The purpose of this dissertation was to explore the mechanism of association between social determinants of health (SDH), particularly limited health literacy, and disparate outcomes related to cardiovascular disease in vulnerable populations. Specific aims were to 1) compare quality of life (QOL), anxiety, and depressive symptoms between genders in implantable cardioverter defibrillator (ICD) recipients; 2) examine the association between multi-morbidity burden and QOL; 3) determine whether health literacy levels independently predict CVD risk in the male prison population; 4) examine the relationship between health literacy and decisiveness regarding end of life (EOL) choices, and 5) examine SDH as predictors of perceived poor health status in ICD recipients. Specific aim one was addressed by analysis of data collected from individuals in the Swedish ICD and Pacemaker Registry. Multiple linear regression was used to determine predictors of anxiety, depression, and quality of life in men and women. A higher prevalence of anxiety symptoms in women was noted with no differences in depressive symptoms noted between the genders. The majority of the variance in the predictive models for QOL was explained by the addition of the psychosocial variables for both genders. Specific aim two was addressed by analysis of data collected from individuals in the Swedish ICD and Pacemaker Registry. Logistic regression was used to determine predictors of QOL. Greater multi-morbidity burden was associated with lower QOL in ICD recipients. Specific aim three was addressed by analysis of data collected from male inmates enrolled in a bio-behavioral educational and counselling intervention program to reduce CVD risk. Nonlinear regression was used to determine whether health literacy was an independent predictor of CVD risk while controlling for social and clinical variables. Inmates with adequate levels of health literacy had lower ten year CVD risk profiles than those inmates with inadequate health literacy. Specific aim four was addressed by analysis of data collected from ICD recipients. Multinomial regression was used to determine predictors of decisiveness regarding EOL choices. Within the context of terminal illness, health literacy and race were found to be predictors of decisiveness regrading generator replacement while gender was found to be a predictor of decisiveness regarding the withdrawal of defibrillation therapy. Specific aim five was addressed by analysis of data collected from ICD recipients. Logistic regression was used to determine predictors of perceived poor health status. Residential status in the Central Appalachian region of Kentucky, not working outside the home, higher levels of health literacy, and comorbid depression were predictors of perceived poor/very poor health status.

The aim of this PhD thesis was to expand the current knowledge of “traditional Sami” diet and lifestyle, and to test aspects of the Sami diet and lifestyle, specifically dietary pattern, macronutrient distribution and coffee consumption, in population-based epidemiological studies of mortality and incident cardiovascular disease and cancer in a general population. In Paper I, semi-structured interviews were conducted with 20 elderly Sami concerning their parent’s lifestyle and diet 50-70 years ago. Questionnaire data from 397 Sami and 1842 matched non-Sami were also analyzed, using non-parametric tests and partial least square methodology.  In Papers II-IV, mortality data and incident cancer data for participants in the Västerbotten Intervention Program (VIP) cohort were used for calculations of hazard ratios by Cox regression. In Paper II, a Sami diet score (0-8 points) was constructed by adding one point for each intake above the median for red meat, fatty fish, total fat, berries and boiled coffee, and one point for each intake below the median for vegetables, bread and fibre. In Paper III, deciles of energy-adjusted carbohydrate (descending) and protein (ascending) intake were added to create a Low-Carbohydrate, High-Protein (LCHP) score (2-20 points). In Paper IV, filtered and boiled coffee consumption was studied in relation to incident cancer. In Paper V, a nested case-control study of filtered and boiled coffee consumption and acute myocardial infarction, risk estimates were calculated by conditional logistic regression. Surprisingly, fatty fish may have been more important than reindeer meat for the Sami of southern Lapland in the 1930’s to 1950’s, and it is still consumed more frequently by reindeer-herding Sami than other Sami and non-Sami. Other dietary characteristics of the Sami 50-70 years ago and present-day reindeer-herding Sami were high intakes of fat, blood, and boiled coffee, and low intakes of bread, fibre and cultivated vegetables (Paper I). Stronger adherence to a “traditional Sami” diet, i.e. a higher Sami diet score, was associated with a weak increase in all-cause mortality, particulary apparent in men (Paper II). A diet relatively low in carbohydrates and high in protein, i.e. a high LCHP score, did not predict all-cause mortality compared with low LCHP score, after accounting for saturated fat intake and established risk factors (Paper III).  