Katarina Bälter

Karolinska Institutet | KI · Department of Medical Epidemiology and Biostatistics

Background Society is facing multiple challenges, including lifestyle- and age-related diseases of major public health relevance, and this is of particular importance when the general population, as well as the workforce, is getting older. In addition, we are facing global climate change due to extensive emissions of greenhouse gases and negative e...

Outdoor office work is an emerging aspect of the concept of 'new ways of working', but only sparse data are available about the environmental qualities of the outdoor office space, experiences of office workers, and work-related well-being of outdoor office work. Here, we present an exploratory pilot study on well-being and outdoor office work in a...

Background Dietary change towards a diet low in greenhouse gas emissions (GHGEs) can reduce climate impact and improve individual-level health. However, there is a lack of understanding if diet interventions can achieve low-GHGE diets. Methods A randomized controlled trial was conducted to assess the effects of an app-based intervention. The inter...

Purpose The purpose of this study was to investigate the association between sustainable and healthy lifestyle factors and the risk of metabolic syndrome, with a focus on promoting sustainable, healthy and environment friendly behaviours. By creating Index for Promoting Sustainable, Healthy and Environment friendly Lifestyles (IPSHEL), we aimed to...

Office workers spend most of their working time being sedentary, contributing to a sedentary lifestyle that increases the risk of developing disease and disability. A gradual decline in cardiorespiratory fitness among adults, along with increased rate of non-communicable diseases across developed countries, makes the workplace an important opportun...

Objective: Being physically active postdiagnosis has been associated with lower rates of prostate cancer progression and mortality, but studies investigating postdiagnostic time spent sitting are lacking. We aim to study the association between leisure time sitting after a prostate cancer diagnosis and overall and prostate cancer-specific mortalit...

Background: Climate change is an urgent global issue and the food sector is a major contributor to greenhouse gas emissions (GHGE). Here we study if a diet low in GHGE could be a nutritious diet compared to the Nordic Nutrition Recommendations (NNR). Methods: The environmental impact of foods from Life Cycle Assessment (LCA) data was linked to a...

Objective: To explore associations between diet-related greenhouse gas emissions (GHGE), nutrient intakes and adherence to the Nordic Nutrition Recommendations among Swedish adults. Design: Diet was assessed by 4d food records in the Swedish National Dietary Survey. GHGE was estimated by linking all foods to carbon dioxide equivalents, using dat...

The development of easy-to-use and accurate methods to assess the intake of energy, foods and nutrients in pre-school children is needed. KidMeal-Q is an online food frequency questionnaire developed for the LifeGene prospective cohort study in Sweden. The aims of this study were to compare: (i) energy intake (EI) obtained using KidMeal-Q to total...

Background The total intake of dietary antioxidants may reduce prostate cancer risk but available data are sparse and the possible role of supplements unclear. We investigated the potential association between total and dietary antioxidant intake and prostate cancer in a Swedish population. Methods We used FFQ data from 1499 cases and 1112 control...

High Body mass index (BMI) has been directly associated with risk of aggressive or fatal prostate cancer. One possible explanation may be an effect of BMI on serum levels of prostate-specific antigen (PSA). To study the association between BMI and serum PSA as well as prostate cancer risk, a large cohort of men without prostate cancer at baseline w...

Background: The current food system generates about 25 % of total greenhouse gas emissions (GHGE), including deforestation, and thereby substantially contributes to the warming of the earth's surface. To understand the association between food and nutrient intake and GHGE, we therefore need valid methods to assess diet-related GHGE in observationa...

Current evidence of an association between body size and prostate cancer is conflicting, possibly due to differential effects of body size across the lifespan and the heterogeneity of the disease. We therefore examined childhood and adult body size in relation to total incident prostate cancer and prognostic subtypes in a prospective cohort of 47,4...

Objective: This study aimed to evaluate the association between perceived stress, social support, disease progression and mortality in a nationwide population-based cohort of men with prostate cancer. Materials and methods: The study surveyed 4105 Swedish men treated for clinically localized prostate cancer regarding stress, grief, sleep habits...

