The Effects of Doxazosin and Nifedipine on Blood Pressure Variability and Uric Acid in Plasma in Hypertensive Patients

Hypertension is one of the most common cardiovascular diseases, which is a major risk factor for stroke and cardiovascular events. Accumulated data has shown that target-organ damage is related not only to 24-h mean intra-arterial BP, but also to BP variability (BPV) in subjects with essential hypertension. There are many studies about the effects of different kinds of drugs on blood pressure, but the clinical researches about the impacts of antihypertensive drugs on BPV are limited, and the conclusion is still controversial.

In addition, recent studies found that the occurrence and development of hypertension, especially essential hypertension, are closely related with hyperuricemia. Serum UA is an independently prognostic indicator for the development of hypertension. Some studies have observed the effects of different kinds of antihypertensive drugs on uric acid level in hypertensive patients. After adjustment, calcium channel blockers are associated with a lower risk of incident gout among people with hypertension. However, the effects of alpha blockers on uric acid in plasma are still not very clear.

Therefore, we performed this study to observe the different effects of alpha blocker and calcium channel blocker on blood pressure variability and uric acid level in hypertensive patients.

Hypertension is one of the most common cardiovascular diseases, which is a major risk factor for stroke and cardiovascular events. Traditionally, cardiovascular risk stratification in hypertensive patients was based on the average blood pressure (BP) measured in the clinic. Accumulated data has shown that target-organ damage is related not only to 24-h mean intra-arterial BP, but also to BP variability (BPV) in subjects with essential hypertension. Growing evidence demonstrated that BPV has considerable prognostic value for all-cause mortality and cardiovascular outcomes, independent of average BP. At present, the normal range of BPV is not very clear. There are many studies about the effects of different kinds of drugs on blood pressure, but the clinical researches about the impacts of antihypertensive drugs on BPV are limited, and the conclusion is still controversial.

In addition, recent studies found that the occurrence and development of hypertension, especially essential hypertension, are closely related with hyperuricemia. Accumulated data has shown that a significant and independent association between the uric acid level and the onset of hypertension in both men and women participants. Serum UA is an independently prognostic indicator for the development of hypertension. Some studies have observed the effects of different kinds of antihypertensive drugs on uric acid level in hypertensive patients. After adjustment, diuretics, β blockers, angiotensin converting enzyme inhibitors and non-losartan angiotensin Ⅱ receptor antagonists are associated with an increased risk of gout. In contrast, calcium channel blockers and losartan are associated with a lower risk of incident gout among people with hypertension. However, the effects of alpha blockers on uric acid in plasma are still not very clear.

Therefore, we performed this study to observe the different effects of alpha blocker and calcium channel blocker on blood pressure variability and uric acid level in hypertensive patients.

Eligibility Criteria:
Inclusion Criteria:

Men aged between 18 and 75 included years old Postmenopausal women who are no more than 75 years older. Patients with essential mild to moderate uncomplicated hypertension (DBP\<110mmHg and SBP\<180mmHg measured with a validated automatic device in sitting position) after initiation or intensification of appropriate healthy lifestyle modification, Without antihypertensive treatment in 2 weeks.

Exclusion Criteria:

History of cerebrovascular disease: ischemic stroke, cerebral haemorrhage and TIA.

History of cardiovascular disease:unstable angina, myocardial infarction, coronary revascularization and congestive heart failure.

History of renal impairment. History of Type I diabetes mellitus or Type II diabetes uncontrolled. History of liver impairment. History of alcoholism or drug abuse. Known symptomatic orthostatic hypotension. Contra-indications to treatment with investigate products.