Neither filtered nor boiled coffee consumption was associated with cancer for all cancer sites combined, or for prostate or colorectal cancer. For breast cancer, consumption of boiled coffee ≥4 versus <1 occasions/day was associated with a reduced risk. An increased risk of premenopausal and a reduced risk of postmenopausal breast cancer were found for both total and filtered coffee. Boiled coffee was positively associated with the risk of respiratory tract cancer, a finding limited to men (Paper IV). A positive association was found between consumption of filtered coffee and the risk of acute myocardial infarction in men (Paper V). In conclusion, the findings of Paper I, in particular the relative importance of fatty fish compared to reindeer meat in the “traditional Sami” diet of the 1930’s-1950’s, suggest that aspects of cultural importance may not always be of most objective importance. The findings of Papers II-V generally did not support health benefits for the factors studied. The relatively good health status of the Sami population is therefore probably not attributable to the studied aspects of the “traditional Sami” lifestyle, but further investigation of cohorts with more detailed information on dietary and lifestyle items relevant for “traditional Sami” culture is warranted. / Syftet med denna avhandling var att beskriva livsstil och kostvanor hos samer. Det var också att undersöka hur en ”traditionell samisk” livsstil påverkar risken att insjukna av eller dö i cancer och hjärt-/kärlsjukdom i en norrländsk normalbefolkning. En majorietsbefolkning har alltså undersökts ur ett minoritetsperspektiv. Avhandlingen belyser framför allt kostvanor, fördelning av de näringsämnen som innehåller energi (kolhydrat, protein, fett) och konsumtion av kok- och bryggkaffe. Bakgrunden till undersökningarna var att samerna, till skillnad från de flesta andra urfolk i världen, kan förvänta sig ett lika långt liv som majoritetsbefolkningen. När det gäller hjärtkärlsjukdom finns inga stora etniska skillnader, men samiska män, särskilt renskötande, har lägre risk att drabbas av cancer än icke-samer. Det finns ingen entydig förklaring till samernas relativt goda hälsa, men det kan finnas ett samband med kostvanor och livsstil. Delstudie I var en intervjustudie med äldre samer och fungerade som bakgrund för de andra delstudierna. Tjugo äldre samer intervjuades om sina föräldrars livsstil och kostvanor för 50-70 år sedan. Dessutom analyserades kostdata från 81 renskötande och 226 icke-renskötande samer och 1842 matchade icke-samer för att se vilka skillnader som fanns mellan grupperna. Intervjuerna visade överraskande att fet fisk kan ha varit viktigare än renkött för samerna i södra Lappland under 1930-1950-talen. Fet fisk äts fortfarande i högre utsträckning av renskötande samer än av andra samer och icke-samer. Saker som har hög kulturell betydelse (i detta fall renkött) behöver alltså inte alltid ha lika stor betydelse ur ett objektivt, vetenskapligt perspektiv. Andra typiska särdrag hos den samiska kosten var en hög andel av fett, blod och kokkaffe och en låg andel av bröd, fibrer och odlade grönsaker. Det dagliga livet hos samerna på 1930-1950-talen präglades också mycket mer av fysisk aktivitet än vad det gör idag. De samiska männen arbetade oftast långt hemifrån, medan kvinnorna hade ansvaret hemmavid för fiske, jordbruk och trädgårdsskötsel (som introducerades under 1930-1950-talen). Kvinnorna tog även hand om hushållsarbetet och barnen. Delstudierna II-V handlade om olika aspekter av samisk kost i relation till dödlighet och sjuklighet. Till dessa användes huvudsakligen data från Västerbottens hälsoundersökningar, men i delstudie V även från MONICA-projektet, som är en del av ett multinationell forskningsprojekt om hjärt-/kärlsjukdom.  Totalt ingick på så sätt data från mer än 80 000 unika individer från en allmän, till största delen icke-samisk, normalbefolkning. Delstudie II byggde på en modell liknande den som använts för att undersöka hälsoeffekter av så kallad Medelhavsdiet.  En poängskala från 0-8 poäng, en så kallad ”Sami diet score”, skapades för att spegla likheter med ”traditionell samisk” kost. Den hälft av deltagarna som åt mest rött kött, fet fisk, fett, bär respektive kokkaffe, fick 1 poäng var, sammanlagt maximalt 5 poäng. Den hälft av deltagarna som åt minst grönsaker, bröd respektive fibrer fick också 1 poäng var, sammanlagt maximalt 3 poäng. Stora likheter med en ”traditionell samisk” kost, det vill säga höga ”Sami diet score” poäng, var förknippade med en svagt ökad dödlighet, särskilt hos männen. Det verkar därför osannolikt att den samiska kosten i sig förklarar den relativt goda hälsan hos samer. Denna fråga är dock mycket svår att undersöka, eftersom kostvanorna kan ha skiljt sig mellan olika samegrupper och över tid. Dessutom äter dagens västerbottningar mycket mindre av vissa livsmedel, jämfört med vad samerna gjorde förr i tiden. Det gäller till exempel fet fisk och bär.  För sådana livsmedel kan det därför vara extra svårt att påvisa samband med dödlighet. Syftet med kostenkäten i Västerbottens hälsoundersökningar är inte heller att spegla en ”traditionell samisk” kost. Det finns till exempel inga frågor om renkött och vilt, utan sådant kött räknas som en del av övrigt rött kött. Det här är första gången som någon undersökt betydelsen av ett ”traditionellt samiskt” kostmönster för hälsan på detta sätt. Fler liknande undersökningar i material med mer detaljerade frågor, som bättre fångar en samisk kost, är önskvärda. Lågkolhydratdieter, som har vissa likheter med den ”traditionella samiska” kosten, är både populära och kontroversiella. Eventuella långtidseffekter för hälsan är till stor del okända. I delstudie III speglades förhållandet mellan kolhydrater och protein i kosten med hjälp av så kallade LCHP (låg-kolhydrat, hög-protein) poäng. Högsta LCHP poäng fick de deltagare som åt minst kolhydrater och mest protein. Höga LCHP poäng påverkade inte risken att dö, eller att dö i cancer eller hjärt-/kärlsjukdom, efter att statistisk hänsyn tagits till intaget av mättat fett och de vanligaste riskfaktorerna. LCHP score användes i denna studie, istället för exempelvis en LCHF (low carbohydrate, high fat) variant. På så sätt kunde betydelsen av total fettmängd och av mättat fett också vägas in i analyserna. Dessutom innehåller kolhydrater och protein samma mängd energi per gram, vilket gör det lättare att byta ut dem mot varandra i en poängskala. Fett innehåller nästan dubbelt så mycket energi per gram som proteiner och kolhydrater. Inte bara olika sorters fett, utan även olika sorters protein och kolhydrater, kan spela roll för hälsan. Det är därför mycket svårt att skilja ut effekterna av mängd och kvalitet av kolhydrater, protein och fett i kosten. I delstudierna IV och V undersöktes risken att bli sjuk i cancer eller få en akut hjärtinfarkt hos västerbottningar som dricker mer respektive mindre kok- och bryggkaffe. De som drack mycket kaffe hade varken ökad generell cancerrisk, eller ökad risk för prostata- eller tjocktarmscancer. Kvinnor som drack kokkaffe ≥ 4 ggr/dag hade minskad risk för bröstcancer jämfört med kvinnor som drack <1 gång/dag.  