Background: Valid physical activity assessment in epidemiological studies is essential to study associations with various health outcomes. Objective: To validate the Web-based physical activity questionnaire Active-Q by comparing results of time spent at different physical activity levels with results from the GENEA accelerometer and to assess t...

Alcohol consumption has been suggested to increase risk of breast cancer through a mechanism that also increases mammographic density. Whether the association between alcohol consumption and mammographic density is modified by background breast cancer risk has, however, not been studied. We conducted a population-based cross-sectional study of 53 0...

BACKGROUND Body Mass index (BMI) has been shown to affect risk and mortality of several cancers. Prostate cancer and obesity are major public health concerns for middle-aged and older men. Previous studies of pre-diagnostic BMI have found an increased risk of prostate cancer mortality in obese patients. OBJECTIVE To study the associations between B...

Background: Childhood obesity is an increasing health problem globally. Obesity may be established already at pre-school age. Further research in this area requires accurate and easy-to-use methods for assessing the intake of energy and foods. Traditional methods have limited accuracy, and place large demands on the study participants and research...

High physical activity has been shown to decrease the risk of breast cancer, potentially by a mechanism that also reduces mammographic density. We tested the hypothesis that the risk of developing breast cancer in the next 10 years according to the Tyrer-Cuzick prediction model influences the association between physical activity and mammographic d...

Few studies have investigated the association between post-diagnosis physical activity and mortality among men diagnosed with prostate cancer. The aim of this study was to investigate the effect of physical activity after a prostate cancer diagnosis on both overall and prostate cancer-specific mortality in a large cohort. Data from 4,623 men diagno...

Knowledge about factors influencing physical activity behavior is needed in order to tailor physical activity interventions to the individual. The aim of this study was to explore and describe the perceived reasons, barriers, and incentives to increased physical activity, as well as preferable activities, among elderly men in Sweden. In total, 150...

Body mass index (BMI) is a modifiable lifestyle factor that has been associated with an increased risk of fatal prostate cancer and biochemical recurrence. The main purpose of the present study was to investigate the association between the exposure BMI at the time of a prostate cancer diagnosis and weight change after diagnosis, and the outcomes o...

The meal- and Web-based food frequency questionnaires, Meal-Q and MiniMeal-Q, were developed for cost-efficient assessment of dietary intake in epidemiological studies. The objective of this study was to evaluate the relative validity of micronutrient and fiber intake assessed with Meal-Q and MiniMeal-Q. The reproducibility of Meal-Q was also evalu...

In this paper we present a case study including 23 students at Williams College, MA, using social media technologies in learning activities during the winter semester 2013. The study was designed to evaluate the students' attitudes before and after participating in collaborative wiki assignments. Results from the study showed a statistically signif...

Syftet med denna rapport var att systematiskt sammanstalla den vetenskapliga litteraturen om rad om mat till, eller faktiskt intag av mat hos personer med fetma. Följande slutsatser begränsas till samband mellan mat och vikt, sjuklighet samt dodlighet hos personer med fetma (definierat som BMI≥30 kg/m2 eller midjeomfang ≥102 cm eller ≥88 cm for man...

The role of body size in prostate cancer etiology is unclear and potentially varies by age and disease subtype. We investigated whether body size in childhood and adulthood, including adult weight change, is related to total, low-intermediate-risk, high-risk, and fatal prostate cancer. We used data on 1,499 incident prostate cancer cases and 1,118...

Objectives: We investigated associations of smoking and coronary heart disease (CHD) by age. Methods: Data came from the Pooling Project on Diet and Coronary Heart Disease (8 prospective studies, 1974-1996; n = 192,067 women and 74,720 men, aged 40-89 years). Results: During follow-up, 4326 cases of CHD were reported. Relative to never smokers...

Meal-Q and its shorter version, MiniMeal-Q, are 2 new Web-based food frequency questionnaires. Their meal-based and interactive format was designed to promote ease of use and to minimize answering time, desirable improvements in large epidemiological studies. We evaluated the validity of energy and macronutrient intake assessed with Meal-Q and Mini...

