scholarly journals The Effect of Magnesium Supplementation on Endothelial Function: A Randomised Cross-Over Pilot Study

Author(s):  
Jennifer Byrne ◽  
Caitríona Murphy ◽  
Jennifer B. Keogh ◽  
Peter M. Clifton

Evidence supports an association between low magnesium (Mg) intake and coronary heart disease and between Mg intake and endothelial function. The aim of this study was to assess the effect of one week of Mg supplementation on endothelial function, assessed by flow mediated dilatation (FMD). Nineteen healthy men and women completed this cross-over pilot study in which participants were randomised to take an over-the-counter magnesium supplement for one week or to follow their usual diet. Weight, FMD and blood pressure (BP) were taken on completion of each intervention and 24 h urine collections and blood samples were taken to assess compliance. Baseline serum Mg was within normal range for all participants. Urinary Mg and urinary magnesium-creatinine ratio (Mg/Cr) significantly increased between interventions, (p = 0.03, p = 0.005, respectively). No significant differences in FMD or BP were found between the interventions. A significant negative correlation was seen between age and FMD (r = −0.496, p = 0.031). When adjusted for age, saturated fat was negatively associated with FMD (p = 0.045). One week of Mg supplementation did not improve FMD in a healthy population.

Author(s):  
Jennifer Byrne ◽  
Caitriona Murphy ◽  
Jennifer B. Keogh ◽  
Peter M. Clifton

Evidence supports an association between low magnesium (Mg) intake and coronary heart disease and between Mg intake and endothelial function. The aim of this study was to assess the effect of one week of Mg supplementation on endothelial function, assessed by flow mediated dilatation (FMD). Nineteen healthy men and women completed this cross-over pilot study in which participants were randomised to take an over-the-counter magnesium supplement for one week or to follow their usual diet. Weight, FMD and blood pressure (BP) were taken on completion of each intervention and 24hour urine collections and blood samples were taken to assess compliance. Baseline serum Mg was within normal range for all participants. Urinary Mg and urinary magnesium-creatinine ratio (Mg/Cr) significantly increased between interventions, (p = 0.03, p = 0.005 respectively). No significant differences in FMD or BP were found between the interventions. A significant negative correlation was seen between age and FMD (r = -0.496, p = 0.031). When adjusted for age, saturated fat was negatively associated with FMD (p = 0.045). One week of Mg supplementation did not improve FMD in a healthy population.


Author(s):  
Byrne Byrne ◽  
Caitriona Murphy ◽  
Jennifer B. Keogh ◽  
Peter M. Clifton

Evidence supports an association between low magnesium (Mg) intake and coronary heart disease and between Mg intake and endothelial function. The aim of this study was to assess the effect of one week of Mg supplementation on endothelial function, assessed by flow mediated dilatation (FMD). Nineteen healthy men and women completed this cross-over pilot study in which participants were randomised to take an over-the-counter magnesium supplement for one week or to follow their usual diet. Weight, FMD and blood pressure (BP) were taken on completion of each intervention and 24hour urine collections and blood samples were taken to assess compliance. Baseline serum Mg was within normal range for all participants. Urinary Mg and urinary magnesium-creatinine ratio (Mg/Cr) significantly increased between interventions, (p = 0.03, p = 0.005 respectively). No significant differences in FMD or BP were found between the interventions. A significant negative correlation was seen between age and FMD (r = -0.496, p = 0.031). When adjusted for age, saturated fat was negatively associated with FMD (p = 0.045). One week of Mg supplementation did not improve FMD in a healthy population.


Nutrients ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1897 ◽  
Author(s):  
David Rogerson ◽  
Diana Maçãs ◽  
Marianne Milner ◽  
Yingshan Liu ◽  
Markos Klonizakis