Både totalt kaffeintag och intag av bryggkaffe var kopplade till ökad risk för bröstcancer hos yngre kvinnor och minskad risk hos äldre. Män som drack mycket kokkaffe hade ökad risk för cancer i luftvägarna. Dessa resultat visar att de som dricker olika sorters kaffe kan ha olika stor risk att drabbas av olika sorters cancer. I tidigare studier har inga starka samband hittats mellan kaffedrickande och cancer. Denna studie var den första att undersöka hur cancerriskerna ser ut hos människor som dricker olika sorters kaffe. När det gäller hjärtinfarkt, hade män som drack mycket bryggkaffe ökad risk, medan inga entydiga resultat kunde visas bland män som drack mycket kokkaffe. Tidigare studier har visat motstridiga resultat när det gäller kaffe och hjärt-/kärlsjukdom, även om kaffekonsumtion är vedertaget förknippat med en del faktorer som kan öka risken att drabbas av hjärtinfarkt, till exempel ökade halter av blodfetter. Betydelsen av kokkaffe har aldrig undersökts tidigare i en studie där uppgifter om kaffedrickande samlats in i förväg. Delstudierna II-V är alla så kallade observationsstudier. I sådana studier följer deltagarna ingen bestämd forskningsplan, utan lever sina normala liv och jämförs sedan med varandra.  I observationsstudier är det mycket svårt att ta hänsyn till alla möjliga störande faktorer som kan finnas i omgivningen. Därför är det i princip omöjligt att bevisa direkta samband mellan orsak och verkan i en observationsstudie. Delstudierna II-V hade emellertid den starkaste design som en observationsstudie kan ha. De byggde på en representativ normalbefolkning (= en befolkningsbaserad kohort), där data samlats in från ett stort antal personer (> 80 000 unika individer) medan de ännu var friska (= en prospektiv kohort).  Resultaten av enstaka observationsstudier har störst betydelse som underlag för att planera nya liknande, eller andra typer av mer riktade undersökningar. De är med andra ord hypotesgrundande. Om däremot flera observationsstudier visar på liknande resultat brukar man utgå från att resultaten är sanna, eller åtminstone sannolika. / (Nordsamiska) Guorahallama ulbmil lea muitalit sámi biepmu ja eallinvuogi birra ja iskat got árbevirolaš sámi borranvierut, makrobiebmama juogustus ja gáffegolaheapmi  váikkuhit jámolašvuođa  ja riskka oažžut borasdávdda dehe váibmo-/ suotnadávdda dábálaš davvi-ruoŧŧelaš ássiid luhtte. Guoktelogi sámi vuorrasa ledje jearahallon daid vánhemiid eallinvuogi  ja borramuša birra 50-70 jagi áigi (Oassedutkan 1). Dasa lassin  397 sámi ja 1842 ruoŧŧelačča biebmandata guorahallojuvvo eahpe-paramehtarlaš iskamiid ja partialalaš unnimus kvadráhta metoda (PLS) mielde. Dát golbma čuovvovaš oassedutkama, gait kohortdutkamat, isket jápminsiva dehe borasdávdabuohccivuođa oaseváldiid luhtte  Västerbottenis dearvas-vuohŧaiskkademiid hárrái (64 603-77 319 iskama) ja riskkaluoitimat leat rehkenaston Cox regrešuvnna  mielde. Oassedutkamis  2  árbevirolaš sámi biebman  lea speadjalaston čuokkesskála vuostá   0 rájes gitta 8 čuoggá.  Dát bealli oaseváldiin geat leat eanemus rukses bierggu, buoiddes guoli, buoiddi, murjiid ja vuoššangáfe borran, lea ožžon 1 čuoggá juohke áidna biebmanelemeanta ovddas, oktiibuot eanemus 5 čuoggá. Vel 3 čuoggá dát bealli oaseváldiin lea ožžon geat lea unnimus šattuid, láibbi ja fiberiid borran, eanemus oktiibuot 3 čuoggá. Oassedutkamis 3 speadjalastá oktavuođa kolhydráhtaid ja proteiinnaid gaskkas  biebmamis  LCHP (vuolit-kolhydráhta, alit-proteiidna) čuoggáid bokte. Alimus LHCP čuoggát (=20) dát oasseváldit leat ožžon geat leat borran unnimus kolhydráhtaid ja eanemus proteiinnaid  ja vuolimus čuoggát (=2)  dát oasseváldit leat ožžon geat leat borran eanemus kolhydráhtaid ja unnimus proteiinnaid. Oassedutkamis 4 riska borasdávdabuohccivuođa ektui guorahallojuvvo brygg- ja vuoššangáffejuhkkiid  luhtte. Oassedutkan 5 lei goallostuvvon dárkkástus-dutkan, gos riska fáhkkatlaš healladávdda oažžut gáffejuhkkiid luhtte rehkenasto logistihkalaš eaktuduvvon regrešuvnna bokte. Sáhttá leahkit nu ahte buoiddes guolli lea rievtti mielde leamašan deaŧaleabbo sámiide go boazobiergu lulli Lapplánddas  1930-1950-logus ja badjeolbmot ain dávjábut borret dan go iežá sámiid ja ruoŧŧelaččat. Iežá sierra erenomášvuohta sámi biebmamis lei alit oassi buoiddis, mális ja vuoššangáfes ja vuolit oassi láibbis, fiberiin ja šaddaduvvon  šattuin (Oassedutkan 1). Stuora seammaláganvuođat árbevirolaš sámi biebmamiin, rievtti mielde alit Sami diet score čuoggát, ledje čatnon veahá aliduvvon jámolašvuhtii  dievdduid luhtte muhto ii fal nissoniid luhtte (Oassedutkan 2). Biebman mas vuolit oassi kolhydráhtaid ja alit oassi proteiinnat, rievtti mielde alit LHCP čuoggát, ii váikkuhan riskka jápmit, maŋŋel go lea statistihkalaččat jurddašan ahte buoiddi borrat ja mat dát leat dát sajáiduvvon riskafáktorat (Oassedutkan 3). Gáffejuhkan ii lean čatnon eaneduvvon borasdávdariskii, iige eaneduvvon riskii oažžut prostata- gassačoalleborasdávdda. Nissoniin mat juhke vuoššangáfe ≥ 4 geardde/beaivái lei geahpeduvvon riska oažžut čižžeborasdávdda go nissonat mat juhke <1 geardde/beaivái.  Ollesgáffe ja brygg-gáffe ledje čatnon eaneduvvon riskii oažžut čižžeborasdávddá nuorat nissoniid luhtte ja geahpeduvvon riskii vuorrasiin luhtte. Dievdduin mat juhke ollu vuoššangáfe lei eaneduvvon riska oažžut borasdávdda (Oassedutkan 4). Dievdduin mat juhke olu brygg-gáfe lei eaneduvvon riska oažžut healladávdda (Oassedutkan 5). Vuorrasit sámiid muitalusat man olu guoli sin vánhemat leat borran boazobierggu ektui 1930-1950-logus, čujuhit ahte bealit main alit kultuvrralaš mearkkašupmi eai dárbbaš seamma nanu objektivalš mearkkašumi atnit. Oassedutkamiid 2-5 bohtosat čujuhit ahte guorahallon bealit árbevirolaš sámi biebmamis ja eallinvuogis eai váikkut gárrasit dearvvašvuođa ja buohccivuođa dábálaš davviruoŧŧelaš ássiid luhtte. / (Lulesamiska) Dán guoradallama ájggom lij sáme biebmov ja viessomvuogev tsuojgodit, ja åtsådit gåk árbbedábak sáme bårråmdábe, stuoräládusebna juohkem ja káffajuhkam nuorttalándak álmmugin, bájnná jábmemav ja bårredávddabalov ja tsåhke-/ varravárredávddabalov. Guoktalågev sáme gatjádaláduvvin sijá äjgádij viessomvuoge ja biebmo birra 50-70 jage dán åvddåla (Oasseåtsålvis 1). Biebbmodáhtá 397 sámes ja 1842 láttes guoradaláduvvin parametragahtes gähttjalimij ja muhtem miere unnemus kvadráhta vuoge (PLS) viehkijn. Gålmmå tjuovvo oasseåtsådime, gájkka kohorttaåtsådime, vuolggin Västerbottena varresvuohtaåtsådimj oassálasstij jábmemårijs jali bårredávddaskihpudagájs (64 603-77 319). Ballamoarremerustallamav dahkin Cox regressionijn.  Oasseåtsådibme 2 spiedjildij avtaárvojt árbbedábak sáme biebmon tjuokkesmåhtajn nållå rájes gávtse tjuoggáj. Dat lahkke oassálasstijs gudi bårrin ienemus ruoppsis biergov, buojdes guolev, buojdev, muorjijt ja máleskáfav, oattjoj avtav tjuoggáv juohkka avta bårråmoases, aktan 5 tjuoggá ienemusát.  Ájn 3 tjuoggá oattjoj dat lahkke oassálasstijs mij båråj binnemus ruonudisájt, lájbijt ja fiberijt, aktan ienemusát 3 tjuoggá. Oasseåtsådibme 3 spiedjilt vidjurijt kolhydráhtaj ja proteijnaj gaskan biebmon nåv gåhtjodum LCHP (vuolle-kolhydráhta, alla-proteijna) tjuoggáj viehkijn.  Alemus LCHP tjuoggájt (=20) oadtjun oassálasste gudi binnemus kolhydráhtajt ja ienemus proteinajt bårrin ja vuolemus LCHP tjuoggájt (=2) oassálasste gudi ienemus kolhydráhtajt ja binnemus proteijnajt bårrin.  Oasseåtsådimen 4 åtsådaláduváj bårredávddaballo brygga- ja máleskáffajuhkkijn. Oasseåtsådibme 5 lij aktijdum guoradim-åtsådibme, gånnå káffajuhkkij tsåhkedávddaballo merustaláduváj aktijdam vihkemáhtsadime baktu. Vuordedahtek lij buojdes guolle ájnnasabbo gå boatsojbierggo sámijda oarjje Lapplándan 1930-1950-lågojn ja ájn vilá ällosáme guolev ienebut bårri gå ietjá sáme ja látte. Ietjá sierra merka sáme biebmon lij alep oasse buojdes, máles ja máleskáfas ja unnep oasse lájbes, fiberis ja sáddjidum ruonudisájs (Oasseåtsådibme 1). Árbbedábak sáme biebmo muoduk biebbmo, alep Sami diet score tjuoggáj, aktijaneduváj lasse jábmemijn sierraláhkáj ålmmåj hárráj (Oasseåtsådibme 2). Biebbmo vuolep kolhydráhttaåsijn ja alep proteijnnaåsijn, alla LCHP tjuoggáj, ittjij jábmembalov bájne, maŋŋel gå statistijkalattjat gehtjadam buojddebårråmijt ja ieme ballovidjurijt (Oasseåtsådibme 3).  Káffajuhkam lij tjanádum juogu de lasse gájkkásasj bårredávddaballuj, jali lasse prostáhta- bahtatjoallebårredávddaj. Kujnajn gudi máleskáfav juhkin ≥ niellji bäjvváj lij binnep njidtjebårredávddaballo gå buohtastahttá kujnaj gudi < akti bäjvváj juhkin. Ålleskáffa ja bryggakáffa tjanáduváj lasse njidtjebårredávddaballuj nuorap kujnaj hárráj ja binnep vuorrasappoj. Ålmmåjn gudi juhkin edna máleskáfav lij lasse bårredávddaballo vuojŋŋamorgánajn (Oasseåtsådibme 4). Ålmmåjn gudi juhkin edna bryggakáfav lij lasse tsåhkedávddaballo (Oasseåtsådibme 5). Vuorrasap sámij tsuojggoma äjgádij guollebårråmis gå buohtastahttá boatsojbierggobårråmijn 1930-1950-lågo, vuosedi biele alla kultuvrak sisanos e agev dárbaha sämmi nanos objektijvak sisanov adnet. Oasseåtsådimij 2-5 båhtusa vuosedi åtsådum biele árbbedábak sámebiebmos ja viessomvuoges e varresvuodav ja skihpudagáv nuorttalándak álmmuga hárráj heva bájne. / (Sydsamiska) Dan goerehtimmien ulmie lea saemien beapmoem jïh jielemevuekiem buerkiestidh jïh dotkedh guktie aerpievuekien saemien beapmoevuekieh, makrobïepmehtimmiej juekeme jïh prïhtjhjovhkeme jaemedem jïh riskem dijpieh vaajmoe-/ jïh soeneskïemtjelassen muhteste noerhtesvöörjen sïejhmi årroji luvnie. Lea göökteluhkie saemien voeresh goerehtamme daej eejtegi jielemevuekien jïh beapmoen dïehre  50-70 jaepiej juassah (Stuhtjedotkeme 1). Dïsse lissine lea beapmoedaatam goerehtamme 397 saemijste jïh 1842 laedtijste ov-parametrihken gïehtjedimmiej jïh partiellen unnemes kvadraaten vuekien mietie (PLS).  Dah golme båetien stuhtjedotkemh, gaajhkh kohortdotkemh, leah dotkeme man gaavhtan jaameme jallh mïetskeåedtjieskïemtjelassh daej luvnie gïeh meatan Västerbottenen healsoedotkemi muhteste (64 603-77 319 dotkemh) jïh riskeryøknemh  dorjeme Cox  regresjovnen viehkine. Stuhtjedotkemisnie 2 lea mohtedamme guktie aerpievuekien saemien beapmoe vaestede låhkoeraajterasse 0 raejeste 8 raajan. Daate bielie daejstie gïeh meatan gïeh jeenemes rööpses bearkoem, buajtehks gueliem, buejtiem, muerjieh jïh voessjemeprïhtjegem byöpmedamme, leah aktem låhkoem åådtjeme fïere guhte beapmoeelementen åvteste, jeenemes 5 låhkoeh. Dïsse lissine 3 låhkoeh åådtje daate bielie daejstie gïeh meatan gïeh unnemes kruanesaath, laejpiem jïh fiberh byöpmedamme, jeenemes 3 låhkoeh. Stuhtjedotkemisnie 3 daelie mohtede kolhydraath jïh proteinh beapmosne LHCP (vuelehks-kolhydraath, jïlle-proteine) låhkoej viehkine. Jillemes LHCP låhkoem åådtjeme (=20) dah gïeh meatan gïeh vaenemes kolhydraath jïh jeenemes proteinh byöpmedamme jïh vueliehkommes