Effects of Magnesium Supplementation on Vascular Structure and Function in Hypertensive Patients

NCT ID: NCT01151683

Last Updated: 2013-01-07

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: PHASE4
• Total Enrollment: 52 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2010-03-31
• Study Completion Date: 2012-11-30

Brief Summary

Introduction: Magnesium has been the target for many experimental and clinical studies due to the negative correlation between its serum and intracellular levels and the prevalence of hypertension and other cardiovascular diseases.

Objective: To evaluate the effects of magnesium supplementation in hypertensive patients who are under diuretic treatment, including correlation of clinical and nutritional parameters with structural and functional aspects of the macrocirculation.

Methods: A prospective, randomized, double blind, placebo controlled study will be performed in hypertensive patients, aged between 40 and 65 years-old, in regular use of thiazidic diuretic as antihypertensive monotherapy,. The patients will be divided in two main groups according to supplementation with placebo or magnesium chelate 300mg twice a day (total of 600mg magnesium element per day). Before and after 3 and 6 months of supplementation, the patients will be submitted to clinical and nutritional evaluation, biochemical analysis, including intracellular magnesium measurement, and study of the macrocirculation with ambulatory blood pressure monitoring, analysis of flow-mediated dilation of brachial artery, measurement of carotid intima-media thickness, and carotid-femoral and carotid-radial pulse wave velocity to estimate central and peripheral arterial stiffness.

Analysis: Data will be expressed as mean±epm. Statistical analysis will be performed using software Prism® (GraphPad, version 5.0). Continuous variables in each group will be compared using "t test", and P<0.05 will be considered statistically significant.

Detailed Description

The main objective of this study is to evaluate whether magnesium supplementation is associated with improved blood pressure control and whether it has beneficial effects on the vascular structure and function in non-diabetic hypertensive patients who are receiving r diuretic therapy.

Patients will be evaluated in a prospective, randomized, double-blind study and will be admitted to the study if they reach all the inclusion criteria and no exclusion criteria.

In this study, magnesium chelate was chosen because of its better absorption rate. The dosages are different in many protocols but in this project the patients will receive 600 mg of magnesium element daily divided in 300 mg twice a day. The patients will be divided in two main groups according to supplementation with placebo or magnesium chelate 300mg twice a day (total of 600mg magnesium element per day). Before and after 3 and 6 months of supplementation, the patients will be submitted to clinical and nutritional evaluation, biochemical analysis, including intracellular magnesium measurement, and study of the macrocirculation with ambulatory blood pressure monitoring, analysis of flow-mediated dilation of brachial artery, measurement of carotid intima-media thickness, and carotid-femoral and carotid-radial pulse wave velocity to estimate central and peripheral arterial stiffness.

Conditions

Hypertension; Endothelial Dysfunction

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: SUPPORTIVE_CARE
• Blinding Strategy: DOUBLE

Study Groups

Magnesium

Magnesium chelate 600 mg per day

Group Type: ACTIVE_COMPARATOR

magnesium

Intervention Type: DIETARY_SUPPLEMENT

Magnesium chelate, 300mg (2 capsules of 150mg) twice a day, per oral Total of 600mg per day

Placebo

Placebo 4 capsules per day

Group Type: PLACEBO_COMPARATOR

placebo

Intervention Type: DIETARY_SUPPLEMENT

Two capsules of placebo per oral twice a day

Interventions

magnesium

Magnesium chelate, 300mg (2 capsules of 150mg) twice a day, per oral Total of 600mg per day

Intervention Type: DIETARY_SUPPLEMENT

placebo

Two capsules of placebo per oral twice a day

Intervention Type: DIETARY_SUPPLEMENT

Other Intervention Names

Mg supplement; Inactive component

Eligibility Criteria

Inclusion Criteria

• Women aged between 40 and 65 years-old
• Hypertension with mild blood pressure elevation:

• Systolic BP between 140 and 159mmHg AND/OR
• Diastolic BP between 90 and 99 mmHg
• Antihypertensive monotherapy with daily use of thiazidic diuretic, at least in the last 30 days
• Signature of the Informed Consent by the patient or his legal representative

Exclusion Criteria

• Evidences for secondary hypertension
• Hypertension in stage 2, SBP ≥ 160mmHg and/or DBP ≥ 100mmHg, before the beginning of supplementation
• Blood pressure > 180 x 100 mmHg in any phase of the study
• Body mass index > 35 kg/m2
• Diabetes Mellitus
• Renal disease presenting glomerular filtration rate < 60ml/min
• Coronary artery disease clinically evident with previous episode of myocardial infarction and/or myocardial revascularization
• Clinical signs of heart failure
• History of stroke
• Any condition, disease or therapy that, under investigator's opinion, may influence objectives, results, or put in risk the safety of the patients.
• Pregnancy
• Patients should not be taking any mineral or vitamin supplements
• Gastrointestinal conditions

• Minimum Eligible Age: 40 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: FEMALE
• Accepts Healthy Volunteers: No

Sponsors

Rio de Janeiro State Research Supporting Foundation (FAPERJ)

OTHER_GOV

Sponsor Role: collaborator

Conselho Nacional de Desenvolvimento Científico e Tecnológico

OTHER_GOV

Sponsor Role: collaborator

Rio de Janeiro State University

OTHER

Sponsor Role: lead

Responsible Party

Mario Fritsch Neves

Full Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Mario F Neves, MD, PhD

Role: PRINCIPAL_INVESTIGATOR

State University of Rio de Janeiro

Locations

Department of Clinical Medicine, State University of Rio de Janeiro

Rio de Janeiro, Rio de Janeiro, Brazil

Countries

Brazil

References

Cunha AR, Medeiros F, Umbelino B, Oigman W, Touyz RM, Neves MF. Altered vascular structure and wave reflection in hypertensive women with low magnesium levels. J Am Soc Hypertens. 2013 Sep-Oct;7(5):344-52. doi: 10.1016/j.jash.2013.04.008. Epub 2013 Jun 2.

Reference Type: DERIVED

PMID: 23735418 (View on PubMed)

Other Identifiers

MG600

Identifier Type: -

Identifier Source: org_study_id