The Mediterranean diet has been shown to improve cardiovascular health. Vegan diets have demonstrated similar benefits, albeit in fewer studies. In a comparative pilot study, we compared the effects of a short-term Mediterranean Diet (MD) and Vegan Diet (VD) on microvascular function and cholesterol levels in a healthy population. Twenty-four young (aged 18 to 35 years) healthy volunteers followed a four-week intervention (MD = 12; VD = 12) ad libitum. Pre and post-intervention anthropometrics, microvascular function (assessed via LDF and expressed as raw CVC and %CVC MAX), dietary-analysis data (Calories, Protein, Carbohydrates, Total Fat, Saturated Fat, Fibre), Mean Arterial Pressure (MAP), Blood Pressure, Total Cholesterol (TC), High Density Lipoprotein (HDL-C) and TC:HDL-C were compared. MD participants reduced Total Fat intake (p = 0.05). Saturated Fat decreased (MD: p = < 0.001; VD: p = 0.004) and Fibre increased (MD: p = 0.02; VD: p = < 0.001) in both groups. Dietary changes reflected improvements in plateau raw CVC in the MD group (p = 0.005), and a reduction in TC (p = 0.045) and weight loss (p = 0.047) in the VD group. The MD led to improvements in microvascular function; the VD led to reduced TC and weight loss. Although both diets might offer CVD risk-reduction benefits, evidence for the MD appeared to be stronger due to changes in vasodilatory ability and NO bioavailability.


Author(s):  
Caitríona Murphy ◽  
Jennifer Byrne ◽  
Jennifer B. Keogh ◽  
Michelle L. Headland ◽  
Peter M. Clifton

Magnesium (Mg) deficiency might be a catalyst in the process of endothelial dysfunction, an early event in the pathogenesis of atherosclerosis. The aim of this study was to determine the acute effect of an oral Mg supplement as compared to control on endothelial function assessed by flow-mediated dilatation (FMD). Nineteen participants (39 years, body mass index (BMI) 22.9 kg/m2) completed this randomized cross-over study. Blood pressure (BP) and FMD were measured and blood samples were taken before participants drank 200 mL water, with or without an over the counter Mg supplement (450 mg and 300 mg for men and women). Measurements were repeated at 60 and 120 min. There was a statistically significant two-way interaction between treatment and time on serum Mg (p = 0.037). A difference of −0.085 mm in FMD was observed 60-min post drink in the control group, as compared to baseline FMD, and no difference was observed in the supplement group as compared to baseline. Despite the non-significant interaction between treatment and time on FMD, once adjusted for baseline, the difference seen in the control group and the lack of change in the supplement group at 60 min post-drink suggests that Mg might attenuate the reduction in FMD post-prandially.


2018 ◽  
Vol 69 (4) ◽  
pp. 961-964
Author(s):  
Andrei Vasile Olteanu ◽  
Georgiana Emmanuela Gilca Blanariu ◽  
Gheorghe Gh. Balan ◽  
Dana Elena Mitrica ◽  
Elena Gologan ◽  
...  

Non-alcoholic fatty liver disease (NAFLD) has become of major interest worldwide, it is estimated that more than 20% of the general population suffer from liver steatosis. NAFLD is highly associated with metabolic risk factors like type 2 diabetes mellitus, obesity and dyslipidemia, the patients diagnosed with NAFLD should adopt a high fiber low calorie diet, with reduced saturated fat and carbohydrates content, leading to weight loss and improvement of metabolic profile. Our study is aiming to shape the profile of the patient interested in being informed related to food quality and chemical composition and to evaluate the aspects on the food products label which are important for the customer. Between June 2017 and December 2017, 83 patients diagnosed with NASH were included in the study, representing the study group, while 33 subjects, without metabolic syndrome or digestive diseases, selected from patient list belonging to two general practitioners, constituted the control group. Related to the interest of being informed about the chemical composition and nutritional value of the products bought, the study showed a low interest for the provided information on nutritional value. lack of confidence in the provided information and complexity of the information are understandable, the high number of subject reasoning through lack of immediate clinical benefit is surprising. Among the healthy population the willingness to pay attention to this aspect is extremely low.


Sports ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 86
Author(s):  
Christoffer Nyborg ◽  
Helene Støle Melsom ◽  
Martin Bonnevie-Svendsen ◽  
Jørgen Melau ◽  
Ingebjørg Seljeflot ◽  
...  