Purpose: Coffee intake has recently been associated with significantly lower risk of lethal and advanced prostate cancer in a US population. Methods: We studied the association between coffee and prostate cancer risk in the population-based case-control study Cancer of the Prostate in Sweden. Dietary data were available for 1,499 cases and 1,112...

Several individual components of the Mediterranean diet have been shown to offer protection against prostate cancer. The present study is the first to investigate the association between adherence to the Mediterranean diet and the relative risk of prostate cancer. We also explored the usefulness of the Mediterranean Diet Score (MDS) in a non-Medite...

Many studies rely on self-reported anthropometric data. While paper-based self-reports have been the standard collection mode, the number of studies collecting self-reported data via the Web is increasing rapidly. Although numerous studies have shown good agreement between self-reported and measured weight using paper-based questionnaires, the vali...

Accurate assessment of children's physical activity is critical in determining associations between childhood physical activity and health later in life. We have developed a web-based questionnaire, KidActive-Q, to assess physical activity in early childhood. The feasibility and reproducibility of KidActive-Q were assessed in a sample of 20 childre...

The Nordic Nutrition Recommendations (NNR) aim at preventing diet-associated diseases such as cancer in the Nordic countries. We evaluated adherence to the NNR in relation to prostate cancer (PC) in Swedish men, including potential interaction with a genetic risk score and with lifestyle factors. Population-based case-control study (Cancer of the P...

Increased use of the Internet provides new opportunities for collecting data in large studies. The aim of our new Web-based questionnaire, Active-Q, is to assess total physical activity and inactivity in adults. Active-Q assesses habitual activity during the past year via questions in four different domains: (1) daily occupation, (2) transportation...

Dietary guidelines are important tools for educating the general public and helping health professionals promote good health and prevent chronic diet-related diseases. However, it is of major public health relevance that the effect of the guidelines per se is evaluated to make sure that they serve their purpose. The aim of this article is to review...

Objective: We explored the use of feedback in interactive web-based questionnaires for collecting data on lifestyle factors in epidemiological studies. Design: Here we report from a cohort study on lifestyle factors and upper respiratory tract infections among 1805 men and women. We introduced interactivity in the form of personalized feedback a...

Antioxidants are regulators of immune function and may play a role in upper respiratory tract infections (URTI). We investigated the potential effects of dietary intake from food and supplement use of vitamins C and E on the risk of self-reported URTI. We conducted a population-based cohort study of 1509 Swedish men and women ages 20 to 60 with a f...

The Nordic countries have published joint dietary recommendations, the Nordic Nutrition Recommendations (NNR), since 1980. We evaluated adherence to the NNR as a measure of a healthy diet and its potential association with self-reported upper respiratory tract infection (URTI). A prospective, population-based study with a follow-up period of 4 mont...

Short sleep duration increases the risk of several diseases, possibly involving compromised immune function. However, most previous studies are based on experimentally induced sleep deprivation, and only a few have studied natural variations in sleep duration. Thus our aim was to study how natural variations in sleep duration affect immune function...

upper respiratory tract infection (URTI) is the most common reason for seeking primary care in many countries. Still, little is known about potential strategies to reduce susceptibility. We investigated the relationships between physical activity level, perceived stress, and incidence of self-reported URTI. we conducted a population-based prospecti...

In a European setting, we know little about the use of dietary supplements among men with prostate cancer (PCa) and to what extent lifestyle, disease or other factors influence such use. We evaluated supplement use in 1127 men with incident PCa and in 900 population controls in Sweden. Age-adjusted binary regression with an identity link was carrie...

Our purpose was to investigate whether alcohol (ethanol) consumption could have an influence on the metabolism of acrylamide to glycidamide in humans exposed to acrylamide through food. We studied a subsample from a population-based case-control study of prostate cancer in Sweden (CAPS). Questionnaire data for alcohol intake estimates was compared...

