课件文案reference汇总30 ma ag 2009

AsiaPacJClinNutr2009;18(1):41- OriginalMicronutrientstatusinanemicandnon-anemicChinesewomeninthethirdtrimesterofpregnancyAi-GuoMaMD1,EvertGSchoutenMD2,YuWangMD3,Rong-XianXuMD4,Ming-CiZhengMD5,YongLi1,QiuzhenWangMM1andYongyeSunMM11InstituteofHumanNutrition,MedicalCollegeofQingdaoUniversity,China2HumanNutritionDivision,WageningenUniversity,theNetherlands3LanzhouMedicalCollege,Lanzhou,ChinaBackground:AnemiaisamajornutritionrelatedprobleminChina.Inadditiontoirondeficiencythismaybeduetodeficienciesofothermicronutrients.Objective:Todescribethemicronutrientstatusofanemicandnon-anemicpregnantwomeninChina.SubjectsandMethods:734clinicallynormalpregnantwomeninthethirdtrimesteraged20-35,wererandomlyrecruitedfromthepopulationofpregnantwomenregularlyreceivingpreg-nantexaminationincommunitymedicalcenters.SerumconcentrationsofvitaminsA,B12andC,ironandzincstatusparameters,andvitaminB2inurineweredetermined.Subjectswerecategorizedaccordingtothepresenceorabsenceofanemiaandcomparedaccordingtomicronutrientstatus.Results:Serumconcentrationsofironandmicronutrientsweresignificantlylowerinanemicwomenthannon-anemicwomen:serumiron909µg/Lversus1109µg/L,ferritin13.8µg/Lversus19.6µg/L,vitaminC308.9µg/Lversus388.1µg/dL,andretinol50.0µg/dLversus59.3µg/dL.Zincconcentrationswerealsolowerinanemicwomen.Subnormalserumiron(<700µg/L)andirondepletion(ferritin<12µg/L)were39.7%and52.6%,significantlymorefrequentinanemicthan23.9%and35.0%innon-anemicsubjects,asweresubnormalvitaminAandascorbicacid.SubnormalvitaminB2andB12werefrequentinbothanemicandnon-anemicgroups.Conclusion:Subnormalconcentrationsofironandmicronutrientsincombinationmaycontributetothissituation.Furtherstudiesonfood-basedorsupplement-basedapproachestryingtoincreaseintakeofironandcertainvitaminsarewarrantedtodecreaseanemiainpregnantChinesewomeninthethirdtrimester.Anemiainpregnancyisacommonandworldwideprob-lemthatdeservesmoreattention.Inmanydevelopingcountries,itsprevalenceisreportedevenashighas75%.Often,anemiaissevereinthesesituations,contributingsignificantlytomaternalmortalityandmorbidity1andtolowbirthweightaswell.2Anemiaisalsoamajornutri-tionrelatedproblemamongpregnantwomeninChina.PrevalenceofanemiadiffersindifferentareasofChina.Somestudiesshowthattheprevalenceofanemiaduringpregnancyis10%to20%.Otherssuggestanemiapreva-lencetobe42%amongpregnantwomeninthethirdtri-mesterinXi’ancity,3and55%inJilincityin1997.Itwashypothesizedthatthemainprobablecausewasanunbal-anceddietthatlacksprotein,ironandcertainvitamins.4Anemiaduringpregnancyhasbeenattributednotonlytoincreasedironrequirementsduringthesecondandthethirdtrimesterofgestation,5butalsotomicronutrientdeficiency.DeficienciesofironandvitaminAwereamongthemajorcontributoryfactors.6Severalstudiesinhumansandanimalshaveshownthatirondeficiencyisaccompaniedwithothermicronutrientdeficiencieslike

