【作者】 李勇；

【导师】 马爱国；

【作者基本信息】 青岛大学 ， 生理学， 2009， 博士

【摘要】 中老年人随着年龄的增长和激素水平的变化,机体代谢逐步出现紊乱,其中以血糖、血脂代谢紊乱最为常见。研究发现,糖尿病、高脂血症、高血压等疾病患者广泛存在镁摄入不足和由此导致的镁缺乏,而补充镁制剂可以对这些疾病起到改善作用。本研究旨在了解中老年人镁的营养状况和膳食摄入情况,以及补镁对其血糖和血脂水平的影响。随机选取青岛市某地324名55-70岁的中老年人为研究对象,进行体检并抽取空腹静脉血,采用全自动生化仪检测空腹血糖,电感耦合等离子发射光谱仪检测红细胞内镁及钙、铁、锌、铜等离子的浓度,采用24小时膳食回顾法了解每日膳食摄入情况。并在此基础上,从以上人群中随机选取160名无严重疾病的中老年人作为研究对象,随机分为4组,C组为对照组,E、M和EM为营养补充组,每天分别补充VE 250mg、镁220mg和VE 250mg+镁220mg,补充时间为3个月。补充前后分别采集空腹静脉血,检测空腹血糖(FBG)、空腹胰岛素(FIns)、总胆固醇(TC)、高密度脂蛋白(HDL)、甘油三酯(TG)、载脂蛋白A(Apo A)和载脂蛋白B(Apo B)。结果表明,中老年人红细胞内镁的平均浓度为2.1±0.7mmol/L,,高血压患者比正常人低(分别为2.0±0.7 mmol/L和2.2±0.7 mmol/L,P＜0.05),镁的每日平均摄入量为342.5±187.6 mg/d,达到适宜摄入量(AI值)的97.8%,但高血压、空腹血糖受损和糖尿病患者镁的摄入量均低于正常同龄人(分别为315.9±161.0 mg/d,331.6±154.5 mg/d,323.3±182.1 mg/d和371.5±213.4 mg/d,P值均小于0.05)。其它离子的红细胞内浓度和每日平均摄入量各组之间不存在显著性差异。在进行为期三个月的营养素补充之后,M组、E组和EM组FBG水平分别较干预前降低0.73 mmol/L,0.67 mmol/L和0.58 mmol/L(P值均小于0.05),但空腹血糖水平仍在正常范围内(3.9-6.1 mmol/L)。与C组相比变化值差异具有显著性(P值均小于0.05)。C组胰岛素水平较干预前升高1.77 mmol/L(P＜0.01),与干预前相比,E、M和EM组胰岛素水平较干预前均有所降低,但差异不具有显著性(P＞0.05)。E组、M组和EM组的TC水平较干预前分别降低了2.77 mmol/L,2.47 mmol/L和1.87 mmol/L(P值均小于0.01)。E组、M组和EM组HDL水平较干预前分别升高了0.24 mmol/L(P＜0.01),0.22 mmol/L(P＜0.01)和0.17 mmol/L(P＜0.05)。对照组TG水平较干预前升高2.28 mmol/L(P＜0.01);而E、M和EM各组TG水平干预后比干预前分别降低了2.83 mmol/L,1.31 mmol/L和2.39 mmol/L(P值均小于0.01)。但Apo A和Apo B各组干预前后及干预后各组间均无显著性差异。通过以上研究,证实中老年人多种矿物质摄入不足,其摄入量不仅达不到中国营养学会推荐的适宜摄入量(AI值),而且较2002年全国营养与健康调查结果公布的全国平均水平低。虽然镁的平均摄入量接近AI值,但患有高血压或血糖异常的的中老年人镁的摄入量低于正常同龄人,高血压患者红细胞内镁离子浓度也显著低于正常同龄人。在经过三个月220 mg/d的镁制剂补充后,有效地降低了中老年人总胆固醇、甘油三酯和空腹血糖水平,并提高了高密度脂蛋白水平,提示适量补充镁制剂对改善中老年人的血糖、血脂代谢具有积极作用。更多还原

【Abstract】 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.更多还原