LHCP låhkoem (=2) åådtjeme dah gïeh meatan gïeh jeenemes kolhydraath jïh vaenemes proteinh byöpmedamme. Stuhtjedotkemisnie 4 riskem goerehtamme mietskeåedtjieskïemtjelassem åadtjodh brygg- jïh voessjemeprïhtjegejovhkiji luvnie. Stuhjtedotkeme 5 lïj tjetskeme-dotkeme gusnie riskem ryöknoe logistihken regresjovnen baaktoe jis maahta  faahketji vaajmoedåeriesmoerh åadtjodh prïhtjhjovhkiji luvnie. Buajtehks guelie meehti vihkielåbpoe årrodh båatsoesaemide goh bovtsebearkoe åarjel Lapplaantesne 1930-1950-låhkosne jïh daamhtah båatsoesaemieh daam byöpmedieh jeenebe goh jeatjah saemieh jïh laedtieh. Jeatjah sïejhmi sjïere vuekieh saemien beapmosne lea jïlle stuhtje buejteste,  maeleste jïh voessjemeprïhtjegistie jïh vuelie stuhtje laejpeste, fiberistie jïh kruanesaatijste (Stuhtjedotkeme 1). Jeenh saemien aerpievuekien beapmoe, jïlle Sami diet score låhkoeh, provhki vuesiehtidh vaenie jeananamme jaemede ålmaj gaskemsh bene ij nyjsenæjjaj gaskemsh (Stuhtjedotkeme 2). Beapmoe man vuelehks stuhtje kolhydraath jïh stoerre stuhtje proteijnh, jeenh LCHP låhkoeh, ij leah dïjpeme riskem jaemedh, dan mænggan goh lea ussjedamme statistihken muhteste man jeene buejtiem byöpmedidh jïh sijjiedahteme riskefaktovrh ussjedamme. (Stuhtjedotkeme 3). Prïhtjhjovhkeme ij leah tjoelmesovveme jeananamme mïetskeåedtjieriskese, jallh jeananamme riskese prostaate-voeresbuejtiemïetskeåedtjiem åadtjodh. Nyjsenæjjah gïeh voessjemeprïhtjegem jovhkeme ≥ 4 aejkien/biejjesne unnemes riskem utnin njammamïetskeåedtjiem åadtjodh nyjsenæjjaj muhteste gïeh jovhkeme <1 aejkien/biejjesne. Ellies prïhtjege jïh bryggeprïhtjege lea tjoelmesovveme jeananamme riskese njammamïestkeåedtjiem åadtjodh noere nyjsenæjjah luvnie jïh unniedamme riskem voeresi luvnie. Ålmah gïeh jeenh voessjemeprïhtjegem juvhkieh jeananamme riskem utnieh mïetskeåedtjiem åadtjodh girsesne (Stuhtjedotkeme 4). Ålmah gïeh jeenh bryggeprïhtjegem jovhkeme jeananamme riskem utnieh vaajmoedåeriesmoerem åadjtodh (Stuhtjedotkeme 5). Dah saemien voeresi soptsestimmieh man jeeneh gueliem daej eejtegh leah byöpmedamme bovtsebearkoem muhteste 1930-1950-låhkosne, vuesehte ahte daate bielie man vihkeles kultuvren sisvege ij eejnegen seamma objektiven sisvegem utnieh. Illeldahkh stuhtjedotkemijstie 2-5 vuesiehtieh ahte  dah bielieh mejtie lea goerehtamme saemien aerpienvuekien beapmoen jïh jielemevuekien muhteste eah healsoem jïh skïemtjelassem dïjph jeenebe goh sïejme noerhtesvöörjen årrojh. / (Umesamiska) Dahte guoreteme suptseste saamien beäpmoen jah jielemevuökien  biire jah giehtjedie guktie aarpievuökien saamien beäpmoeh, oajviebeäpmoeh jah kaavoeh mietete jaameke vahkake jah  cancerenne jah vajmoen/ virreveättennea nuorthen  allmetjeih luunie. Guökteluhke saamieih boariesh gihtjedihke lie elltie eihtegeh jielemevuökien jah beäpmoen biire dann baelie 50-70 jaapieh (Oasie 1). Jieneh beäpmoe-dataede dahkedihke lie 397 saamieiheste jah 1842 ruotseiheste dennake viehketihenne ieh parmetriske giehtjedemeh jah  partiellen unnemes kvadraten vuökien miete (PLS). Dah gullme oasieh boatien kohort- luhkemeh, allkemme lie jaamemeste jall canceremeste mieteih Västerbottenen varaasgiehtjemeih luunie (64603-77319 ollu) vahkake-tsiehkesjeme dahkedihke Cox-enne regressione. Oasienne 2 vuöjnedihke leh akte laakatjenne aarpievuökien saamien beäpmoeh vuösstede akte tsiehkesjerairoe 0 – 8. Dahte bielie deistie gieh jienemes ruöpses beärrkoede, buöjteks guöliede, buöjtiede borrein jah vuossjeme kaavoede juukein, akte tsiehkie fierte beäpmoih outeste otjoin, jienemes 5 tsiehkieh.Vielie 3 tsiehkieh dahte bielie otjoin gieh unnemes jaamoede jah urhtsede, laipiede jah fiberede borrein, jienemes 3 tsiehkeh. Oasienne 3 vuöjnedihke aktevuotta gasske kolhydrateh jah proteieneh beäpmoenne LCHP-esne (vuöleke kolhydrateh, jylloeke-proteineh) tsiehkie. Jyllemes LCHP tsiehkieh (=20) dainie mietenne unnemes kolhydrateh jah ollomes proteineh borrein jah unnemes LCHP tsiehkieh (2) dainie mietenne ollomes kolhydrateh jah unnemes proteineh borrein. Oasienne 4 giehtjedihke vahkake cancerede brygg- jah vuossjeme kaavoe juukejenne. Oasie 5 tjohkenne lin kontrolle- giehtjedeme vahkake hiehke vaajmoe-narrenne kaavoe-juukejenne tsiehkiesjdihke logistiske regressionenne. Buöjteke guölieh borretdihke mahtein vieliebe buutsebeärrkoeste saamieihesne oarrjel  saamien eätname 1930-1950 jaapienne jah vieliebe borretdihke buutsesaamieiheste guh jeätja saamieh jah ruotse-allmetjeh. Jeätja siejhme sierreme saamien beäpmoesne lin akte jylloeke oasie buöjtie-, viire-, jah vuossjeme kaavoeste jah akte vuöleke oasie laipie-, fibere-, joamoe jah urhtseste (Oasie 1). Ollu aktelaaka aarpievuökien saamien beäpmoeh, ollu Sami diet score tsiehkieh tjohkan lin vieliebe jaameme ollmaihenne sierrelaaka (oasie 2). Beäpmoihenne unne kolhydrateh jah ollu proteineh, ollu LCHP tsiehkie, ieh vahkake lasste jaamet, dann mingjelen guh statistiske ussjede valltedihke leh borremmiean gallane buöjtieste jah vihties vahkake faktoreiheste (oasie 3). Kaavoejuukeminne lin ieh vielebe aarpievuökien cancer-vahkake tjohkenne, jall vielebe vahkake prostate-kolorektale-cancere. Nyesenejah guh vuossjeme kaavoe juukein ≥4  aikieh/biejvie  unnebe vahkake nitje-cancereb lin muhteste nyesenejanneh gieh  <1 aikie/biejvie juukein. Gaihkekaavoe jah brygg-kaavoe lie tjoahkan vielebe nitje cancereb nyesenejanne jah unnebe vahkake boariesh nyesenejaihenne. Ollma guh ollu vuossjeme kaavoeb juukein cancereste gonkelmesenne vieliebe vahkake otjoin (oasie 4). Ollma guh ollu brygg-kaavoe vajmoe-narreme vieleb vahkake otjoin (oasie 5). Dah boariesh saamieh suptsestemeh man jingje guöliede elltie eihtegeh buutsebeärrkoeh borrein 1930-1950-aikie, vuösiete dahte bielie veäksekes kulture miele ieh gaihke aikie darpesjedennake veäksekes objektive miele leh. Oasie 2-5 vuösiete dah giehtjedemes dahte bielie aarpievuökien saamien beäpmoen jah jielemen vuökien ieh varaas jah skieptjeme mietete ieh nuorthen almetejeh ollu.