We assessed endothelial function by flow-mediated dilatation (FMD), levels of the NO-precursor L-arginine, and markers of endothelial inflammation before, at the finish line, and one week after the Norseman Xtreme triathlon. The race is an Ironman distance triathlon with a total elevation of 5200 m. Nine male participants were included. They completed the race in 14.5 (13.4–15.3) h. FMD was significantly reduced to 3.1 (2.1–5.0)% dilatation compared to 8.7 (8.2–9.3)% dilatation before the race (p < 0.05) and was normalized one week after the race. L-arginine showed significantly reduced levels at the finish line (p < 0.05) but was normalized one week after the race. Markers of endothelial inflammation E-Selectin, VCAM-1, and ICAM-1 all showed a pattern with increased values at the finish line compared to before the race (all p < 0.05), with normalization one week after the race. In conclusion, we found acutely reduced FMD with reduced L-arginine levels and increased E-Selectin, VCAM-1, and ICAM-1 immediately after the Norseman Xtreme triathlon. Our findings indicate a transient reduced endothelial function, measured by the FMD-response, after prolonged strenuous exercise that could be explained by reduced NO-precursor L-arginine levels and increased endothelial inflammation.


Angiology ◽  
2021 ◽  
pp. 000331972110100
Author(s):  
Lei Cao ◽  
Miao Hou ◽  
Wanping Zhou ◽  
Ling Sun ◽  
Jie Shen ◽  
...  

Type 1 diabetes (T1DM) is a strong risk factor for the development of cardiovascular disease. Flow-mediated dilatation (FMD) is an early noninvasive marker of endothelial function and it predicts future cardiovascular disease. However, the changes in FMD among T1DM children are still controversial. The present meta-analysis aimed to investigate whether FMD is impaired in children with T1DM. PubMed, EMBASE, Cochrane library, and Web of Science were searched for studies comparing FMD in children with T1DM and healthy controls. The Newcastle-Ottawa quality assessment scale for case–control studies was used to assess study quality. Data were pooled using a random effects models to obtain the weighted mean differences (WMD) in FMD and 95% CIs. Overall, 19 studies with 1245 patients and 872 healthy controls were included in this meta-analysis. Children with T1DM had significantly lower FMDs compared with healthy controls (WMD: −2.58; 95% CI: −3.36 to −1.81; P < .001). Meta-regression analysis revealed that low-density lipoprotein cholesterol levels impacted the observed difference in FMD between T1DM and healthy children. This meta-analysis showed that T1DM children have impaired endothelial function, which indicates they are at higher risk of developing cardiovascular disease in later life.


2001 ◽  
Vol 101 (6) ◽  
pp. 629-635 ◽  
Author(s):  
Sagar N. DOSHI ◽  
Katerina K. NAKA ◽  
Nicola PAYNE ◽  
Christopher J.H. JONES ◽  
Moira ASHTON ◽  
...  

Flow-mediated dilatation (FMD) of the brachial artery assessed by high-resolution ultrasound is widely used to measure endothelial function. However, the technique is not standardized, with different groups using occlusion of either the wrist or the upper arm to induce increased blood flow. The validity of the test as a marker of endothelial function rests on the assumption that the dilatation observed is endothelium-dependent and mediated by nitric oxide (NO). We sought to compare the NO component of brachial artery dilatation observed following wrist or upper arm occlusion. Dilatation was assessed before and during intra-arterial infusion of the NO synthase inhibitor NG-monomethyl-l-arginine (l-NMMA) following occlusion of (i) the wrist (distal to ultrasound probe) and (ii) the upper arm (proximal to ultrasound probe) for 5min in ten healthy males. Dilatation was significantly greater after upper arm occlusion (upper arm, 11.62±3.17%; wrist, 7.25±2.49%; P = 0.003). During l-NMMA infusion, dilatation after wrist occlusion was abolished (from 7.25±2.49% to 0.16±2.24%; P < 0.001), whereas dilatation after upper arm occlusion was only partially attenuated (from 11.62±3.17% to 7.51±2.34%; P = 0.006). The peak flow stimulus was similar after wrist and upper arm occlusion. We conclude that dilatation following upper arm occlusion is greater than that observed after wrist occlusion, despite a similar peak flow stimulus. l-NMMA infusion revealed that FMD following wrist occlusion is mediated exclusively by NO, while dilatation following upper arm occlusion comprises a substantial component not mediated by NO, most probably related to tissue ischaemia around the brachial artery. FMD following wrist occlusion may be a more valid marker of endothelial function than dilatation following upper arm occlusion.


