Magnesium and Vascular Stiffness

Study Overview
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Brief Summary
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Observational epidemiologic studies have observed an inverse relationship between daily dietary magnesium intake and blood pressure (BP). Except for BP, 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. To examine the integrated effects of interventions on cardiovascular risk, vascular stiffness may therefore serve as a marker at the later stage of cardiovascular disease development. Therefore, it is imperative to examine in a 24-week, randomized, double-blind, placebo-controlled, two-way parallel-group human intervention study, the effect of magnesium on vascular stiffness. Focus will be on carotid-femoral pulse wave velocity (PWV), the gold standard for the evaluation of vascular elasticity, to quantify vascular stiffness. Urinary excretion of magnesium will be used to assess dietary magnesium uptake. Furthermore, time courses of an increased magnesium intake on changes in BP, other markers reflecting vascular function, and plasma biomarkers related to low-grade inflammation and vascular activity will be measured to unravel possible cause-effect relationships.

Official Title
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The Effects of Magnesium on Vascular Stiffness: A Long-term Study in Healthy Overweight and Slightly Obese Men and Women

Conditions
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Metabolic Syndrome, Obesity

Intervention / Treatment
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* Dietary Supplement: Magnesium Citrate
* Dietary Supplement: 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 Serum triacylglycerol < 4.5 mmol/L 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 or medication known to treat blood pressure, serum lipid or glucose metabolism No use of dietary supplements or an investigational product within another biomedical within the previous 1-month 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 Exclusion Criteria: High habitual dietary magnesium intake 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 or medication known to treat blood pressure, serum lipid or glucose metabolism Use of dietary supplements or an investigational product within another biomedical within the previous 1-month 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: 70 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> | Dietary Supplement: Magnesium Citrate<br>* One capsule thrice daily that contains magnesium citrate (total daily dose: 350 mg elemental magnesium) at breakfast, lunch and dinner for 24 weeks<br>|
| Placebo Comparator: Placebo<br> | Dietary Supplement: Placebo<br>* One capsule thrice daily that contains placebo at breakfast, lunch and dinner for 24 weeks<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Vascular stiffness: effects of magnesium citrate supplementation | Carotid-femoral pulse wave velocity (PWV) | Baseline (0 weeks) and after medium-term (12 weeks) and long-term (24 weeks) magnesium citrate supplementation | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Vascular function markers: effects of magnesium citrate supplementation | Flow-mediated dilation (FMD) of the brachial artery, pulse wave analysis (PWA) (also at 12 weeks), peripheral arterial tonometry (PAT) and retinal microvascular diameters (also at 12 weeks) | Baseline (0 weeks) and after long-term (24 weeks) magnesium citrate supplementation | 
| Metabolic risk markers related to the metabolic syndrome: effects of magnesium citrate supplementation | Biomarkers for low-grade inflammation and endothelial activation | Baseline (0 weeks) and after medium-term (12 weeks) and long-term (24 weeks) magnesium citrate supplementation | 
| Blood pressure: effects of magnesium citrate supplementation | Office (also at 12 weeks) and 24-hour ambulatory blood pressure | Baseline (0 weeks) and after long-term (24 weeks) magnesium citrate supplementation | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Metabolic Syndrome, Obesity, Magnesium Supplementation, Vascular Stiffness, Vascular Function