Background Low aerobic fitness and obesity are associated with atherosclerosis, and thereforegreatly increase the risk of cardiovascular disease (CVD) and early death. It has long been known that atherosclerosis my begin early in life. Despite this fact, it remains unknown how obesity and aerobic fitness early in life influence the risks of atherosclerosis, CVD and death. Furthermore, it is unknown whether high aerobic fitness can compensate for the risks associated with obesity, and how genetic confounding affects the relationshipsof aerobic fitness with CVD and all-cause mortality. Thus, the main aims of this thesis were to investigate the associations of aerobic fitness in late adolescence with myocardial infarction (Study I), stroke (Study II) and all-cause mortality (Study III), and how genetic confounding influences the relationshipsof aerobic fitness with CVD, diabetes and death (Study IV). Methods The study population comprised up to1.3 million men who participated in mandatory Swedish military conscription. During conscription, all conscripts underwent highly standardized tests to assess aerobic fitness, body mass index, blood pressure and cognitive function. A physician also examined all conscripts. Data on subjects’ diagnoses, death and socioeconomic status during follow-up were retrieved using record linkage. Subjects were subsequently followed until the study endpoint, date of death or date of any outcome of interest. Associations between baseline variables and the risks of adverse outcomes were assessed using Cox’s proportional hazard models. Genetic confounding of the relationships between aerobic fitness and diabetes, CVD and death was assessed using a twin population and a paired logistic regression model. Results In Study I, low aerobic fitness at conscription was associated with an increased risk of myocardial infarction (MI) during follow-up (hazard ratio [HR] 0.82 per standard deviation increase). Similarly, in Study II, high aerobic fitness reduced the risk of stroke (HR 0.84 for ischemic stroke, HR 0.82 for hemorrhagic stroke; P < 0.001 for all), and obesity was associated with an increased risk of stroke (HR 1.15 for ischemic stroke, HR 1.18 for hemorrhagic stroke; P < 0.001 for all). In Study III, high aerobic fitness was also associated with reduced all-cause mortality later in life (HR 0.49, P < 0.001). High aerobic fitness exerted the strongest protection against death from substance and alcohol abuse, suicide and trauma (HRs 0.20, 0.41 and 0.52, respectively; P < 0.001 for all). Obese individuals with aerobic fitness were at higher risk of MI and all-cause mortality than were normal-weight individuals with low fitness (Studies I and III). In Study IV, fit twins had no reduced risk of CVD or death during follow-up compared with their unfit twin siblings (odds ratio 1.11, 95% confidence interval 0.88–1.40), regardless of how large the difference in fitness was. However, the fitter twins were protected against diabetes during follow-up. Conclusions Already early in life, aerobic fitness is a strong predictor of CVD and all-cause mortality later in life. In contrast to the “fat but fit” hypothesis, it seems that high aerobic fitness cannot fully compensate for the risks associated with obesity. The associationsof aerobic fitness with CVD and all-cause mortality appear to be mediated by genetic factors. Together, these findings have implications for the view of aerobic fitness as a causal risk factor for CVD and early death.

Cardiovascular risk scores predict an individual’s risk of developing cardiovascular disease. Many were developed and validated in study cohorts on risk-factor lowering treatment – a cause of inaccuracy. In addition, risk scores are criticised as being biased towards the elderly due to the prominence of age as a risk predictor. Although present guidelines advocate the use of short-term (5-10 year) absolute risk scores, other approaches to redress this perceived imbalance such as lifetime risk scores are being considered. The overall objective of this thesis is to identify the most appropriate cardiovascular risk score for use in general practice, taking account of the impact of treatment and time on assessed risk. This objective was met by three different methods. First, a systematic review of cardiovascular risk scores was conducted. This explored the derivation of each score, including the extent of treatment. Next, doctors were interviewed in depth to understand their perception and use of risk scores. Finally, mathematical models were devised to determine whether a true difference in life expectancy exists at different ages but the same short-term cardiovascular risk. The models incorporated age-specific case fatality rates, competing risks and time preference to estimate the potential years of life lost due to a five-year treatment delay in different age groups with the same short-term coronary heart disease risk. The findings demonstrate that cardiovascular risk scores do not take account of treatment effects. This significantly affects their application in clinical practice. In addition, there is little difference in potential life years lost between ages at the same risk level because of higher case-fatalities in older people. When time preference is considered, any residual case for treating the same level of short-term risk differently at different ages is abolished. The overall conclusion is that the five to ten-year absolute cardiovascular risk score is the most appropriate approach to primary cardiovascular disease prevention. By overestimating risk in the young, other approaches benefit the few at the expense of the many.

