The Effects of Nifedipine and Metoprolol on Blood Pressure Variability in Northern Chinese

Study Overview
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Brief Summary
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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.

Detailed Description
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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. The hypertension prevalences in the high latitude and cold regions are much higher than those in the low latitude and warm regions. In China, the prevalences of hypertension are gradually increased from the South to the North. Heilongjiang province is the high-risk region for hypertension, with a prevalence of 30.48%. This may be due to the combined effects of lower average temperature and higher intake of salt and saturated fatty acid, which Increased sympathetic nerve excitability, and eventually lead to elevation of blood pressure. Therefore, it is essential to formulate the best treatment of hypertension according with the physical characteristics of northern Chinese. 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.

Official Title
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The Effects of Nifedipine and Metoprolol on Blood Pressure Variability in Northern Chinese: a Randomized Crossover Study

Conditions
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Hypertension

Intervention / Treatment
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* Drug: metoprolol
* Drug: Nifedipine


Participation Criteria
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Eligibility Criteria
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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.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: A<br>To observe the effects of metoprolol (95 mg) on blood pressure variation after 12 weeks of treatment.Then to observe the effects of Nifedipine (30 mg) on blood pressure variation after 12 weeks of treatment. | Drug: metoprolol<br>* Metoprolol was given orally in a dose of 95 mg/day to treat patients in the metoprolol group for 12 weeks.<br>Drug: Nifedipine<br>* Nifedipine was given orally in a dose of 30 mg/day to treat patients in the amlodipine group for 12 weeks.<br>|
| Active Comparator: B<br>To observe the effects of Nifedipine (30 mg) on blood pressure variation after 12 weeks of treatment. Then to observe the effects of metoprolol (95 mg) on blood pressure variation after 12 weeks of treatment. | Drug: metoprolol<br>* Metoprolol was given orally in a dose of 95 mg/day to treat patients in the metoprolol group for 12 weeks.<br>Drug: Nifedipine<br>* Nifedipine was given orally in a dose of 30 mg/day to treat patients in the amlodipine group for 12 weeks.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 24-hour Ambulatory Blood Pressure Monitoring |  | 3 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| plasma uric acid level |  | 3 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Blood pressure variability, CCB, beta-receptor blockers, heart rate