A Meta-analysis On The Association Of Dietary Magnesium Intake With Stroke And Cardiovascular Mortality

Background:Magnesium is an abundant mineral in the body. Magnesium plays a role in the maintenance of normal function of nerve and muscle, cardiac excitability, Neuromuscular conduction, muscular contraction, vasomotortone, normal blood pressure, b one integrity, and glucose and insulin metabolism. Despite a vital role for magnesium in metabolism, its deficiency among general population is a common problem. It was reported that prevalence of magnesium deficiency was 81% and 82% in male and female respectively among adults aged more 70 years.Animal studies showed that magnesium deficiency could lead to the development of atherosclerosis. Epidemiologic studies showed a significant and positive association of magnesium deficiency and left ventricular hypertrophy, cardiovascular mortality and all-cause mortality. These results suggested that magnesium deficiency was a risk factor for stroke and cardiovascular events. During the past decades, some epidemiologic studies explored the relationship between dietary magnesium intake and stroke or cardiovascular mortality, generating inconsistent results. Some but not all studies showed an inverse association between them. There was no meta-analysis on the relationship between dietary magnesium intake and cardiovascular mortality up to date published in Chinese.Meta-analysis is an effective method to solve the problem of inconsistent results from individual study by combining various studies on the same study aim. Therefore,this study aimed to explore the the relationship between dietary magnesium intake and stroke or cardiovascular mortality by pooling relevant cohort studies.Objective:1. To explore the the relationship between dietary magnesium intake and strokemore precisely by pooling cohort studies and conducting a meta-analysis.2.To explore the the relationship between dietary magnesium intake and cardiovascular mortality more precisely by pooling cohort studies and conducting a meta-analysis.Methods:1. We searched the Pub Med,Web of Science, Cochrane Library databases,CNKI and Wanfang Data Knowledge Service Platform according to presented strategy and inclusion criteria. All the articles were screened and eligible articles were included.2. Data extraction was performed using a standardized data-collection form. The following data were abstracted: the first author’s name; the publication year; the country of origin; the number of cohort; study duration; whether the reported RR or HR was adjusted for age, gender, or other potential confounders. The quality of the included studies was evaluated by NOS scale.3. The study-specific most adjusted RR or HR was used to compute a summary RR and its 95%CI. Heterogeneity across studies was tested. Potential publication bias was assessed by Egger’s and Begg’s test. The influence of a single study on the overall risk estimate was investigated by omitting 1 study in each turn.Results:1. A statistically significant reduction in total stroke risk in the highest category of Dietary magnesium intake compared with the lowest category of magnesium intake was observed, independently of common risk factors, such as age, sex, smoking,hypertension, diabetes,hypercholestorolemia, BMI et al. When analyzed respectively,dietary magnesium intake was inversely associated with ischaemic stroke but not haemorrhagic stroke. There was no evidence of heterogeneity among the overall studies.2. An inverse trend towards the association between dietary magnesium intake and cardiovascular mortality was observed, but not reaching statistical significance.There was evidence of great heterogeneity among the overall studies. There was no evidence of publication bias according to the results of Egger’s and Begg’s test.3. Omission of each study in turn did not influence the results significantly.4.Sample size, publication year and race were considered as variables and put into the equation of meta-regression. The result showed that none of these variables contributed significantly to the heterogeneity.Conclusions:1. The present meta-analysis indicates that a higher magnesium intake is associated with a reduced risk of total and ischaemic stroke, but not haemorrhagic stroke.2. There was a inverse trend towards the association between magnesium intake and cardiovascular mortality, but not reaching statistical significance, warranting further studies to elucidate the relationship.