{"id":6159,"date":"2026-10-19T09:48:34","date_gmt":"2026-10-19T09:48:34","guid":{"rendered":"https:\/\/phd.hi.is\/doktorsvorn\/doktorsvorn-i-lydheilsuvisindum-oskar-orn-halfdanarson\/"},"modified":"2026-10-19T09:48:34","modified_gmt":"2026-10-19T09:48:34","slug":"doktorsvorn-i-lydheilsuvisindum-oskar-orn-halfdanarson","status":"publish","type":"phd_defence","link":"https:\/\/phd.hi.is\/en\/doktorsvorn\/doktorsvorn-i-lydheilsuvisindum-oskar-orn-halfdanarson\/","title":{"rendered":"Doktorsv\u00f6rn \u00ed l\u00fd\u00f0heilsuv\u00edsindum – \u00d3skar \u00d6rn H\u00e1lfd\u00e1narson"},"content":{"rendered":"
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F\u00f6studaginn 8. mars ver \u00d3skar \u00d6rn H\u00e1lfd\u00e1narson doktorsritger\u00f0 s\u00edna \u00ed l\u00fd\u00f0heilsuv\u00edsindum vi\u00f0 L\u00e6knadeild H\u00e1sk\u00f3la \u00cdslands. Ritger\u00f0in ber heiti\u00f0: Proton pump inhibitor use among adults:\u00a0<\/strong>Mapping the landscape of PPI use and exploring its effect on cancer risk and mortality. Notkun pr\u00f3t\u00f3nupumpuhemla \u00e1 \u00cdslandi: Kortlagning PPI notkunar og m\u00f6guleg \u00e1hrif hennar \u00e1 krabbameins\u00e1h\u00e6ttu og lifun.<\/strong><\/p>\n

Andm\u00e6lendur eru dr. Helga Gar\u00f0arsd\u00f3ttir, lektor og lyfjafaraldsfr\u00e6\u00f0ingur vi\u00f0 H\u00e1sk\u00f3lann \u00ed Utrecht \u00ed Hollandi, og dr. Nele Brusselaers, l\u00e6knir og d\u00f3sent \u00ed faraldsfr\u00e6\u00f0i vi\u00f0 Karolinska Institutet \u00ed Sv\u00ed\u00fej\u00f3\u00f0.<\/p>\n

Umsj\u00f3narkennari var dr. Helga Zo\u00e9ga, pr\u00f3fessor vi\u00f0 L\u00e6knadeild, og me\u00f0lei\u00f0beinendur voru dr. Eir\u00edkur Steingr\u00edmsson og dr. Helga M. \u00d6gmundsd\u00f3ttir, b\u00e6\u00f0i pr\u00f3fessorar vi\u00f0 L\u00e6knadeild. Auk \u00feeirra s\u00e1tu \u00ed doktorsnefnd \u00fe\u00e6r Margr\u00e9t H. \u00d6gmundsd\u00f3ttir, a\u00f0junkt vi\u00f0 L\u00e6knadeild, og Katja Fall, d\u00f3sent vi\u00f0 H\u00e1sk\u00f3lann \u00ed \u00d6rebro, Sv\u00ed\u00fej\u00f3\u00f0.<\/p>\n

Ingibj\u00f6rg Har\u00f0ard\u00f3ttir, pr\u00f3fessor og varaforseti L\u00e6knadeildar H\u00e1sk\u00f3la \u00cdslands, stj\u00f3rnar ath\u00f6fninni sem fer fram \u00ed H\u00e1t\u00ed\u00f0asal H\u00e1sk\u00f3la \u00cdslands og hefst kl. 14:00.<\/p>\n

\u00c1grip af ranns\u00f3kn<\/strong><\/p>\n

Pr\u00f3t\u00f3nupumpuhemlar (PPI) eru s\u00fdrubindandi lyf sem eru almennt notu\u00f0 vi\u00f0 me\u00f0fer\u00f0 \u00e1 \u00fdmsum magas\u00fdrusj\u00fakd\u00f3mum. Notkun PPI-lyfja er \u00fatbreidd \u00e1 heimsv\u00edsu og s\u00fa umtalsver\u00f0a aukning sem hefur or\u00f0i\u00f0 \u00e1 notkun \u00feeirra hefur veri\u00f0 gagnr\u00fdnd \u00ed lj\u00f3si m\u00f6gulegrar ofnotkunar og \u00f3vissu sem r\u00edkir um m\u00f6gulegar ska\u00f0legar aukaverkanir. S\u00fdrubindandi virkni PPI-lyfja hefur hins vegar einnig veri\u00f0 talin hafa m\u00f6guleg krabbameinshindrandi \u00e1hrif vegna h\u00e6fni \u00feeirra til a\u00f0 hindra virkni s\u00e9rh\u00e6f\u00f0ra s\u00fdruseytandi ens\u00edma. Tali\u00f0 er a\u00f0 sl\u00edk ens\u00edm taki \u00fe\u00e1tt \u00ed myndun \u00e1 s\u00faru utanfrumuumhverfi krabbameinsfruma.<\/p>\n

Markmi\u00f0i\u00f0 var a\u00f0 nota l\u00fd\u00f0grunda\u00f0a gagnagrunna \u00e1 \u00cdslandi til a\u00f0 I) kortleggja notkun PPI-lyfja me\u00f0al fullor\u00f0inna einstaklinga \u00e1 \u00cdslandi, II) meta \u00e1h\u00e6ttu PPI-notenda \u00e1 \u00fev\u00ed a\u00f0 greinast me\u00f0 brj\u00f3stakrabbamein, bl\u00f6\u00f0ruh\u00e1lskirtilskrabbamein e\u00f0a sortu\u00e6xli \u00ed h\u00fa\u00f0, og III) meta m\u00f6guleg verndandi \u00e1hrif PPI-lyfjanotkunar \u00e1 lifun sj\u00faklinga me\u00f0 bl\u00f6\u00f0ruh\u00e1lskirtilskrabbamein.<\/p>\n