vitaminAandascorbicacid.7,8Studiesalsohaveshownthatsupplementationwiththesevitaminsmayimproveironstatusasmeasuredbyhematologicalindices.9How-ever,dataonironstatusandmultivitaminlevelsinpreg-nantwomenwithanemiainChinaareinsufficient.Inthisstudy,weassessedandcomparedthemicronutrientstatusofpregnantwomenwithanemiaandthosewithoutane-SUBJECTSANDThiscross-sectionstudywasdesignedandconductedbetweenNovember1999andApril2001.SevenhundredCorrespondingAuthor:Prof.AiguoMa,InstituteofHumanNutrition,MedicalCollegeofQingdaoUniversity,38DengzhouRoad,266021,QingdaoP.R.china.Tel:+8653282991503;Fax:+86532Email:Manuscriptreceived9April2008.InitialreviewcompletedOctober2008.Revisionaccepted24Decemberandthirtyfourclinicallynormalpregnantwomenaged20-35andinthethirdtrimesterofpregnancywereran-domlyrecruitedfromfoursitesinGansu,thenorthwestofChina;Guangxi,thesouthwest,Shandong,thenorth-eastandFujian,thesoutheastofChinaforhematologicandmicronutrientmeasurements.Thesubjectswerehealthypregnantwomenwhodidnotexperienceabnor-malbleeding,didnotsmokeordrinkanyalcoholicbev-erages,andhadtakennodietarysupplementsforthepast2months.ThisstudywasapprovedbytheResearchandEthicsCommitteeoftheInstituteofHumanNutrition,MedicalCollegeofQingdaoUniversity.Theinformedconsentwasobtainedfromallsubjectspriortothetrial.SamplecollectionandbiochemicalanalysisApproximately5mlofvenousbloodand10mlofurinesamplesweretakenonthedayoftheprenatalexamina-tion,andstoredinicefortransporttothelocallaborato-riesofthefoursites.Hematocritandhemoglobinconcen-trationsweremeasuredinheparinizedblood.Serumwasseparatedfromtheremainderofthebloodbycent-rifugationat2000×gfor15minatroomtemperatureuponarrival.Serumsampleswerestoredseparatelyat-80Cinthedarkandtransportedbyairortraintothelabo-ratoryoftheInstituteofHumanNutrition,MedicalCol-legeofQingdaoUniversityforanalysesofferritin,vita-minA,ascorbicacid,riboflavin,vitaminB12andfolate.Hemoglobinconcentrationwasmeasuredbythecyanomethemoglobinmethodandhematocritbythemi-cromethod.Astandardhemoglobincyanidesolutionwasusedforqualitycontrolofhemoglobinmeasurements.Measurementsofserumferritinwereperformedbyradio-immunoassay10asdescribedbythemanufacturer(TheNorthBiolTecInstitute,Beijing,China).Transferrin(TRF)wasdeterminedbyacommerciallyavailablekit(YaduBiotechCo.Shanghai,China).Serumretinolcon-centrationsweremeasuredbyreversed-phasehigh-performanceliquidchromatography(HPLC)(Beckman5000withdetectorof168,USA)11andthewithin-assayandbetweenassayCVswere3%and8%,respectively.Thenutritionalstatusofriboflavinwasdeterminedbytheratioofurineriboflavin/creatinine,andtheerythrocyte

glutathionereductaseactivitycoefficient(EGRAC)wasmeasuredforassessingriboflavinstatus.12Urinaryribo-flavinwasmeasuredbyfluorometricprocedures.Underconditionsofadequateintake,theamountexcretedperdayismorethan80mgpergramofcreatinine.FolicacidandvitaminB12weremeasuredbyradioimmunoassaymethod(DiagnosticProductsCorporationDPC,USA).13Serumconcentrationsofiron,zincandcopperweremeas-uredby710-ESICPOpticalEmissionSpectrometer(Var-ianMedicalSystem,USA).BasedonthereportoftheInternationalAnemiaCon-sultativeGroup,14thecriterionforadiagnosisofanemiawasHb<110g/L.Thefollowingresultswereconsideredabnormal:hematocrit<33%