Light to moderate alcohol consumption is associated with a reduced risk of coronary heart disease. This protective effect of alcohol, however, may be confined to middle-aged or older individuals. Coronary heart disease incidence is low in men <40 years of age and in women <50 years of age; for this reason, study cohorts rarely have the power to inv...

High serum levels of macrophage inhibitory cytokine 1 (MIC-1) are strongly associated with metastatic prostate cancer, suggesting MIC-1 is a biomarker for prostate cancer prognosis. We conducted a prospective cohort study of 1,442 Swedish men with a pathologically verified diagnosis of prostate cancer between 2001 and 2003. Blood was drawn either p...

Somatostatin (SST) and its receptors (SSTR1-5) may have a role in prostate cancer by influencing the IGFI hormone axis or through direct effects on prostate epithelia. We have investigated if genetic variation in the SST and SSTR1-5 genes influences prostate cancer risk and/or circulating IGFI and IGFBP3 hormone levels. We analyzed 28 haplotype tag...

Acrylamide, a probable human carcinogen, is formed during the cooking of many commonly consumed foods. Data are scant on whether dietary acrylamide represents an important cancer risk in humans. We studied the association between acrylamide and prostate cancer risk using 2 measures of acrylamide exposure: intake from a food frequency questionnaire...

A considerable fraction of prostate cancers harbor a gene fusion between the androgen-regulated TMPRSS2 and ERG, one of the most frequently over-expressed proto-oncogenes in prostate cancer. Here, we investigated if inherited genetic variation upstream of ERG alters prostate cancer risk and survival. We genotyped 21 haplotype tagging SNPs (htSNPs)...

Saturated fatty acid (SFA) intake increases plasma LDL-cholesterol concentrations; therefore, intake should be reduced to prevent coronary heart disease (CHD). Lower habitual intakes of SFAs, however, require substitution of other macronutrients to maintain energy balance. We investigated associations between energy intake from monounsaturated fatt...

The etiologic role of physical activity in prostate cancer development is unclear. We assessed the association between lifetime total physical activity and prostate cancer risk in a Swedish population-based case-control study comprising 1,449 incident prostate cancer cases and 1,118 unaffected population controls. Information regarding physical act...

Although it is well known that multiple genes may influence prostate cancer risk, most current efforts at identifying prostate cancer risk variants rely on single-gene approaches. In previous work using mostly single-gene approaches, we observed significant associations (P < 0.05) for 6 of 46 polymorphisms in five genes in a Swedish prostate cancer...

Deletion polymorphism of the UDP-glucuronosyltransferase 2B17 (UGT2B17) gene has been associated with an increased prostate cancer risk in two previous independent studies. Here we determine the risk in a large-scale population-based case-control study. Genotyping was conducted with a 5'-nuclease activity assay to distinguish those with one or two...

Single-nucleotide polymorphisms (SNPs) in five chromosomal regions--three at 8q24 and one each at 17q12 and 17q24.3--have been associated with prostate cancer. Each SNP has only a moderate association, but when SNPs are combined, the association may be stronger. We evaluated 16 SNPs from five chromosomal regions in a Swedish population (2893 subjec...

The consistent finding of a genetic susceptibility to prostate cancer suggests that there are germline sequence variants predisposing individuals to this disease. These variants could be useful in screening and treatment. We performed an exploratory genome-wide association scan in 498 men with aggressive prostate cancer and 494 control subjects sel...

Elevated levels of circulating IGF-I have consistently been associated with increased prostate cancer risk. We recently found a haplotype in the 3' region of the IGF-I gene associated with increased risk of prostate cancer, and we hypothesized that the observed association is mediated by circulating IGF-I. We analyzed haplotypes and three haplotype...

The methylenetetrahydrafolate reductase (MTHFR) enzyme may influence cancer development by affecting DNA methylation, synthesis and repair. The MTHFR 677C-->T single nucleotide polymorphism (SNP) has been associated with decreased enzyme activity and has therefore been implicated in cancer development. We analyzed the MTHFR 677C-->T SNP in 2,777 in...

