Magnesium and Vascular Stiffness

Study Overview
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Brief Summary
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This four-arm randomized controlled trial was designed to study the effects of magnesium supplements (total daily dose: 450 mg elemental magnesium) on vascular stiffness in healthy overweight and slightly obese men and women. In addition, the effects of magnesium supplements on blood pressure and gut microbiota will be evaluated. Three groups will receive magnesium supplements (magnesium oxide, magnesium citrate or magnesium sulphate) and one group will receive a placebo.

Detailed Description
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Observational epidemiologic studies have observed an inverse relationship between daily dietary magnesium intake and blood pressure. Except for blood pressure, magnesium may also beneficially affect other cardiovascular risk markers. Whether all these effects translate into improved vascular function is not known. Different vascular function markers at various stages on the pathway between diet and disease exist. One of these markers, vascular stiffness, is closely related to the process of atherosclerosis, an independent cardiovascular risk factor, and predictive of future cardiovascular events and mortality. A recently published intervention study showed that oral magnesium citrate supplementation of 350 mg per day for 24 weeks was well-tolerated and improved vascular stiffness by 1.0 m/s. Importantly, it was not established whether the beneficial effect on vascular stiffness was due to the supplementation of magnesium or due to citrate. This may involve effects on gut microbiota and systemic metabolic effects. The current study was designed to (1) reproduce the result of the earlier study and to (2) investigate whether there is a difference between different commonly used magnesium salts (magnesium citrate, magnesium sulphate and magnesium oxide) in terms of effects on vascular stiffness, blood pressure and gut microbiota.

Official Title
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The Effects of Magnesium Salts on Vascular Stiffness: A Randomized Controlled Trial in Healthy Overweight and Slightly Obese Men and Women

Conditions
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Vascular Stiffness, Blood Pressure

Intervention / Treatment
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* Dietary Supplement: Magnesium Citrate
* Dietary Supplement: Magnesium Sulfate
* Dietary Supplement: Magnesium Oxide
* Drug: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Aged between 45-70 years Women postmenopausal: two or more years after last menstruation BMI between 25-35 kg/m2 (overweight and slightly obese) Plasma glucose < 7.0 mmol/L Serum total cholesterol < 8.0 mmol/L (further testing is recommended for excessive hyperlipidemia (serum total cholesterol ≥ 8.0 mmol/L) according to the Standard for cardiovascular risk management of the Dutch general practitioners community (NHG)) Serum triacylglycerol < 4.5 mmol/L (Friedewald formula) No current smoker No diabetic patients No familial hypercholesterolemia No abuse of drugs Less than 21 alcoholic consumptions per week Stable body weight (weight gain or loss <3 kg in the past three months) No use of proton pump inhibitors No use of magnesium supplements No severe medical conditions that might interfere with the study, such as epilepsy, asthma, kidney failure or renal insufficiency, chronic obstructive pulmonary disease, inflammatory bowel diseases, auto inflammatory diseases and rheumatoid arthritis No active cardiovascular disease like congestive heart failure or cardiovascular event, such as an acute myocardial infarction or cerebro vascular accident Willingness to give up being a blood donor (or having donated blood) from 8 weeks before the start of the study and during the study No difficult venipuncture as evidenced during the screening visit Written informed consent Exclusion Criteria: High habitual dietary magnesium intake (defined as urinary magnesium excretion of 7.0 or 5.9 mmol/24-h or more for men and women, respectively) Plasma glucose ≥ 7.0 mmol/L Serum total cholesterol ≥ 8.0 mmol/L Serum triacylglycerol ≥ 4.5 mmol/L Current smoker, or smoking cessation <12 months Diabetic patients Familial hypercholesterolemia Abuse of drugs More than 21 alcoholic consumptions per week Unstable body weight (weight gain or loss > 3 kg in the past three months) Use of proton pump inhibitors Use of magnesium supplements Severe medical conditions that might interfere with the study, such as epilepsy, asthma, kidney failure or renal insufficiency, chronic obstructive pulmonary disease, inflammatory bowel diseases, auto inflammatory diseases and rheumatoid arthritis Active cardiovascular disease like congestive heart failure or cardiovascular event, such as an acute myocardial infarction or cerebro vascular accident Not willing to give up being a blood donor (or having donated blood) from 8 weeks before the start of the study and during the study Not or difficult to venipuncture as evidenced during the screening visit

Ages Eligible for Study
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Minimum Age: 45 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Magnesium Citrate<br>450 mg of Magnesium Citrate per day | Dietary Supplement: Magnesium Citrate<br>* 450 mg of Magnesium Citrate per day (6 capsules per day) for 24 weeks<br>|
| Experimental: Magnesium Sulfate<br>450 mg of Magnesium Sulfate per day | Dietary Supplement: Magnesium Sulfate<br>* 450 mg of Magnesium Sulfate per day (6 capsules per day) for 24 weeks<br>|
| Experimental: Magnesium Oxide<br>450 mg of Magnesium Oxide per day | Dietary Supplement: Magnesium Oxide<br>* 450 mg of Magnesium Oxide per day (6 capsules per day) for 24 weeks<br>|
| Placebo Comparator: Placebo<br> | Drug: Placebo<br>* The placebo capsules will contain starch (Amylum solani) for 24 weeks<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in vascular stiffness | Measured from carotid-femoral pulse wave velocity (PWV). For this assessment, a SphygmoCor will be used (SphygmoCor v9, AtCor Medical). | Baseline, FU-1 (2 weeks), FU-2 (12 weeks), and FU-3 (24 weeks) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in blood pressure | Measured from a semi continuous blood pressure monitoring device | Baseline, FU-1 (2 weeks), FU-2 (12 weeks), and FU-3 (24 weeks) | 
| Change in gut microbiota | Measured from fecal samples | Baseline, FU-1 (2 weeks), FU-2 (12 weeks), and FU-3 (24 weeks) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Magnesium, Supplements