,ferritin<12mg/L,transferrin<2.1g/L.Thefollowingvalueswereconsideredmal:serumiron<700mg/L,vitaminA<30mg/dL,ascor-bicacid<400mg/dL,riboflavin/creatinine<80mg/ginurine,folicacid<3.0ng/mLandvitaminB12<200Thesignificanceofdifferenceswasdeterminedbyinde-pendentsamplest-testandthechi-squaretest.TheStatis-ticalPackageofSocialSciences(SPSS)version10.0wasusedforstatisticalanalysis.Thepercentilesdistributionsofserumiron,ferritin,folicacid,retinol,ascorbicacidandvitaminB2werecomparedbetweenanemicandnon-anemicwomen.Two-sidedpvalues<0.05wereconsid-eredstatisticallysignificant.ResultswithrespecttoironstatusinTable1showsthatthereweresignificantdifferencesintermsofserumhe-moglobin(-24%),ferritin(-30%),transferrin(-6%)andserumiron(-18%)betweenanemicandnon-anemicpreg-nantwomen.MeanconcentrationsofserumvitaminC(-20%),zinc(-5%),retinol(-16%)andvitaminB2inurine(-21%)intheanemicgroupweresignificantlylower.Therewerenosignificantdifferencesofserumcopperlevels,vitaminB12andfolate.Thefrequencyofsubnormalserumironandmicronu-trientsisshowninTable2.Prevalenceofsubnormalse-rumiron(<700µg/L)andirondepletion(ferritin<12Table1.Ironstatusandmicronutrientlevelsinanemicandnon-anemicpregnantpnnHaemoglobin-Haematocrit-Ferritin-Transferrin-Retinol-VitaminC-VitaminB12Folate--Iron-Zinc-Copper-Table2.Prevalenceofsubnormalmicronutrientsinanemicandnon-anemicSubnormaln%%n%pSerum<700<12<400<30<200<3.0<80µg/L)was39.7%and52.6%intheanemicgroup,com-paredto23.9%and35.0%inthenon-anemicgroup(p<0.003,p<0.001).SubnormalvitaminA(23%vs7%)andsubnormalascorbicacid(69%versus61%)werealsosignificantlymorefrequentinanemicpregnantwomen(p<0.001,p<0.02).Nevertheless,with38%and25%,frequenciesofsubnormalriboflavinandfolatewerenotsignificantlydifferent.Thepercentilesdistributionsofironstatusandvitaminconcentrationsaccordingtopresenceorabsenceofane-miaispresentedinFigure1andshowadifferentiatedpicturesofserumferritin,serumiron,serumascorbicacid,serumretinol,andvitaminB2/creatinineinurine.More-over,thecurvesofHb<110g/LandHb≥110g/Linfer-ritin,serumiron,vitaminCandvitaminB2/creatinineoverlapinthelowerendofthedistribution,whiletheupperendisdistinct.However,theretinoldistributionswereentirelydistinctfornon-anemicandanemicsubjects,andthereisnodifferenceinserumfolatebetweennon-anemicandanemicsubjects.Resultsformthisstudythatinvestigatedinpartofruralandlow-economictownsinChinashowedthatanemicpregnantwomen(Hb<110g/L)hadalowerserumironconcentration,ferritinandtransferrinlevelsthannon-anemicpregnantwomen;moreover,micronutrientsweresignificantlylowerinanemicwomenthannonanemicwomenintermsofserumvitaminC,serumretinolandvitaminB2inurine.SerumsubnormalvitaminAandascorbicacidlevelsweresignificantlymorefrequentinanemicthaninnonanemicwomen.Thisstudyhasseveraladvantagesoverpreviousstud-iesthatexaminedmicronutrientstatusduringpregnancy.Apartfromhavingalargesamplesize,awiderangeofmicronutrientswasexaminedsimultaneouslyinChineseruralareas.Inaddition,wereportedtheextenttowhichmultipledeficienciescoexist,datafrombothruraldevel-opingcountrysettingsaswellastownsarescarce.Re-sultsfromthisstudyalsohavethepotentialtoprovidevaluablereferencevaluesforassessingnutritionalstatus.However,theassessmentofvitaminandmineralstatusduringpregnancyiscomplicatedbecausethereisagen-erallackofpregnancy-specificlaboratoryindicesfornu-tritionalevaluation16,andpregnancyitselfmayalter.Thesubjectswerefromthepopulationlivinginlowormiddlesocio-economiclevelsandundevelopedareas,whichwasexpectedtoberepresenttheaveragemicronu-

trientsandanemiastatusinpartsofthenation.Informa-tiononthecharacteristicsandratesofanemiaaswellasirondeficiencyofthesubjectshavebeenpreparedforpublicationinanotherpaper;whilethestratifiedstudymayneedalargerpopulationbyarea,whichwillbede-signedonthelargerscale.Althoughthemostcommoncauseofanemiaisirondeficiency,deficienciesofvitaminB12,folate,vitaminAandevenzinccontributeeithersinglyorincombinationtomaternalanemia.17Womenindevelopingcountrieshaveahighprevalenceofirondeficiencybutalsotendtobedeficientinothermicronutrientssuchaszinc,5vitaminA,folateandvitaminB12.Irondeficiencyrarelyoccursinisolationandisoftenaccompaniedbyothermicronutrientdeficiencies.18Makola19confirmedthatmicronutrientdeficienciesareprevalentinthefemalepopulationofTanzaniaandtheprevalenceofanemia(63%).Inourstudy,lowlevelsofserumvitaminC,retinol,riboflavin,occurredbothintheanemicandnonanemiagroups,butthethreemarginalvitamindeficienciesweremoresevereinpregnantwomenwithanemiathanthosewithout,whichshouldberesultedinpartbytheadditionalre-quirementsofthefetusandthepregnantwomenthem-selves,aswellaslowintakes.Thesubjectsintheinvesti-gationcouldnotgetenoughgreenvegetablesandanimalfoods.20UnlikeWesternsocieties,foodisnotroutinelyfortifiedwithironinruralareasofChina.Moreover,greenvegetableswerescarceinthesubjects'dietsduringthewinterseason.Therefore,thelowintakesandshortageofhemeironandfreshvegetablesmaycontributetolowaverageserumlevelsofretinal,ascorbicacidandlowironinanemicwomeninourstudy.Retinolstatusisaputativefactorforimprovedironstatusorironabsorption.VitaminAdeficiencymayalsoresultinanemiainhu-mansandanimalsthatcanbereversedonlybyvitaminAsupplementation.21VitaminAandβ-carotenemayformacomplexwithiron,keepingitsolubleintheintestinallumenaswellaspreventingtheinhibitoryfactorsonironabsorption.22Ascorbicacidisconsideredapromoterofonnon-heme-ironabsorption.InthegeneralChinesediet,vegetablesarecommonlystratified,andfreshfruitsareseldomeatenwithameal.Therefore,theamountandavailabilityofvitaminCpresentinthedietareevenmorecompromisedbyheatsusceptibility,explaininglowse-rumconcentrationsofvitaminCbothinanemicandnonanemicwomen.SimultaneousoccurrenceofbothvitaminCandironinthegutisnecessaryforeffectiveinterac-tion.23Inthisstudy,percentageofsubnormalvitaminB12SerumfSerumferritin(ug/Serumiron(ug/1,1,1,1, PercentilSerumvitaminC(ug/ Percentil 20.18.16.14.12.10.8.6.4.2.0. Percentil SerumretiSerumfolate(ng/Figure1.Thedistributionofconcentrationsofferritin(a),serumiron(b),serumvitaminC(c),vitaminB2inurine(d),serumretinol(e)andserumfolate(f)accordingtopresenceorabsenceofanemiaasdifferentiatedbyHb<110andHb‡110.(<200pg/mL)were13.9%intheanemicand11.2%innon-anemicpregnantwomen,respectively,buttherewasnosignificantdifferencebetweenthem(p=0.271),whichmayhaveconfoundedtheenhancingeffectofascorbicacidonironstatus.24