2006 ◽  
Vol 110 (4) ◽  
pp. 475-482 ◽  
Author(s):  
Mikko J. Järvisalo ◽  
Laura Jartti ◽  
Jukka Marniemi ◽  
Tapani Rönnemaa ◽  
Jorma S. A. Viikari ◽  
...  

Brachial artery FMD (flow-mediated dilatation) is widely used as a marker of systemic arterial endothelial function. FMD, however, shows considerable 25% day-to-day variation that hinders its clinical use. The reasons for this variability are poorly characterized. Therefore the present study was designed to clarify factors responsible for the hourly variation in endothelial function, including consuming a low-fat meal and circadian rhythms in endogenous hormonal levels. Brachial artery FMD, along with serum glucose, triacylglycerols (triglycerides) and levels of several hormones were measured six times per day on two separate days 1 week apart. On one day, the subjects (healthy males: n=12, mean age, 24 years) ate a light breakfast and a standardized lunch (23.5% fat, 48.7% carbohydrate and 27.8% protein). On the other day, they had a similar breakfast after which they fasted. Postprandial FMD values (both after breakfast and after lunch) were similar to baseline FMD. FMD showed a 28% hourly variation and 27% weekly variation. Variation in plasma levels of insulin (P=0.02) associated negatively and DHPG (3,4-dihydroxyphenylglycol) (P=0.001), a marker of sympathetic nervous activation, associated positively with variation in FMD. The effects of DHPG and insulin on FMD were independent of changes in baseline brachial artery diameter, although DHPG was also inversely associated with baseline diameter. Eating a regular low-fat meal does not have any measurable effects on brachial artery endothelial function. These data suggest that strict requirements for fasting conditions may be unnecessary when measuring peripheral endothelial function using the ultrasound technique. Circadian variation in serum insulin and sympathetic tone are physiological determinants of endothelial function.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Michael Miller ◽  
Valerie Beach ◽  
Charles Mangano ◽  
Jeffrey Rhyne ◽  
Christina Dobmeier ◽  
...  

Background : While the effect of popular diets on weight loss has been extensively studied, less is known in the absence of weight loss. We hypothesized that a diet high in total and saturated fat would be associated with adverse effects on LDL-C, endothelial function and biomarkers of atherothrombosis compared to lower fat diets. Methods : We tested 3 popular diets, including Atkins (50% fat), South Beach (30% fat) and Ornish (10% fat) in a randomized and counterbalanced, crossover study. Subjects completed each of the three 4-week dietary intervention phases followed by a 4-week washout period. They were weighed weekly and caloric adjustments made if weight change exceeded 1 kg. At the completion of each dietary phase, 3-day food records were analyzed, fasting blood was sampled and brachial artery reactivity testing (BART) performed. Results : Eighteen of 26 adults (mean age: 30.6 ± 9.6 yrs, 50% female) completed all 3 dietary phases. There were no changes in weight at the conclusion of each phase. However, non-significant increases in LDL-C occurred during the Atkins phase (pre: 96.5, post: 112.9 mg/dL; P=0.12 ), whereas LDL-C was reduced during the Ornish (pre: 110.1, post: 84.6 mg/dL; P=0.006 ) and South Beach phases (pre: 101.7, post: 91.5 mg/dL; P=0.01 ). BART testing revealed a significant inverse correlation between flow-mediated vasodilation and intake of total fat (r 2 =−0.29; P=0.03 ), saturated fat (r 2 =−0.31; P=0.02 ) and monounsaturated fat (r 2 =−0.35; P=0.01 ). Microarray analysis demonstrated increased expression of several leukocyte biomarkers including, ICAM2 (37%; P=0.002 ), SELL (26%; P=0.007 ) and SOD1 (42%; P=0.04 ) at the completion of the Atkins diet compared to baseline. In contrast, expression of atherothrombotic biomarkers was not increased after the South Beach or Ornish phase. Conclusions: In the absence of weight loss, the high fat Atkins diet is associated with increased LDL-C, reduced endothelial vasoreactivity and increased expression of biomarkers of atherothrombosis. As such, these data suggest that isocaloric conversion to the Atkins diet may negatively impact cardiovascular health as compared to the South Beach or Ornish Diet.


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