Disputas – master in Public Health Sunday Oluwafemi Oyeyemi (Streames)
Sunday Oluwafemi Oyeyemi disputerer for ph.d.-graden i helsevitenskap og vil offentlig forsvare avhandlingen:
“Lifestyle factors and colorectal cancer: The Norwegian Women and Cancer Study”
Avhandlingen er tilgjengelig her / The doctoralthesis
På grunn av koronautbruddet er auditoriet stengt for publikum. Disputasen vil i stedet bli streamet. Lenke til streaming.
Opptak av disputasen vil være tilgjengelig i en uke.
The auditorium will be closed to the public because of the corona outbreak. The defense will be streamed. Link for streaming.
A recording of the disputation will be available for one week.
Populærvitenskapelig sammendrag av avhandlingen:
Colorectal or bowel cancer (BC) is a major global disease. In Norway, it is the most common cancer affecting both men and women. The frequency of occurrence has increased rapidly within the past 50 years, and the frequency among Norwegian women is currently the highest in the world. Lifestyle factors have substantial influence on the risk of having BC. However, it is not clear whether these factors are responsible for the high occurrence in Norwegian women, or whether they play a role in BC survival.
The aim of this doctoral project was to study the relationship between physical activity patterns and BC occurrence in Norwegian women; to determine whether the geographical distribution of lifestyle factors is responsible for the geographical variations in BC occurrence; and to investigate the relationship between lifestyle factors before the BC diagnosis and its survival.
We used information from the Norwegian Women and Cancer (NOWAC) Study. The NOWAC Study started in 1991 and has more than 172,000 women participants from all counties of Norway. The participants answered questionnaires regarding their health, lifestyle, and diet. Information on cancer, emigration, and death were obtained from Cancer Registry of Norway and Statistics Norway.
First, we used information on physical activity pattern collected from 79,184 women. After making corrections for other lifestyle factors, we found that there was no association between physical activity levels and the risk of BC in women. Second, we used information on lifestyle factors from 96,898 women, and categorised Norwegian counties into groups according to BC occurrence. We then used statistical methods to study the extent to which lifestyle factors accounted for the observed variations in BC occurrence between the county groups. We found that adult height, being a former smoker who smoked for more than 10 years; or current smoker who has smoked for more than 10 years, were associated with increased risk of BC. A higher education level, and a fruit and vegetable intake of more than 300 g per day, were associated with reduced risk of BC. However, these lifestyle factors together, did not explain the variations in the risk of BC between areas of low and high BC occurrence in Norway. Finally, we used information on lifestyle factors of 1,861 women before they were diagnosed of BC, to find the relationship between lifestyle factors before diagnosis and BC survival. We found that those who had an intake of vitamin D of more than 10 μg per day before diagnosis had a 25% reduced risk of CRC death.
In conclusion, our results suggest that: (1) women may need to look further than physical activity in order to reduce their risk of BC. (2) Even though height, smoking status, a higher education level, and fruit and vegetable intake were significantly related to BC risk, they did not explain geographical variations in BC occurrence. (3) Vitamin D intake before BC diagnosis could improve BC survival.
Hovedveileder førsteamanuensis Kristin Benjaminsen Borch, Institutt for samfunnsmedisin, Det helsevitenskapelige fakultet, UiT Norges arktiske universitet
Biveileder førsteamanuensis Tonje Braaten, Institutt for samfunnsmedisin, UiT Norges arktiske universitet
Biveileder Professor Eiliv Lund, Institutt for samfunnsmedisin, UiT Norges arktiske universitet
Professor Elsebeth Lynge, Københavns Universitet, Danmark - 1. opponent
Professor Tom Ivar Lund Nilsen, NTNU – 2.opponent
Professor Tom Wilsgaard, Det helsevitenskapelige fakultet, Institutt for samfunnsmedisin, UiT Norges arktiske universitet – leder av komité
Disputasleder: Professor Guri Skeie, Institutt for samfunnsmedisin, Det helsevitenskapelige fakultet, UiT Norges arktiske universitet
Prøveforelesning over oppgitt emne holdes kl. 10.15, samme sted:
“Balancing selection bias and confounder control in epidemiological studies”
Prøveforelesningen vil også bli streamet. Trykk her.
The trail lecture will also be streamed. Click here.