VitaminB2inurine,estimatedbyaratioofvitaminB2andcreatinine,wasalsofoundtobelowerinanemicwomenthaninnonanemicwomen.Subnormalfolatewasnotprevalentinthisstudythoughitisassociatedwithanemiaandothermicronutrientdeficiencies.Itmayalsobetheresultoflowintake,decreasedintestinalabsorption,orincreaseddemand.25,26Theserumzincandironconcentrationswereposi-tivelyrelatedwithmaternalhemoglobin.27Thedistribu-tionsofhemoglobinconcentrationtozincandironindi-catedthatdeficienciesofthetwoelementswerecommonandmoresevereinanemicpregnantwomen.Thepossiblereasonisnotonlyanexpansivebloodvolumeandanin-creasingneedofzincandironbypregnantwomen,butalsopoorintakeandlowbio-absorptionofzincandiron.Zincsupplementationmayimprovepregnancyoutcomesforchronicallydeficientpregnantwomen.Prophylacticdosesof20-25mgelementalzincperdayhavegenerallybeenusedinpregnantwomenindevelopingcountries.28Soweshouldalsopayattentiontozincsupplementationduringironsupplementationbecauseironcaninterferewiththeabsorptionofzinc.Adverseeffectsonzincme-tabolismwereobservedafteringestionof100mgFe/d.Anincreaseintheefficiencyofzincabsorptionwasob-servedduringlatepregnancy.29Inconclusion,inthismulti-centercrosssectionalstudyweobservedahighprevalenceofanemiainthethirdtri-mesterofpregnancyinruralareasaswellassub-urbanarea.TherewasahighprevalenceofanemiainChinesepregnantwomen,andtheprevalenceofirondeficiency(ID)andirondeficiencyanemia(IDA)was42%and19%,respectively.30Thesewomenoftenhaveapoornutritionalstatus,lackingsufficientdietaryintakeofmultiplemicro-nutrients.Thepresentstudyindicatedthatanemiainpreg-nantwomenwasstillasevereandpossiblynutritionre-latedproblem.Itwashypothesizedthatthepossiblerea-sonsforthedifferenceinprevalencebetweenthefoursitesweregeographicfactors,unbalanceddietsandpoornutritionaleducation.4Furthermore,concentrationsofserumferritin,iron,retinol,zincandurinaryexcretionofriboflavinwerelowerinanemicwomenthaninnon-anemicwomen.Thismaybetheconsequenceofanun-balanceddietwithalowamountofironandmicronutri-ents.Therefore,supplementationwithacombinationofironandothermicronutrientsshouldbeencouragedforpregnantwomenandbemorebeneficialtoanemicpreg-nantwomeninthethirdtrimesteraswell.WesincerelyacknowledgeProfessorsJosephHautvastandDrPaoloSuterfortheirkindhelp.TheauthorsalsothankZhangXiuzhen,LiangHui,DuWei,XuHongwei,andZhangShehuafortechnicalassistance.WethankWangXinformanagingthecontactswithsubjects.Therearenoconflictsofinterestandthemanuscripthasbeenreadandapprovedbyallauthors.Wesin-cerelyacknowledgetheNestléFoundationforthegranttothisAUTHORMaAG,SchoutenEG,WangY,XuRX,ZhengMC,LiY,WangQZandSunYY,noconflictsofinterest.vandenBroekN.Anemiaandmicronutrientdeficiencies.BrMedBull.2003;67:149-60.RamakrishnanU.Nutritionandlowbirthweight:fromre-searchtopractice.AmJClinNutr.2004;79:17-21.

