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- Nilsson, Lena Maria, 1965-
(författare)
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Sami lifestyle and health : epidemiological studies from northern Sweden
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- 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.
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| 2. |
- Bordás, Pál, 1955-
(författare)
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Evaluation of the effectiveness of mammography screening in Northern Sweden.
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Service screening with mammography was implemented in Northern Sweden between 1989 and 1998, covering 190,000 women aged 40-74 years constituting the target population in the area. The aim of this thesis was the evaluation of mammography screening in Northern Sweden with special focus on selected screening performance indicators and on the disease outcome. We analysed interval cancer (IC) incidence and episode sensitivity in the Norrbotten Mammography Screening Programme (NMSP) for the period 1989-2002. An overall IC rate at 1.1/1000 and IC rate ratio at 38% was found and epsiode sensitivity was estimated at 62-73%, in concert with reference values of the European guidelines. Radiological classification of the IC cases in three rounds of the NMSP showed that true, occult, missed and minimal signs IC, were present in 48%, 10%, 14% and 28% of the cases. We analysed early death from breast cancer (n=342) in Northern Sweden during the first five years of mammography service screening. Most fatal cases were advanced and incurable on diagnosis. In a few screen-detected cases with favourable prognostic factors the fatal outcome was unexpected. We estimated breast cancer survival by detection mode in 5120 women with breast cancer. We found a significantly favourable survival among IC cases compared to cases among uninvited. We studied breast cancer mortality in relation to mammography screening. Our findings indicated a long-term reduction of breast cancer mortality by 26-30% among women invited to screening and by 31-35% among women screened compared to not screened. We conclude from our evaluation of the mammography screening in Northern Sweden that women benefited from this public health intervention in form of improved survival and reduced mortality.
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| 3. |
- Grönberg, Henrik, 1961-
(författare)
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Prostate cancer : epidemiological studies
- 1995
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Prostate cancer is a large and increasing medical problem both in Sweden and in the rest of the developed world, with about 300.000 new cases diagnosed world wide annually. Despite the high incidence of this disease, little is known about the aetiology of prostate cancer. The aim of this study was to try to understand more about the natural history and to find possible a etiological risk factors for this tumour.In a population based study of prostate cancer cases in northern Sweden it was found that the large increase in prostate cancer during the last two decades was mainly caused by well (Gl) and moderately (G2) differentiated tumours. However, the incidence of poorly differentiated (G3) tumours remained unchanged. The introduction of new diagnostic methods is the most plausible explanation for the increase of these low grade tumours.The relative survival in prostate cancer was found to be independent of patient age at diagnosis, indicating that tumour proliferation and the aggressiveness of this disease is equal in all ages. However, due to the increasing occurrence of concurrent diseases with growing age the number of lost years caused by prostate cancer decreases dramatically in older age groups. The overall cause specific mortality for prostate cancer was found to be around 50%. In accordance with most other cancer tumours, the annual mortality rate decreased with longer survival also for prostate cancer patients.In a study from the Swedish Twin Register it was found that the proband concordance rates for prostate cancer were 4,5 time greater among monozygotic compared to dizygotic twins. In a large nation-wide cohort study of men who had a father with prostate cancer, the overall standardised incidence ratio (SIR) was 1.70 for prostate cancer. Younger age at diagnosis among the fathers were associated with an increased risk among sons. This cohort study and the twin study indicates that both inherited and familial factors are of importance in a subgroup of prostate cancer patients.In a prospective case-control study, both a high body mass index (BMI) and a high food intake were found to be independent risk factors for prostate cancer. Both BMI and a high food intake might be indicators of a high fat diet, which so far is the most consistent exogenous risk factor for prostate cancer. The use of tobacco or alcoholic beverages were not associated with prostate cancer risk.
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