Magnesium Status And Effects Of Magnesium Supplementation On The Metabolism Of Glucose And Lipid In The Middle-aged And Older People

Evidences indicate that magnesium deficiency is associated with diabetes, dyslipidemia,hypertension and other metabolic syndrome related diseases,and magnesium supplementation can improve metabolic syndrome and its components. Although there are scholars conducting research related to metabolic syndrome,but the nutritional status of magnesium and effects of magnesium supplementation on metabolism syndrome are seldom studied in China.This study is going to evaluate the magnesium status and dietary intakes of middle-aged and older people,and to evaluate the effects of magnesium supplementation on metabolism of blood glucose and lipid. A total of 324 middle-aged and older people(55-70 yrs) were randomly selected as subjects.Magnesium,calcium,iron,zinc,and copper concentrations in red blood cell were measured by emission spectrum,and dietary intakes were surveyed by 24-hr recall questionnaires.All the subjects were divided into four groups as the normal group(N), the hypertension group(H),the impaired fasting glucose group(IFG) and the diabetics group(D) for analysis.And 160 people from these subjects were randomized into four groups:group C as the control group,group E taking VE 250 mg/day,group M taking magnesium 220 mg/day,and group EM taking both VE 250 mg/day and magnesium 220 mg/day.Venous blood samples were taken from each subject before and after the 3-month trial for measurements of fasting blood glucose(FBG),fasting insulin(FIns), total cholesterol(TC),high density lipoprotein(HDL),triglyceride(TG),apoprotein A (Apo A),and apoprotein B(Apo B).Results show that the average magnesium concentration is lower in group H than in group N(2.0±0.7 mmol/L vs 2.2±0.7 mmol/L,P <0.05).Groups H,IFG and D take less magnesium than the normal group(315.9 mg, 331.6 mg and 323.3 mg vs 371.54 mg,P<0.05).There are no differences in the concentrations and dietary intakes of other minerals.After 3 months supplementation, FBG decreased 0.73mmol/L,0.67 mmol/L and 0.58 mmol/L in groups E,M and EM(all P-values are lower than 0.05).TC levels of control groups E,M,and EM decreased 2.77 mmol/L,2.47 mmol/L,and1.87 mmol/L,respectively(all P-values are lower than 0.01). HDL increased 0.24 mmol/L(P＜0.01),0.22 mmol/L(P＜0.01) and 0.17 mmol/L(P＜0.05) respectively in groups E,M and EM.And all the changes were significantly different with the control group(P＜0.05).TG increased 2.28 mmol/L in group C (P＜0.01),and decreased 2.83 mmol/L,1.31 mmol/L and 2.39mmol/L in groups E,M and EM(all P-values lower than 0.01).And there were significant differences in mean differences with the control group(P＜0.01).There were no significant differences in blood levels of Apo A and Apo B.Results of this study confirmed that the average magnesium concentration in RBC and dietary intake are lower in those who are suffering hypertension,impaired fasting glucose or diabete.Magnesium supplementation may effectively reduce TC,TG and FBG levels and increase the HDL level,suggesting that adequate magnesium supplementation can improve the middle-aged and older people's blood glucose and lipid metabolism.Further research should be conducted to find the moderate dosage and duration of the supplementation.