JinH,HanQ,LiangCA,LiL,WuYZ,ZhaoQ.Theepide-miologicalstudyofirondeficiencyinpregnangwomen.JournalofXi'anMedicalUniversity.1995;16:437-9.LiuLJ,LaiYH,HuZH,JiW,WuYJ,LiuCQ.Investiga-tionofanemiaof158pregnantwomeninJilincity.JiLinYiXueYuanXueBao.998;18:45-47.InternationalAnemiaConsultativeGroup(INACG).Irondeficiencyinwomen.Washington,D.C.TheNutritionFoundation1981:5-36.BrabinBJ,Prinsen-GeerligsPD,VerhoeffFH,FletcherKA,ChimsukuLH,NgwiraBM,LeichOJ,BroadheadRL.HaematologicalprofilesofthepeopleofruralsouthernMa-lawi:anoverview.AnnTropMedParasitol.2004;98:71-83.MejiaLA,HodgesRE,RuckerRB.ClinicalsignsofanemiainvitaminAdeficientrats.AmJClinNutr.1979;32:1439-MakolaD,AshDM,TatalaSR,LathamMC,NdossiG,MehanshoH.Amicronutrient-fortifiedbeveragepreventsirondeficiency,reducesanemiaandimprovesthehemoglo-binconcentrationofpregnantTanzanianwomen.JNutr.BloemMW,WedelM,vanAgtmaalEJ,SpeekAJ,Saowa-konthaS,SchreursWH.VitaminAintervention:short-termeffectsofasingle,oral,massdoseonironmetabolism.AmJClinNutr.1990;51:76-9.ChuSL,ChenYZ,XueJZ,NiQG,WangYL.Measurementofclinicalapplicationofferritinbyradioimmunoassay.ChinJHematol.1983;4:296-8.HandelmanGJ,ShenB,KrinskyNI.Highresolutionanaly-sisofcarotenoidsinhumanplasmabyhigh-performanceliquidchromatography.MethodsEnzymol.1992;213:336–SauberlichHE,JuddJH,Jr.NichoaldsGE,BroquistHP,DarbyWJ.Applicationoftheerythrocyteglutathionereduc-taseassayinevaluatingriboflavinnutritionalstatusinahighschoolstudentpopulation.AmJClinNutr.1972;25:756–62MagnusEM,Bache-WiigJE,AandersonTR,MelbostadE.FolateandvitaminB12(cobolamin)bloodlevelsinelderlypersonsingeriatrichomes.ScandJHaematol.1982;28:WHO.Maternalhealthandsafemotherhoodprogram.Theprevalenceofanemiainwomen:Atabulationofavailableinformation.2nded.Geneva,Switzerland:WorldHealthOr-ganization,1992.(WHO/MCH/MSN/92.2)ShilsME,OlsonJA,ShikeM.Modernnutritioninhealthanddisease.8thedition.Lea&Febiger;Philadelphia,2000;JiangT,ChristianP,KhatrySK,WuL,WestLP.Micronu-trientDeficienciesinEarlyPregnancyAreCommon,Con-current,andVarybySeasonamongRuralNepaliPregnantWomen.JNutr.2005;135:1106–12.VandenBroekNR&LetskyEA.EtiologyofanemiainpregnancyinSouthMalawi.AmJClinNutr.2000;72:247S–Azais-BraescoV,PascalG.VitaminAinpregnancy:re-quirementsandsafetylimits.AmJClinNutr.MakolaD,AshDM,TatalaSR,LathamMC,NdossiG,MehanshoH.AMicronutrient-FortifiedBeveragePreventsIronDeficiency,ReducesAnemiaandImprovestheHemo-globinConcentrationofPregnantTanzanianWomen.JNutr.MaAG,ChenXC,ZhengMC,WangY,XuRX,LiJS.IronstatusanddietaryintakeofChinesepregnantwomenwithanemiainthethirdtrimester.AsiaPacificJofClinNutr.BloemMW,WedelM,EggerR,SpeekAJ,ShrisjverJ.IronmetabolismandvitaminAdeficiencyinchildrenintheNorthwestThailand.AmJCli