Ni\u00f0urst\u00f6\u00f0ur verkefnisins benda til \u00feess a\u00f0 PPI-lyfjanotkun hafi aukist umtalsvert \u00e1 \u00cdslandi yfir s\u00ed\u00f0asta \u00e1ratuginn. Ni\u00f0urst\u00f6\u00f0ur verkefnisins benda hvorki til \u00feess a\u00f0 PPI-lyfjanotkun hafi \u00e1hrif \u00e1 \u00e1h\u00e6ttu \u00e1 brj\u00f3stakrabbameini, bl\u00f6\u00f0ruh\u00e1lskirtilskrabbameini, e\u00f0a sortu\u00e6xlum, n\u00e9 a\u00f0 h\u00fan hafi \u00e1hrif \u00e1 lifun me\u00f0al sj\u00faklinga me\u00f0 krabbamein \u00ed bl\u00f6\u00f0ruh\u00e1lskirtli.<\/p>\n

Abstract<\/strong><\/p>\n

Proton pump inhibitors (PPIs) are commonly prescribed drugs that are used to treat acid-related disorders of the gastrointestinal tract. PPI use has increased worldwide, causing concerns due to reports of unsubstantiated long-term use and potential adverse effects. However, PPIs have also been suggested to promote antineoplastic effects in certain cancer settings via inhibition of specialized proton pumps. These proton pumps are involved in pH regulation in eukaryotic cells and believed to act as facilitators for the acidification of the tumor microenvironment (TME).<\/p>\n

The overall aim of this study was to use the population-based resources available in Iceland I) to assess the utilization of PPIs among the adults in Iceland, II) to explore spotential antineoplastic effect of PPIs by estimating the risk among PPI users of being diagnosed with a first-time breast cancer, prostate cancer, or malignant melanoma, and III) to assess the potential influence of post-diagnosis PPI use on mortality among prostate cancer patients.<\/p>\n

The study results indicate that PPI use in Iceland has increased considerably over the last decade. The results do not support a chemopreventive role of PPIs in attenuating the risk of being diagnosed with a first-time breast cancer, prostate cancer, or malignant melanoma. Finally, our findings do not indicate that post-diagnosis PPI use influences mortality among prostate cancer patients.<\/p>\n

Um doktorsefni\u00f0<\/strong><\/p>\n

\u00d3skar \u00d6rn H\u00e1lfd\u00e1narson er f\u00e6ddur \u00e1ri\u00f0 1984. Hann lauk BS-pr\u00f3fi \u00ed l\u00edffr\u00e6\u00f0i fr\u00e1 H\u00e1sk\u00f3la \u00cdslands \u00e1ri\u00f0 2011 og meistaragr\u00e1\u00f0u \u00ed l\u00edf- og l\u00e6knav\u00edsindum fr\u00e1 sama sk\u00f3la \u00e1ri\u00f0 2013. \u00d3skar hefur samhli\u00f0a doktorsn\u00e1mi sinnt kennslu vi\u00f0 Mi\u00f0st\u00f6\u00f0 \u00ed l\u00fd\u00f0heilsuv\u00edsindum auk \u00feess a\u00f0 sinna \u00fdmsum ranns\u00f3knartengdum verkefnum vi\u00f0 H\u00e1sk\u00f3la \u00cdslands.<\/p>\n

Foreldrar hans eru H\u00e1lfd\u00e1n \u00d3skarsson og Sigr\u00ed\u00f0ur Hr\u00f6nn J\u00f6rundsd\u00f3ttir. Samb\u00fdliskona \u00d3skars er Halla \u00d3lafsd\u00f3ttir.<\/p>\n<\/div><\/div>","protected":false},"featured_media":2092,"template":"","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"_phd_date_start":"2019-03-08T14:00:00+00:00","_phd_date_end":"2019-03-08T17:00:00+00:00","_phd_location":"A\u00f0albygging H\u00e1t\u00ed\u00f0asalur","_phd_admission":"A\u00f0gangur \u00f3keypis","_phd_thesis_title":"Proton pump inhibitor use among adults: Mapping the landscape of PPI use and exploring its effect on cancer risk and mortality. Notkun pr\u00f3t\u00f3nupumpuhemla \u00e1 \u00cdslandi: Kortlagning PPI notkunar og m\u00f6guleg \u00e1hrif hennar \u00e1 krabbameins\u00e1h\u00e6ttu og lifun","_phd_source_url":"https:\/\/gamli.hi.is\/vidburdir\/doktorsvorn_i_lydheilsuvisindum_oskar_orn_halfdanarson","_phd_source_node_id":"315735","_phd_source_type":"vidburdir","_phd_member_id":665,"footnotes":""},"phd_school":[119],"phd_discipline":[120],"class_list":["post-6159","phd_defence","type-phd_defence","status-publish","has-post-thumbnail","hentry","phd_school-thverfraedilegt-framhaldsnam","phd_discipline-phd-i-lydheilsuvisindum"],"_links":{"self":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence\/6159","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence"}],"about":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/types\/phd_defence"}],"version-history":[{"count":0,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_defence\/6159\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media\/2092"}],"wp:attachment":[{"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/media?parent=6159"}],"wp:term":[{"taxonomy":"phd_school","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_school?post=6159"},{"taxonomy":"phd_discipline","embeddable":true,"href":"https:\/\/phd.hi.is\/en\/wp-json\/wp\/v2\/phd_discipline?post=6159"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}