Effects of Magnesium Supplementation on Vascular Structure and Function in Hypertensive Patients
Condition: Hypertension; Endothelial Dysfunction
MeSH terms: Hypertension
Study type: Interventional
Phase: Phase 4

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.
    

Intervention name(s): magnesium; placebo
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): Magnesium chelate, 300mg (2 capsules of 150mg) twice a day, per oral Total of 600mg per day; Two capsules of placebo per oral twice a day
Other intervention name(s): Mg supplement; Inactive component
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Supportive Care
Keywords: hypertension; endothelial dysfunction