| 1. |
- Hallström, Helena
(författare)
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Coffee Consumption in Relation to Osteoporosis and Fractures : Observational Studies in Men and Women
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- During the past decades, the incidence of osteoporotic fractures has increased dramatically in the Western world. Consumption of coffee and intake of caffeine have in some studies been found to be associated with increased risk of osteoporotic fractures, but overall results from previous research are inconsistent. Despite weak evidence, some osteoporosis organisations recommend limiting daily coffee or caffeine intake.The primary aim of this thesis was to study the association between long-term consumption of coffee and bone mineral density (BMD), incidence of osteoporosis and fractures. A secondary aim was to study the relation between tea consumption and fracture risk.An increased risk of osteoporotic fractures in individuals who consumed ≥ 4 cups of coffee vs < 1 cup coffee per day was demonstrated in a study of 31,257 Swedish middle-aged and elderly women (a part of the Swedish Mammography Cohort - SMC) when calcium intake was low (< 700 mg/day). However, no higher risks of osteoporosis or fractures were observed in the full SMC with increasing coffee consumption. In the full SMC (n = 61,433) the follow-up was longer and the number of fractures was higher. Similarly, no statistically significant associations between consumption of coffee (≥ 4 cups of coffee vs < 1 cup) and incidence of osteoporotic fractures were observed in the Cohort of Swedish Men (COSM), including 45,339 men. Calcium intake did not modify the results from the investigations performed in the full SMC or COSM.Nonetheless, a 2 - 4% lower BMD at measured sites was observed in men participating in the PIVUS cohort and in women from a sub-cohort of the SMC who consumed ≥ 4 cups of coffee vs < 1 cup daily. Individuals with high coffee intake and rapid metabolism of caffeine had lower BMD at the femoral neck.No association between tea consumption and risk of fractures was found in the studies.In conclusion, the findings presented in this thesis demonstrate that high consumption of coffee may be associated with a modest decrease in BMD. However, there was no evidence of a substantially increased incidence of osteoporosis or fractures typically associated with osteoporosis.
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| 2. |
- Svensson, Katherine
(författare)
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Early life environmental exposures and children's growth : A longitudinal study evaluating prenatal exposure for endocrine disrupting chemicals and nutrition in relation to children's growth up to seven years of age
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Endocrine disrupting chemicals (EDCs) have the potential to disrupt the endocrine system in humans and animals with importance for health and development. Additionally, optimal nutrition during pregnancy is critical for fetal growth and pregnancy outcomes. However, further knowledge on the importance of EDC mixtures and nutrition, on birthweight and growth during childhood is needed. The overall aim of this thesis was to evaluate the associations between prenatal exposure to EDC mixtures and nutrition respectively, with birthweight, growth and body composition in early- and mid-childhood, and to determine if these associations differed by sex. Data from mother-child pairs in the Swedish Environmental Longitudinal, Mother and child, Asthma and allergy (SELMA) study was analyzed, including 26 EDCs in prenatal urine and serum samples, children’s anthropometric and body composition measures up to seven years of age, and sociodemographic data from questionnaires and registers.Results suggest that higher prenatal exposure to EDC mixtures were associated with lower birthweight, and slower weight gain in early childhood, including a later peak growth velocity among girls. At 5.5 and 7 years of age, EDC mixtures were associated with lower BMI, less odds of overweight and less body fat among girls, but more body fat among boys at 7 years of age. Chemicals of concern in the mixtures were e.g., phthalates, bisphenols, perfluorinated alkyl substances (PFASs) and pesticides. Finally, maternal nutrition during pregnancy, i.e., better adherence to nutritional guidelines, was associated with more body fat for boys but less body fat for girls.In conclusion, prenatal exposure to both EDC mixtures and nutrition suggests to have an influence on birthweight, and children´s growth. Several of the found associations also differed by sex.
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| 3. |
- Wirén, Sara, 1981-
(författare)
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Prospective studies of hormonal and life-style related factors and risk of cancer
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: Androgens are important in prostate cancer development but how circulating levels of androgens affect risk of prostate cancer of different aggressiveness is not clear. Being childless has been associated with a lower risk of prostate cancer, but it is not clear if this association is causal or a result of residual confounding. Fathering of dizygotic twins, a marker of high fertility, has not been studied in relation to risk of prostate cancer.Another marker of life-long hormonal exposure is height, which has been associated with increased risk of cancer and cancer death. However, the association to separate cancer sites has not been consistent.The aims of this thesis were to study hormonal factors (paper I), and proxies of hormonal factors (paper II and III), and risk of prostate cancer; as well as height and risk of cancer and cancer death by separate sites (paper IV).Methods: Study designs were i) case-control studies, nested within the Västerbotten Intervention Project (paper I), and in Prostate Cancer database Sweden 2.0 (PCBaSe 2.0) (paper II and III), and ii) cohort study, in the Metabolic Syndrome and Cancer project (Me-Can) (paper IV).Results, prostate cancer: In paper I, increasing levels of serum androgens were not associated with risk of prostate cancer overall or in tumor risk categories. In paper II, childless men had a lower risk of prostate cancer, overall and in all risk categories, compared to fathers, an association which was in part explained by differences in marital status and educational level. In paper III, fathers of dizygotic twins did not have an increased risk of prostate cancer, either overall or in risk categories, when compared to fathers of singletons.Results, cancer overall: In paper IV, height was associated with an increased risk of cancer and cancer death overall in both women and men. The strongest association for cancer was to malignant melanoma in both women and men, and for cancer death to post-menopausal breast cancer in women and renal cell carcinoma in men.Conclusions: These studies indicate that hormonal factors, when studied as serum levels or when studied using proxies of fertility, do not have a major impact on the risk of prostate cancer. The association between height and an increased risk of cancer appears robust for total cancer and cancer death, as well as for several separate cancer sites.
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