Radiotherapy has been shown to increase the subsequent risk of heart disease among survivors of breast cancer, but little is known about factors, other than the dose of radiation delivered to the heart, which determine the magnitude of the risk. In addition, survivors of teenage and young adult cancer are internationally acknowledged as an understudied population, and limited information is available on their late health risks. This thesis sought to utilise the largest observational datasets available to date for these populations: the Collaborative Group on Observational Studies of Breast Cancer Survivors and the Teenage and Young Adult Cancer Survivor Study. These were used to firstly characterise the radiation-related risks of heart disease and lung cancer, and secondly to provide an overview of the long-term risk of heart disease for the entire spectrum of cancers diagnosed in teenagers and young adults aged 15 to 39. Initially, a methodology study and systematic review demonstrated that selection effects and other biases can be very problematic during analyses of observational cohorts, particularly when using a radiotherapy comparison. However, in the case of heart disease and lung cancer, one can take advantage of the breast being a paired organ and use a laterality comparison, particularly when laterality played little effect in treatment selection. This comparison was used throughout the analyses of breast cancer patients. This thesis demonstrated that adjuvant radiotherapy for breast cancer significantly increased the risk of heart disease among women with left-sided breast cancer and those patients with ipsilateral lung cancer. Interestingly, younger women were at the highest risk of heart disease, and a progressive proportional decrease in risk with increasing age at diagnosis was found, which has not been shown before. It also suggested that radiotherapy and chemotherapy combined may further increase the risk of heart disease among breast cancer patients. Survivors of teenage and young adult cancer, particularly Hodgkin lymphoma, were at a significantly raised cardiac mortality risk compared to the matched general population. The findings of this thesis provide evidence to support continued follow-up for cancer patients, as survivors were found to be at a substantial risk into the second or third decade after treatment. It has permitted the detection of groups of individuals at particularly increased risks, for example younger patients and survivors of Hodgkin lymphoma diagnosed in teenagers and young adults, for whom closer monitoring for late effects or measures to reduce the risk, such as adaptations to treatment, may be appropriate. Finally, evidence was also presented to support the development of clinical follow-up guidelines specifically for survivors of teenage and young adult cancer.

Modulation of cardiac rate and contraction through calcium-dependent and independent means are of central import to the ability of an organism to adapt to its environment. Nicotinic acid adenine dinucleotide phosphate (NAADP) is a potent calcium-releasing second messenger across a broad range of tissues and organisms. In cardiac myocytes, NAADP is thought to stimulate calcium release from acidic stores which then bolsters filling and release during CICR. Questions remain: as to the potential need for amplification to generate the size of responses observed and the physiological role of the NAADP pathway. In contractile myocytes, photorelease of NAADP caused significant increase in calcium transient amplitude and velocity of transient upstroke and decay. Effects were absent during NAADP photorelease in the presence of Ned-19 or CaMKII inhibitors. Cellular calcium transient responses to β-adrenergic stimulation were significantly reduced in the presence of inhibitors of the NAADP pathway. These data support the hypothesis that NAADP-induced calcium release is relevant during adrenergic stimulation and requires amplification through CaMKII. Rate modulation at the sino-atrial node can occur through the hyperpolarisation-activated current I_(f). Basal cardiac rate is a major determinant in cardiac mortality and compounds which specifically affect rate have clinical utility. A compound currently used to treat inflammatory conditions was found to have a significant rate-reducing effect in sino-atrial node preparations mediated by inhibition of I_(f). Apelin, an endogenous peptide, has been reported to potently generate improved contractility without development of hypertrophy. Study of its effects in single cells have provided conflicting information, at least in part because of the difficulty in working with the compound. A method for the consistent observation of apelin-mediated contractile responses is presented, focusing on the timecourse of cell contraction. These observations suggest a role for apelin in both inotropy and lusitropy and will enable further research.

Cardiac stem cells (CSCs), isolated from heart tissue explants and expanded via the formation of cardiospheres (Csp), are a promising candidate for cell therapy to prevent heart failure following myocardial infarction. To allow early administration to patients, isolation and expansion of CSCs must be performed in the shortest time possible. Hence, this project aimed to optimize culture conditions and characterize the cardiac explant-derived cells (EDCs), Csp and Csp-derived cells (CDCs) produced. Rat neonatal EDCs contained 4-7% c-kit⁺ cells, measured using flow cytometry. Optimal Csp growth conditions were determined, such that plating 3 x 10^4 EDCs per well of a 24-well plate coated with 16.7 µg/ml poly-D-lysine, in CGM containing 7% serum, improved Csp production and generated 1.5 x 10^7 CDCs in 16 days, a sufficient number for cell therapy. The CDCs expressed the stemness markers; c-kit, Oct3/4, SOX2, and Klf-4, and the cardiac differentiation markers; GATA4 and Nkx2.5. The therapeutic effect of CDCs may be limited by the low, 3 ± 0.1%, c-kit⁺ cell numbers. To increase c-kit⁺ cells in CDCs, an alternate culture method for Csp and different extracellular matrices (ECM) for cell expansion were tested. The hanging drop culture method produced Csp with higher levels of c-kit⁺ cells (9 ± 2%) than poly-D-lysine-coated and low-bind culture dishes. Of five ECM tested, collagen IV was found to enhance EDC migration and CDC proliferation, and produced 11 ± 0.4% c-kit⁺ cells, with Csp cultured in hanging drops. Intramyocardial injection of CDCs improved left ventricular ejection fractions of infarcted rat hearts by 9% and prevented the peri-infarct wall from thinning, measured in vivo using MRI over 16 weeks. To improve cell tracking using MRI, two MR positive contrast agents, gadolinium-DTPA and gadonanotubes were tested. Gd-DTPA had low sensitivity after labelling (1.4 x 10^5 cells/mm2); whereas gadonanotubes did not provide positive contrast at 11.7 T. Thus, neither contrast agent could be used for cell tracking using high magnetic field. In conclusion, CDCs were an effective source of stem cells that could be used for heart repair, although cells could not be tracked using positive MR contrast.

