + hydrochlorothiazide (Hyzaar, n = 476) and SBP was lower than 140 mm Hg in 69.40% and DBP was less than 90 mmHg in 85.30% EH patients 6 weeks after antihypertensive treatments. SUA was significantly increased (43.81 micromol/L +/- 71.79 micromol/L) low dose diuretics group (P < 0.01 vs. pretreatment), significantly reduced (44.96 micromol/L +/- 90.63 micromol/L) in losartan group (P < 0.0001 vs. pretreatment) and remained unchanged in Hyzaar group (7.46 +/- 84.72 micromol/L, P > 0.05 vs. pretreatment). Serum potassium was significantly decreased (0.30 +/- 0.44 mmol/L) in diuretic group (P < 0.01 vs. pretreatment) and remained unchanged in losartan group (+0.06 +/- 0.43 mmol/L) and Hyzaar group (-0.04 +/- 0.44 mmol/L, all P > 0.05 vs. pretreatment).

Hyperuricacidemia prevalence was 25.83% and associated with higher BMI and abnormal renal function in examined EH patients. The low dose thiazide diuretics could further aggravate hyperuricacidemia and induce hypopotassemia while losartan could reduce hyperuricacidemia in EH patients.