Hormonal manipulation is the mainstay treatment of prostate cancer, notably in advanced stages. Despite initial favorably response, the cancer eventually develops hormone resistance resulting in disease progression and death. However, little is known about genetic determinants of disease progression and prostate cancer-specific death. We analyzed a...

Prostate carcinoma is the most common cancer in men. Its primary pathogenesis is mostly unknown. Dairy products containing lactose have been suggested to be risk factors for prostate cancer. Digestion of lactose is dependent on lactase activity in the intestinal wall. A single nucleotide polymorphism C to T residing 13,910 bp upstream of the lactas...

Insulin-like growth factor-I (IGF1) stimulates cell proliferation, decreases apoptosis, and has been implicated in cancer development. Epidemiological studies have shown elevated levels of circulating IGF1 to be associated with increased risk of prostate cancer. To what extent genetic variation in the IGF1 gene is related to prostate cancer risk is...

Dietary intake of marine fatty acids from fish may protect against prostate cancer development. We studied this association and whether it is modified by genetic variation in cyclooxygenase (COX)-2, a key enzyme in fatty acid metabolism and inflammation. We assessed dietary intake of fish among 1,499 incident prostate cancer cases and 1,130 populat...

The growth hormone receptor (GHR) is potentially involved in prostate cancer through its role in stimulating insulin-like growth factor I production and its cellular effects on prostate epithelium. We have used a haplotype-based tagging approach within CAncer Prostate Sweden, a large retrospective case-control study of 2,863 cases and 1,737 control...

The mechanisms through which diet may influence the development of non-Hodgkin's lymphoma (NHL) are unclear but can be better understood by examining associations between nutrient consumption and NHL risk. Between 2000 and 2002, 591 NHL cases and 460 population-based controls in Sweden completed a semiquantitative food frequency questionnaire. Unco...

Association studies have become a common and popular method to identify genetic variants predisposing to complex diseases. Despite considerable efforts and initial promising findings, the field of prostate cancer genetics is characterized by inconclusive reports and no prostate cancer gene has yet been established. We performed a literature review...

Prostate cancer risk may be influenced by single genetic variants in the hormone-regulating genes androgen receptor (AR), cytochrome P450 (CYP17), and steroid-5-alpha-reductase type 2 (SRD5A2). In this study, we comprehensively investigated polymorphisms in these three loci and their joint effect in a large population-based study. We selected 23 ha...

Recently identified associations of prostate cancer risk with several genes involved in innate immunity support a role of inflammation in the etiology of prostate cancer. Considering inflammation is regulated by a complex system of gene products, we hypothesize sequence variants in many other genes of this pathway are associated with prostate cance...

The causes of prostate cancer are poorly understood, but genetic factors may be more important than for many other malignancies, and dietary phytoestrogens may be protective. Because phytoestrogens bind tightly to the estrogen receptor-beta, we conducted an epidemiologic investigation of synergistic effects between phytoestrogen intake and estrogen...

COX-2 is a key enzyme in the conversion of arachidonic acid to prostaglandins. The prostaglandins produced by COX-2 are involved in inflammation and pain response in different tissues in the body. Accumulating evidence from epidemiologic studies, chemical carcinogen-induced rodent models and clinical trials indicate that COX-2 plays a role in human...

With the increasing incidence of prostate cancer, identifying common genetic variants that confer risk of the disease is important. Here we report such a variant on chromosome 8q24, a region initially identified through a study of Icelandic families. Allele -8 of the microsatellite DG8S737 was associated with prostate cancer in three case-control s...

After cloning of the second estrogen receptor, estrogen receptor beta (ERbeta) in 1996, increasing evidence of its importance in prostate cancer development has been obtained. ERbeta is thought to exert an antiproliferative and proapoptotic effect. We examined whether sequence variants in the ERbeta gene are associated with prostate cancer risk. We...

Chronic or recurrent inflammation has been suggested as a causal factor in several human malignancies, incl