Myocardial and skeletal muscle high energy phosphate metabolism is abnormal in heart failure, but the pathophysiology is not understood. Plasma non-esterified fatty acids (NEFA) increase in heart failure due to increased sympathetic drive, and regulate the transcription of mitochondrial uncoupling protein-3 (UCP3), through peroxisome proliferator-activated receptor-α. The aim of the work in this thesis was to determine whether cardiac PCr/ATP ratios and skeletal muscle PCr kinetics during exercise were related to cardiac and skeletal muscle UCP3 levels respectively, thus providing a mechanism for the apparent mitochondrial dysfunction observed in heart failure. Patients having cardiac surgery underwent pre-operative testing, including cardiac and gastrocnemius 31P magnetic resonance spectroscopy. Intra-operatively, ventricular, atrial and skeletal muscle biopsies were taken for measurement of mitochondrial protein levels by immunoblotting, along with mitochondrial function by tissue respiration rates. Fasting plasma NEFA concentrations increased in patients with ventricular dysfunction and with New York Heart Association (NYHA) class. Ventricular UCP3 levels increased and cardiac PCr/ATP decreased with NYHA class, however, demonstrated no relationship to each other. In skeletal muscle, maximal rates of oxidative ATP synthesis (Qmax) related to functional capacity. Skeletal muscle UCP3 levels increased with NYHA class but were unrelated to skeletal muscle Qmax. Tissue respiration experiments revealed no relationship between ventricular function and indices of mitochondrial coupling, furthermore, indices of mitochondrial coupling were unrelated to tissue UCP3 levels. No evidence was found to support mitochondrial uncoupling, mediated through UCP3, as a cause of the abnormalities in cardiac and skeletal muscle high energy phosphate metabolism.

Stroke is a major cause of premature death and disability throughout the world and atrial fibrillation (AF) is one of the most common preventable causes of stroke. AF affects about 10% of individuals aged ≥80 years, but warfarin is substantially under-used in this age group despite being effective in preventing AF-related thromboembolic events. AF-related ischaemic strokes tend to be severe and incur high care costs, and non-cerebral systemic embolism secondary to AF is also a major clinical burden. Despite that, there are few population-based studies on AF-related ischaemic stroke, and no recent study of the burden of AF-related thromboembolism and the population impact of under-treatment. I have used data from the Oxford Vascular Study (OXVASC), a prospective, population-based incidence study of vascular disease in all territories, which was started in April 2002 and is on-going. The study population comprises of 92,728 individuals registered with 100 family physicians in nine general practices and uses multiple overlapping methods of “hot” and “cold” pursuit to achieve near-complete ascertainment of all patients with acute vascular events. There are several findings described by the research in this thesis which have important implications for public health and can be utilised to improve secondary prevention in stroke. First, I have shown that one-third of all incident embolic events were related to AF and 60% of AF-related embolic events occurred at ≥80 years. Second, I have shown that only 9% of patients aged ≥80 years with incident embolic event related to known prior AF were on premorbid warfarin, and consequently three quarters of those previously independent were dead or disabled six months post event. Third, I have shown that there has been no reduction in age-specific incidence of AF-related ischaemic stroke in Oxfordshire over the last 25 years. Fourth, I have shown that assuming age-specific incidence does not continue to rise, if prevention is not improved, the number of embolic events at age ≥80 years would be expected to treble by 2050 (72,975 AF-related embolic events), with 84% of events at all ages occurring at age ≥80. Fifth, I have shown through a meta-analysis that one in five incident strokes had a history of prior AF of which only 19% were on premorbid warfarin, and AF was related to one in three incident ischaemic strokes. Sixth, I have shown that 1 in 5 stroke patients with known prior AF subsequently became institutionalised and incurred high acute and long-term care costs. Seventh, I have shown that one in five patients with undetermined cerebral ischaemic event subsequently had AF-related late recurrent stroke. Eighth, I have shown that even though TIA or ischaemic stroke patients who subsequently turned out to have new AF at follow-up had significantly higher baseline NT-proBNP compared to non-AF group, its utility is limited by low sensitivity and specificity. Ninth, I have shown in another meta-analysis that the duration of cardiac monitoring after cerebral ischaemic events was the main determinant of the observed rate of pAF, and that 5-7 days of monitoring may be adequate in unselected patient populations. Finally, I have shown that using 5-day event loop recording in clinic patients with TIA and minor ischaemic stroke could detect 12% new AF and the delay in monitoring did not reduce the sensitivity of pAF detection.

The endothelial nitric oxide synthase (eNOS) co-factor tetrahydrobiopterin (BH4) has been shown to play a pivotal role in maintaining endothelial function in experimental vascular disease models. In BH4-deficient states, eNOS becomes enzymatically ‘uncoupled’, generating reactive oxygen species instead of nitric oxide, thus promoting endothelial dysfunction. In humans with coronary artery disease (CAD), higher vascular BH4 levels have been shown to be associated with improved endothelial function, and genetic variation in endogenous BH4 synthesis has implicated a causal role. Accordingly, BH4 has been proposed as a potential therapeutic target in vascular disease states. The work in this thesis aims to further elucidate the roles of exogenous and endogenous BH4 in humans. In a randomised, placebo-controlled clinical trial of oral BH4 therapy in patients with CAD, exogenous BH4 had no effect on endothelial function or vascular oxidative stress. Subsequent pharmacokinetic and pharmacodynamic analysis revealed that oral BH4 significantly augmented BH4 levels in plasma and in venous tissue (but not in arterial tissue), but also increased levels of the oxidation product dihydrobiopterin (BH2), which lacks eNOS cofactor activity. Thus, there was a null effect on overall biopterin redox status. To further understand the mechanics of exogenous BH4 oxidation, ex vivo studies of human blood and vascular tissue demonstrated that exogenous BH4 is very rapidly oxidised to BH2; co-administration with an antioxidant had only a modest effect on preventing BH4 oxidation in blood, with no beneficial effect on biopterin redox state in the vasculature. Finally, using a “Mendelian randomisation” approach, I studied the effects of a haplotype of GCH1 (the gene encoding the rate limiting enzyme in BH4 synthesis) on endogenous BH4 bioavailability and vascular function in healthy individuals. In patients with CAD, this haplotype has been associated with decreased BH4 bioavailability and eNOS uncoupling, however in healthy individuals the haplotype exerted no significant effect, likely due to reduced inflammatory stimulation of GCH1.